Author Topic: For the vindication of Eleusis - Methylamine  (Read 24555 times)

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Organikum

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For the vindication of Eleusis - Methylamine
« on: February 15, 2004, 01:09:00 AM »

Patent DE468895


IG Farben 1925

translated as good as possible by ORGANIKUM

....
It was found that the formation of CO2 whilst the production of mono or dimethylamine can be mostly or completely avoided by the addition of alcohol to the reaction mixture. Practically 1 mol alcohol or more to 2 mol of aldehyde are used. There is then the formate of the added alcohol formed besides the salt of the amine.
The reaction of formaldehyde and ammoniumchloride in presence of alcohol proceeds after this formula:

2HCOH + NH4Cl + C2H5OH = CH2NH2.HCl + H2O + HCOOC2H5

The produced ethylformate can be distilled out during or whilst the reaction. Besides the fact that the oxidation of formaldehyde to CO2 is avoided the addition of alcohol has the advantage that the reaction temperatur is diminished as the reaction proceeds already at 75°C whereby without alcohol the reaction starts over 90°C, also the the reaction proceeds faster this way. The tendency to form higher methylated amines is strongly reduced.
According to the reaction conditions it is possible to  produce methylamine or dimethylamine. An excess of ammoniumsalts favors usually the formation of the primary amine, a excess of formaldehyde the formation of the secondary amine. Aquaous formaldehyde, polymeres of the aldehyde or alcoholic solutions of formaldehyde can be used.

Example:
17 parts of 40% formaldehyde, 7 parts of 96% alcohol and 8 parts of ammoniumchloride are heated up to the boilingpoint of the mixture (about 75°C). The reaction proceeds mostly during the heating up, the NH4Cl goes into solution and a mostly of ethylformate consisting upper layer forms, which is removed by destillation.
After the excess of ammoniumchloride is removed and the water is destilled away a product remains which consists almost exclusivl< from monomethylamine.
......

Interesting points to reaction conditions and else I think.
Eleusis wasnt so wrong - if not in the theory but in the practice at least.


Bond_DoubleBond

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cleaner reaction, easier distillation, and...
« Reply #1 on: February 15, 2004, 04:05:00 AM »
cleaner reaction, easier distillation, and better yields?  say it works with meoh and that'll be enough for swim.

sYnThOmAtIc

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Uhhh?
« Reply #2 on: February 15, 2004, 04:22:00 AM »
I think he mantioned ethylformate and 96% alcohol. I assume that would mean ethanol  :P

SPISSHAK

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I don't think methanol would be a good substitute
« Reply #3 on: February 15, 2004, 04:55:00 AM »
I has the tendancy of condensing with the formaldehyde to give dimethyl acetal (I think) I know it does undergo aldol condensation so methanol is out.

Organikum

  • Guest
MeOH
« Reply #4 on: February 15, 2004, 05:01:00 AM »
Ups, sorry, one sentence before I started translating is stated that the formate formed depends on the alcohol used. This would mean that not only EtOH can be used but other alcohols also. The examples are only with ethylalcohol so.

The proof is in the eating of the pudding.
It is worth a try, chances are good, nothing in the patent speaks against it.  ;)


Bond_DoubleBond

  • Guest
Q's
« Reply #5 on: February 15, 2004, 09:55:00 PM »
But isn't methanol used to stabalize aqueous formaldehyde solutions? 

Swim's definitely gonna try this.

Since, meoh has a lower bp than etoh, will the reaction need to run longer to completion?  If so, any idea's on how much?  Also, is there a way for swim to determine if the reaction has completed besides running several synths and purifications each at differing reaction times?  ph maybe?

Organikum

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I suggest the following procedure
« Reply #6 on: February 15, 2004, 11:31:00 PM »
Heat the the reaction mixture on a water bath SLOWLY up until the boiling point is reached, then start to distill away the formed methylformate. When all methylformate is distilled out the reaction is finished.

As the patent states clearly that the bigger part of the reaction proceeds BEFORE the boiling point is reached it is advantegous to give enough time here.

EDIT:
Dont wonder if not all ammoniumchloride dissolves from start. This doesnt matter - the patent states clealy that the NH4Cl will dissolve whilst heating up/reaction starts. Stirring is advised to help this process.



terbium

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Possible but ....
« Reply #7 on: February 22, 2004, 09:35:00 PM »
I find it hard to believe that addition of ethanol would lower the reaction temperature and time so much. If it does work why hasn't Vogel, Organic Synthesis or anyone else adopted this? Still, it would be interesting if someone with real laboratory equipment (not their mom's baking dishes) and who knows what methylamineHCl looks like would try this.

Nevertheless, even if this does work, and I doubt it, the Eleusis procedure is so hoplessles muddled that it would be shear luck if anyone could obtain a good result by following it.


Organikum

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You will be astonished Terbium,
« Reply #8 on: February 23, 2004, 09:24:00 AM »
but I found this patent referenced in the discussion part of the methylamine.HCl preparation at Organic Synthesis.  ;D

And muddled or not - Eleusis used this patent for his methylamine from hexamine preparation - not the Brochet and Cambier method from 1895 - he only fooled Rhodium by telling this....
I did the math and the ratios are exactly those from the patent - just with hexamine as starting compound instead of formaldehyde/ammoniumchloride.

So I am curious myself I am running this synthesis as outlined by now.

Would I suffice your requirements for a writeup Terbium? I wont post anything just to hear I am probably not able to:
- weigh correctly
- to separate ammoniumchloride and methylamine
- to differ between ammoniumchloride and methylamine
or such.

ORG

PS. Vogel´s is exorbitant good. But he has not always the highest yielding procedures described and he seems to have some special problems with germans. Organic Synthesis does not say that this are the best ways to synthesize a compound - in special when those compounds are drug-related (ketene with a 20 flame furnace, whereby only 14 are burning....hey!). The main point there is that the procedures are checked.

methylamine.HCl made by the method of the posted patent (slightly modified). Still a little bit IPA wet....




ephemeral

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Methylamine proceedure
« Reply #9 on: March 11, 2004, 05:54:00 PM »
Organikum-
          did you maintain the ratios as stated in your fist post?  .  Would you kindly post the alcohol used (it was ETOH, yes?) ratios, and running times along with yields?
DId you use T-but to prify?
Thanks for any info, as it would be interesting to try this out.  BTW, the ref did say product was strictly mono, with no di or tri, correct?  Thanks for your time  :)


Organikum

  • Guest
The alcohol used by me was simple denaturated...
« Reply #10 on: March 12, 2004, 11:30:00 AM »
The alcohol used by me was simple denaturated ethylalcohol, I started with 100g hexamine which I dissolved in 100 ml water (what is probably not necessary at all, I will dissolve the hexamine in 30% HCl/EtOH next time directly without additional water) added 20g ammoniumchloride and heated slowly until ethylformate started coming over at about 50°C to 60°C measured on top of a vigreux column. Be careful not to distill away the alcohol before the reaction takes place, what will happen if heating is done to fast. Refluxing the reaction for one hour before distilling is advised. Then the reaction was hold at reflux for two more hours, the water removed under vacuum and the remaining slush extracted with hot IPA trice. Yield after recrystallisation and washing with with chloroform and drying was about 125g methylamine.

Addon
The ref says there is almost no dimethylamine formed, triethylamine will never be formed as the temperatures are far to low. The residue from the chloroform wash was about 1,5gram - and as the chloroform was not ABSOLUTE dry this as well may be monomethylamine. Anyways, also if it is dimethylamine it is a tolerable amount in my eyes, low enough for me to skip the chloroform wash in future.
(this is of course a personal opinion and decision and by no way an advise)


runne

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MeOH? Tried yet?
« Reply #11 on: March 12, 2004, 02:28:00 PM »
Has anybody tried this with MeOH yet? What are the chances this would work?

ephemeral

  • Guest
Tremendous yield
« Reply #12 on: March 14, 2004, 05:03:00 AM »
thanks Organikum, for your time.  This sounds like a very fast, simple route with cheap, easy reagents.  Could it be so? (In no way is this questioning your results!)  This has to be explored and reports will follow.  Swim will do the MeOh as well over the near future and report.

terbium

  • Guest
Very interesting.
« Reply #13 on: March 15, 2004, 12:36:00 AM »
Nice work!


Bond_DoubleBond

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excellent procedure. swim yielded 120g ...
« Reply #14 on: March 30, 2004, 02:22:00 PM »
excellent procedure.  swim yielded 120g recrystallized meam.hcl.  and that is with vacuum-less distillation of the remaining water.

good find org.

lugh

  • Guest
Methyl Formate
« Reply #15 on: March 31, 2004, 11:46:00 PM »

Has anybody tried this with MeOH yet? What are the chances this would work?




As the Organic Synthesis procedure produces methyl formate,  mentioned in note 1 of that procedure which states how to convert this into methylal and sodium formate; it seems rather likely that this methyl formate results from the methanol added to the formaldehyde to stabilize it reacting with it when the temperature reaches about 75° C  ;D  Thus it would be very surprising if it didn't work with methanol, and other alcohols which easily form esters with formic acid  ;)




abolt

  • Guest
You should probably try and use Ethanol, Den.
« Reply #16 on: April 02, 2004, 06:24:00 AM »
You should probably try and use Ethanol, Den. alcohol, Methylated spirits, if you can get them.

Orgy makes note that it is important to heat the reaction slowly and bring it to a reflux for some time before distilling off the Formate, so as not to lose any alcohol, before the reaction has completed.

Methyl Formate B.P. - 32 Celcius
Ethyl Formate B.P. - 54 Celcius


abolt

  • Guest
The alcohol used by me was simple denaturated...
« Reply #17 on: April 13, 2004, 08:31:00 AM »
The alcohol used by me was simple denaturated ethylalcohol, I started with 100g hexamine which I dissolved in 100 ml water (what is probably not necessary at all, I will dissolve the hexamine in 30% HCl/EtOH next time directly without additional water) added 20g ammoniumchloride and heated slowly until ethylformate started coming over at about 50°C to 60°C measured on top of a vigreux column. Be careful not to distill away the alcohol before the reaction takes place, what will happen if heating is done to fast. Refluxing the reaction for one hour before distilling is advised. Then the reaction was hold at reflux for two more hours,

Orgy, Swim put this information to the test and copied the reaction with the exception that no reflux was continued after the formate was distilled, the water was immediately distilled as well.

The left over sludge was extracted with 300 ml boiling MeOH.

Result - a lot of left over NH4Cl and very little MeNH3Cl isolated from the OH.

It appears that:

Heat the the reaction mixture on a water bath SLOWLY up until the boiling point is reached, then start to distill away the formed methylformate. When all methylformate is distilled out the reaction is finished.
 
is not entirely correct, and that the additional aqueous reflux plays a significant part in the MeNH3Cl formation.

If this is the case then alcohol may play a part in lowering the reaction temperature, but the distillation of the formate does not complete the reaction.


Organikum

  • Guest
You may be right Abolt, also this might be...
« Reply #18 on: April 13, 2004, 11:29:00 AM »
You may be right Abolt, also this might be simplified by doing it like told here:

Post 498089

(Bond_DoubleBond: "excellent procedure. swim yielded 120g ...", Methods Discourse)


Distilling the water softly away without vacuum - this equals the reflux I guess and lets ask Bond_DoubleBond if he refluxed before he distilled the water away.

I described how I did it and the results - i made some suggestions which maybe wrong I admit, I never claimed to have found the best way to do this though.  :)

Together we will work it out I would like to say.

Did you add some NH4Cl, Abolt?
Did you mix the alcohol and the acid before adding it to the hexamine and did you dissolve the hexamine in some water (partially at least)?
And did you give the hexamine some time to hydrolize before starting the reaction?

No critics, just collecting information.

Bond_DoubleBond, would you share some more detailed information on yours please?


Bond_DoubleBond

  • Guest
Nothin special, but here ya go . . .
« Reply #19 on: April 13, 2004, 04:51:00 PM »
Swim's procedure went as follows:

100g hexamine (pulverized fuel tablets) and 30g nh4cl were added to a 1L rbf, followed by 120g den. etoh, followed by 330g 31.45% hcl.  This mixture was stirred vigorously and heat was evolved.  Gradual heating was applied with an oil bath (took three hours to reach >60c).  Two layers formed and distillate was collected between 34c and 60c with the majority of it around 55c.  Once no more distillate came over in that range, the heat was turned up and the remaining alcohol was distilled out. The flask was then cooled to room temperature and the solids were filtered.  The water in the remaining mixture was then quickly distilled away with an oil bath of ~150c.  The isolated methylamine was recystallized with anhydrous ipa to yield ~120g meam.hcl.

abolt: swim thinks that removal of the created formates by distillation is not necessary for the reaction, but an indicator of how the reaction is progressing. 

Swim was carefull not to heat to fast so the formate came over slowly.  All the formate was collected in the propper temp range and only after the formate stopped distilling and the heat was turned up did any alcohol come over.

The meam that was synthed has since been used in an amination successfully.

Chromic

  • Guest
Thoughts
« Reply #20 on: April 13, 2004, 08:29:00 PM »
>the oxidation of formaldehyde to CO2 is avoided

From what I understand, that's not a problem. In fact, you WANT formaldehyde to be oxidized.

It's formaldehyde that's oxidized to form formic acid--that's rxn drives the reduction of the methyleneimine. That HCOOH is of course further oxidized (but ask yourself the question--what is reduced?) to water and carbon dioxide.

So if you answer that question, maybe it's that further oxidation of formic acid occurs because it's being used to reduce more methyleneimine.hcl. But that's just a guess. I don't know enough about the mechanism of this rxn -- except what's on

https://www.thevespiary.org/rhodium/Rhodium/chemistry/methylamine.html



Dimethylamine production is a problem and results from formaldehyde reacting with methylamine. (how would addition of alcohol supress that? other than to keep the temperature low, which is somethign that could be accomplished by slow heating anyways... my guess would be that perhaps removal of the formic acid helps drive the reduction of methyleneimine, a Le Chatlier principle thing but who knows... and but why not add methanol instead of ethanol? methyl formate would have a lower BP than ethyl formate)

Also, Organikum, are you sure what you got is pure methylamine hydrochloride? If so, I believe 10g of it will dissolve in less than 10ml of water. Check that to make sure it all goes into the water, if not, then you know you've got ammonium chloride as well. Eleusis made a mistake where he thought his yields were awesome when they were filled with mostly ammonium chloride

Abolt, make sure your methylamine hydrochloride was absolutely dry (not a sludge... it should be a rock hard CHUNK in your flask after distilling off the water) to make sure you really got all of the methylamine hydrochloride from the rxn via recrystallizing with methanol.

Organikum

  • Guest
I know nothing about the rection mechanism and
« Reply #21 on: April 13, 2004, 10:28:00 PM »
I know nothing about the rection mechanism and I will stay away from making any guesses about it.
I found a patent.
I tried the procedure twice.
I posted the results.
The results were successfully reproduced by other bees.
(not only Bond_DoubleBond)

Regarding the solubility of ammoniumchloride in IPA I am very sure that the gained methylamine.HCl is quite pure. Had a look at the pic? Thats no ammoniumchloride for sure. As told I also did a chloroform and acetone wash.

I am sure we will find out what went wrong as Abolt tried it. If he likes to find it out of course.

Hey! It is even possible that adding NH4Cl to the reaction and do as always - without alcohol - will boost yields. But it wont reduce the reaction time and temperature as the addition of alcohol does very well.


ADDON: I believe the reaction mechanism as described on Rhodiums page is ONE POSSIBLE reaction mechanism, but by no way the ONLY POSSIBLE one - even not the most probable one I guess......


PS:

make sure your methylamine hydrochloride was absolutely dry (not a sludge... it should be a rock hard CHUNK in your flask after distilling off the water)


I never heard this before. Do you want to say "after distilling off the water and cooling down" ? Or do you actually say you can distill off the water UNTIL the MeAm.HCl is left as "rock-hard chunk"? Could you please clear this up for me?




abolt

  • Guest
k.c.nicolaouoaouaoau was not a bullshitter.
« Reply #22 on: April 14, 2004, 09:58:00 AM »
Orgy

Did you add some NH4Cl, Abolt?

Yes, 25 grams. Otherwise, the amount and type of reactants were the same as mentioned in your write up.

Did you mix the alcohol and the acid before adding it to the hexamine and did you dissolve the hexamine in some water (partially at least)?

And did you give the hexamine some time to hydrolize before starting the reaction?


The Hexamine was crushed up and the liquid reactants were poured in straight on top.

The reaction was then heated and stirred on a water bath and was taken to reflux from room temperature over a period of 4 hours.

The reflux was then maintained for 75 minutes, before the formate portion was distilled.

The first fraction distilled at 67 Celcius.(???????)

Vacuum was then applied and the water portion removed.

BDB

Thanks for the tip. It appears that Terbium's reservations, about the temp that the reaction takes place, were correct.

It appears that the only real difference between SWIM's failure and the successes of others is the raising of the distillation temp of the H2O.

Chromic

Thanks, will do.


Bond_DoubleBond

  • Guest
2 cents
« Reply #23 on: April 14, 2004, 11:13:00 AM »
abolt, swim doesn't think that you can derive any conclusions about your reaction when your distillation didn't produce either methyl or ethyl formate.

did you add hcl directly to the hexamine?  the following was taken from rhodium's site:

If the hydrochloric acid is added directly to the HMTA, a lot of it is lost, as ammonium chloride starts to separate almost immediately.

swim doesn't know what this means, but it could be a possible reason for your reacion failure.

when swim performed this reaction, he used a small excess of alcohol.  once the formate stopped distilling, swim turned up the temp and a small amount of ethanol was recovered (just under the amount one would expect based on the excess alcohol swim used).

this leads swim to believe that formate distillation is an accurate indicator of the reaction progress, and that if the temperature of the reaction mixture is controlled properly, the ceasing of distilling formate indicates the end of the reaction.

nearly exactly the amount of alcohol reacted that was expected, based on the amount recovered.  so, if exactly the amount of formate expected is produced, then the same yield could be expected of the meam.hcl.  theoretical yield from 100g hexamine is 139g meam.hcl.  org got 90% of that and that's with a chloroform wash that he suspects contained water, thus cutting into yield.  add that to normal product isolation losses, and it looks possible that this reaction produces near quantitative yields of meam with sub-atm distillation of the h2o.

just swims thoughts.

abolt

  • Guest
************
« Reply #24 on: April 14, 2004, 11:26:00 AM »
abolt, swim doesn't think that you can derive any conclusions about your reaction when your distillation didn't produce either methyl or ethyl formate.

The B.P. of 67 Celcius is quite puzzling. Maybe a dodgy thermometer.

If the hydrochloric acid is added directly to the HMTA, a lot of it is lost, as ammonium chloride starts to separate almost immediately.

This is not the problem. AFAIK, Hexamine is a combination of Formaldehyde and Ammonium Chloride. The addition of HCl merely disassociates the two.

Personally, I think that the OH is not necessary.

Time and testing will tell.


Chromic

  • Guest
more...
« Reply #25 on: April 14, 2004, 03:14:00 PM »
Yeah, I agree... what you've got really looks like MeAm. Ammonium chloride is barely soluble in even boiling IPA, so you'd have to have some pretty bad lab technique to end up with AmCl in your recrystallized MeAm...

The hard chunk that forms occurs once the water has been boiled off from the rxn only forms after it cools down (it's a bit of a slush while it's hot). If it's not a solid rock then you've left water in there and recrystallizations (either with IPA or MeOH) will give really low yields.

I'll have to try this sometime.

Rhodium

  • Guest
French Methylamine Articles to Translate
« Reply #26 on: April 27, 2004, 08:16:00 PM »
Préparation de la monométhylamine
A. Brochet & R. Cambier

Bull. Soc. Chim. [3] 13, 533-537 (1895)

(https://www.thevespiary.org/rhodium/Rhodium/pdf/menh2-hmta-1895.pdf)

The classic paper Brochet & Cambier paper Eleusis based his procedure on - they describe procedures using formalin and NH4Cl to produce methylamine, as well as HMTA and HCl, and mentions that methylal is evolved in the first procedure, as the commercial formalin contains methanol.
____ ___ __ _

Sur une nouvelle méthode de preparation de la méthylamine ainsi que sur la constitution de l'hexaméthylènetétramine
Trillat & Fayollat

Bull. Soc. Chim. [3] 11, 22-24 (1894)

(https://www.thevespiary.org/rhodium/Rhodium/pdf/menh2-hmta-1894.pdf)

This is an article Organikum will like - it is actually a preparation of methylamine involving the reduction of HMTA with Zn/HCl. They have gotten the structure of HMTA really wrong, but forgive them - they did this 108 years ago. They also describe the preparation of ethylamine by the Zn/HCl reductive amination of the acetaldehyde ammonia trimer*

* Also called Hexahydro-2,4,6-trimethyl-sym-triazine, and is commercially acailable. It can also be made by the addition of acetaldehyde dropwise to a 4x molar excess of concentrated aqueous ammonia, chilled in a freezing mixture [JOC 1973; 38; 3288]



biffman

  • Guest
Temperature of boiling off
« Reply #27 on: April 28, 2004, 05:22:00 PM »
I was wondering about the final stage where you are evaporating the liguid to leave the methylamine.  Apparently it has been claimed that it can be done with or without vacuum. 
  As the liquid decreases and thus the concentration of methylamine increases in the solution during the final boiling off the temperature will increase I assume because of the increasing concentration of the MeamHCl.  I was wondering if this might be a point where dimethylamine might be produced since the temperature can go significantly above 100C.  Even with moderate vacuum. (Swim knows by experience).
  Swim was not willing to fire up the stronger pump just for this, so was wondering if anybody who has performed this monitored the temperature during the final evaporation of the liquid.

Organikum

  • Guest
A quick question on the french articles: Can...
« Reply #28 on: April 28, 2004, 08:57:00 PM »
A quick question on the french articles:
Can somebody tell me if I am right when I assume that the french chemists in these times used CELSIUS as unit for temperature measurements? The article doesnt specify this further.

Thanks.
ORG


hypo

  • Guest
yes
« Reply #29 on: April 28, 2004, 09:00:00 PM »
without looking at the articles in question: usually they do.
(fahrenheit = wacko german in the eye of frenchmen)


Sredni_Vashtar

  • Guest
Units
« Reply #30 on: April 29, 2004, 12:33:00 AM »
Does anyone not use Celsius or Kelvin for scientific measurement nowadays?

Rhodium

  • Guest
degrees
« Reply #31 on: April 29, 2004, 03:56:00 AM »
Yes, nowadays everybody uses °C or K, but those articles were written over a century ago.


abolt

  • Guest
I was wondering if this might be a point where
« Reply #32 on: April 30, 2004, 07:52:00 AM »
I was wondering if this might be a point where dimethylamine might be produced since the temperature can go significantly above 100C. 

If the reaction has been held for a suitable time to allow for the formation of Methylamine, then slowly turn up the heat to distill the left over formate.

This leaves nothing but water and (hopefully) Methylamine ands maybe some residual Ammonium Chloride. You can now turn the heat up and safely distill the water at temperatures over 100.C.


biffman

  • Guest
Good results
« Reply #33 on: May 02, 2004, 11:52:00 PM »
Thanks for all the info everyone. The method does work nicely and is definitely an improvement over swims previous method.  Quicker and less hassle.

Vaaguh

  • Guest
temperature during distilling
« Reply #34 on: May 10, 2004, 03:43:00 PM »
Is it normal during the end of the distillation for the temperature of the boiling mixture itself to bee around 80-95 °C when there are still fractions comming over between 45 and 55 °C?

Or would this indicate that most of the ethanol has been distilled away?


Organikum

  • Guest
This says your reaction is still running and...
« Reply #35 on: May 10, 2004, 05:08:00 PM »
This says your reaction is still running and ethylformate is still formed. Not sooo fast please. Anyways, 80°C to 95°C is still far away enough from the point of formation of dimethylamine (over 104°C as I remember) so this should be no problem at all.

Go a little slower perhaps - less heat - but actually I can see no problem at here. btw. at this temperature you havent even started to boil the water away - so this cannot be called "at the end of the distillation".

Yields ok?


Vaaguh

  • Guest
slowed things down
« Reply #36 on: May 10, 2004, 06:06:00 PM »
The problem was that when the oil bath temperature was below 110 °C no distillate came over at all, which is probally caused by heat loss using a rather long vigreux column, so basically all the reaction mixture did was reflux the entire time with little distillate comming over while the temperature of the solution was starting to rise over 100 °C .

The column was switched for a simple still head and the oil bath temperature is lowered to 85 °C and the reaction temperature is now around 80 °C.

Distillate is comming over at 55 °C while the solution is not visually boiling.

Apparently Merck and Chemfinder both state that the bp of Methylamine HCl is 225-230 °C @ 15 mmHg, perhaps for purifcation purposes it is nice to vacuum distill the Methylamine HCl or will this bee an impossible task /unnecessary ?

Btw. Is it normal for the solution to turn a bit darker then being whiteish during the reaction ? All reagents used where labgrade except for the denatured 96% EtOH


Organikum

  • Guest
Reflux was ok. Distillation needs no column,...
« Reply #37 on: May 10, 2004, 06:27:00 PM »
Reflux was ok. Distillation needs no column, what comes over now is the ethylformate, so everything is ok. Go on until no more formate comes over, then distill the water away. Temperature in the flask will rise over 100°C then - understood, but this doesnt matter as the reaction is over.

The residue in the flask was always very orange colored and the white crystals came after extraction/recrystallization from IPA as described.
Distilling methylamine.HCl is no good idea this stuff starts subliming at far lower temperatures. You will have no methylamine left when you reach 200°C+. Alcohol (IPA)extraction and recrystallization are the way to go.

Stop distilling the water away when the residue looks like a very wet mush or you will loose all methylamine. (sublimation, as told)
Dont worry about the color.


Bond_DoubleBond

  • Guest
Hmmmmm...... Methylal........
« Reply #38 on: May 11, 2004, 02:37:00 AM »
I don't believe this works with methanol.  Judging by the temps that the distillates came over, very little methyl formate is formed (if at all), and a substantial amount of methylal is made.  _Lots_ of amcl was recovered.  No meam was isolated.

Temps were recorded at the top of a 200mm vigreux column and the distillate never came over at more than 1 drop / 4-5 seconds (i.e, heating was done slowly and carefully).  Nearly all distillate prior to methanol was collected in the 40-44c range.

I guess the meam never gets a chance at those low temps with the dimethoxymethane sucking up all the ch2o.

Save your methanol and hex.

madprosr

  • Guest
benefits of stripping solvent with an aspirator
« Reply #39 on: May 11, 2004, 08:43:00 AM »
1) you and your lab don't smell like eleusis for the next week
2) your methylamine is not rearranged to dimethylamine
3) it's faster!

Vaaguh

  • Guest
Re: The flask was then cooled to room ...
« Reply #40 on: May 12, 2004, 01:43:00 PM »

The flask was then cooled to room temperature and the solids were filtered.




Where these solids recrystalized with IPA aswell or discarded ?

Finally after 30 hours of slow distilling the distillate has reached the >60° celcius mark.

Unfortunately it will be a couple more days before the IPA will arive and the extraction can be performed.




Vaaguh

  • Guest
the good ole "parts"
« Reply #41 on: May 12, 2004, 07:20:00 PM »

17 parts of 40% formaldehyde, 7 parts of 96% alcohol and 8 parts of ammoniumchloride




Just for clarification purposes these parts can be converted into molar ammounts right?

(1 mol formaldehyde : to 1,176 mol ammonium chloride)




Organikum

  • Guest
Parts are always weight.
« Reply #42 on: May 12, 2004, 08:15:00 PM »
Parts are always weight.


Vaaguh

  • Guest
finished
« Reply #43 on: May 15, 2004, 08:33:00 PM »
Alright everybody thanks for all the help the procedure seems to have worked niceley.

In a 500 ml RBF equiped with a reflux condenser containing 50 g (0,36 mol) hexamine and 10 g ammonium chloride there was added 60 g denatured EtOH diluted with 60 g H2O. While the whole was being stirred 142 gram (1,43 mol) 37% HCl was slowly added which caused a little bit of white smoke travel up the condenser, during the initial stirring a little heat was evolved after no more heat evolved the mixture was slowly heated on a water bath to 40 °C causing all the solids to dissolve after 1 hour the temperature was increased to 50 °C, 2 layers where noticed.

After 2 hours the wather bath was switched for an oil bath and the mixture was slowly heated to 75 °C this caused the solution to boil. After 2 hours of refluxing the condenser was switched for a vigreux column and fractions where collected in the range of 40 °C to 55 °C. After 8 hours of distilling the solution stopped boiling and no more distillate came over the bath was heated further to 85°C and fractions between 45 °C and 60 °C started to come over at around 2-3 drops per minute, another 6 hours later the mixture stopped boiling causing no more distillate to come over.

The mixture was heated to make it boil again which was at 100 °C. The distillate came over at a annoying slow pace of around 1 drop per 1-2 minutes and the solution started to turn brown and the only fractions that came over where between 40 °C and 45°C.

Another 12 hours later it was decided that the droplets came over too slow and the vigreux column was switched for a normal still head the now orange reaction mixture was heated to 80°C and altough the reaction mixture did not visually boil there was distillate comming over between 45 °C and 65 °C over. At the around the 4th hour point the distillate reached 65 °C the heat was turned off and the solution was cooled down to 15 °C, the solids where filtered off.

About 30 g of white fluffy powder was collected and the remaining liqour was vacuum distilled to give orange tinted crystals. The slightly wet crystals where extracted and recrystalized with warm IPA to give beautiful almost transparent crystals (which is hopefully methylamine hcl).

The crystals still need to bee dried to calculate the yields.

From now on a vigreux collumn will not be used again.

Probally the best way is to slowly increase the heat of the reaction to 75 °C over a 4 hour span and reflux the solution for another 2-3 hours. From there switching the condenser for a a still head while maintaining the heat at 75 °C or to 85 °C at most even if things stop boiling dont heat things up but allow the distillate between 40 °C and 65 °C to come over. When the distillation is finished between that range reflux the mixture for 2 more hours, cool down, filter, extract and recrystale.

Btw. Seeing how dimethylamine is soluble in chloroform perhaps for making the cleanup more easy would it perhaps be an idea to use the stochiometric ammounts 20 HCOH + 9 NH4Cl + 10 C2H5OH as a ratio or would this mess things up?


armageddon

  • Guest
explosive by-product?
« Reply #44 on: June 10, 2004, 01:04:00 AM »
Tested, works good!

I'm not sure about the insolubles after reflux: Could it be that soemthing like hexamethylenetriperoxidediamine or HMTD (powerful primary explosive!  :o ) is formed?

I ask because I know that HMTD can be prepared using fuel tabs (AKA hexamine), a strong oxidizer and a weak organic acid in aequous solution, and that it is insoluble in almost everything (not in boiling alcohol, nor in acetone) - which are exactly the properties of this white, hard clumpy substance that was filtered from the rxn mixture....

(NO, the substance is NOT unchanged hexamine - dil HCl does nothing to it, And I KNOW, there are no strong oxidisers present, but it is the only substance i know derived from hexamethylenetriamine - and being that INSOLUBLE..  ;) )

greetz A


Bond_DoubleBond

  • Guest
not to worry . . .
« Reply #45 on: June 11, 2004, 03:39:00 AM »
...it's probably just wax and other binders from the hex (if you're using fuel tabs).  although swim has run amcl/paraform reactions and gotten small pebbles of insolubles.

also, for anyone having difficulty with this reaction, after the formate is distilled off hold the mix at 85-90c, otherwise the imine reduction does not take place.

swim ran three reactions a couple of days ago at 1/4 vogel scale with paraformaldehyde, amcl, and denatured alcohol.  the first two were stopped after the formate was distilled off, and the third was held at 90c for an hour afterwards.  the first two had an off white hue with _hints_ of yellow and blue.  the third was a pale defined yellow.  the amcl was separated from each.  near all amcl was recovered from the first after separation, distillation, etc., and most from the second upon the first filtration.  52g (92%) methylamine hydrochloride was recovered from the third reaction, none from the first.  the removed amcl was added back to the second, and the mix was heated to 90c and held there for an hour and 53g meam.hcl (94%) was recovered.

good call abolt.

abacus

  • Guest
food for thought
« Reply #46 on: June 11, 2004, 01:03:00 PM »
While we are on the subject of methylamine syths that actually work in practice, I draw astute readers to the following syth that DOES NOT work thereby allowing newcomers to avoid making such errors.

Org you posted the following ref in your post numbered 410425 (how do I get that to link again??).  

I put it to the court that the following words by K.C Nicolaou are bullshit (which is not your fault Org).



K.C. Nicolaou  posted 12-02-1999 12:28 AM
                      ---------------------------------------------------
                      I think that Sumerian was full of shit on that
                      one. He didn't remove his NH4Cl. Excess HCl does
                      not pose a problem for this rxn, although not
                      having enough is a problem. Vacuum has no other
                      effect than to make temp regulation easier, to
                      dispell another myth.
                      However,
                      Maximum theoretical yield from 140g Hex = 270g
                      MeAm HCl
                      Ways to *theoretically* increase the yield of MeAm
                      HCl would be allowing the rxn to run for a longer
                      amount of time, refluxing rather than allowing
                      vapors to escape, having less water present(you
                      need some, just not too much), and addition of
                      excess NH4Cl to your hexamine/HCl rxn.
                      Using the ratio of reactants
                      140g Hex
                      135g NH4Cl
                      110mL 31.45% HCl
                      100ML dH2O
                      and heating at 100C with a reflux condensor for
                      ~24hr gives yields of up to 210g of MeAm HCl(78%)
                      after chloroform wash and 2x recrystalization from
                      dry IPA. At this dilution your condensor can get
                      plugged by solids crystalizing out on the cold
                      surfaces(I don't know if that's from splashing of
                      the sol'n or a sublimation/evaporation type of
                      thing). SWIWIWN (Someone Who I Wish I Was Not) had
                      a rxn do that and then blow ~200g of stinky-ass
                      Methylamine all over the ceiling, breaking a
                      condensor and a thermometer(luckily it was the
                      only non-mercury unit in the room). Watch out.
                      Also, before someone says some stupid shit like
                      "doood, you don't have to add that extra NH4Cl," I
                      know, you don't. But, it increases the yield per
                      amount of hex, suppresses DiMeAm formation, and is
                      all recycled after the alcohol
                      recrystalizations(which you HAVE to do) anyway. So
                      I do it.

As very experienced hand at making methylamine.hcl via hexamine and HCL, SWIM initially noted that you can not replace HCL ions by simply adding NH4CL, as the HCL needs to be added to hexamine in the right molar ratio of 4:1 to get the desired amount of formaldehyde and NH4CL that the reaction requires.  The molar ratios above are clearly wrong.

Even though SWIM was skeptical, experiments using the above ratios were carried out which indeed proved worthless; there was very little resulting formaldehyde in the reaction flask and a huge excess of NH4CL, not to mention the often talked about smell (which incidentally doesn’t occur in a proper hexamine and HCL reaction).   The amount of methylamine.hcl that was finally recovered was insignificant.

The conclusion that SWIM made was, that clearly K.C N was talking bullshit or had made a mistake in the amount of HCL added to the flask. 

One other point, adding 30-35% HCL to hexamine DOES NOT cause the NH4CL to precipitate out.  What happens is it that it dissolves into a clear solution (slightly exothermix), upon heating (without ethanol) the clear solution sometimes becomes cloudy and sometimes it does not.

SWIM is looking forward to experiments with adding ethanol to increase yields if he ever has access to a lab again.

Abacus

abolt

  • Guest
Thought food is yummy
« Reply #47 on: June 12, 2004, 05:40:00 AM »
Abacus, that is slightly misleading.

Whilst I have no comment to make on KCN's explanation of the reaction I think you will find that KCN states further along in that thread that a much greater portion of HCl is required.(A 440 ml amount, if I remember correctly)

Go back and check it out. ;)

BDB, good work.

FWIW, I think that the reaction that Orgy is talking about in this thread is nothing but a fandangled, arse about version of the one listed in Vogels with the exception that Hexamine and HCl are used instead of Formaldehyde and NH4Cl.

The only benefit from the addition of Ethanol, is that it removes any excess Formaldehyde at a lower B.P. as Ethyl Formate, thereby eliminating any chance of the Di or Tri (methylamine ) forming.

The added benefit of the NH4Cl is that by reacting it with excess Formaldehyde, the yield is increased. If formate is distilling over then that means that there is even more Formaldehyde to be taken advantage of.

By adding even more NH4CL(see the thread mentioned by abacus above), could we increase yields of Methylamine even further???????

In discussions with bees I have learned that some have had success with this synthesis using a vigreux column and failures when not using a vigreux column.

The more commonly known literature tells us that Methylamine is formed in best yields at 103 - 104 Celcius internal reaction temperature via the NH4Cl/Formaldehyde route and at 105 -110 internal reaction temperature via the Hexamine/HCl route.

Has it dawned on any of you guys that when you are distilling the formate portion at the top of a vigreux that the internal reaction temperature is what is forming the Methylamine and not the rate of Formate distillation????????????

This could also explain why reactions without a Vigreux have failed, due to the less heat required to force distillation, thereby lowering the internal reaction temperature, disallowing methylamine production to commence.

I have a strong hunch that methylamine can be made in good yields with simple or even (ghetto) equipment.

There is any easy and simple way to find this out.

Could someone please try the following?

* Using the same ratio of reactants as Orgy stipulates at the start of this thread. Set up a standard distillation rig and place a thermometer in the oil bath only and slowly raise the oil bath temperature, and collect any distillate that comes over.

* When the oil bath reaches anywhere between , say, 106 - 109 Celcius, hold the temperature and allow the reaction to stir for 3 - 4 hours.

* Add vacuum and raise temperature to drive of the rest of the aqueous portion.

* extract MeNH3Cl with hot IPA or MEOH and cool down to recrystallise.

If my hunch is correct then we could add increasing portions of NH4CL until no formate is collected. Thereby maximising yields, and putting this baby to rest. :)


abacus

  • Guest
abolt, I'll check
« Reply #48 on: June 12, 2004, 01:04:00 PM »
Abolt, I  must have missed the correction by KCN, sorry about that I thought i had the whole thread and had no knowledge of a correction.

Good methylamine.hcl is not that hard at all, in fact, really simple using hexamine (solid camping fuel tablets)and HCL.  

I also go so far to say from experience that the reaction occurs below 103-104DegC.  The reaction (without ethanol) starts at about 80DegC and further heating in a hot water bath so that the flask temperature hovers around 95-100DegC works like a charm (which is not the method org suggest using ethanol).

Abacus

Organikum

  • Guest
Re: FWIW, I think that the reaction that Orgy...
« Reply #49 on: June 12, 2004, 02:22:00 PM »

FWIW, I think that the reaction that Orgy is talking about in this thread is nothing but a fandangled, arse about version of the one listed in Vogels with the exception that Hexamine and HCl are used instead of Formaldehyde and NH4Cl.



The reaction I talk about here is from a patent and was first proposed by Eleusis. It was new enough that the IG-Farben got this patent granted, so I guess it is not a "fandangled arse about version" but something different. What you think is actually not important, important is that it works fine and produces better yields in much shorter time than the method proposed before (the one outlined in Vogels 3rd). There is no difference if formaldehyde and ammoniumchloride or hexamine and HCl are used. Read the thread and you MIGHT be able to realize this.
I used hexamine because I HAVE it. Thats the only reason and I told it.

abolt, find something better and post it, or fuck the shut up, ok? I have the impression that quite a lot of bees like this "fandangled arse about version" very well and I cant understand what you complain about if not your own incapabilities.

regards  :P
ORG




armageddon

  • Guest
Abolt: firstly the reaction temperature will...
« Reply #50 on: June 12, 2004, 03:25:00 PM »
Abolt:

Firstly the reaction temperature will still hang around 50-60°C, even if no column is used and oil bath temp. is above 100°C - it simply can't get significantly higher as long as there are formic acid esters and alcohol present (with bp's being lower than 100°C), and only if these two are distilled away completely, temp. can rise to more than the bp of the higher boling compound (i.e. ethanol). The only reason why a vigreux could raise the bp of a reaction is its operating pressure (the pressure that builds up inside it), and this is not woth mentioning. Perhaps you have to apply more heat because of energy losses in the column (no isolation?), but this results only in quicker evaporation, NOT in higher bp!!!

And as there is in fact ethylformate formed, the removal of it drives the reaction forward (ever heard of the LeChatelier principle? like A+B<->C+D and if D is contiuously removed, more C is formed as the equation shifts to the right) - using a vigreux just helps separating the fractions and allows for a proper separation as the bp's of ethylformate and ethanol are closer together than 30°C...

Secondly, I wouldn't try extracting methylamine*HCl from ammonium chloride with (hot) methanol - NH4Cl is pretty soluble in it, so separating the two with MeOH is not advised.

Just some of the reasons why the patented procedure posted by Orgy will work, whereas your proposed procedure will probably fail (or produce mainly NH4Cl)...

(I tried it BTW, quick heating/distillation simply results in incomplete reaction - only advised if you need loads of ammonium chloride  :P )

So please don't flame Organikum because you tweaked too much!

Greetz A


Bond_DoubleBond

  • Guest
possible mechanism
« Reply #51 on: June 13, 2004, 03:03:00 AM »
swim firmly believes that the reaction involving ethyl formate is independent of the methylamine creation.

CH2O + C2H5OH -> C2H5OCHO + 2 extra hydrogens.

swims' observations:

1. if the reaction is stopped after all the ethyl formate is collected, nearly all of the ammonium chloride can be recovered. 

2. if the reaction is allowed to proceed at higher temperatures, near qualitative conversion to methylamine is had.

perhaps the imine fomation proceeds just as according to

https://www.thevespiary.org/rhodium/Rhodium/chemistry/methylamine.html

.

NH4Cl + CH2O -> [H2C=NH].HCl + H2O

judging from reports of alcohol-less methylamine synth writeups and from swim's own experience completing this reaction after the formate has been collected, it seems that the imine formation occurs at around 80c.  At this point, half of the formaldehyde has already been consumed into formate, and the other half now to the imine.  and there are the unaccounted for hydrogens to do the reducing somehow. 

swim is still a novice at org chem as far as book-learnin goes, but this mechanism seems to correlate all of swim's observations.

thoughts?

Antoncho

  • Guest
The mechanism
« Reply #52 on: June 13, 2004, 08:58:00 AM »
NH4Cl + 2HCHO __> CH3NH3Cl + HCOOH

Thus formed HCOOH reacts with ethanol:

HCOOH + C2H5OH __> HCOOC2H5 + H2O

forming ethyl formate, which is removed by dictillation.

Thus, it is precisely that Le Chatelier thingy which drives the rxn forward, IMHO.

Bond_DoubleBond

  • Guest
that is certainly not it.
« Reply #53 on: June 14, 2004, 12:03:00 AM »
that is certainly not it.  you can reflux and distill away all the ethyl formate and stop the reaction and you will get nearly all your ammonium chloride back.  however the amcl reacts in this whole process, it doens't do it (at any appreciable rate, at least) until the temperature far surpasses that of the boiling point of the mixture (ethyl formate vapor).

armageddon

  • Guest
Well if the water isn't removed too, there is...
« Reply #54 on: June 14, 2004, 01:15:00 PM »
Well if the water isn't removed, the following equation shifts to the left:

HCOOH + C2H5OH <> HCOOC2H5 + H2O

(ethyl formate is somewhat soluble in hot H2O, dissociating into formic and ethanol, shifting everything to the left - and more formic is available)

..more unreacted formic acid in the reaction inhibits the formation of methylamine (just LeChatelier backwards)..

NH4Cl + 2HCHO <> CH3NH3Cl + HCOOH

(remember that methylamine is ONLY made if the formed formic acid is REMOVED from the reaction, too much water/too little alcohol inhibits this)

That might be the reason why heating to just 80°C (and evaporating first ethylformate, then slowly the ethanol) results only in unreacted ammonium chloride/formaldehyde, whereas driving off the water gives appreciable yields...

Or perhaps you simply distilled away the alcohol too fast, together with the formate?

Greetz A


n00dle

  • Guest
Maybe offtopic but could the top of the reflux
« Reply #55 on: June 14, 2004, 04:31:00 PM »
Maybe offtopic but could the top of the reflux column or end of condensor be put under a small amount of hcl to salt out any dimeam that is causing stinky fish smell?

(One also thinks the slight pressure of the water might raise the bp's for the rxn which might be in our favour?)

Organikum

  • Guest
Thats not off-topic
« Reply #56 on: June 14, 2004, 10:07:00 PM »
but complete bullshit.
Dont post if you dont have ANY clue whats a thread or certain reaction is about.

Regards
ORG


abolt

  • Guest
Well, well, well..............it seems that I...
« Reply #57 on: June 15, 2004, 06:04:00 AM »
Well, well, well..............it seems that I have stirred this thread back into life.

abacus:Abolt, I  must have missed the correction by KCN, sorry about that I thought i had the whole thread and had no knowledge of a correction.

No need for an apology. ;)  Its just that I didn't want other bees to be discouraged by that thread because you left something out.

Good methylamine.hcl is not that hard at all, in fact, really simple using hexamine (solid camping fuel tablets)and HCL.

I am aware of that, Swim has seen MeNH3Cl in good yields by substituting with Hexamine and Hcl and following the Vogel's procedure.

I also go so far to say from experience that the reaction occurs below 103-104DegC.  The reaction (without ethanol) starts at about 80DegC and further heating in a hot water bath so that the flask temperature hovers around 95-100DegC works like a charm (which is not the method org suggest using ethanol).

That may be correct, I only quoted what the most common literature stated.

orgy: What you think is actually not important,

Well it seems to be important enough to get an over the top, egotistical reply from you.

It was new enough that the IG-Farben got this patent granted, so I guess it is not a "fandangled arse about version" but something different.

Then, unless you are saying that BDB and Swim are both liars, how is it different?

BDB and Swim have stated that when All the Formate and Ethanol has been distilled the reaction is incomplete, so aside from removing formaldehyde at a lower reaction temp, what part does it play??????

important is that it works fine and produces better yields in much shorter time than the method proposed before (the one outlined in Vogels 3rd).

...........and where did I say that it didn't????????

There is no difference if formaldehyde and ammoniumchloride or hexamine and HCl are used. Read the thread and you MIGHT be able to realize this.

I have stated the same thing. Read the thread and YOU MIGHT be able to realize this.

abolt, find something better and post it, or fuck the shut up, ok?

GO AND GET YOUR GUTS FUCKED!!!!!!

I have the impression that quite a lot of bees like this "fandangled arse about version" very well and I cant understand what you complain about if not your own incapabilities.

I am not complaining, I am merely trying to give my understanding of the reaction. My opinions are based on the actual research of Swim and another bee.

Orgy, I find it quite hypocritical that you would take an egoistic approach to my statements after all the crap you have stated about moderators having "ego problems".

FWIW, I don't care if I am right or wrong.........for if I am proven correct, then I know something...........and if I am proven incorrect.......then I learn something.

EITHER WAY I WIN!

By not allowing my ego to enter into things I hope to attain wisdom.

I SUGGEST YOU DO THE SAME!!!!!!!!

Armageddon: Secondly, I wouldn't try extracting methylamine*HCl from ammonium chloride with (hot) methanol - NH4Cl is pretty soluble in it, so separating the two with MeOH is not advised.

That's strange, the information I have states that NH4Cl is only slightly soluble in Methanol, and from what I have learned at the Hive, small amounts of NH4Cl are tolerable in aminations due to the selectivity of Methylamine in the reaction.

Just some of the reasons why the patented procedure posted by Orgy will work

.........for the second time, where have I stated that it will not.

whereas your proposed procedure will probably fail (or produce mainly NH4Cl)...

How did you arrive at that conclusion, it is virtually the same procedure?

(I tried it BTW, quick heating/distillation simply results in incomplete reaction - only advised if you need loads of ammonium chloride )

Which further validates the point that Swim and BDB have been making that the reaction is not finished after the distillation of formate/ethanol and that a further higher reaction temperature is required.

So please don't flame Organikum because you tweaked too much!

............for the second time, I did not flame Orgy!!!!!

..........at least up until this post.

(remember that methylamine is ONLY made if the formed formic acid is REMOVED from the reaction, too much water/too little alcohol inhibits this)

......are you saying that the addition of alcohol is essential to the formation of Methylamine via hexamine and HCl??


Otherwise thanks for taking the time to write your explanation as to how the reaction proceeds. :)

BDB & Antocho: Thank you for your contributions. I will study what you have stated closely.


Bond_DoubleBond

  • Guest
meoh -> good separation
« Reply #58 on: June 15, 2004, 12:18:00 PM »
according to chromic's work,

Post 247196 (missing)

(Chromic: "Recrystallizing Methylamine Hydrochloride", Newbee Forum)


a boiling meoh recrystallization will result in a product that is 94% pure.  close enough for swim.

and a big thanks to chromic for that data.  handy info.

abacus

  • Guest
Alcohol is not vital
« Reply #59 on: June 15, 2004, 12:48:00 PM »
Nobody is seriouly saying alcohol is needed for the reaction to occur at all are they???, surely not???, Thats stupid to suggest that.

SWIM's reactions using hexamine and HCL NEVER involved adding alcohol and still ended up with good methylamine.hcl proving to that bee that alcohol was not important or required at all.  Likewise i think abolt has a few posts somewhere that never used alcohol.

I Think the point on the thread was to use it to increase yields.

Maybe a few people should go back and study Rhodiums excellent summary of this reaction on his page, and then use the addition of ethanol in some experiments.

The standard reaction using hex/HCL or formaldehyde/NH4CL itself is not the problem, the problem is the recovery, following Vogels procedure of distilling half the water away, crashing out the NH4CL, distilling again to crystalise the methylamine.HCL is were I believe most bees have trouble.

Heres my 2 cents worth with some details.

After distilling down to half original volume, let cool and filter out the NH4CL.

Setup for redistillation and distil again at atmospheric pressure UNTIL the flask contents temperature is OVER 150DegC, Then pour into a container and cool.  This will cause the whole solution to form a solid.  This seems like a lot of crystallising methylamine.hcl but its not.

When solid, crush up and vacuum filter with a buchner, rinse crystals in cold ethanol once, rinse once in acetone, and dry on newspaper for about 10-20 minutes, then store in a sealable container.  The recovered methylamine.hcl is fine for animations and recystallising is not required NOR is washing with chlorofrom (in fact chloroform washes do nothing from Swims experience and a quick acetone wash just gets rid of the residual ethanol and helps fast drying of the methylamine.hcl, when the reaction is carried out using a hot water bath for good temp control)

Washing with cold ethanol takes some product with it but it also takes most of the impurities leaving very good colourless methylamine.hcl

Then redistill the filtrate once more until liquid temp is 150-160DegC, again cool, let solidify, crush and filter, rinse with small amount cold ethanol, acetone if you want and dry and store.  Throw the filtrate away unless really keen to try to get a third crop (normally wont get any)

The point is, you have to let the mother liquid heat up to over 150DegC if you want a decent amount of it crystalising from the solution.

Yields using hexamine and HCL (without adding alcohol that this thread is dealing with) are usually 400g methylamine.hcl from 600g Hexamine.

Btw, how do I delete my posts on using nitro, this bee with never waste so much time with nitro ever again, when its so much better using methylamine.hcl, hehe

live and learn I suppose
Abacus

Organikum

  • Guest
again
« Reply #60 on: June 15, 2004, 06:05:00 PM »
The advantage of this is it is faster and it can give better yields if done right.

How the reaction works - I dont know.
Nobody exactly knows.
Rhodium layed out one POSSIBLE mechanism. It is not the the only one possible and it is not the most probable one IMHO. (terbium for example also always doubted this AFAIK)

Its probably true that the reaction needs some boiling after distilling the formate out - some boiling without distilling the formate out does the job also, a powerful condensor is needed though. 

In difference to BDB and armageddon you strictly refrained from posting anything useful abolt.
You are a troll.
And pissed because I shitfiled you I guess.
LOL....
I like it  ;)
ORG


abolt

  • Guest
Yields using hexamine and HCL (without adding...
« Reply #61 on: June 16, 2004, 09:52:00 AM »
Yields using hexamine and HCL (without adding alcohol that this thread is dealing with) are usually 400g methylamine.hcl from 600g Hexamine.

Swim has seen similiar.

I wonder if adding a further excess of NH4CL and leaving alcohol out all together, would improve yields?

How the reaction works - I dont know.

Then where the hell do you get off saying ANYTHING to ANYONE!

Nobody exactly knows.

............and if people follow your example, we never will.

It is not the the only one possible and it is not the most probable one IMHO.

........and since when has your opinion ever been humble?

In difference to BDB and armageddon you strictly refrained from posting anything useful abolt.

Well, it seems that BDB would disagree with you and armageddon has provided nothing other than theoretical views.

You are a troll.
And pissed because I shitfiled you I guess.


........and you are an fragile, egotistical, thought nazi, threatened by the thought that people with far less theoretical knowledge than yourself, may actually prove you incorrect.

Time will tell.


runne

  • Guest
SWIM's experience.
« Reply #62 on: June 16, 2004, 02:48:00 PM »
All using just: Ammonium Chloride + Formaldehyde + 45% EtOH

Attempt #1
In the beginning of the thread SWIM didn't know what temperature the new procedure should be followed at. So he started with keeping it at 80c until no more distillate came over. Then worked up as normal. Yield: 90%+ Ammonium chloride.

Attempt #2
Same as attempt #1 except refluxed at 80c or so for 3 hours.
Yield: 80% ammonium chloride, 20% methylamine.hcl.

Attempt #3
Heating on oil bath to approx. 104c for 3 hours, refluxing. Then setup for simple distill and removed all alcohol.
Followed regular workup by boiling away water etc.
Yield: 80% methylamine.hcl!, 20% ammonium chloride

Could somebody confirm my conclusions?:
1) The internal temp must go up to around 104 or so for the methylamine to form?
2) Can I start to distill from the beginning? Just being sure to go slow on the heatup? (1 to 2 hours to 80c or so?) Then up to 104c?


Thanks. Hope this helps.

armageddon

  • Guest
glasshouse and stones
« Reply #63 on: June 17, 2004, 09:43:00 PM »
Well abolt I tried it SEVERAL times, distillation/removal of EtCOOH IS necessary when using alcohol - which in turn is used to avoid CO2 evolution and formaldehyde stink (not necessary, but nice)!!

(one time I thought distillation was finished, cooled everything, filtered the solids and guess what? When recommencing with distillation, a small portion of EtCOOH came over, followed by alcohol and then water - and during the next try, I added some additional EtCOOH to the rxn - very little yield, lots of unreacted alcohol left...)

IMO this proves that my "LeChatelier"-statement is not THAT wrong...

BTW I also mentioned earlier that I tested the described (PATENTED) procedure successfully - so please don't start saying I didn't prove anything! Better tell me how I could verify a patented procedure other than trying to reproduce its results??

I think the only one who said "It doesn't work" or "not necessary to do it this way" without proving anything is YOU - just based on the fact that you didn't manage to get it to work!

(Whereas other bees USUALLY only make conclusions when they're sure they didn't make any mistakes)  ;D



Orgy: my concentrated MeAm*HCl solution isn't orange but rather greenish (similar to P2P  :) ) - but it works like a charm, doesn't even need recrystallization!

(I usually concentrate, filter, then repeat the process several times (2-3), collecting all solids. When the volume of the mother liquor is next to nothing, I crash out the amine salts with tone, combine them with all solids, rinse again w/acetone and extract by refluxing in dry iPrOH - the resulting solution has a slight greenish color, but the crystals after concentrating and cooling it are HUGE and TRANSPARENT (like your picture) - as long as they are still acetone-wet!

 - But how do you manage to properly dry the crystals after filtering/washing them?

I have problems even putting them into a wide-mouthed flask fast enough - they absorb moisture, cake and disappear, leaving little puddles, as soon as the solvent is removed... (at least I can be sure it is no ammonium chloride, eh?  ::) )

Greetz A


bio

  • Guest
Worked for me and was much faster on a 16 mole
« Reply #64 on: June 18, 2004, 04:34:00 AM »
Worked for me and was much faster on a 16 mole batch than the old standby O/S method with a little better yield.

Thanks Organikum!

abolt

  • Guest
Thick
« Reply #65 on: June 18, 2004, 08:04:00 AM »
Well abolt I tried it SEVERAL times,

Then post your results, as others have graciously done.

I think the only one who said "It doesn't work" or "not necessary to do it this way" without proving anything is YOU

I said no such thing. I took Orgy's word for granted that the synthesis worked and merely played around with the synthesis in order to find out if the perameters could be tweaked even further. This is a concept known as research

What hasn't yet dawned on you lot, is that I deliberately set out to do what I did in order to gain understanding.

BDB, kindly, took that research a step further, and shared it with you ungrateful assholes.

I swear, If everybody in the world took your attitude towards things we would still be riding around on horse back.


armageddon

  • Guest
riding on a horses back
« Reply #66 on: June 19, 2004, 02:25:00 AM »
Well if you mean more precise results than "it works" (which I still believe to be enough info), here we go:


- Use slight excess of alcohol and HCl (doesn't hurt)

- heat on oilbath *very* slowly to 70°C over 4 hours
  (two layers form, and reflux sets in)

- quickly change condenser with distillation setup, slowly heat up to 85°C (oilbath temp.) over ~1 hour
  (ethyl formate distills over at max. 48°C steam temp.)

- raise bath temp. until dist. of excess ethanol is finished

- cool down to 15°C, filter solids and save them

- continue heating/refluxing for 1 hour, then concentrate
   (bath temp. will rise over 150°C even if vacuum is used, that's OK)

- let cool, filter, collect solids

- repeat as necessary (2-3x, until no more solids are fomed on cooling)

- combine solids, wash with anhydr. acetone, extract by refluxing in IPA (repeat 3-4x with fresh IPA)

- combine IPA extracts, concentrate, let cool

- filter the formed crystalline shiny plates, rinse with acetone, put in dessicator to dry


No recrystallisation is needed, no CO2 is evolved, (almost) no stinky diMeAm or formaldehyde vapors..

I hope this is enough information for you, abolt.
Although it is almost exactly the same thing like in the original patent - and I don't understand why you want to modify the reaction/procedure to not using any alcohol - the patent doesn't say alc is NEEDED but that its presence helps avoiding gas evolution, quote from the first post:

"(...)It was found that the formation of CO2 whilst the production of mono or dimethylamine can be mostly or completely avoided by the addition of alcohol to the reaction mixture."

And Organikum *started* the thread with these words BTW.
If you like using other methods, alright - but if you want to avoid above downsides you should just shut up.

Yiiiiehaaaaah!!!!!!!!!

[EDIT] Oops, the cowboy forgot mentioning the yield: 49g HMTA, 90ml EtOH, 55ml H2O, some ??g NH4Cl (about 10-15g) and 160ml HCl 31% resulted in 40g MeAm*HCl (of excellnt purity) when above procedure was applied to them [/EDIT]

A


abolt

  • Guest
armageddon
« Reply #67 on: June 19, 2004, 03:27:00 AM »
If you like using other methods, alright - but if you want to avoid above downsides you should just shut up.

Are you saying that the synthesis of Methylamine via Hexamine/Hcl cannot be optimised any further and therefore any further discussion on the matter is futile?


Why does this synthesis fail when substituting Methanol for Ethanol?


abacus

  • Guest
wheres the part that you remove the NH4CL from IPA
« Reply #68 on: June 19, 2004, 09:47:00 AM »
Armageddon

Please elaborate on how the ammonium chloride is removed???

The solids collected are a mixture of mostly NH4CL and methylamine.hcl. 

Extracting the methylamine.hcl can be done by heating the resulting mix with boiling IPA, then FILTERING the huge amount of non dissolved NH4CL from the hot IPA, then one can proceed to concentrate and cool the IPA and let the methylamine.hcl crash out. 

I see no reference to this filtering or so thats why i ask the question???  I assume this is an oversight that should be corrected

Abacus

Organikum

  • Guest
orange or green....
« Reply #69 on: June 19, 2004, 04:17:00 PM »

Orgy: my concentrated MeAm*HCl solution isn't orange but rather greenish (similar to P2P ) - but it works like a charm, doesn't even need recrystallization!


armageddon, the mixture of MeAm and NH4Cl and gunk before extracting with IPA is always VERY orange when I do this, but the extracted MeAm and parts of the crystals are quite greenish tinted thats true.....


But how do you manage to properly dry the crystals after filtering/washing them


I dont dry the MeAm.HCl anymore. I did it once using vacuum and a dessicator and lots of time. This is to tedious in my eyes and makes no sense as I use the methylamine as base in alcohol (or ether). So I just distill the excess IPA out (for reuse) add a little water again to get a slurry and drop this onto excess NaOH. The gas is vented into alcohol (95% denat.) or ether in a cooled receiving vessel. Amount of MeAm is determined later by weighing the resulting solution.

ORG




armageddon

  • Guest
NH4Cl removal / leuckart methylamine
« Reply #70 on: June 20, 2004, 06:53:00 PM »
Abacus: If you'd read my post carefully, you would have realized that your proposed separation method is exactly what I did - concentrate, suction filter the solids, repeat - then rinse collected solids with acetone - then reflux them in IPA for some 30 minutes, repeat with fresh IPA, combine IPA xtractions, concentrate, let cool - et voilà...

The ammonium chloride stays in flask as a solid, the MeAm*HCl dissolves in the hot IPA - which is decanted...

BTW abolt: I adapted the workup from a different procedure, which might give you some new thought perspectives about the subject  :) :

Gattermann, Ludwig: "Die Praxis des Organischen Chemikers" p. 356 ff., (sorry for my bad translation...)

"LEUCKART REACTION

Methylamine through reductive methylation


2NH3 + 3CH2O ---> 2H2NCH3 + CO2 + H2O

250g ammonium chloride (4.7 mol) are slowly heated with 570g 35% formaldehyde solution in a distilling flask fitted with downward condenser. The temperature (thermometer reaching below surface of rxn) is slowly raised to 104°C and held there until no more distillate comes over (4.5h from beginning). The distillate will consist of 100-120g water and methanol (from the 35% formalin solution). After cooling down the dist.flask content, the precipitated ammonium chloride is filtered with suction and the filtrate is reduced to half of its volume on a steam bath. After cooling, the NH4Cl is again separated with suction filtering and the remaining liquor is concentrated until it forms a surface skin. After cooling, the MeAm*HCl is filtered out (suction) and the mother liquor further concentrated (residual water being removed with a vacuum exxicator/NaOH(s) or H2SO4). The residue is freed from di- and trimethylammoniumchloride by washing w/chloroform and dried with suction. Together with the first crystallization, 110-125g of crude MeAm'HCl are collected.
To free the crude salt from residual NH4Cl, it is extracted by boiling with 250ml abs. alcohol for 0.5 hours.
The alcohol is cooled, precipitated MeAm*HCl is filtered and the mother liquor is used for another exctraction. After five extractions, one gets approx. 100g (37% of theory).

With the carbinolamines, the hydroxyl group cannot only be replaced by nucleophile C-bonds (like with the MANNICH reaction) but also under reduction with anionic hydrogen - in above methylamine synthesis, this hydrogen is donated by the excess formaldehyde which in turn is reduced to formic acid (formate), which again serves as reducing agent and is being oxidized to CO2. These reactions (especially the first) are somewhat similar to the Cannizzaro reaction, which is discussed later (p. 377).

The unavoidable formation of di- and trimethylamine becomes the main reaction if the formaldehyde concentration is raised, because primary amine is further methylated according to same mechanism (formaldehyde as reducing methylating agent for amines, ESCHWEILER). According to CLARKE better yields can be obtained by adding additional formic acid at the beginning."

The reductive amination of carbonyl compounds, according to LEUCKART, is generally done with ammonia and formic acid (or its esters) or formamide. Primary and secondary amines (often as N-formyl derivatives) and tertiary amines are made, depending on the starting amine and proportions of reagents."




---I think "optimizing" Orgy's procedure would result in exactly the same procedure (no alcohol) - if you compare the yiels you will see the advantage that lies in the given patent (and in using alcohol)....

(and methylformate just distills over too quickly to allow for a slow temp. rise over hours, therefore methanol is bad - and IPA is bad too because the bp of isopropylformate is almost same as the bp of IPA - impossible to separate!)

BTW abolt as you can see, most usable routes to MeAm have been invented by "nazis"... (I think even methylamphetamine is their invention - or was it the japanese? Maybe collective meth overdose in germany/japan caused WW2?  :-[ )

Oh, and as I reread my post, I realize that over-alkylation is only a major problem when NO alcohol is used, leading to excess formic acid present - so the presence of ethanol helps also in avoiding the formation of polymethylated amines. "temp is kept low" and "CO2 evolution is suppressed" are NOT the main reasons for using ethanol...

(abolt: your so-called "research" consists mainly of not reading the literature about the topic, isn't it? In fact, doin it without alcohol means no "improvement" but a step backwards... If you would've read some standard organic chemistry book about it, you surely would have realized too that the patent states (and many bees already have proven so) that almost no di- or trimethylamine is formed - in contrast to the standard procedures, resulting in lots of diMeAm!)

A


abolt

  • Guest
(abolt: your so-called "research"...
« Reply #71 on: June 21, 2004, 09:07:00 AM »
(abolt: your so-called "research" consists mainly of not reading the literature about the topic, isn't it? In fact, doin it without alcohol means no "improvement" but a step backwards...

For the third and last time, I did it to gain an understanding of the reaction, as the explanation provided by Organikum was incorrect. Please read:

Post 500514

(abolt: "The alcohol used by me was simple denaturated...", Methods Discourse)


For an educated person, you really are very stupid.

explained If you would've read some standard organic chemistry book about it, you surely would have realized too that the patent states (and many bees already have proven so) that almost no di- or trimethylamine is formed - in contrast to the standard procedures, resulting in lots of diMeAm!)

The avoidance of Di & Tri -methylamines can and has been easily achieved without the use of alcohols.

I believe the second explanation you gave is the most convincing one I have seen so far.

Post 513300

(armageddon: "Well if the water isn't removed too, there is...", Methods Discourse)



Organikum

  • Guest
reaction mechanism
« Reply #72 on: June 21, 2004, 01:08:00 PM »
Actually this is a reductive amination and it can proceed through several pathways depending on the way it is done. Most probably it proceeds through a mixture of several pathways I guess.
If done with hexamine a Delepine style reaction is not impossible at all.
The Zn/HCl and the electrolytic reductions deserve further investigation I believe - the drawback of 1/3 trimethylamine formed might be overcome by some changes in the ratios of the starting compounds, maybe even adding excess ammoniumchloride would suffice, other metals should be able to do the trick to. Al/Hg would I guess, but this would be a waste. SnCl2 perhaps or plain Al? Hmm.

Future will show.

abolt, please refrain from cluttering the thread further with your ignorance. Thanks.

ORG  ;)


armageddon

  • Guest
Probably true
« Reply #73 on: June 21, 2004, 07:11:00 PM »
Probably true - even with alc the temperature needs to be rised to 104°C (i.e. refluxing after alc removal) to get good yields´- but the method described in "Gattermann, Ludwig" (and retyped and translated by me for stupid, ignorant bees like abolt) DEFINATELY yields lots of diMeAm and little MeAm (compared to the patented method) ALTHOUGH the temp. is high enough (104°c), showing that the alcohol is helpful.

For Abolt (last time): the alcohol aids in removing excess formic acid from the reaction (at least if dist. is done carefully enough - no MeOH should be used therefore) and maybe in slowing the heating process. The excess formic acid would otherwise lead to overalkylation (quote from my last post: "The unavoidable formation of di- and trimethylamine becomes the main reaction if the formaldehyde concentration is raised, because primary amine is further methylated according to same mechanism (formaldehyde as reducing methylating agent for amines, ESCHWEILER)" and THIS IS THE REASON WHY ALCOHOL HELPS IN AVOIDING THE FORMATION OF DI- AND TRIMETHYLAMINE!!

So would you please stop ranting about other methods being better for producing methylamine from hydrolyzed hexamine?
(proposing alternative routes has NEVER helped me in understanding other routes BTW)


Bond_DoubleBond

  • Guest
what happened to civility?
« Reply #74 on: June 21, 2004, 08:07:00 PM »
how exactly do you know that that is how this alcoholic reaction works?

So would you please stop ranting about other methods being better for producing methylamine from hydrolyzed hexamine?

jesus, some of you must just simply read the first line of other bees posts and choose to predict what rest is stated.

or maybe english just isn't a strong point for some of you.

waiting for the next condescending nonsense post.

bdb

armageddon

  • Guest
yup.. sorry!
« Reply #75 on: June 22, 2004, 01:57:00 AM »
You're probably right - it's only a discussion about a patented procedure for making MeAm*HCl, there was no need for me to freak out like that... my apologies.

Nevertheless I still think that the purpose of the alcohol might be to remove excess formic acid instantly through forming ethyl formate, thus favoring monomethylation...

BDB: yeah I'm guessing too, but considering the fact that excess formic/no alcohol can result in much di- and trimethylamine if heated too high (standard procedure) - whereas removal of excess formic with alcohol and careful distillation (lechatelier..) gives almost no di-/trimethylamine although temp. climbs pretty high at the end of rxn - leads to the conclusion that the main benefit of alcohol is removing excess formic, n'est-ce pas?
(besides, it allows of course for a slow temp. rise - ala Leuckart)

I think Antonchos rxn mechanism isn't that wrong.. (

Post 513107

(Antoncho: "The mechanism", Methods Discourse)
)

And proposing to simply reflux hexamine/HCl/NH4Cl isn't exactly what helps in further developing/fine-tuning this special, patented procedure with its special benefits (due to using alcohol!) towards a better, smoother-running, and/or higher-yielding procedure, so I really can't understand why abolt did so?!  ;D

And the bee who started w/flaming other bee's asses because of different opinions on the subject was not me, just to remember... (but I will happily continue throwing shit into the fan - if anyone desires so...  ;) )

Oh - BTW, Runne:

Could somebody confirm my conclusions?:
1) The internal temp must go up to around 104 or so for the methylamine to form?
2) Can I start to distill from the beginning? Just being sure to go slow on the heatup? (1 to 2 hours to 80c or so?) Then up to 104c?


I think your conclusions are right so far.. but better heat up even slower (5 hours?), remember you have to give it enough time for

 a) hydrolysis of hexamine
 b) imine formation
 c) formation/removal of ethylformate
 d) removal of excess alcohol
 e) imine reduction/water removal

- and I doubt that all that can be accomplished within 2 hours as these rxns somewhat depend on each other.. ;)

A


abolt

  • Guest
Revenge is sweet
« Reply #76 on: June 23, 2004, 06:17:00 AM »

armageddon

  • Guest
hm
« Reply #77 on: June 23, 2004, 02:20:00 PM »

armageddon

  • Guest
simplification (slow heating)
« Reply #78 on: July 20, 2004, 05:39:00 PM »
Hi!

It has been a while since the posts of this thread were informative... ::)

Here's a small improvement of the discussed procedure:

When heating (at the beginning), the problem usually lies in slow temp. rise. This can be simplified by adjusting the vertical position/heigth of the heating bath in a way that the ethylformate layer is 2-3 cm above the surface of the heating liquid. If done this way, the heat can be raised to 60°C within 2h without any problems, as the ethylformate is only heated from below, not from the sides - and when stirring is set to low, this will cause the ethylformate to not evaporate, until temperature is well above 60°C. (assuming the flask used is big enough, double rxn volume at least...)

Distillation can then be done by adjusting the stirring rate while *SLOWLY* raising bath temp. - faster stirring results in more surface between the two layers, the ethylformate is able to absorb more heat and evaporates faster. Stirring the rxn rather violently will almost surely initiate the ethylformate to come over...

Greetz A


abolt

  • Guest
thick as 2 planks
« Reply #79 on: July 21, 2004, 06:47:00 AM »
Or..........you can distill off the formate as quick as you like and then reflux the mixture at 90C for one hour.

Post 512674

(Bond_DoubleBond: "not to worry . . .", Methods Discourse)



armageddon

  • Guest
oh no - not again
« Reply #80 on: July 21, 2004, 07:32:00 AM »

abolt

  • Guest
You sure do seem to contradict yourself a lot.
« Reply #81 on: July 21, 2004, 12:00:00 PM »
You sure do seem to contradict yourself a lot. First you say:

I DID NOT STATE THAT ANY DISTILLATION HAS TO BE DONE SLOWLY TO GET GOOD RESULTS WITH SAID IG_FARBEN PATENT!!!

.....and then you say:

THE CAREFUL DISTILLATION IS BTW NEEDED IN ORDER TO AVOID DISTILLING AWAY SOME ETHANOL BEFORE ALL EXCESS FORMIC HAS HAD ENOUGH TIME TO REACT WITH IT!

DID YOU REALLY MEAN YOUR SUGGESTION AS A SERIOUS RESPONSE TO MY LAST POST??

I think you are an "armchair expert" and a plagiarist.

I tried it, and if temperature is controlled in the way described above, it is possible to collect ALL of the theoretical amount of ethylformate in a temp. range BELOW 43°C

Brilliant.........you manage to distill Ethyl Formate below it's Boiling Point of 54 Celcius.

http://ptcl.chem.ox.ac.uk/MSDS/ET/ethyl_formate.html




abacus

  • Guest
I agree abolt
« Reply #82 on: July 21, 2004, 12:48:00 PM »
arm chair expert, I mean "arm chair useless", is full of words such as.

"I think, I would believe, maybe you, i suggest, might be, I wouldn't advise" etc etc ...it doesn't convince me armegeddon has actually tried this synth.

This thread is supposed to teach us new and improved ways of increasing our yields from bees that have actually gotten home from school and tried to make some shit, useless debate from armchair experts isnt making it any easier.

But the challenge has been made, so experimental reports on the effect of adding ethanol to this procedure will soon follow.

Abacus

armageddon

  • Guest
useless for morons...
« Reply #83 on: July 21, 2004, 05:12:00 PM »

abacus

  • Guest
QED
« Reply #84 on: July 22, 2004, 12:16:00 PM »

Bond_DoubleBond

  • Guest
swim has had great success with refluxing,...
« Reply #85 on: July 23, 2004, 01:48:00 AM »
swim has had great success with refluxing, distilling off the formate quickly, then allowing the reaction to proceed at ~100c. 

slow heating and distillation is NOT necessary.

abolt

  • Guest
slow heating and distillation is NOT ...
« Reply #86 on: July 23, 2004, 05:12:00 AM »

moo

  • Guest
Sheesh.... grow up.
« Reply #87 on: July 23, 2004, 06:18:00 AM »

armageddon

  • Guest
oh - how pissed of I am now!!
« Reply #88 on: July 23, 2004, 07:35:00 AM »
swim has had great success with refluxing, distilling off the formate quickly, then allowing the reaction to proceed at ~100c. 

slow heating and distillation is NOT necessary.


Not necessary for what - for just making methylamine? Noone said so....

You can even reflux just hexamine, NH4Cl and HCl and hold at 105°C and get good yields, and nobody wants to keep you from doing so (at least if you are the only person working in your lab - cough, cough..)

Did you use a column? At which temp. came the ethylformate over? And (most important to me) did you get any diMeAm, what about formaldehyde stink - was there any? Most important: how was the yield?

All in all, your statement is of no more reliability than mine - how about sharing some details? It seems you don't consider it necessary to properly separate the EtCOOH from unreacted EtOH? Could you please tell us if/why/how you came to that conclusion/observation/whatever?

Abolt, it appears that you should consider yourself lucky that I don't know you personally. Don't want to lose any more words about credibility, besides of this: In no way will I get A NEW USERNAME just because some debile dumbass screams "You were wrong, you were wrong" when some other bee writes he has had success with some slightly different procedure. And most surely I won't do so just because ABOLT is the one to scream.. (abolt, do you often change your user name when you fear about your credibility??? coward..)

(everybody else - make your own opinion about credibility of my posts)

I sadly fail to understand Abolts motivation: do you want to convince all readers of this thread to use the standard NH4Cl/HCHO method? Or do you believe the method is just bogus and doesn't work better than any other one??

If that's the case: ABOLT, MAY I SUGGEST YOU MAKE YOUR OWN THREAD THEN??????????

Greetz A


armageddon

  • Guest
reliable or not - my thoughts...
« Reply #89 on: July 23, 2004, 08:12:00 AM »

Organikum

  • Guest
The method like outlined by BDB works well...
« Reply #90 on: July 23, 2004, 10:52:00 AM »
The method like outlined by BDB works well after my experience, it is for sure the FASTEST way to make methylamine from hexamine in yields which dont stand back to those yielded with the old timeconsuming method.

The other ways discussed by armageddon and amalgum are not as fast but promise better yields. It are optimisations on yields.

There is no contradiction.

I want to thank all who post practical experiences here - there is more than one way to skin a cat, lets discuss it  ;D . Its always good to have choices, some with better equipment and more time will prefer a slower but higher yielding method, the method as told by BDB is a present to all whos time is pressing.

Nevertheless I am astonished what kind of behaviour of a certain immature member is tolerated here - I thought this forum is moderated.

thanks
ORG


abolt

  • Guest
The "optimised" BDB/abacus version
« Reply #91 on: July 23, 2004, 10:55:00 AM »
armageddon & organikum

You have both taught me a valuable lesson, and that is that a bee that is prepared to roll up his/her sleeves, put some glassware together, and do some actual research is worth more than all the bullshitting "armchair experts" on the planet.

Nevertheless I am astonished what kind of behaviour of a certain immature member is tolerated here - I thought this forum is moderated.

Do you think that the reason that I have not been, as you say, "moderated", is that I may have a point?

I am quite happy for the members to go back over this thread and make up there own minds as to who has been productive and counter productive.

Let's agree to not pollute this thread with any more of your stupidity.

To save yourselves any further public embarressment, you can P.M. your apologies to me.

Now, here is some more USEFUL information.

After reading the interesting words of abacus:

Setup for redistillation and distil again at atmospheric pressure UNTIL the flask contents temperature is OVER 150DegC, Then pour into a container and cool.  This will cause the whole solution to form a solid. 


in his (EDIT - THE WORD THREAD HAS BEEN REPLACED WITH THE WORD POST, APOLOGIES FOR THIS OVERSIGHT, ALTHOUGH I ASSUME THAT MOST OF YOU WOULD HAVE BEEN INTELLIGENT ENOUGH TO WORK THIS OUT ANYWAY :) ) post:

Post 513530

(abacus: "Alcohol is not vital", Methods Discourse)


abacus, then goes on to say:

This seems like a lot of crystallising methylamine.hcl but its not.

Maybe so abacus my friend, but if you substitute the first part of the I.G.Farben patent as mentioned by BDB:

Post 500578

(Bond_DoubleBond: "Nothin special, but here ya go . . .", Methods Discourse)


for the Vogel procedure you are left with a MeNH3Cl that is suitable for the Osmium Al/Hg. ;)

Swim set about to do another experiment, using some of abacus's interesting workup.

After formate distillation, excess NH4CL removal and the 1 hour reflux, glassware was set up for distillation and the oilbath was raised to 155 Celcius (as measured by a thermometer dipping into the reaction) and held there until water distillation ceased. The distilling flask was quickly removed and the contents poured into a beaker whilst still hot.

The beaker was left to cool to room temperature and formed a hard white sheet of solids, that was crushed up and vacuumed filtered to allow for around 10 mls of liquid that was crashed out with dry acetone to give a very small amount of MeNH3Cl. The resulting dry crystals in the buchner was thoroughly rinsed again with dry acetone and vacuum filtered again and gave no appreciable weight loss. Tests done on the crystals showed them to be at least 93% weight MeNH3Cl.

This research is also in accordance with the yields noted by BDB (92% & 94%):

Post 512674

(Bond_DoubleBond: "not to worry . . .", Methods Discourse)


My point is that MeNH3Cl for a standard 3 x excess Osmium Al/Hg, can be made without recrystallisation, the use if vacuum or vacuum filtering and with "ghetto" equipment if need be.

I know this might offend some of the purists out there, but please consider:

Simply add the required amount of reactants, quickly distill off the formate, reflux, filter, distill and hold reaction temp at 155 C until H2O distillation ceases, quickly pour out, let cool, crush up solids and add aqueous 25% naoh until neutral.

Easy as pie :)  

This is just bits and pieces of other peoples techniques.


Thank god for research. ;)


Organikum

  • Guest
You are telling me to stay out of my own ...
« Reply #92 on: July 23, 2004, 11:42:00 AM »

armageddon

  • Guest
finally something worth reading!!!!
« Reply #93 on: July 23, 2004, 11:45:00 AM »
Thanks abolt - I was starting to think you REALLY were an armchair expert, now I know better.

But, sorry to question you again, and this is ABSOLUTELY NOT meant as an accuse/flame or anything negative:

The only difference between yours and mine procedure, as far as I can see, is the time needed for formate distillation (you: quick - me: slow) and the workup (you: dirty - me: clean)...

Your 1h reflux is essentially the same as my normal H2O dist./removal at ambient pressure WITHOUT refluxing before - the temp. at least is exactly the same, whether refluxing or distilling water. So maybe it isn't even necessary to perform the one hour extra reflux.

How do you be sure about the crystalline solids being 92%+ MeAm*HCl? Any test/analysis? And how then? (only interest, not disbelief)




And another thing that looks a bit strange in my eyes..

You say:

"Swim set about to do another experiment, using some of abacus's interesting workup.

After formate distillation, excess NH4CL removal and the 1 hour reflux, glassware was set up for distillation and the oilbath was raised to 155 Celcius (as measured by a thermometer dipping into the reaction) and held there until water distillation ceased. The distilling flask was quickly removed and the contents poured into a beaker whilst still hot.
"

Where is "abacus' interesting workup"? Is it the pouring of the concentrated solution, the vacuum filtering or the acetone rinse? (not to offend you abacus) I mean, none of these results in separation of side- and main products (DiMeAm, MeAm and AmCl) AFAICS.

And the temperature of heating baths is measured by placing a thermometer below the surface of the heating liquid - with measuring inside the flask, it is called "reaction tempearature", not oil bath temperature...

Oh BTW you really don't have to strictly refrain from referring to other bees posts - BDB is not the only one having had success with it, and Orgy did "discover" the patent for the hive, translated it and tested its workability before posting about it - do you really think you can tell him what to do and not in this HIS OWN thead, while discussing YOUR variation of said patent inside this thread? Again, this is IN NO WAY meant as an accuse: maybe you should just open a new thread, called "Easy Ghetto Methylamine in +90% yield" or something like that maybe - I'm sure it would be read by *lots* of bees.

But really, you wouldn't know about ANY pros/cons of ethanol addition to hex/HCl if Organikum wasn't here... Ask yourself the question: is it right to flame him (me = OK  ;D ) - just because he did so with you? Remember that you first questioned what you now seem to accept as a fact (ethanol=good). And I can understand quite well why Org. flamed you for not believing him in the beginning...

(my personal apologies - for being that hard with you...  ;D )

A


abolt

  • Guest
How do you be sure about the crystalline ...
« Reply #94 on: July 23, 2004, 11:59:00 AM »

armageddon

  • Guest
faker!
« Reply #95 on: July 23, 2004, 12:00:00 PM »

hypo

  • Guest
like who cares?
« Reply #96 on: July 23, 2004, 12:13:00 PM »

abolt

  • Guest
^^^^^Nervous breakdown in progress^^^^^
« Reply #97 on: July 23, 2004, 12:14:00 PM »

armageddon

  • Guest
better not
« Reply #98 on: July 23, 2004, 12:37:00 PM »
I recommend you try to overead each of his nonsense posts - especially the one where he claims a 93% (and more!!) yield/purity of MeAm, although it is obvious that some ammonium chloride will stay in solution even after removal by fractional crystallization.

It is ABSOLUTELY pure bullshit to claim the YIELD being 93 percent - without making sure that the product in question is really what you made/isolated!

Just cooling between reflux and concentrating precipitates by far not all ammonium chloride - a healthy amount will stay in solution UNLESS you use a technique based on different solubilities COMBINED with drying the solid salts to be separated BEFORE attempting this technique - which is commonly called "soxhlet" or solid/liquid extraction - useful solvents are alcohols in this case, the higher the better...

(I don't care if abolt is stupid as bread or not, I justz want to prevent others from getting disappointed)

A


abolt

  • Guest
POST No.100
« Reply #99 on: July 23, 2004, 12:49:00 PM »

armageddon

  • Guest
-
« Reply #100 on: July 23, 2004, 01:26:00 PM »

moo

  • Guest
Moderators?
« Reply #101 on: July 23, 2004, 04:38:00 PM »
Back at it again, huh? Where the heck are the moderators? It's obvious that the dicksizing is getting harmful to the Hive collective. Take it to the couch or PM if you really have to, this place is for discussing chemistry. Neither one of you is going to "win the argument with the other one", it is futile. Why's that? Because it appears neither one of you is going to admit the other one was right nor are you going to reach an agreement/compromise/synthesis because all that seems to matter is "I was right, thus he's an asshole". Is that so important?


Bond_DoubleBond

  • Guest
armageddon: swim recrystallizes with methanol...
« Reply #102 on: July 24, 2004, 04:47:00 AM »
armageddon:

swim recrystallizes with methanol and knows how to separate amcl from meam.  watch who's yields you call bullshit.

edit: sorry, i though you were talking to me.

armageddon

  • Guest
repeating my guess
« Reply #103 on: July 24, 2004, 06:57:00 AM »
BDB: I surely don't question your skills, and believe honestly you belong to the bees having mastered the patented procedure very well. Sorry if you got any other impression - was just a bit upset, actually I was referring to Abolt's claimed 93% yield..
(in fact your yields are quite good I think!)

And to repeat something hidden in one of my downrated posts, but which I still consider being of importance - here we go:

here's my thoughts on why the patent uses additional alcohol:

I think the reason for using ethanol is to remove excess formic acid (the formic would otherwise methylate the MeAm further to diMeAm) resulting from too much formaldehyde. This means the reaction evolves no CO2 and doesn't stink from formaldehyde escaping the apparatus.

And this process of "removing" the formic by reacting it with ethanol is easily controllable by adjusting the distillation of formed ethylformate - because a reaction from which one (or more) products (and NOT educts like alcohol) are contiuously removed DEFINATELY proceeds faster, according to LeChatelier (or why else should dean-stark traps work for Knoevenagel rxn for example??).

And as the difference between the boiling points of ethylformate and ethanol is less than 30°C, it is necessary to distill carefully (either by using some column or by distilling slowly) in order to properly separate the formed ethylformate WITHOUT distilling the unreacted ethanol together with it.

If these two aren't separated properly and/or distilled away too quickly (i.e. before all formaldehyde has reacted), their use is obsolete, as the removal of excess formic is not possible anymore - it simply decomposes, and part of it causes polymethylamine formation.



I honestly believe (and can come up with explanations for every of my statements, if anyone desires so) that this is the reason for using alcohol, and the advantages arising from using it justify well why the IG-Farben company got the patent granted back then..





And to complete my suggestion about the possible benefits of the patent, here is a precise translation of some "key sentences", translation more accurate than the one provided by Orgy (no flame Org;  but I spent ALMOST an hour to retranslate these few sentences as EXACTLY as possible because I believe they are vital to understanding for non-german-speaking bees, and I doubt you did so when discovering/testing/posting the whole lot back then..  ;) )

"Besides of avoiding the oxidation of formaldehyde to carboxylic acid, the use of additional alcohol also has the advantage of allowing the reaction to proceed at 75°C, whereas without alcohol the reaction only sets in at >90°C.
Other advantages being the reaction speed is increased considerably and the tendency for forming higher methylated amine gets significantly reduced.
"

It might be helpful to keep this in mind before speculating further about the topic, so here you can reread about what advantages this patented procedure should offer if done correctly.

(BTW: WOW! Now that's what I call a "rating session"! Thanks.)

Greetz A


abolt

  • Guest
(Post deleted by abolt)
« Reply #104 on: July 26, 2004, 05:32:00 AM »
(empty)


Organikum

  • Guest
obsolete now
« Reply #105 on: July 26, 2004, 05:57:00 AM »
obsolete after Abolt deleted his post.

LaBTop

  • Guest
Now youz' all BEEhave again,
« Reply #106 on: July 26, 2004, 02:36:00 PM »
after reading this carefully:
 
--------------------------------------------------------------------------------
Not long ago I expressed the view that the lack of general education and of thorough training in chemistry of quite a few professors of chemistry was one of the causes of the deterioration of chemical research in Germany. Will anyone to whom my worries seem exaggerated please read, if he can, a recent memoir by a Herr van’t Hoff on ‘The Arrangements of Atoms in Space’, a document crammed to the hilt with the outpourings of a childish fantasy. This Dr J H van’t Hoff, employed by the Veterinary College of Utrecht, has, so it seems, no taste for accurate chemical research. He finds it more convenient to mount his Pegasus (evidently taken from the stables of the Veterinary College) and to announce how, on his daring flight to Mount Parnassus, he saw the atoms arranged in space.

Hermann Kolbe (1877).

This lacerating type of criticism was not uncommon in the 18th and 19th centuries. G.S.Ohm was rendered incapable of working as a result of the vitriol heaped on his work which led to Ohm’s Law. Kolbe was no chemical slouch; he was one of the foremost chemists of his day. Unfortunately he was dead by 1900, when J H van’t Hoff received the first Nobel Prize in chemistry – for his work on the shapes of molecules!
--------------------------------------------------------------------------------

All of you _could_ be one day famous underground chemists.
Don't lactate your future reputation with so much unnescessairy venom in our chemistry forums.
LT/


bbeeasheets

  • Guest
my first meam.hcl synth
« Reply #107 on: July 29, 2004, 09:28:00 PM »
Here is what I did.

100g pulverized hexamine.
30g nh4cl

put in 1L RBF
added 130 mls denatured ethanol (distilled to 95%)
added 330g muratic acid (beaker on scale, tared, poured hcl to 330g..? not sure if this is the way to calculate this. I tried to calculate by weight of hcl, but volume was 968 mls or something, so volume was to great.

Here is where i noticed my first problem, the powder did not completely disolve no matter how much stirring i did.

Gradual heat applied to distilling app.
(since I have never used this plate before it took almost 6 hours to reach 60C and distill the formates.

at this point i turned up heat and bolied until it reached 100C

I then cooled to room temp and vacuum filtered the solids, then returned them to clean RBF to distill out water

vacuum applied not very strong, h20 boiled over at 90C
I boiled until the crystals around the edges started to look a little crispy.

I then put in 200mls of boiling ipa.
This point my second problem showed up. Very little of the solids dissolved, but i filtered anyway. let cool to rt and stuck in freezer over nite.

the remaining undisolved solids i washed once more with boiling ipa and then added 200 mls of dh2o. The solids all dissolved immediatly. this can't be nh4cl can it?

so i redistilled the water out of the batch of crystals that were redissolved in water. is it worth going any farther with these crystals?

the small batch of cystals that were formed in the 1st ipa wash were filtered and then washed with hot methanol (anhydrous). However I wonder if I used to much methanol, because  they won't recrytallize even at -15C

thanks for any help. yes I am a newbie and I expect flames if you must... hopefully they will help me with my lab technique.

Organikum

  • Guest
You should give the methylamine.HCl some time...
« Reply #108 on: July 29, 2004, 11:13:00 PM »
You should give the methylamine.HCl some time to dissolve in the IPA - that doesnt happen so fast. Give time and stirr whilst keeping it hot.

Why does everybody expect this going in seconds? Even tablesalt also takes quite some time to dissolve in water.

This is no "washing" but extracting with IPA. Whats not in the IPA is ammoniumchloride.

The ways how to do this for best results was extensivly discussed and described in this thread. Read it up, you didnt use the best way, this may be disclosed here and now.


armageddon

  • Guest
big error!!
« Reply #109 on: July 30, 2004, 08:03:00 AM »
bbeeasheets:

The problem of your low yield might lie in your bad extraction technique (better REFLUX in IPA several times than to wash with it!) - but there is a much bigger error in your synthesis, may I quote:

at this point i turned up heat and bolied until it reached 100C

I then cooled to room temp and vacuum filtered the solids, then returned them to clean RBF to distill out water.


...but...

You dont are to collect the SOLIDS gotten after cooling the rxn mixture/before commencing with distillation, these are NH4Cl and should be discarded or better saved for reuse in next batch, IN NO WAY PUT IN A CLEAN RBF AND HEATED!!!! Instead, keep the liquid you separated from the solids, put THIS in clean RBF and reduce its volum by distillation, until no more water comes over or 150°C are reached. hen cool to room temp, and THEN extract the formed, almost-dry, crystalline mass by refluxing it in isopropyl alcohol, reapeating several times with fresh IPA, combining the extracts, concentrating them and then cooling the concetrated solution in the fridge to precipitate methylamine hydrochloride. ALL SOLIDS COLLECTED BEFORE THE IPA XTRACTION ARE MAINLY AMMONIUM CHLORIDE!!


(BTW Organikum: IPA/HCl is indeed smarter!  :) )

[EDIT]OK, the post was "un-shouted"..[/EDIT]

A


armageddon

  • Guest
oh well
« Reply #110 on: July 30, 2004, 08:35:00 AM »
Bbeeasheets: your problem is that you collected the solids and heated them to dry'em - COMPLETELY wrong! You should've separated solids from liquid after cooling to room temp., but kept the LIQUID! This you should've distilled with heating to max. 150°C and then cooled to precipitate ammonium chloride salts, which you then could've xtracted by boiling in IPA...

next time, hm?

[EDIT] Obsolete after my previous post is visible again  :)  [/EDIT]




Huh!? Are you moderating or adjudicating??

To the moderator whoever you are at the moment: could u please un-rate this post?? Not that I care for bad karma, have enuff good to compensate - but I consider the information helpful for Bbeeasheets, as he really made a big mistake. I just edited the text into "sub" markup,

And hey!
   WHY is My PoSt RaTeD aS "aLl CaPs"????? in fact they aren't all capitals, only the relevant part was "capitalized"..

Or is my written presence in this thread not desired?? I mean, NO PROBLEM! I at least AM capable of synthin MeAm, and do understand the talked about patent quite well - if u have the opinion that I should keep my knowledge to myself instead of helping bees with no xperience w/this patent - just go ahead to tell me.

A


Rhodium

  • Guest
You aren't supposed to write in ALL CAPS ...
« Reply #111 on: July 30, 2004, 09:53:00 AM »
WHY is My PoSt RaTeD aS "aLl CaPs"????? in fact they aren't all capitals, only the relevant part was "capitalized"..

Thus the "relevant part" will be the most hard to read section of your post...

You aren't supposed to write in ALL CAPS because it is very hard to read as well as being "shouty" writing.
I have unrated your post, but please uncapitalize that paragraph and use bold markup for emphasis instead.


bbeeasheets

  • Guest
first time errors
« Reply #112 on: August 01, 2004, 06:28:00 PM »
thanks for not flaming me on my stupid mistake(s). Thought I had read everything in this thread well. Anyways maybe I can get as better yeild if it is done right.

Just a few more questions before my next attempt (these are newbie questions, should they be posted in newbie forum?)

alcohol and hcl are stated in grams. does the weight include the water (just weigh an appropiate volume on scale?) or should i calculate the weight by percentage?

thanks

armageddon

  • Guest
measuring volume/weight of liquids...
« Reply #113 on: August 01, 2004, 09:05:00 PM »
alcohol and hcl are stated in grams. does the weight include the water (just weigh an appropiate volume on scale?) or should i calculate the weight by percentage?

As far as I know, the weight is stated for a certain concentration, i.e. 220grams of 31,45% HCl...
(read the first few posts again maybe? I'm sure the concentration is mentioned...  ;) )

So if you use other concentrations of acid and/or alcohol, you should of course calculate for the missing percent - weigh your diluted reagents, but use more... (the extra water won't hurt)

Or if you know the density of certain concentrations of HCl/EtOH, you could as well use a certain volume of each  - probably the easiest way, a slight excess of acid/alcohol is in fact desirable.

Oh, and while we're at it:

Alcohol extraction/recrystalizing of the crude product is ABSOLUTELY necessary to assure you don't have a healthy amount of ammonium chloride in your final product. When the extraction is done properly, ALL remaining solids are pure NH4Cl, and EVERY F****N crystal crashing out of the extract upon cooling is PURE methylamine hydrochloride CH3NH3Cl! 

- just in case you like a clean product of course... ;D

(no offense, but while "mixed amine salts" undoubtedly may be of advantage sometimes (Al/Hg on MDP2P - dont attempt it of course, it's pretty illegal - as the product is MDA/MDMA mixture..), in other cases purity is desired/essential and a NH4Cl/CH3NH3Cl mixture of whatever percentage just isn't suited very well for certain applications... ;) )

BTW thx for unratin me post.. ;)
Greetz A


armageddon

  • Guest
another variation
« Reply #114 on: August 03, 2004, 12:32:00 AM »
Hi!

Based on my reflections about the *real* advantage of adding ethanol to a hexamine/NH4Cl/HCl methylamine leuckart (in fact its a leuckart with formaldehyde!), I just decided to give the procedure outlined in

Patent DE468895

another try, and tried to modify the rxn parameters to challenge the following statements:

    
- According to the patent, one of the benefits would be that the reaction already succeeds at below 75°C, whereas normally >90°C are required.

- Also (and maybe far more important), the formaldehyde, upon oxidation, does result in formic acid - and this formic could normally serve as a methylating reducing agent for MeAm, resulting in diMeAm formation. But with ethanol being present, the acid should ideally be completely converted to its ester (ethylformate), and through removal by distillation, all formed formic acid should (ideally) be removed as it is formed.



These two main statements in the original text can be well taken to the test: by quickly heating the reaction exactly to the point at which ethylformate begins to come over (based on previous runs, I know this point is 85°C on my variac/heating mantle), then holding it there for a long time to make sure all formaldehyde has reacted, all formic was esterified and all formed ethylformate has been removed by distillation (i.e. let it run overnight).

If the above claimed benefits are correct, the reaction should be finished at this stage, as the temperature was held above 75° for many hours and in theory, all "harmful" formic acid should've been removed completely, i.e. from 48g hexamine, one should get 2.05mol of HCHO which in turn can act on 1.63 mol NH4Cl - therefore, ~131ml ethylformate should be formed in theory...

(..and this is well in accordance with the following observation: even far below 80°C, formaldehyde obviously reacts readily with "something" to produce formic which in turn esterifies to EtCOOH - at least there is ethylformate formed long before this temp. is reached! In fact, the threshold for its formation to occur was observed being ~43°C rxn temp...)

And as there are excess ethanol and NH4Cl present, the reaction should ideally give almost quantitative yields (calculated from formaldehyde) of pure methylamine hydrochloride (and the remaining excess of NH4Cl of course) without any di- or even trimethylamine impurities... theoretically at least, or so to say, if the inventors knew what they got patented back then...

So far the theory.




As already said, I wanted to challenge this. The following procedure was used:

48g hexamine (fuel tabs) were dissolved in 100ml warm tap water and filtered through a pad of celite with the aid of vacuum in order to remove any waxes and binders. The resulting clear solution was put in a 500ml two-neck RBF along with a big ass stirbar. Then were added 14g NH4Cl, followed by 90ml EtOH. The RBF was fitted with a distillation rig and 160ml 31% HCl were added through the side neck which afterwards was equipped with a (second) thermometer submerged into the rxn liquid for measuring the rxn temp. HCl addition caused a bit of white smoke to travel down the condenser and the exothermic hex hydrolysis caused the rxn temp to climb to 40°C and everything became slightly milky.

Using a heating mantle equipped w/variac, the rxn was then brought to 80°C (internal rxn temp.) over the course of exactly 1 hour, causing the formation of a clear ethylformate top layer and, upon reaching the said temp., a slight reflux. At this point, the cloudiness had disappeared completely (waterlike, clean).

When the variac controller setting was raised to >80°C (82.5° internal rxn temp.), the ethylformate slowly started to distill with a steam temp. of 42-58°C (I didn't allow it to climb higher but cooled it if it happened; as the proper separation of ethanol and formate isn't warranted anymore if this happens).

The upper layer disappeared quickly within one hour, but formate still came over at a rate of 1 drop every 5-6 seconds while steam temp levelled of at 53°C (rxn. temp. 80.5° C). This is now heated at 85°C overnight...



I'll get back with the results tomorrow!


(just in case...: anyone impeaching above procedure before results are in is immediately catalogued on my "personal asshole N°1"-list as one of the top ranks forever... So control your temper until you can fully judge about it please!!)




[EDIT] exactly 9 hours and 20 minutes of careful heating have passed since I combined the reagents, the internal rxn temp. is still 85°C with ethylformate coming over at a steam temp. of 49°C at a rate of 1 drop every 10 seconds - and interestingly, the solution has become slightly greenish tinted, although the amount of distillate collected is only about 60ml... Just cranked the variac up to 90°C - think I'll let it run for a few more hours.

I'll be back soon...

BTW did you realize the similarities to a leuckart? Slow heating over long time, resulting in faint bubbling due to *slow* decomposition of the reducing agent (only that it decomposes just to formic rather than complete decomposition to CO2 - like would be the case with *real* leuckart - but faint bubbling can be seen in both cases....) [/EDIT]

Greetz A


armageddon

  • Guest
another variation - part II
« Reply #115 on: August 04, 2004, 02:14:00 AM »
After 11 hours of heating (with raising the temperature of my heating mantle to 150°C during the last 2 hours), the rxn temp was 112°C, with steam temp being 100°C - and then I broke the long thermometer - aaargh! (no more rxn temp. measurements  :( )

Anyway: the solution was concentrated to 2/3 of its original volume and turned to a yellow color while no formaldehyde smell could be detected anymore.
 
It was cooled to 7°C, vac filtered and the crystalline mass extracted by boiling in 100ml IPA for 10 minutes (just to be sure), then the crystals were washed sparingly with cold IPA and dry acetone and upon drying became crunchy and bone-dry (i.e. only NH4Cl, as CH3NH3Cl is pretty hygroscopic).

The mother liquor and washings were combined with the IPA extract and concentrated to about 180ml (variac set to 155°C) and poured into a beaker while still hot (HCl fumes evolved),  cooled in the fridge, vac filtered (this time the precipitate had quite a bit of MeAm in it, judging from the many little plate-shaped crystals) and the precipitate again extracted with boiling IPA (2x with 80ml this time). The combined extractions, washings and mother liquor (deep yellow now!) were then again freed from solvent through vacuum distillation (variac still set to 155°C, pretty quick dist.!). As the volume of the remaining liquid reached ~150ml, *lots* of little shiny platelets appeared in it, while a small amount of white "smoke" appeared inside the condenser - probably HCl(g), as it dissolved in the distilled IPA before having passed half way down the condenser...

As soon as the IPA had been removed completely, the crystals floating in the solution redissolved completely (higher solubility of MeAM*HCl in water than in IPA). Concentration was continued (variac setting 200°C) until signs of crystal formation again became visible on the side walls, then the hot solution (which had changed colour to deep orange) was poured into a beaker(crystallized immediately), the flask rinsed with boiling IPA, and everything (concentrated soln. and IPA rinse) was slowly cooled to -7°C.

the result was one hard lump of orange crystals which were vac filtered, rinsed with a bit ice-cold IPA followed by acetone, sucked dry by pulling air through them for ~5 minutes and placed in a clean, dry 500ml 2-neck RBF. To this was added 150ml IPA and everything was refluxed for 30 minutes, then (after the boiling had just subsided) the IPA extract was carefully poured off into a big erlenmeyer, and the process was repeated 4x with fresh IPA. The remainder was isolated by vac filtration and rinsed with boiling IPA followed by acetone, the combined IPA extracts and washes were then concentrated, resulting in a small amount of NH4Cl precipitating on the flask walls, and the IPA solution became clear again. Upon further concentrating, much MeAm*HCl crystallized ( hexagonal shiny plates). The still hot IPA soln. was then poured into a beaker and cooled to -7°C.

The decanted solution solidified to a slightly orange-tinted, crystalline mass consisting of  *lots* of tiny little plates. The crystals were vacuum filtered, washed sparingly with cold acetone and the mother liquor again concentrated and crashed out with dry acetone. The (still moist) crystalline MeAm*HCl was then slurried with some water, put in a 2-neck RBF and conc. NaOH solution dripped onto it - the resulting methylamine gas was taken up in ice-cold MeOH which was weighed before and after gassing, to determine the amount of MeAm(g) taken up.

(...)






The theory behind the workup is that the NH4Cl precipitates far earlier than CH3NH3Cl because of the better solubility of MeAm*HCl - and it does so when being concentrated and cooled as well as when acetone is added.
By doing several "partial extractions" like described, all ammonium chloride should theoretically have completely precipitated, as soon as methylamine hydrochloride crystals start crashing out.

And through diluting the mother liquor several times with a solvent forming an azeotrope with water/HCl, it should become almost water-free without having to heat it very much, a thing also called "azeotropical drying". IPA forms an azeotrope with water; and although having no proof for it, I'm quite sure that acetone carries lots of aequ. HCl with it when being distilled from aequous, acidic HCl salt solutions...
But after some conversation with other bees, I'm no longer sure about the azeotrope drying - as MeAm*HCl is pretty soluble in IPA, and I suspect that many HCl salts in fact hold back HCl while allowing water to evaporate, thus HCl concentration rises, and solubility of MeAm*HCl is increased...(contrary to what is desired!)

anyway: IPA carries at least something with it when being distilled, and it simply evaporates much quicker upon vac distillation than aequ. HCl for example...)

So far the theory on the workup.





Results and discussion...

Well - since I spilled the last washings (LOTS of IPA/acetone/MeAm*HCl on the lab floor - cough...), and since I freebased the product directly without proper isolation/weighing, the yields obtained are a bit vague... ::)

But as MeAm has a higher pKb than NH3, some residual NH4Cl shouldn't make any difference when the product is to be used in reductive aminations (regardless whether Al/Hg or othe reduction methods) - methylamine is a stronger base and displaces ammonium ions, so if the excess of amine is big enough, the only amine reacting should be methylamine - in theory. (you see abolt I AM capable of admitting if I was wrong - at least if I REALLY was..) So probably the legthy workup isn't required at all - but I just like having clean products, as I can be sure the reason for failures is not lack of purity but rather my skillz... ;)

{this post is still under construction  ;) }


armageddon

  • Guest
another variation - part III
« Reply #116 on: August 05, 2004, 09:56:00 PM »
I can tell you, never before have I spent that much time in my lab just to complete one synth...

Anyway: the resulting MeAm/MeOH solution (minus the small amount that was lost because of a minor suck-back while gassing) was thoroughly dried over 4A molecular sieves while keeping in the fridge, and 20ml of this dried solution (volume 423ml in total) were diluted to 60ml. This was divided into two portions and each was triturated with aequ. 2N HCl using phenolphtalein indicator, until color disappeared.



Results:

          first trituration: 8.7ml 2N HCl  -> 0.0174 mol CH3NH2(g)
         second    "      : 8.65ml 2N HCl -> 0.0173 mol CH3NH2(g)

    0.0173 mol  +  0.0174 mol  /  2  =  0.01735 mol => 0.5389g CH3NH2 per 10ml undiluted solution

(meaning a concentration of roughly 5.4% w/v of methylamine/methanol)

    423ml * 0.05389 = 22.79 grams methylamine(g) in total

For better comparison: this equals 49.55 grams MeAm*HCl or a molar 45 percent yield, calculated from NH4Cl (which is the limiting reactand I think). Not too bad, dare I say - taken into account my usual spillages and other losses during gassing... ::)  8)

Now you all are invited to happily tear to pieces what I described - I don't care anyway... :)

BTW does anybody know if it is possible to distinguish between primary and secondary (and maybe tertiary?) amines using Nesslers reagent? Or anything similar? Any input would be greatly appreciated...

Greetz, A


lugh

  • Guest
Hinsberg Test
« Reply #117 on: August 06, 2004, 03:21:00 AM »
The Hinsberg test is the recommended procedure, since the nitrous acid test can produce carcinogens of unknown potency   ;)

Procedure

To 0.3 mL or 300 mg of unknown in a test tube, add 5 mL of 10% NaOH solution and 0.4 mL of benzenesulfonyl chloride. Stopper the test tube, and shake the mixture vigorously. Test the solution to make sure that it is still alkaline. After all of the benzenesulfonyl chloride has reacted, cool the solution and separate the residue, if present, from the solution. Test the residue for solubility in 10% HCl solution. If no residue remains, then treat the solution with 10% HCl solution and observe whether a precipitate forms.
Positive Test

1° amines - dissolves in base and precipitates from acid is a positive test.

2° amines - precipitates from base and no change from acid is a positive test.

3° amines - precipitates from base and dissolves in acid is a positive test.

Complications

Amphoteric compounds give erroneous results.

Some sodium salts of benzenesulfonamides of primary amines are insoluble in the Hinsberg solution and may appear to be secondary amines.

Some tertiary amine hydrochloride salts are insoluble in dilute HCl and water and may also appear to be secondary amines.


http://www.chemistry.ccsu.edu/glagovich/teaching/472/qualanal/tests/hinsberg.html



8)


armageddon

  • Guest
hm...
« Reply #118 on: August 06, 2004, 04:25:00 AM »
Let's say one poor bee hadn't any benzenesulfonyl chloride lying around, but some HNO3 - and is hopelessly impatient but still very brave and doesn't fear carcinogens... :)

How would the nitrous acid test look like? (just out of pure interest of course!  ;) )

(thanks anyway for your "Hinsberg" response Lugh!  8)  Seems like another versatile reagent I'll have to buy someday...)

Greetz A


lugh

  • Guest
Qualitative Tests
« Reply #119 on: August 06, 2004, 04:35:00 AM »
Dr. Glagovich has entire page devoted to the various qualitative tests:

http://www.chemistry.ccsu.edu/glagovich/teaching/472/qualanal/tests/tests.html



Why don't you just bookmark it and start studying?

:P


armageddon

  • Guest
qualitative analysis
« Reply #120 on: August 06, 2004, 09:20:00 AM »
THX again Lugh!  :P

According to the nitrous acid test, secondary alipathic amines should give a yellow colouration without gas evolution upon treating a cooled solution of said amine  hydrochloride with aequous NaNO2 solution - in contrast to primary alipathic amines, which give vigorous gas evolution when said nitrite solution is added...

...and when testing 2ml's of my gassed MeAm/MeOH solution, there was vigorous gas evolution and no yellow colouration after rxn had subsided (the smell reminded me of pool supply stores BTW...  ;) )

This means no dimethylamine was formed when using the "IG-Farben" patent! (at least nothing to bother with  :) !)

Now when someone tells me how to differentiate between ammonia and amines, I'll be happy!!  :P

Greetz A


DoctorFeelgood

  • Guest
Foolproof methylamine synthesis
« Reply #121 on: August 06, 2004, 03:37:00 PM »
reading cubliums post yesterday, made me post this synthesis, which is easy and hard to fuck up. of course this might be nothing new to you, but as one could read, buying meam is a very bad idea. maybe one wants to look at the following procedure (thanx to ... for his help):

Chemicals needed:
Hexamine (easy to get,used e.g. in cheese manufacturing)
H2O
Muriatic Acid
Icecold Ethanol & Acetone

Note:      
Molar ratio Hexamine : Muriatic Acid = 1 : 4   

Equipment:   
rbf (min. 1l)
heating/stiring combo + eggshaped magnetic stirbar
liebig condenser + cooling setup
vertical vacuumadapter with stopper on top
hose attached to vacuumoutlet, leading e.g into toilette
buchner filter

Add in THIS order: (depends on your available flasksize)

(Version1)   
600g Hexamine + 400g H2O + 2100 ml Muriatic Acid    or

(Version2)    
200g Hexamine + 133g H2O + 700ml Muriatic Acid   or   

(Version3)   
128g Hexamine + 85g H2O + 450ml Muriatic Acid      

Note: you must add the water before adding the HCl, or Ammoniumchlorid will separate immediately in your flask, lowering the yield.

Step1:

Set up for reflux, place a tube from the vacuumadapter on top of the condenser down the sewer (ie toilet) so that the smells won’t be a problem.  Slowly heat e.g. on a steam bath (flask in a pot full of water) until the flask temp is around 100C.  If you heat too fast, the exothermic reaction will take off and heat up to 110C which isn’t a problem, just heat slowly. Then keep stiring at around 100C for 6 hours.

Step2:
Then change setup for distillation.  Distil half of the liquid away and cool to room temp.
This crashes out the ammonium chloride.  When cool, vacuum filter (can’t be done without a buchner filter) the solution and eventually save the ammoniumchlorid for further use.

Step3:
Then distill the filtrate (at atmospheric pressure) until the flask liquid temperature reached 150-160C. Immediatly pour the flask liquid into a sealable container.  When cool, the methylamine.hcl will solidify.

Vacuum filter the solid with your buchner, forget washing the crystals with chloroform or acetone - its a waste of time.  Wash the crystals (while in the buchner) with icecold ethanol.  Suck some air through the buchner filter to remove some residual ethanol and place wet crystals in a sealed container.  You can now use these filtered crystals as is if you like (but make sure you allow for the extra weight due to the alcohol, or dry them on a tissue for a couple of minutes.
The ethanol wash does take some methylamine.hcl with it, but it also takes the dimethyl and trimethyl crap as well.  You can distill off the ethanol, heat again and get a second – of course smaller – amount of meam.hcl .

Molar yield should be above 80%.

This is really easy, i did it several times and never failed . so don't be stupid, buy some methylamine from a chem supplier - and get busted!

greetings :)

Organikum

  • Guest
Dr Feelgood, thanks! You show again how one...
« Reply #122 on: August 06, 2004, 08:08:00 PM »
Dr Feelgood, thanks! You show again how one single idiot can destroy a whole thread easily.

Dumbass!
80% molar yield? Not only dumbass but either incompetent or a liar too.

fuck you.
ORG


psytech

  • Guest
haha dr
« Reply #123 on: August 06, 2004, 08:30:00 PM »

armageddon

  • Guest
well
« Reply #124 on: August 06, 2004, 09:24:00 PM »
You can distill off the ethanol, heat again and get a second – of course smaller – amount of meam.hcl

Yup - And if you use this "smaller amount" and process it further, you indeed will end up with a 8% molar yield of pure methylamine hydrochloride, which upon gassing it into ice-cold MeOH would result in 6% being taken up maybe - but your 80% yield is in no way comparable with others, as it tells us the yield of NH4Cl/CH3NH3Cl mixture you obtained...


I get the impression that the standard hex/HCl method evolves apparently lots of toxic fumes - at least up to date, no bee using the hex/HCl method was able to realize the difference between this patented procedure and theirs, and many try to sell their alcohol-less methods as being of more advantage...
Must be some nasty stuff these folks are breathing!  ;D


...BTW are the 80% molar yield calculated from hexamine?? With the equation 1 Hexamine + HCl -> 6 HCHO + 4 NH4Cl, this makes little sense! When you divide your 80% through 4, you will get 20% yield calculated from the NH4Cl you used - more realistic if your product was indeed only methylamine hydrochloride - which I seriously doubt...

(really sad)


Oh, and you can as well use the following procedures, as long as you don't post about it in this "methylamine from hex WITH alcohol"-thread...

https://www.thevespiary.org/rhodium/Rhodium/chemistry/methylamine.chemhack.html


https://www.thevespiary.org/rhodium/Rhodium/chemistry/eleusis/methylamine27.html


https://www.thevespiary.org/rhodium/Rhodium/chemistry/eleusis/zwit.menh2.html


https://www.thevespiary.org/rhodium/Rhodium/chemistry/methylamine.html


https://www.thevespiary.org/rhodium/Rhodium/chemistry/methylamine.acetamide.html


https://www.thevespiary.org/rhodium/Rhodium/chemistry/methylamine.pdc.html



(couldn't resist)  :P


Greetz A


armageddon

  • Guest
please..
« Reply #125 on: August 11, 2004, 12:16:00 AM »
To all doubting bees and especially Abacus: if you really want to discuss any differences between this procedure and the "Vogel's" standard procedure in public, you should consider that I never wanted to accuse anyone using the Vogel's method, nor did I say it wouldn't work for making methylamine suited for a "Osmium style" Al/Hg reductive amination of certain ketones! I merely think that the talked-about patent has its own advantages, and in my opinion the patented procedure is one of the easiest ways for making pure methylamine I ever saw. And to give proof of this, I tried to work out a procedure that challenges the claimed advantages (low rxn temp, no overalkylation, no gas evolution). In no way did I claim it being the perfect way of making methylamine. I even miscalculated the ratios of reactands, and used an excess of formaldehyde, in case you didn't notice. And evidently, still no overalkylation happened... guess why?

I just don't understand why the fact that there might be another usable method repeatedly results in the belief that I would want to offend anyone with liking it..

And if it was of interest to me, I would've opened a new thread about the advantages of the Vogel's procedure time ago - believe me!

Post 310000

(Rhodium: "Everybody at the Hive always wait for someone ...", Chemistry Discourse)
 ;)
(BTW I'm almost sure that the reaction time could be shortened by using a vigreux, due to higher rxn temp. while still allowing for a sharp separation of educt and product..)

A


biffman

  • Guest
How can you not love this thread?
« Reply #126 on: August 11, 2004, 04:43:00 AM »
First off, thanks lugh for that link for the ID tests.  Since I no longer have access to a USP I have been waiting for a compound ID reference site, so it is much appreciated.
 And thanks for hanging in there armageddon now that the bitch slap with abolt seems to have gone by the wayside (for the moment anyways).
  Personally SWIM never had a problem with Vogel's (or obtaining MeAm for that matter previously) but caution is always a good plan and SWIM thought that the exploration of other avenues is not only warranted but also fun.
  When SWIM has an endless supply of Ammonium Chloride as well as formaldehyde certain other considerations come into play, but none are too important if you don't have to worry about precursor depletion.  Experiment is not only king but also entertaining.
  Sassy supply however is another matter nowdays.
  Thanks for all the input everyone.

placebo

  • Guest
New Hex method. Thoughts...
« Reply #127 on: August 11, 2004, 05:25:00 AM »
New Hex method.
Thoughts...
4:1 molar ratio of HCL to Hexamine
4 mol HCl + 1 mol hexamine = 6 mol form and 4 mol NH4Cl = 1.5:1
Standard Vogel procedure is -
500gm 35% form  = 6.16 mol
250gm nh4cl     = 4.67 mol = 1.32:1
Therefore: for 4 mol of NH4Cl (x1.32) there should be 5.28 mol of formaldehyde. So for the 6 mol of fomaldehyde, the NH4Cl should be 4.55 mol.
New Org Patent ratio is -
"17 parts of 40% formaldehyde, 7 parts of 96% alcohol and 8 parts of ammoniumchloride"
170gm 40% form = 2.26 mol
80gm NH4Cl     = 1.50 mol = 1.51:1
70gm EtOH      =
As stated above, Hex and HCl gives us 1.5:1 already, 0.2 mol more then Vogel.
Why add the extra NH4Cl and why the extra water?
Surely the ratio as stated in the patent is by mol not weight, but Org stressed it was by weight. Should it be...
1278gm 40% form = 17 mol
427gm NH4Cl     =  8 mol = 2.13:1
322gm EtOH      =  7 mol
This would be different to the Vogel procedure in that there is an even larger excess of formaldehyde:NH4Cl to drive the reaction faster while having the ethanol to control DiMeam production.
This makes more sense, it also means that by adding more NH4Cl, surely you are defeating the purpose of the patent. As I understand the formaldehyde must be in excess to drive the reaction. If one were to have it in 1:1 ratio, nothing would happen?

How much NH4Cl should be recovered?

Some bee performed the reaction at these ratios following DBD's and Org's example...

Methylamine...
140gm Hexamine x 5 = 700
42gm  NH4Cl    x 5 = 210   (Org 28gm)
170gm EtOH     x 5 = 850   (Org 140gm)
420gm 35% HCl  x 5 = 2100

The hexamine, EtOH and NH4Cl were added to a RBF, followed by the HCl. Heat and mag-stirring was applied on a mantle. It was then refluxed for 3 hours. STP distillation was started and ethyl formate collected, first at 67c and then lowering to 40c (Therefore despite 3 hour reflux, ethyl formate was only just being produced) and slowly rising again until the water was coming over. The heat was turned up and water was distilled until volume reduced by half. Then the flask was cooled to room temperature and the solids were filtered (~600gm NH4Cl recovered- ~11mol). The water in the remaining mixture was then vacuum distilled .......methylamine is still being worked up.
Results to follow.
It is also noted that it is not faster.
It is also noted that any hex->Meam procedure is a pain in the ass compared to Vogels form/NH4Cl procedure which is easier, faster, cleaner alas the bee has no formaldehyde.


armageddon

  • Guest
nope - parts by weight
« Reply #128 on: August 11, 2004, 07:27:00 AM »
As I understand the formaldehyde must be in excess to drive the reaction. If one were to have it in 1:1 ratio, nothing would happen

That's puzzling, because I don't think formaldehyde has to be present in larger excess - why do you think a 1:1 ratio would result in nada? I would rather guess that with the Vogel's method, a healthy excess of HCHO is necessary to get things going, whereas with alcohol, the LeChtelier principle accomplishes that, through pushing the (ever-present) equilibrium between unreacted formaldehyde/ammoniumchloride/alcohol->reacted methylamine/formic acid/ethylformate to the right..

And the patent says: "17 parts by weight of 40% formaldehyde solution, 8 parts by weight ammonium chloride and 7 parts by weight 96% alcohol" ("Gewichtsteile" is parts by weight) - so Orgy was absolutely right with his proportions, and the patent uses exactly the same amounts like the Vogel's method (0.01 mol difference  ;) )...

Greetz A


placebo

  • Guest
That's fine if it's by weight, I just worked...
« Reply #129 on: August 11, 2004, 07:34:00 AM »
That's fine if it's by weight, I just worked out both weight and mol for my own understanding. I don't speak german. :)
But it aint the same ratio as Vogel as you can see.
My point is it has an even higher ratio of formaldehyde then vogel.
Secondly, by using hex instead of form/NH4Cl you get the exact ratio as the patent suggests, so why add NH4Cl?
If you add NH4Cl then you are defeating the purpose of the patent.
Are you not?


That's puzzling, because I don't think formaldehyde has to present in larger excess - why do you do a 1:1 ratio would result in nada?



If that were the case, why is it always done?
I guess you don't understand this reaction as well as you think, despite your rants. Not to say I do, but I've read a shitload on it and that is my understanding.




armageddon

  • Guest
really
« Reply #130 on: August 11, 2004, 07:51:00 AM »
I guess you don't understand this reaction as well as you think, despite your rants

I guess you are just about to start becoming insultive... ;)

...do YOU understand exactly why there obviously has to be an excess of formaldehyde? My guess would be that Vogels method uses an excess to be able to start things - the patent inventors just copied these ratios (common sense back in those those days) without questioning them, as they were approved to work fine...

On the other hand - they postulated the following overall reaction scheme:

      2 HCOH + NH4Cl + C2H5OH ---> CH3NH2*HCl + H2O + HCOOC2H5

Explains the amount of formaldehyde used - although the reaction scheme is rather simplified...

If you add NH4Cl then you are defeating the purpose of the patent.
Are you not?


170 grams of 40% w/v formaldehyde meaning 68g formaldehyde = 2.2644023mol
80 grams NH4Cl = 1.4956066mol

still 1.51:1 formaldehyde:ammoniumchloride - wierd, as the patent says that an excess of ammonium salt generally favors primary amine formation, whereas excess formaldehyde leads to dimethylamine formation..

I wonder what they meant with this! (?)

Someone should try to run this reaction twice using same conditions, only one time with no additional NH4Cl, and the other with enough NH4Cl to make for a healthy excess over formaldehyde - should reveal which ratios are really favorable!

Greetz A


placebo

  • Guest
If you edit your post then state it.
« Reply #131 on: August 11, 2004, 07:54:00 AM »
If you edit your post then state it.
Now to answer your edit, you just prove my point.
You insinuate that the NH4Cl is added to bring the ratio back to that of Vogel, and I'm asking why you would change the ratio that is stated on the patent? (The ratio which is already available in hex)
Secondly if an excess of formaldehyde was not necessary then why don't you add enough NH4Cl to make the molar ratio 1:1 ie.
170gm 40% form = 2.26 mol
80gm NH4Cl     = 1.50 mol + 0.76 mol = 40.69gm

I am just trying to understand this and I don't think your qualified to read my statements and questions let alone answer them. No offence.


placebo

  • Guest
Yes I already did the math... see above.
« Reply #132 on: August 11, 2004, 07:59:00 AM »
Yes I already did the math... see above.
Vogel... 1.3:1
Patent.. 1.5:1
Hex..... 1.5:1
Org & evervyone adds NH4Cl, why?
[edit]Is it bringing the ratio to 1:1?
I guess it does
100 hex gives 60 form and 40 NH4Cl so an extra 20 NH4Cl makes it 1:1
So I guess those Farben kids didn't spend a whole lot of time optimising the patent.


armageddon

  • Guest
reasons for ratios
« Reply #133 on: August 11, 2004, 08:10:00 AM »
OK I edited my post - your problem if you answer within five minutes... :)

there are two possibilities:

1. Excess formaldehyde normally would result in overalkylation - other story if you use alcohol to avoid it. And therefore the patent uses more formaldehyde than Vogel's, with the intention to push yields of primary amine and get back less unreacted NH4Cl.

2. They just wanted to show that even with excess formaldehyde, only monomethylamine is formed - in conrast to the standard hex/HCl method...


The example they give in the patent indeed doesn't use excess NH4Cl - but nevertheless it is stated that doing so favors monoalkylation!

I am just trying to understand this and I don't think your qualified to read my statements and questions let alone answer them. No offence

Well you are free to have your own opinion about my qualification - as long as you don't insult me by bragging about it in public (you just did so again)..

A


armageddon

  • Guest
those Farben kids were PhD's... *lol*
« Reply #134 on: August 11, 2004, 08:15:00 AM »
So I guess those Farben kids didn't spend a whole lot of time optimising the patent.

Probably. They just give an example, and leave it to the intelligent reader to make conclusions from the claims and modify their given example...

See also

Post 519651

(Lego: "How reliable is the patent literature?", Chemistry Discourse)
 ;)

How about just giving it a try? Experiment is king...
Maybe with using excess NH4Cl and trying to collect all ethylformate below 50°C to check if the patent could be optimized? That would bring this thread forth...

Greetz A


placebo

  • Guest
Re: I am just trying to understand this and I...
« Reply #135 on: August 11, 2004, 08:40:00 AM »

I am just trying to understand this and I don't think your qualified to read my statements and questions let alone answer them. No offence

Well you are free to have your own opinion about my qualification - as long as you don't insult me by bragging about it in public (you just did so again)..



Sorry, I tend to do that when people respond to me with statements that show how little they read of my post.

With the old methods the extra formaldehyde is necessary to drive the reaction. You suggest that the EtOH (and subsequent removal of ethyl formate) does this. If, with Org's added NH4Cl the ratio is 1:1, one would think some excess is necessary to start it. But some of you have already had good results.

So far I see no increase in speed (possibly longer) and dimeam is never a problem in any procedure if done correctly. Yeild will tell... coming soon.




armageddon

  • Guest
another reason
« Reply #136 on: August 11, 2004, 09:08:00 AM »
As you don't like edited posts, Placebo - here's another new one..

Another reason why Vogel's and the standard hex/HCl method use excess formaldehyde: due to high rxn temperatures, a lot of it decomposes to formic/carbocxylic before being able to act on any ammonium ions, therefore excess is needed.

Still doesn't explain the ratios used in the patent - 1.5x excess, although said oxidation shouldn't occur at all - as alcohol is used to avoid this...

Wierd.

But if the statement "oxidation of formic to carboxylic acid is suppressed by adding ethanol to rxn" (said oxidation would result in overalkylation) is correct, there would be no need to use excess formaldehyde, and the use of additional NH4Cl should present no problem but rather result in higher yields (while still not allowing for dimethylation AND keeping rxn temp low) - and in fact the yields are better when more ammonium chloride is used.


What we know so far is:

1. Additional ethanol results in lower rxn temp and no dimethylamine being formed

2. Excess ammonium chloride gives better yields than excess formaldehyde (calculated from aldehyde!) when using this patent

3. Reaction time is lengthened with alcohol


Its up to you to make guesses. IMO the alcohol makes sense when excess formaldehyde is used - but excess NH4Cl is only desirable when rxn temp is kept low, which is also accomplished by the use of EtOH - somewhat contradictory...

A


abacus

  • Guest
I agree placebo
« Reply #137 on: August 11, 2004, 12:59:00 PM »
SWIM carried out seperate experiments to explore this idea of using alcohol.

Experiment 1.  Usual method as done many times

1 mole hex
4 moles HCL in 32% solution
NO addition of NH4CL, not needed in my opinion (I agree with placebo on that)
100mls water (to stop solution being saturated)

Reaction time of 6 hours at 100DegC (water bath).
Reduced to half volume by atmospheric distillation and cooled (vogel workup, except vac not used).
NH4CL that precipitated was filtered.
Liquid again distilled until 160DegC mother liquid temp
Cooled, which formed a solid.
Solid crushed up and vac filtered, washed with ice cold ethanol, acetone and recovered methylamine.hcl dried

Filtrate again heated, cooled, and crystals collected.

Finally left with a concentrated syryp that refuses to crystalise which, correct me if i'm wrong,  Vogel states as being mostly trimethylamine
 
So, recovered colourless methylamine.hcl (with insigificant impurities IMHO) that dissolves completely in cold alcohol.  EDIT, I mean room temp methanol, and hot ethanol.

Yields range from 60-80% w/w based on starting hexamine.

Experiment 2.  Same as above, except with the additon of ethanol

1 mole hex
4 moles HCL in 32% w/w solution
NO extra NH4CL added
3 moles ethanol
100mls water

Heated to reflux for a couple hours (bath temp around 75DegC), then the formed ethyl formate was distilled out.  Once that had stopped, heated to around 100DegC for another 4 hours.

Then exact same work up as previous experiment

Yield of dried methylamine.hcl ( as opposed to the product contained in Orgys picture in this thread) was 55% w/w based on starting hex

Conclusion

Adding ethanol made temp control easier.

Less gas, slower reaction, but somewhat more pleasent.

Yield was if anything worse, following the vogel type workup as normally done, and written, by SWIM

Last point

Do you think it's possible that some bees doing IPA extractions, simply boil the IPA away and then claim that the hardened mass is their yield.  Whereas others then crush up said solid, filter, wash and dry?? which would explain some discrepancies IMO.

;)

Abacus

armageddon

  • Guest
I don't agree placebo - but anyway..
« Reply #138 on: August 11, 2004, 04:23:00 PM »
Nice! Some useful, informative post!

Now we just need someone who does the same with an excess of NH4Cl, and everything is tested out and we can all decide which procedure may be the best one... ;)

About your test of dissolving your product in MeOH or EtOH: Merck index says that ammonium chloride is soluble in both (although maybe just very slightly), so a better test would surely be using anhydrous iPrOH or even better t-BuOH or something similar...

Your syrup is supposedly diMeAm - trimethylamine cannot be formed under these conditions. They both form hydrochlorides though, so the fact it doesn't crystallize doesn't classify it as trimethylamine.

And you can in fact just boil the IPA away and claim that as your yield, if you used the IG-farben patent (with vac filtering and some acetone rinse for better drying maybe), as the procedure doesn't produce any di- or trimethylamine if done right (which you did AFAICS) - remember the hinsberg and nitrous acid test?  ;)  Therefore the IPA xtractions should only contain MeAm*HCl and HCl in traces...

[EDIT] Just realized that you wrote:4 moles HCL in 32% w/w solution - I don't know, maybe your HCl differs from mine; but usually the strength is stated as percent weight/volume (i.e. 1 liter 31.45% HCl contains 314.5 grams) - but it shouldn't make any big difference[/EDIT]

Greetz A


abacus

  • Guest
I knew you'd say that
« Reply #139 on: August 12, 2004, 10:26:00 AM »
I mistakenly omitted some information that I assumed we all knew. 

I forgot to point out that experiments involving washing the recovered methylamine.hcl with DCM and/or chloroform AND then evaporating the solvent to look for the dimethylamine residue, showed there was NO such residue, so no dimethylamine was ever formed in the reaction IMHO.

Other bees have also reported such findings, if you want, UTFSE and you'll find such agreement from others. 

As I said, I assumed we all knew this and took it for granted by now. ;)

HCL strength is stated in either w/w or w/v, depends on manufacturer, point is, make allowances to get 4 moles per mole hexamine.

Abacus

placebo

  • Guest
I concur abacus, yeilds of above were 50% of...
« Reply #140 on: August 12, 2004, 10:33:00 AM »
I concur abacus, yeilds of above were 50% of hex weight and also ended in that orange thick syrup that would not crystalise again even at freezer temp.
Second rxn running with...
700gm hex
2100gm HCl
100gm NH4Cl
I can tell you it has taken no longer or smellier then with EtOH.

Then it will be done without any NH4Cl


armageddon

  • Guest
I don't get it
« Reply #141 on: August 12, 2004, 11:00:00 AM »
Well yield of my unoptimized, experimental procedure was >100% w/w if you want to calculate yields from hexamine....

49g methylamine hydrochloride from 48g hexamine means 102.08% yield w/w to hexamine! Huh!?...
but 49g methylamine*HCl from 87g ammonium chloride means 45.11% molar yield calculated from NH4Cl...

(also note that my yield was calculated from the amount obtained after gassing...)

See why I calculate yields from molar amount of formaldehyde or ammoniumchloride, not weight of hexamine?

A


placebo

  • Guest
Mate you work it out any way you like, I just...
« Reply #142 on: August 12, 2004, 11:23:00 AM »
Mate you work it out any way you like, I just gave you figures.
But my 350gm MeNH2.HCl from 700gm of hex is a long way short of others alleged yeild.


armageddon

  • Guest
your personal molar yield calculator sez:
« Reply #143 on: August 12, 2004, 11:45:00 AM »
Your personal molar yield calculator Armageddon sez:

350g CH3NH3Cl from 700g hexamethylenetetramine corresponds to a molar yield of 25.95% calculated from the NH4Cl gotten from hex hdrolysis.


    700g hexamine = 4.9932 mol (140.19g/mol)
    350g methylammonium chloride = 5.1837 mol(67.52g/mol)
   
    4.9932 mol hexamine gives 19.9728 mol ammonium chloride upon hydrolysis
    (1 hexamine + 4 HCl -> 6 HCHO + 4 NH4Cl;  m(NH4Cl) = 53.49g/mol )


    5.1837 mol / 19.9728 mol = 0.259538
    ...meaning 25.95% molar yield.


And the molar yield calculator further sez: Of course you don't have to believe in my "alleged yields"!  :)

Greetz A


abacus

  • Guest
Placebo, another bee with REAL experience
« Reply #144 on: August 12, 2004, 12:35:00 PM »
Placebo, so correct.

I have done this hex/hcl reaction for years, from a 600g run of hexamine maximum yield i (I mean my professer) got, after said procedure, of removing NH4CL, and removing that orange syprup (that other bees keep locked up in solid mass) was 485g methylamine.hcl

Typically 600 grams hex makes 300-350g clean, dried methylamine.hcl.  Molar yields in the 30% range

Adding extra NH4CL does little IME, water did though so not to saturaate the solution and kicking the formaldehyde out of the reaction.

Other bees have previously stated that they are highly skeptical of anybody claiming a better result, I couldn't agree more.

Abacus

placebo

  • Guest
I concur again abacus, about the water added.
« Reply #145 on: August 13, 2004, 10:16:00 AM »
I concur again abacus, about the water added. I think the bad results with EtOH are probably due to no added water. I know it definately affects rxns without EtOH. I would have thought the added EtOH would do the same job as the water and stop saturation.
Results of second rxn are not forthcoming. Alas, due to unforeseen circumstances it was overheated and turned brown. But about 150gm was still isolated, the rest was fried. But it definately looked better then the first rxn (with EtOH), this opinion is based on the amount of NH4Cl recovered.

Further study required. Hexamine rxn of any kind still sucks. 500gm of Meam could be made in less then half the time, and cleaner and easier workup with formalin + NH4Cl. I think the extra time is better spent on looking for a source of formalin or para. Mind you the hex is a good source of NH4Cl.  :P

Nobody answered my question about how much NH4Cl should be recovered?

Next attempt with EtOH would be with water added.


cyrax

  • Guest
evaluation of reactions
« Reply #146 on: August 14, 2004, 04:53:00 AM »
empty

abacus

  • Guest
whats all this nonsense
« Reply #147 on: August 14, 2004, 02:20:00 PM »
Here we go, another analysis based on posts rather than first hand experiences.

Woops, I seem to have made an error in reporting my "yields" in experiments using ethanol, how silly of me. 

Please make adjustments in your evaluation

Did I say 300g, I meant 600g, and guess what, I made a perpetual motion machine as well so factor that in, and then come back and give us the results when done.

Abacus

cyrax

  • Guest
Re:
« Reply #148 on: August 14, 2004, 03:08:00 PM »
Well then, no nonsense

armageddon

  • Guest
at the moment, the world is a disk...
« Reply #149 on: August 18, 2004, 10:15:00 AM »

Post 310000

(Rhodium: "Everybody at the Hive always wait for someone ...", Chemistry Discourse)
 ;D

Greetz, A


Organikum

  • Guest
A deep lack of understanding shows up again.
« Reply #150 on: August 18, 2004, 12:42:00 PM »
A deep lack of understanding shows up again.

Hexamine rxn of any kind still sucks. 500gm of Meam could be made in less then half the time, and cleaner and easier workup with formalin + NH4Cl



Oh my. Hexamine + HCl + water = ammoniumchloride and formaldehyde (hydrolysis).

Maybe your hexamine is shit?

And this thread is not a universal methylamine production thread. It is on a old-new method using alcohol for reasons of shorter reaction times with equal or better yields. Please discuss "traditional" hexamine to methylamine.HCl procedures in the related threads which are by the hundred on this board and refrain from posting here off-topic. Here are bees at work - not at talk, and repeating over and over old stuff which is only regarded worthy because it is old and was repeated over and over again is not very helpful at all.

regards
ORG




abacus

  • Guest
food for thought
« Reply #151 on: August 18, 2004, 01:40:00 PM »
ok

I’ll try to be as concise as possible

I tried the ethanol in reaction and it made no difference to me, ended up with slightly less amount of cleaned and dried methylamine.hcl and leftover syrup as usual.  No dimethyl or trimethyl was formed in the reaction, if your theory or the patent has any validity. 

Ethanol did provide benefits as previously posted.

But the difference was the workup, your write up does involve alcohol extractions whereas I followed the Vogel procedure (without vacuum).

Incidentally, previous experiments when reducing the liquid volume using vacuum still got the same result.

These differences in the post reaction workup are the only unexplored variables in my mind.

I get the same mass of solidified product by doing a post reaction Vogel type workup as Orgy’s does in his/hers posts by doing an IPA extraction and then boiling all the IPA away to leave the residue.

I then go on to crush up the solidified mass, vacuum filter, wash, and dry to be left with clean methylamine.hcl crystals as well as syrup that simply refuses to solidify no matter what (incidentally, soluble in water, ice cold ethanol, not soluble in acetone). 

The resulting dried methylamine.hcl is about half the mass of original solidified mass before crushing and washing, the difference being this liquid.

This result was the same when using ethanol in the reaction, ie made no difference.

Previously in this thread, Orgy mentioned very high yields after “recrystallising”.

Well, if that’s true I am left with a simple question.  

Maybe, the real benefit of the patent is the workup by way of alcohol extractions, keeping the temp down, avoiding side reactions etc, whereas the workup done by me is somehow causing this orange syrup thereby substantially lowering the observed yields.

And that to me is the only unanswered question.

At this point in time, I still doubt the idea that adding ethanol to the reaction itself stops this syrup, or increases yields, because I saw no evidence of this in my experiments and remain yet to be convinced by other posts.

I have no problem being wrong, and remain fully open to any suggestions.

If swapping to alcohol extractions does indeed solve my stated issues, fantastic.

Abacus

Organikum

  • Guest
As told before, my workup consists of hot-IPA...
« Reply #152 on: August 18, 2004, 03:02:00 PM »
As told before, my workup consists of hot-IPA extractions of the orange mass, removing the IPA from the joined extracts (collected for reuse for future extractions). I then add an excess of NaOH - not at once, over some time and in the cold - and collect the methylamine-gas in denat. EtOH. (94%) Some water will come over but this does by no way cause any problems in Al/Hg reactions.

But thats just mine.
I dont recommend it, I dont propose it, I dont tell it is "the best way" - no. I solely tell it as its comparable fast and gives me methylamine-base in EtOH/water and thats what I am after.


Do as you prefer, use what works best for YOU. If what works well with good yields for me doesnt work the same for you - cant help it, sorry.
When you have found YOUR preferred method, make a nice writeup and start a NEW thread. I will not jump into this thread then and post that other procedures are better, promised.

And Abacus: Let it go now. Its enough, I cant see what you are after except more annoyance. But I have seen in earlier threads of yours that you plain dont know when to stop. STOP IT NOW!

btw. I have posted in this thread solely as Organikum and as nobody else. Thats obviously more than others can claim. The strange ways of doublethink......


tryin

  • Guest
methylhydroxylamine hydrochloride
« Reply #153 on: August 18, 2004, 04:36:00 PM »
Could one use this method to make methylamine then convert to methylhydroxylamine? If so what would be the best way?

armageddon

  • Guest
yes
« Reply #154 on: August 19, 2004, 02:46:00 PM »
Yes - you can use this method quite well for making methylamine. But for hydroxylation questions, this is again the wrong thread... :)

Maybe halogenation, followed by hydroxylation with NaOH? Dunno... (UTFSE)




Abacus: Maybe re-read 

Post 514413

(armageddon: "NH4Cl removal / leuckart methylamine", Methods Discourse)
, especially those lines:

"250g ammonium chloride (4.7 mol) are slowly heated with 570g 35% formaldehyde solution in a distilling flask fitted with downward condenser. The temperature (thermometer reaching below surface of rxn) is slowly raised to 104°C and held there until no more distillate comes over (4.5h from beginning). The distillate will consist of 100-120g water and methanol (from the 35% formalin solution). After cooling down the dist.flask content, the precipitated ammonium chloride is filtered with suction and the filtrate is reduced to half of its volume on a steam bath. After cooling, the NH4Cl is again separated with suction filtering and the remaining liquor is concentrated until it forms a surface skin. After cooling, the MeAm*HCl is filtered out (suction) and the mother liquor further concentrated (residual water being removed with a vacuum exxicator/NaOH(s) or H2SO4). The residue is freed from di- and trimethylammoniumchloride by washing w/chloroform and dried with suction. Together with the first crystallization, 110-125g of crude MeAm'HCl are collected.
To free the crude salt from residual NH4Cl, it is extracted by boiling with 250ml abs. alcohol for 0.5 hours.
The alcohol is cooled, precipitated MeAm*HCl is filtered and the mother liquor is used for another exctraction.
After five extractions, one gets approx. 100g (37% of theory)."



Perhaps this helps in understanding.

As you can see, even with the common methods, it is advised to purify the crude MeAm*HCl by extracting repeatedly with hot alcohol and recrystallizing.

So this cannot be the main benefit of the IG-Farben patent.



But:

- In case you believe what I posted earlier on, you know that the patent results in no di- or trimethylamine WITHOUT chloroform washes - I tested it.

- In case you believe in Organikums and my (and others) high yields of pure methylammonium chloride, you know they are higher than yours and even Placebo's with the Vogel's method, although Placebo seems to bee quite xperienced and knowledgable..

Now combine those two benefits with the minor advantages (nicer rxn) you already know, and you might understand why some bees start getting angry when you doubt the usefulness of this patent and criticize them... ;)

Greetz, A


bbeeasheets

  • Guest
strange distillate?
« Reply #155 on: August 20, 2004, 03:00:00 AM »
after 4 tries, following as close to posted trials as i can

100g hexamine
100ml dH20
330g Muratic acid
120g denatured alcohol

slow heat until 60 (reaction temp) reflux for 4 hours
no distillate at thiis temp
raised temp slowly
distillate started to come over at (81deg reaction temp)
vapor temp 67 degrees!

4 tries exactly the same  (i only went thru alcohol removal, reflux 4 hours and water removal once)

is there any way to definatively check for methylamine without a GC or mass spec?

also what could the strange distillate be? could impurities from denaturant or from the hexamine raise the bp of ethyl formate by that much?

armageddon

  • Guest
vapor separation
« Reply #156 on: August 20, 2004, 03:47:00 AM »
Try adjusting the heat more carefully - every time I did the reaction, applying too much heat resulted in steam temp. climbing to above 60°C - which is not what is wanted (EtCOOH bp 53°C)...

Did you choose an appropriately sized flask, at least 2x rxn volume? With a half-filled flask and standard dist. setup (without claisen), the difference between reaction temp. and steam temp. is usually around 30°, so your reaction temp. should allow for a good separation of the vapors (EtOH and EtCOOH).
But if your flask is more than half-filled, it could well be that the space between surface of the rxn liquid and still head isn't big enough, and the missing extra headroom doesn't allow for a proper separation before the vapor mixture gets cooled - with properly sized flasks, the space between liquid and still head works like an easy column.

Maybe you should try using some sort of column, or maybe just some big glass tubing - the vapors separate quite well if you give 'em enough time and space, and it is possible to collect pure EtCOOH, believe me...

(and I started to distill from the beginning, no reflux was done before. I just heated very slow to 80°C during the first hours... remember this is in fact a leuckart reaction!  :) )

Greetz A


abacus

  • Guest
I agree
« Reply #157 on: August 20, 2004, 11:42:00 AM »
Alright, I'm sick of this bullshit, and I'll get straight to the point.

First off, Orgy, I have only one user name and this is it.   If you cant handle a peer review too bad. 

Secondly, Armageddon, I know this, I also agree with 37% yields.

So with that in mind.

1 mole hex, 140g, makes in theory 202g methylamine.hcl

37% of that is 75g.

100g hex in theory makes 144g methylamine.hcl, 37% yield gives 53g

So has it ever crossed anybody's mind how anybody can claim 125g methylamine.hcl from 100g hex, which is more than TWICE the result that would be expected based on the literature.

Abacus

armageddon

  • Guest
wrong calculation?
« Reply #158 on: August 20, 2004, 01:42:00 PM »
Hi!

You say:

"1 mole hex, 140g, makes in theory 202g methylamine.hcl

37% of that is 75g.

100g hex in theory makes 144g methylamine.hcl, 37% yield gives 53g."



Actually, I'm not completely satisfied with your calculation!  ;)


I think you refer to the post linked below when you wrote this:

Post 500578

(Bond_DoubleBond: "Nothin special, but here ya go . . .", Methods Discourse)


So let's recalculate the molar proportions bouble bond used:


100g hexamine + 104.03g HCl + 77.12g H2O  ->  152.62g NH4Cl + 128.53g HCHO

(The remaining water from the HCl amounts to 226.22g - 77.12g (used for hexamine hydrolysis) = 149.1g (or ml))


152.62g NH4Cl + additional 30g  ->  182.62g NH4Cl


(if the concentration of the acid BDB used was w/w, he used in fact 103.76g HCl instead of 104.03g - but that's neglectible, let's simply say he had used the correct amount  :) )

So the ratio of reactands are:


    3.41 mol NH4Cl
    4.28 mol HCHO
    2.11 mol EtOH (again not exactly 2x the molar amount of HCHO, but close enough)


The limiting reactand is obviously the NH4Cl.


Now I don't see how you came to your statement that 100g hexamine results in 144g MeAm*HCl theoretically - because the max. theoretical yield would be 3.41 mol * 67.52g/mol = 230.24g methylamine hydrochloride

He claimed having got 120g pure product (anhydr. IPA recrystallization). Therefore:


    230.24 / 120 = 0.5212  ==>  52.12 percent of theory


There's nothing wrong with getting twice as much as with standard, well-known procedures if you use some new/unknown improvement. And the claimed yields seem achievable, at least seen from the mathematical point of view...

I got 45.11 percent of theory BTW, and that was after gassing - I think "BubbleBond"s (nice nick  ;D ) 52.12 percent correspond pretty well with that...

Greetz, A


Organikum

  • Guest
Lets see: 100g hexamine (0,71 mol) hydrolyses...
« Reply #159 on: August 20, 2004, 01:51:00 PM »
Lets see:

100g hexamine (0,71 mol) hydrolyses to
- 152g NH4Cl (2,84 mol)
- 128g CH2O (4,26 mol)

You see there is excess formaldehyde present.

I add 20g NH4Cl, thus we have 172g and we have a theoretical yield of 218,6g methylamine.HCl. Yes?(*)

I get 125g methylamine.HCl yield which represents about 57% of theory and is not so far from the 40-45% yield by the Vogel´s method (your 37% is low - why? Its not on the method its on you I guess) - if it is done right.
Therefor I always told that this method gives slightly better yields and its main advantage is that it doesnt take so long.

Based on the literature for this variation - this literature is the patent from the first post and nothing else - the yields I claim are absolutely correct. The patent actually tells near to 145g yield to expect - based on the reactionpathway presented and the claims - and hey! Patents ARE scientific literature per definition.

In short:
Theoretical yields: 218g (by molecules present, not by reactionpathway presented in the patent)
Yields claimed by patent: near 145g (by the reactionpathway)
My yields: 125g

Remark: Reactionpathways are merely ideas and the patent clearly states that it is THOUGHT that the reaction proceeds this way. It may, or it may not - nobody REALLY knows. Claiming that a certain reaction DEFINITIVLY goes by a certain pathway is nothing but a mishabit. The old chemists knew this well, modern chemists often forget about this.

And now dear abacus you will perhaps understand why you are not regarded as a peer to me. And not by anyone else with knowledge on chemistry.

(*) Please anybody be aware that the added alcohol by no way reacts to 100% - how much reacts strongly depends on how this reaction is done. Therefor the amount of alcohol to add depends on how one plans to run the reaction. Also the quality of the hexamine and the denaturants in the ethylalcohol may be of importance - distilling the alcohol from salts and recrystallazing the hexa may help here.

abacus, I asked you to stop this shit. You PM´d me you will NEVER stop it. Ok. Go on showing off what idiot you are not able to do simple calculations and such. I will have lots of fun with you I guess.  :P


armageddon

  • Guest
hehe
« Reply #160 on: August 20, 2004, 01:57:00 PM »
I WAS FASTER, I was faster.... ;D

(at least nobody believes that we are one person anymore, isn't it?  :) )

Also the quality of the hexamine and the denaturants in the ethylalcohol may be of importance

Propably right - I once used lab grade EtOH and got a greenish-tinted solution upon concentrating, but with standard den.EtOH, it is orange. I think the different denaturants cause side products. Anybody wanting to try it with expensive non-denat. alcohol maybe? Just to be sure?  ;)

And just for the record: BDB, Orgy and me weren't the only bees claiming the patent being of advantage:

  

Post 504433

(biffman: "Good results", Methods Discourse)
  
  

Post 507343

(Vaaguh: "finished", Methods Discourse)


(...)

A


abacus

  • Guest
ok
« Reply #161 on: August 20, 2004, 10:23:00 PM »
Org/Armageddon , whoever you are

I said 202g, from 1 mole HEX, I said nothing about adding extra ammonium chloride did I.

1 mole hex + 4 moles hex + 6 mole water = 4 moles NH4CL + 6 mole CH2O

So limiting factor is the formaldehyde in the reaction between the NH4CL and CH2O to make methylamine.hcl via hydrolysis of hexamine

You work it out anyway you like.

My reference to not stopping was based on your comments telling me to stop, obviously you didn't want anymore scrutiny.

But have it your way, I will stop now, go ahead and fool lots of bees with your claims, I have provided enough commentary for others to make up their own mind and hopefully, they will see through your fake claims like i have.

Abacus

armageddon

  • Guest
the patent is about adding extra NH4Cl, no?
« Reply #162 on: August 20, 2004, 11:19:00 PM »
The patent is about adding extra NH4Cl, isn't it?

Anyway: 140g hexamine gives 4 mol NH4Cl upon hydrolysis, this equals 213.96 grams.

Theoretically, this should result in 270g CH3NH3Cl, so your 202g are a molar 74% yield.

Who said that? Who claimed 75% yield?

So limiting factor is the formaldehyde in the reaction between the NH4CL and CH2O to make methylamine.hcl via hydrolysis of hexamine

Surely not. The limiting reactand is always present in smaller amounts than others, therefore he limits the amount of product that can form. And when you don't add any NH4Cl but use plain hexamine, the HCHO is clearly present in 50% excess (3:2 aldehyde/chloride)...

And about the fact that we (orgy and me) used additional NH4Cl whereas you didn't: well, who got higher yields in the end?

And the molar yield is well comparable, as it only tells about how much of the limiting reactand was converted - and in both cases, this means just how much of the NH4Cl became methylated, regardless whether it was added in addition to the hexamine or not.

The different yields just show that the amount of formed MeAm*HCl can be increased without using more formaldehyde, but by adding more NH4Cl. That's all about it. It is commonly called "proof" if something like this is elaborated.

Now what's your problem with both our calculations being made for reactions that involve the use of additional NH4Cl?? Your calculation is still wrong, and ours are both more ore less correct - so why do you try to start a new flamewar again?

I don't get it why you first doubt the results of other bees using additional NH4Cl, and try to prove them wrong by recalculating their yields, then others prove that you were wrong with your calculations, whereupon you start saying that those other bees calculated the yield for the wrong type of reaction!?!? You were trying to show that our yields were bogus by recalculating them, so why is it suddenly all wrong when we recalculate them??  :(  Your criticizm is absolutely not scientific but rather personal, I believe. (and I'm NOT Orgy BTW!!!)


>:(  >:(  >:(

A


Organikum

  • Guest
wuhahah...
« Reply #163 on: August 20, 2004, 11:28:00 PM »

I said 202g, from 1 mole HEX, I said nothing about adding extra ammonium chloride did I.


You critisized the 125g yields I claim and these were made by addition of NH4Cl. Thats the point and nothing else, cheap tricks now? - just funny.  ;D


So limiting factor is the formaldehyde


completely wrong, dumbass. Do the math. There is more than enough formaldehyde as 1 mol hexamine hydrolises to 4 mole ammoniumchloride and 6 mole formaldehyde. Good laugh - thanks baby.  ;)


go ahead and fool lots of bees with your claims


Now you tell I am a liar, yes? And some other bees obviously too?
You are dead meat asshole.  >:(




abacus

  • Guest
math this
« Reply #164 on: August 21, 2004, 06:28:00 AM »
Balanced equation is this

1 HEX  +  4 HCL  + 6 H2O >>>>>  4 NH4CL  +  6 CH2O

Correct???

The 6 moles formaldehyde reacts with ONLY 3 moles of the formed ammonium chloride as such, leaving an extra mole of NH4CL.

3 NH4CL  +  6 CH2O  >>>  3CH3NH3CL  +  3 HCOOH

Correct???

see posts

Post 513107

(Antoncho: "The mechanism", Methods Discourse)

Post 488683

(Organikum: "For the vindication of Eleusis - Methylamine", Methods Discourse)


So the combined equations give

1 HEX  +  4   HCL + 6 H2O  >>>>  3 CH3NH3CL  +  3 HCOOH + 1 NH4CL

Remove formic as formate if you wish by adding ethanol.

EDIT: 3 moles of ethanol is required and the reaction is this.

1 HEX  +  4 HCL + 6 H2O + 3 CH3CH2OH  >>>> 3 CH3NH3CL  +  3 HCOOHC2H5 + 1 NH4CL + 3 H2O

That’s the equation that my calculations are based on.

So 1 mole hex, 140g, would make 3 moles methylamine.hcl which is …202g

37% yield would be ..... 53g/100g hex like i said

All the formaldehyde is used, left over 1 mole unused ammonium chloride, thats why I said the formaldehyde from the hexamine hydrolysis is the limiting reagent.   

Knock yourself out with that.

Over AND OUT.

armageddon

  • Guest
So you made the astonishing discovery that no...
« Reply #165 on: August 21, 2004, 10:06:00 AM »
So you made the astonishing discovery that no matter if you add NH4Cl to hexamine/HCl or not, the NH4Cl will always be present in excess - or better said that numerous bees aren't able to calculate molarities whereas you show them after hundreds of posts about the subject that the AAAALL were WROOONG...(in case you didn't notice it: THIS WAS IRONY!)

Sure.

Go home and whine. But please don't start ranting about "only three out of four NH4Cl react, therefore formaldehyde is the limiting reactand".

It is NH4Cl, because everything else in present in excess.
(period)

A


Organikum

  • Guest
No, abacus
« Reply #166 on: August 21, 2004, 11:45:00 AM »
Thats wrong again. You mix things up because you dont know shit. Theoretical yields have been calculated by me plain by the molecules/atoms in the soup - as I told. The reaction mechanisms proposed by antoncho and the in the patent are guesses nothing else. A patent needs an explanaition how things happen to be accepted - nobody really would bet his ass that it proceeds this way in reality. So it is written "it is nelieved that....". And antoncho says also that "in his humble opinion" this is this way. Opinion. No prove.

The way things happen in chemistry is: Molecules in the box. Close box. Shake box. Open box, look at the results and make up a reaction mechanism which explains why one doesnt get theoretical yields of the desired compound or something complete different as thought.
The hen and the egg. Where you start your definition? Chemists love to start at the point where it makes yields look better. Simple.

Nevertheless: It is your problem if you are not able to run easy reactions in a way which provides you with the yields other bees get. I would like to say that you lack knowledge and more important you lack any patience and any insight. Search for failures at your own - but no, you prefer to look for somebody "guilty", somebody else to blame for your own mistakes. What do you believe is happening here? A multiple bee methylamine-conspiracy? Or do you believe I am posting with X usernames? You are mentally very ill boy. For sure you are.
Look I spent lots of time here because of your selfrightenousness. I look always if it was not I who made a mistake, so I redid all the calculations three times - this costs time, nerves and is overall not enjoyable. I almost believed that you are just fucking around with me.
The point is: You fucked it up again and you want to blame somebody else. You fuck quite a lots of things up yes? BzCl from BzOH, for example where you claimed "quantitative yields" and wondered about HCL in the second distillation. Hey, you are not the King of Chem - cant you see it. I am not the King of Chem either, but I know it and look at myself first when its on searching somebody to blame. And thats one difference between you and me. The other difference is that my mental illness makes me not as antisocial and annoying as yours makes you.

On topic: As long nobody shows me an article where intermediates have been isolated or radioactive isotopes were used (or equal methods applied) to determine the reaction mechanism I say that the mechanism is unknown - everthing told are barely educated guesses, nothing else. Like reading the future from the innards of a dead animal.

A remark to antonchos mechanism:

NH4Cl + 2HCHO __> CH3NH3Cl + HCOOH

Thus formed HCOOH reacts with ethanol:

HCOOH + C2H5OH __> HCOOC2H5 + H2O

forming ethyl formate, which is removed by dictillation.




The patent states that removal of the formate by distillation is NOT necessary. The formate dissoziates in aqueous solution to formic acid and ethylalcohol and the formic acid could then react again with ammoniumchloride, a Leuckard variation.
Just one possibility.
There are more thinkable ways and some unthinkable ones.  ;D

And now its over. You wont be ridden from sudden insight abacus (and at least two other names in this thread which are you - dont lie. btw.- any admin can prove that I and armageddon are NOT identical) - no chance to see this happen. Best you do as ever, get a bottle of booze and swap your frustration down, beat up your wife and your kids so available and hopefully go to jail for doing so. Or get some real help. You need it.


I spent to much time here trying to bring some good stuff - tried and true and reproduced by others - to the community.

Hereby I BEG some moderator to LOCK this thread now after this post. I dont ask for favors often as its known - now I do. I started the thread, grant me the last post and close it - PLEASE. There is nothing useful to come anymore - the work is done, there is more experimental data than anyone can ask for - close it.

Up to then I ask everybody with some decency left to refrain from posting here - as this should be the

END




armageddon

  • Guest
couldn't resist
« Reply #167 on: August 21, 2004, 09:54:00 PM »
As the thread is still open, I will take the opportunity to criticize something Organikum said - something else after all that flamewar, hm?  :)

The patent states that removal of the formate by distillation is NOT necessary. The formate dissoziates in aqueous solution to formic acid and ethylalcohol and the formic acid could then react again with ammoniumchloride, a Leuckard variation.

The ethylformate will surely not dissociate into formic and ethanol as long as there is a large excess of water and ethanol present; which is the case in this reaction, until the last drop of EtCOOH has distilled. Reason is that every reaction is reversible, but this doesn't happen as long as the educts are present in excess - again leChatelier...

If the formic would react on ammoniumchloride, it would be fine; but I don't think this is possible. The "Gattermann" states that overalkylation is caused by formic acid acting as a methylating reducing agent, and the patent tells that alcohol circumvents the problem of overalkylation - and as we all know that it is alcohol reacting with the formic when using the patent, I draw again the conclusion that the removal of formic acid (gotten from oxidizing HCHO) through esterification with EtOH serves the purpose of avoiding overalkylation of already formed methylamine hydrochloride through leuckart-like reductive methylation.

So, the Leuckart similarity I mentioned earlier on is not the desired methylation of NH4Cl through HCHO but rather the undesirable methylation of CH3NH3Cl by reaction with HCOOH. But then again, there are also leuckart reactions using HCHO as reducing agent - maybe you're right? Anyway, I guess you were thinking about my "methylamine leuckart" post when you wrote this, so I wanted to clarify what I originally meant with "Leuckart-like"...

but the topic "Leuckart reductive methylation" sounds interesting - maybe it would be possible to directly methylate primary amphetamines (3,4MDA as well as plain benzedrine) via this route? (Of course only if a high-yielding method would be found/elaborated - with present yields being lower than 50%, I would of course rather methylate a precursor than to do same thing on primary amine - but things like MDA or MDMA are illegal to manufacture, so I probably will have to wait for my permission to synth controlled substances before trying anything like that  :) )

Last thing left to say: I strongly support Organikum's begging for the thread to be closed! Please, Rhodium - make an end to this, making methylamine with this patent is a topic being discussed enough IMO. And maybe others will beecome encouraged to start their own threads...

(dabei wurde es gerade soo lustig!)

A


placebo

  • Guest
Org, some of us are not putting down the ...
« Reply #168 on: August 22, 2004, 12:25:00 PM »
Org, some of us are not putting down the procedure, just trying to understand it. Care to respond to some of my questions above? I think the answer to the bad results is due to addition of water.


Organikum

  • Guest
?
« Reply #169 on: August 22, 2004, 03:28:00 PM »
Placebo, you wrote before that you believe the bad yields come due to not enough water

I think the bad results with EtOH are probably due to no added water


in

Post 525218

(placebo: "I concur again abacus, about the water added.", Methods Discourse)
Now you write


I think the answer to the bad results is due to addition of water


in

Post 526757

(placebo: "Org, some of us are not putting down the ...", Methods Discourse)
So you ask a question impossible to answer for me.

I can tell that I have got my best results by dissolvong the hexamine and the additional NH4Cl in water (not all NH4Cl dissolves, this doesnt matter), premixing HCl and EtOH and adding this - chilled - to the hexa/NH4Cl/water.
As described here:

Post 494587

(Organikum: "The alcohol used by me was simple denaturated...", Methods Discourse)


Points which maybe of importance:
- The denaturants in the alcohol
- Impurities in the HCl
- Impurities in the Hexamine
- The order in which compounds are added and the time given after every addition
- The temperature at which alcohol/HCl/hexa/ammoniumchloride are admixed - I recommend to do all this in the cold, mix well and heat up slowly then.
Eleusis rcommended to add HCl to the hexamine and to give lots of time for complete hydrolysis - might be a good idea.
Me myself learned that adding the HCl to alcohol and to let this chill down and then to add this in the cold to the hexa/NH4Cl/water (100g hexa, 20g NH4Cl partially dissolved in 100ml H2O, first dissolve the hexa then add NH4Cl) worked well for me.
The method as told by Eleusis - complete hydrolysis of the hexamine to formaldehyde and ammoniumchloride by giving mucho time is closer to the text of the patent. He didnt add more NH4Cl - I did and I recommend to do this.

There is more experimental data posted by BDB and armageddon - have a look there too.

By my best will I cannot tell what causes you problems, I only can tell what works for me and what not. Reactions with OTC reagents are often difficult to reproduce by others, this well known. You may see from the five points named by me only two are related to procedure.

After my OPINION more water doesnt hurt but is favorable, not enough water will. The french article states the importance of enough water, so I am not standing alone here. If the hexamine is hydrolysized first as Eleusis did it, I would say to thin the HCl (he uses 31%) down to 20%-25%.

The 125g methylamine.HCl from 100g hexa and 20g NH4Cl were not one-shot and for sure not first-shot. They were the result in three cinsecutive runs after three or four runs I fucked up for different reasons. Everybody to expect a foolprove receipt without own effort, fed on a silverspoon lives in fairyland and knows nothing about the mysteries of chemistry.

PS: A usual kitchenmixer is very helpful in the described procedures, a small paintmixer is preferred though (the kitchenmixer often tends to mix air into, paintmixers are designed not to do so) - hexamine dissolving etc. Also liquids dont mix perfectly just by addition in a second or two. Usually mixing IN THE COLD is the way to go when a reaction is to proceed with admixed compounds (liquid or solid makes no difference) in the heat. Say, you mix the cold stuff as intimately as any possible before applying heat. This is basic knowledge but rarely told not even in the better books. (or I overlooked it there... ;D )

Now you got:
- two possible procedures
- several points for failure analysis
- some always useful tips on howto do certain things in org-chem.
- and my opinion on the role of water in the reaction

hopefully you are satisfied.
ORG




java

  • Guest
Syntheses of Methyl amine as per Organic synthesis
« Reply #170 on: August 23, 2004, 03:33:00 AM »
Going through the recent made available Organic Synthesis ....

Post 526805

(java: "E-Books: Organic Syntheses Volumes", Chemistry Discourse)
I noticed the synthesis of methyl amine in volume 3 page 67, of Organic Synthesis , where the method discribed by Organikum is discussed. Ref and other methods are referenced there also . I thought I might interject this bit of info to this thread......java


armageddon

  • Guest
thanks
« Reply #171 on: August 23, 2004, 06:58:00 AM »
Exactly what was needed - and on the bottom of page 68, the following is stated about the yield (lo and behold!):

"The yield of recrystallized methylamine hydrochloride is 600-750g (45-51 per cent of the theoretical amount, based on the ammonium chloride used up in the process)."

...and that is for 2000g NH4Cl and 4000ml 35-40% aequ. HCHO solution. It is further said that 850-950g NH4Cl are isolated unchanged, meaning that ~1100g NH4Cl react to give ~675g CH3NH3Cl.

(Next time when I synth some MeAm I will weigh the isolated NH4Cl and then come back with some 70+ percent yields calculated from NH4Cl "used up in the process" instead of the standard % of theory, I promise!  :) )


And they don't use 1 mol alcohol per 2 mol aldehyde (only small amount of MeOH from stabilizing the formalin), so they have significant diMeAm inpurities and therefore do chloroform washes.


So the "Org.Syn" method is essentially the same, except that they don't use excess NH4Cl. And they don't add alcohol.



Left with the question: what has this procedure in common with the patented use of additional alcohol described by Organikum? Besides questioning higher yields than they got (common practice with methylamine manufacture  ;D ), the authors of this Or.Syn chapter don't do anything that hasn't been mentioned before, besides stating that EtOH isn't sufficient for purification purposes - I said it before, but nobody believed me - oh well...

In fact it is exactly the same procedure as posted by me  in this thread before (my translation of a part from "Die Praxis des organischen Chemikers",L.Gattermann, the one with the title "Leuckart reaction - methylamine through reductive methylation"), only difference that the Org.Syn authors did it big scale...

At least we have one more literature reference for this reaction - but, sorry to flame you Java, the patent DE468.895 isn't referenced to in Org.Syn. (only other old german patents), so your post is not really helpful, rather re-posting old news...

A


Organikum

  • Guest
You are wrong armageddon - the patent I ...
« Reply #172 on: August 23, 2004, 09:02:00 AM »
You are wrong armageddon - the patent I presented IS referenced in Organic Synthesis in the "discussion" part. I posted this already as an answer to Terbium here, but this thread got so fucking useless long that the snakes end seems not to be able to see its own head - already the danger arises that the snake will regard itself as prey and start eating itself.

Its Org. Synt. where I discovered it.

ORG

PS: Its ok that Java posted this here, it shows how shitty abacus´s yields are already on the original pathway and that his problems have to be based in his technique and not the method.

PS2: And now for the slower ones: The method using commercial formaldehyde is better yielding just because this contains alcohol for preservation - so the methods with formaldehyde are in part running after the pathway of the patent and in part after the Leuckard - thats very obvious. THATS why hydrolized hexamine SEEMS to give lower yields, it would give identical yields if the alcohol which is in commercial formaldehyde would be added to the reaction. In my opinion the alcohol suppresses formaldehyde destroying and CO2 evolving reactions - thats it.

PS3: Things come together. Times ago Terbium and Chromic did the dinosaur-fight here. Terbium said he had no CO2 evolved and the reaction just sat around. Chromic said - no CO2, no reaction. And both were right, as Chromic started with hexa and Terbium with formaldehyde stabilized by serious amounts of alcohol. Uh. Yes?

Addon: Learned is now that ethyl seems to work better as methylalcohol does. That more alcohol is better - about 1/2 molar of the formaldehyde present or a little bit more. That the addition of about 20% ammoniumchloride is favorable then. That the reactionpathway as outlined at Rhodiums page in the "Methylamine FAQ" doesnt fit to reactions with alcohol present, at least not as primary.
Still to learn: The optimal amounts of alcohol and NH4Cl for best yields and some details of the howto - distill away or siphon out the ethylformate at etc.

ORG


armageddon

  • Guest
didn't find it
« Reply #173 on: August 23, 2004, 02:25:00 PM »
Sorry if I did oversee it for the second time, but I wasn't able to relocate the patent number in the Org.Syn. text, neither in 2) Notes nor in 3) Other preparations or in the references they give.

Only thing referenced to in 2) notes is J.Chem.Soc. 11,850 (1917) (on bottom of page 69).

Now where exactly do they reference to the IG-Farben patent? Just for the sake of knowing I was really wrong... :)  (if this was the case; sorry then Java!)

Greetz A


java

  • Guest
Organic Syntheses :Methylamine HCl....
« Reply #174 on: August 23, 2004, 03:23:00 PM »
All right here is the Organic Syntheses article and in bold red letters the patent Organikum  was referring to...... this is the internet version ....... java

http://www.orgsyn.org/orgsyn/default.asp?formgroup=basenpe_form_group&dataaction=db&dbname=orgsyn




Organic Syntheses, CV 1, 347
METHYLAMINE HYDROCHLORIDE
Submitted by C. S. Marvel and R. L. Jenkins.
Checked by J. B. Conant and F. C. Whidden.
1. Procedure
In a 5-l. round-buttoned flask, fitted with a stopper holding a condenser set for downward distillation and a thermometer which will extend well into the liquid, are placed 4 kg. (3711 cc., 47–53 moles) of technical formaldehyde (35–40 per cent; sp. gr. 1.078 at 20°) (see Note 1 on p. 378) and 2 kg. (37 moles) of technical ammonium chloride. The mixture is heated on the steam bath until no more distillate comes over and then over a flame until the temperature of the solution reaches 104°. The temperature is held at this point until no more distillate comes over (four to six hours). The distillate, which consists of methylal, methyl formate, and water, may be treated as described in (Note 1).
The contents of the reaction flask are cooled to room temperature (Note 2), and the ammonium chloride which separates is filtered off and centrifuged (Note 3). The mother liquor is concentrated on the steam bath under reduced pressure to 2500 cc., and again cooled to room temperature, whereupon a second crop of ammonium chloride is obtained. The total recovery of ammonium chloride up to this point amounts to 780–815 g.

The mother liquor is again concentrated under reduced pressure until crystals begin to form on the surface of the solution (1400–1500 cc.). It is then cooled to room temperature, and a first crop of methylamine hydrochloride, containing some ammonium chloride, is obtained by filtering the cold solution and centrifuging the crystals (Note 3). At this point 625–660 g. of crude product is obtained. The mother liquor is now concentrated under reduced pressure to about 1000 cc. and cooled; a second crop of methylamine hydrochloride (170–190 g.) is then filtered off and centrifuged.

 This crop of crystals is washed with 250 cc. of cold chloroform, filtered, and centrifuged, in order to remove most of the dimethylamine hydrochloride which is present; after the washing with chloroform the product weighs 140–150 g. The original mother liquor is then evaporated under reduced pressure, as far as possible, by heating on a steam bath, and the thick sirupy solution (about 350 cc.) which remains is poured into a beaker and allowed to cool, with occasional stirring, in order to prevent the formation of a solid cake (Note 2). The thick paste so obtained is centrifuged, and the crystals (170–190 g.) are washed with 250 cc. of cold chloroform; the solution is filtered and the crystals are centrifuged, thus yielding 55–65 g. of product. There is no advantage in further concentrating the mother liquor.

The total yield of crude centrifuged methylamine hydrochloride is 830–850 g. This product contains, as impurities, water, ammonium chloride, and some dimethylamine hydrochloride. In order to obtain a pure product, the crude methylamine hydrochloride is recrystallized from absolute alcohol (Note 4). The crude salt is placed in a 5-l. round-bottomed flask fitted with a reflux condenser protected at the top with a calcium chloride tube; 2 l. of absolute alcohol is added and the mixture heated to boiling. After about one-half hour the undissolved material is allowed to settle and the clear solution is poured off. When the alcoholic solution is cooled, methylamine hydrochloride crystallizes out. It is filtered off and centrifuged, and the alcohol used for another extraction.
 The process is repeated until the alcohol dissolves no more of the product (about five extractions are necessary). In the flask 100–150 g. of ammonium chloride remains, making the total recovery of ammonium chloride 850–950 g. The yield of recrystallized methylamine hydrochloride is 600–750 g. (45–51 per cent of the theoretical amount, based on the ammonium chloride used up in the process) (Note 5) and (Note 6).

2. Notes

1. Methylal and sodium formate may be obtained from the first distillate of the main reaction mixture. The crude distillate is placed in a flask fitted with a reflux condenser, and to it is added a solution of 200 g. of sodium hydroxide in 300 cc. of water. The methyl formate is hydrolyzed to sodium formate. The methylal layer is separated, dried over calcium chloride, and distilled. In this way 240–260 g. of methylal, boiling at 37–42°, is obtained. By evaporating the watery portion to dryness, a residue of about 280 g. of crude sodium formate is obtained.

2. The methylamine hydrochloride solutions should be cooled rapidly in order to bring the salt down in small crystals which may be easily purified.

3. Centrifuging the precipitates is the only satisfactory method of drying, as all the products tend to take up water when allowed to stand in the air.

4. Since ammonium chloride is not absolutely insoluble in 100 per cent ethyl alcohol (100 g. dissolve 0.6 g. at 15°), the methylamine hydrochloride purified in the manner described contains appreciable traces of it. A purer product can be prepared by recrystallizing from n-butyl alcohol, in which the solubility of ammonium chloride even at the boiling temperature is negligibly small. Methylamine hydrochloride is somewhat less soluble in this solvent than in ethyl alcohol, but as a rule three extractions carried out at 90–100° with 4–6 parts of fresh butyl alcohol for each extraction result in a substantially complete separation. Since the last traces of the solvent are not readily removed by exposure to air, a solution of the recrystallized material in a small quantity of water should be distilled until free of alcohol, and allowed to crystallize.
An entirely different method for preparing pure methylamine hydrochloride free of ammonium chloride has been described.1 It is based on the fact that when a mixture of methylamine and ammonia reacts with an insufficient quantity of hydrochloric acid the methylamine is preferentially neutralized and the ammonia left free.

5. The literature2 claims a yield of methylamine hydrochloride amounting to 79 per cent of the weight of ammonium chloride used up in the reaction. This figure is probably based on the weight of crude methylamine hydrochloride and not of the recrystallized material.
6. Methylamine can be purified through its benzal derivative, which is distilled and then hydrolyzed by concentrated hydrochloric acid.3 This method has been checked and found satisfactory by one of the editors.
3. Discussion
Methylamine can be prepared by the action of ammonia on methyl iodide,4 methyl chloride,5 dimethyl sulfate,6 methyl p-toluenesulfonate7 and methyl alcohol with a catalyst and at elevated temperatures;8 by the action of bromine and alkali9 and of bleaching powder10 on acetamide; by the action of sodamide on methyl iodide;11 by the reduction of chloropicrin,12 hydrocyanic or ferrocyanic acid,13 hexamethylenetetramine,14 nitromethane,15 methyl nitrite,16 or formaldoxime;17 from acetyl chloride and sodium azide;18 and by the action of formaldehyde on ammonium chloride.19

References and Notes

   1. Sharp and Solomon, J. Chem. Soc. 1477 (1931).
   2. Werner, J. Chem. Soc. 111, 850 (1917).
   3. Sommelet, Compt. rend. 178, 217 (1924).
   4. Hofmann, Ann. 79, 16 (1851).
   5. Vincent and Chappuis, Bull. soc. chim. 45, 499 (1886).
   6. Ephrian and Gurewitsch, Ber. 43, 139 (1910); Denham and Knapp, J. Chem. Soc. 117, 236 (1920).
   7. Rodionov, Bull. soc. chim. (4) 45, 109 (1929).
   8. Davis and Elderfield, J. Am. Chem. Soc. 50, 1786 (1928); E. I. du Pont de Nemours and Co., U. S. pat. 2,017,051 [C. A. 29, 8001 (1935)].
   9. Hofmann, Ber. 15, 765 (1882); François, Compt. rend. 147, 430, 680, 983 (1908).
  10. Bader and Nightingale, U. S. pat. 1,489,380 [C. A. 18, 1836 (1924)].
  11. Chablay, Compt. rend. 156, 328 (1913).
  12. Geisse, Ann. 109, 282 (1859); Wallach and Boehringer, Ann. 184, 51 (1877); Frankland, Challenger, and Nicholls, J. Chem. Soc. 115, 159 (1919).
  13. Mendius, Ann. 121, 139 (1862); Debus, Ann. 128, 201 (1863); Denham, Z. physik. Chem. 72, 674 (1910); Riedel, Ger. pat. 264,528 [Frdl. 11, 110 (1912–14)]; Dreyfus, U. S. pat. 2,072,247 [C. A. 31, 2619 (1937)].
  14. Meister, Lucius, and Brüning, Ger. pat. 73,812 [Frdl. 3, 15 (1890–4)]; Trillat and Fayollat, Bull. soc. chim. (3) 11, 23 (1894); Kundsen, Ger. pat. 143,197 [Frdl. 7, 24 (1902–4)]; Meister, Lucius, and Brüning, Ger. pat. 148,054 [Frdl. 7, 26 (1902–4)]; Isono, J. Pharm. Soc. Japan No. 397, 209 (1915) [C. A. 9, 2232 (1915)].
  15. Pierron, Bull. soc. chim. (3) 21, 783 (1899); Mailhe and Murat, ibid. (4) 7, 954 (1910); Zerewitinov and Ostromisslensky, Ber. 44, 2403 (1911).
  16. Gaudion, Bull. soc. chim. (4) 7, 824 (1910); Ann. chim. phys. (8) 25, 136 (1912).
  17. Takaki and Ueda, J. Pharm. Soc. Japan 58, 276 (1938) [C. A. 32, 5376 (1938)].
  18. Naegeli, Grüntuch and Lendorff, Helv. Chim. Acta 12, 227 (1929).
  19. Brochet and Cambier, Bull. soc. chim. (3) 13, 534 (1895); François, Compt. rend. 147, 429 (1908); Werner, J. Chem. Soc. 111, 848 (1917); Jones and Wheatley, J. Am. Chem. Soc. 40, 1411 (1918); Wietzel and Köhler, Ger. pat. 468,895 [C. A. 23, 846 (1929)].

Appendix
Compounds Referenced (Chemical Abstracts Registry Number)

benzal derivative

chloropicrin

hydrocyanic or ferrocyanic acid

ethyl alcohol, alcohol (64-17-5)

calcium chloride (10043-52-4)

hydrochloric acid (7647-01-0)

Acetamide (60-35-5)

ammonia (7664-41-7)

methyl alcohol (67-56-1)

ammonium chloride (12125-02-9)

sodium hydroxide (1310-73-2)

formaldehyde (630-08-0)

acetyl chloride (75-36-5)

chloroform (67-66-3)

bromine (7726-95-6)

dimethyl sulfate (77-78-1)

methyl chloride (74-87-3)

butyl alcohol, n-butyl alcohol (71-36-3)

Methyl iodide (74-88-4)

Methylamine hydrochloride (593-51-1)

methylal (109-87-5)

methyl formate (107-31-3)

dimethylamine hydrochloride (506-59-2)

sodium formate

methylamine (74-89-5)

hexamethylenetetramine (100-97-0)

Nitromethane (75-52-5)

methyl nitrite (624-91-9)

sodium azide (26628-22-8)

sodamide (7782-92-5)

Methyl p-toluenesulfonate (80-48-8)


armageddon

  • Guest
that's quite puzzling
« Reply #175 on: August 24, 2004, 10:39:00 AM »
Strange - I apologize for doubting what you said, java; but for justifying my doubts I want to mention that the references you cite are not the same as the references in Org.Syn. Vol. 3 (1923) page 70 (downloadable "offline"  version;

http://rzv073.rz.tu-bs.de/bib/dir1/Books/Chembooks/Polytom/orgsyn/OrgSyn-03-1923.djvu

).

Here is what it says on page 70 (references of the methylamine hydrochloride chapter; the first ref is on bottom of page 69, it is J.Chem.Soc. 111, 850 (1917)):

  2. Ber. 18, 1922 (1885)
 3. Jahresb. 1873, 686; Ann. chim. phys. (5) 1, 444 (1874)
 4. Ann. chim. phys. (5), 23; 316 (1881)
 5. Ann. 71, 332 (1849)
 6. Ann. 79, 16 (1851)
 7. Bull. soc. chim. 45, 499 (1886)
 8. Compt. Rend. 48, 344 (1959); Ann. 110, 255 (1859); Jahresb. 1862, 327; Ann.chim.phys. (5), 23, 321 (1881)
 9. Ber. 43, 139 (1910); J. Chem. Soc. 117, 236 (1920)
10. Ber. 8, 458 (1875)
11. Ber. 17, 639 (1884)
12. D.R.P. 64.346, Frdl. 3, 13 (1890-94)
(...)
20. Bull. soc. chim. (3) 13, 534 (1895); Compt. Rend. 147, 429 (1908); J. Chem. Soc. 111, 848 (1917); J. Am. Chem. Soc. 40, 1411 (1918)


Don't want to retype the whole reference list; but in the offline version you linked to, there is no patent DE468.895! As you can see, the list differs completely from the one you provided us with.

The Brochet&Cambier article is referenced to (red letters), but not the IG-Farben patent Orgy posted about...

Now that's strange, isn't it?! (but you see why I doubt what you just said, I guess  :) ) And as the offline version is a scan of a printed one, I suspect that the error is due to the online version being updated, which is impossible with printed texts... ::)

Greetz, A


lugh

  • Guest
Issues With Chronology
« Reply #176 on: August 24, 2004, 11:25:00 AM »

Now that's strange, isn't it?! (but you see why I doubt what you just said, I guess) And as the offline version is a scan of a printed one, I suspect that the error is due to the online version being updated, which is impossible with printed texts...




All that typing when a simple inpection of the dates of publication solves your puzzle, the IG Farben patent was granted a few years after the publication of the volume of Organic Synthesis that was uploaded  ;D  The Collective Volume of Organic Syntheses was published after the IG Farben Patent, thus it was incorporated into the text  ;)




abacus

  • Guest
interesting
« Reply #177 on: August 24, 2004, 01:26:00 PM »
Orgy I think it would be better for you to keep your comments about me within the scope of science.

Lets see, Javas  post from Organic Synthesis.

We have already established that ammonium chloride and formaldehyde can be made by the reaction between hexamine and HCL and water, and that the end result is the well published reaction between the resulting ammonium chloride and formaldehyde.

That is, 1 mole hex + 4 HCL + 6 H2O >>>  4 NH4CL + 6 CH2O

The reaction is then as per Javas post, this involves.

37 moles NH4CL, this can be made from 37/4 = 9.25 moles hexamine, ie 1295g

47-53 moles formaldehyde, this can be made from 47/6 = 7.83 moles hexamine, ie 1096g hexamine (minimum)

So to get to the minimum level of reactants in the synthesis in Organic Synthesis via the hydrolysis of hexamine, we would need at least 1096g hexamine.

Much more if anyone thinks NH4CL is the limiting reactant (I don’t, as already indicated).

The result as published is 600-750g pure methylamine.hcl. 

Exactly the range that I have already stated what my yields were and not surprising as this is basically the procedure that I followed, and I get the same results, except I used hexamine and HCL as my starting ingredients.

You can claim I have shitty yields if you like, but at least I know it’s no worse than the authors of the published synthesis.

Abacus

java

  • Guest
Old stuff ...same topic methylamine syntheses....
« Reply #178 on: August 25, 2004, 12:37:00 AM »
Going through the archives looking for gems I ran into this thread that may be of some historical or enlighting information.......java

Post 108244

(smokemouth: "Methylamine - better yields - Rhodium", Novel Discourse)



armageddon

  • Guest
ever did read a chemistry textbook? *lol*
« Reply #179 on: August 25, 2004, 03:14:00 AM »
Abacus, you wrote:

37 moles NH4CL, this can be made from 37/4 = 9.25 moles hexamine, ie 1295g

47-53 moles formaldehyde, this can be made from 47/6 = 7.83 moles hexamine, ie 1096g hexamine (minimum)

So to get to the minimum level of reactants in the synthesis in Organic Synthesis via the hydrolysis of hexamine, we would need at least 1096g hexamine.

Much more if anyone thinks NH4CL is the limiting reactant (I don’t, as already indicated).


Wrong (of course). To get the minimum amount of reactands used by the Org.Syn. method, one would need 1295g - as with 1096g one would only get 31.3 mol NH4Cl instead of 37 mol, which is the smallest amount "allowed". And you said "level of reactands", so I assume you don't want to change ratios!? So the only solution to achieve same ratio with minimum HCHO but still same ratio of reactands when you use hexamine ís: add some NH4Cl to the hex/HCl/EtOH!

And as you have noticed that the amount of HCHO is variable; why do you think it is the limiting reactand? Usually non-limiting reactands can be added in excess without any difference, whereas the limiting reactand becomes non-limiting reagent when a certain amount is reached...

And the factor "limiting reactand" wasn't invented by me or Organikum, dumbass: its a commonly known definition for the reactand limiting the reaction, and this is always the reagent of which you have the smallest amount present - and because its lack of availability, it limits the overall reaction, whereas all other reagents are present in excess (compared to the limiting reactand) and therefore they don't limit the yield. And that's it. No considering or believing, just learn by heart and know it.

Your yields may be fine for the Vogel's procedure; they are nevertheless shitty when seen in comparison with the yields other bees were able to obtain with the IG-Farben patent. Come on, open a new thread about how cool your yields are when using standard methods - then you have no need to distract this thread (which is NOT about the Vogel's method, nor about comparing it with other methods... :) )

One last note: I wonder why you start thinking about it only when Java posts it; I really translated exactly the same procedure/method from the "Gattermann", and nobody seems to have noticed it in retrospect!? (

Post 514413

(armageddon: "NH4Cl removal / leuckart methylamine", Methods Discourse)


Oh and about yield differences: ever thought about the fact that Org.Syn. states the yield as molar percent of the NH4Cl being used up, whereas other bees here at the hive stick to the standard non-fake yield calculation method and state their yields as molar percent of the NH4Cl that they put into the reaction. Of course this means that the Org.Syn. yield is in fact even lower, calculated from the NH4Cl used by the chemist (and not "used up" by any mechanism!). for example: 100g NH4Cl present, 30g are isolated unchanged. The chemist gets 35g of the remainder to react, giving some ??g CH3NH3Cl, and claims 50% yield, calculated from the 70g that were "used up in the process". In fact, he gets to react only 35g out of 100g starting material he used, so his yield is in fact just 35%. See what I mean?

But of course it sounds better if he first checks how much starting material remains unchanged and then calculates how much of the remaining compound forms the desired product and how much of it gives rise to side products, and calculates his yield on that basis. Especially when he is about to publish in a chemistry journal! Oh, other common cheat when publishing: claiming high yields in the first line of the abstract, but telling on the last page that you calculated the yield from the amount of dang expensive specialty catalyst you used - and that the ratio reactand/catalyst is something like 50000:1, so to say that 90% of the few mmol of your catalyst reacted successfully on several mol of starting compound, giving 0.9 times a few mmol of product. Usually nobody realizes the fraud.  :P




Java: Nice thread, they had the same problems (not knowing about how the reaction works in detail, just experimenting with adding EtOH or changing ratios of NH4Cl/HCHO) - but someone in that old thread said EtOH would lower yield...
This is true; but only if the yield is calculated from HCHO, which is not the limiting reactand  :P  - as the alcohol should ideally be added in a 1:2 ratio to the aldehyde - but wait! It happens that I have the patent lying in front of me; and the first lines are:

"It is known that the corresponding salts of mono- and dimethylamine can be obtained by treating ammonium salts with formaldehyde or paraformaldehyde. Usually only a small part of the formaldehyde is involved in forming the amine; whereas a great part of the aldehyde is transformed into carboxylic acid. It has now been found that during the production of mono- or dimethylamine (or their salts) through action of formaldehyde (or formaldehyde releasing compounds) on ammonium salts, the formation of carboxylic acid can be mostly if not completely avoided if alcohol is added to the reaction/reactands, preferably in a ratio of 1 (or more) mol alcohol per 2 mol aldehyde ".

- Now that sounds exactly the other way round?!? Like alcohol would cause ~50% of the formaldehyde to react, in contrast to a smaller part reacting when no alc is used? Reason: two partial reactions happen in this rxn; and through adjusting the rate of the one, the other gains benefit - no idea about how this could look like though.

But I think this is meant, because the somewhat spontaneous thermal decomposition of HCOOH (sonds dangerous, eh?  :) ) to CO2 (less dangerous then..) is made controllable through adjusting the rate of esterification, which replaces the (uncontrolled) plain oxidation to CO2 with subsequent diMeAm formation, in case some additonal EtOH is used.
Some kind of alcohol buffered reaction between HCHO and NH4Cl if you want to call it that way - just like when acids aren't "agressive" anymore when buffered, because there is always some buffer ion for the H+ to stick to.
And exactly this is what the alcohol brings about too - preventing an unwanted reducing agent from doing bad things, by intercepting its harmful dissociated ions. And this means a more controlled reaction, and this in turn means the molecules are forced to find their counterparts in this dance, therefore less HCHO remains unchanged. (?) Same principle behind it, isn't it?

Just my thoughts. (think I need some sleep  :P )

A


Organikum

  • Guest
What smokemouth wrote and Rhodium wrote this...
« Reply #180 on: August 25, 2004, 09:16:00 AM »
What smokemouth wrote and Rhodium wrote this also in his FAQ, is of course right. Hexamine, paraformaldehyde - no alcohol present, the reaction proceeds through a pathway where serious amounts of formaldehyde are transformed into CO2 and lost for the reaction. Therefor the formaldehyde is the limiting reagent here, adding some (para)formaldehydewill give better yields but this and the temperatures (109°C) will form more di-methylamine.

Reactions with (ethyl)alcohol added form, so done right no CO2 as stated in the patent and proven by experiment. The loss on formaldehyde is then limited by the amount of alcohol present. The addition of ammoniumchloride presents an good excess of this and suppresses together with the lower temperatures the formation of di-methylamine almost completely.

There is no contradiction, we talk about two different reactions, the reaction of commercial formaldehyde containing alcohol represents probably a mixture of them. Ethylalcohol is preferable over methylalcohol.

I hope this clears things up.
ORG

PS: I am not going further into wild speculations on what exactly happens. I merely presented a patent which was referenced in one of the leading journals of or. chemistry, I had good success in reproducing procedure and claims of the patent and others too. I posted a picture where it can be seen how methylamine looks like freshly recrystalled from IPA. Most pictures I had seen looked somehow like a lot of ammoniumchloride to me.  :(  
I will do some work on the workup soon - it seems to be not trivial for many here and indeed the extraction of methylamine.HCl from a lot of ammoniumchloride is not trivial - time, heat and stirring etc., but thats no problem of this synthesis I presented. If one has problems to get the workup going as described by me, use the one from Vogel´s or from Org-Synth.
There are several methods on howto do the synth and the workup available - dont blame others if you have problems but try another way which may suit you better.


armageddon

  • Guest
practical info
« Reply #181 on: August 26, 2004, 02:15:00 AM »
Of course I could be wrong; but it could very well be that the following is true, when seen in comparison with my observations, no?

When using the following ratios, the IG-Farben reaction was a clear solution at the beginning; upon heating, a white fluffy precipitate appeared (NH4Cl) and disappeared when the rxn temperature surpassed 47°C. This IMO means that the amount of water is at the minimum of what is possible to get the reaction still going - enough to dissolve everything in the beginning, but as soon as any EtCOOH is formed, the solution gets not only milky but the solubility of NH4Cl suddenly gets reduced, because EtOH (low solubility of NH4Cl) is replaced by EtCOOH (NH4Cl insoluble) and therefore the overall solubility of NH4Cl in the reaction is lowered - and as soon as the temp. is high enough to cause partial evaporation of EtCOOH (accompanied by rxn becoming clear again), the solubility of NH4Cl rises again (white precipitate disappears again).


Now here are the ratios:


200g hexamine
24.5g NH4Cl
200ml H20
220ml EtOH
675ml HCl 31.45% (and a pinch to compensate for evap losses during addition)

(As said, I think that this nears the absolute minimum amount H20 that can be used sucessfully, maybe even less works too - but remember Placebo who got bad yields without any water...)


Now here's another variation, adapted to fit abacus'/placebos complains about molar ratios being detrimental  ;) :

Chill everything, mix in said order, place in oil bath, set up for distillation and gradually apply heat over 3h *slowly*, until 75-80°C rxn temp. are reached and formate starts to come over (with steam temp no higher than 50°C!), then heat to 95°C *very* slowly over the course of the next three hours while watching for those small bubbles starting directly below surface instead of big ones arising from the flask bottom/stirbar (leuckart-like!) and collect almost pure EtCOOH which, upon washing with dilute brine and drying, amounts to ~165ml; meaning a NH4Cl/HCHO ratio of 1 to 1.53 after esterification - calculate it for yourself...  :)
- oh, and in case I had used more additional NH4Cl like Organikum did originally, the molar ratio after partial esterification, i.e. the ratio of formaldehyde:NH4Cl reacting would be 1.42:1 - isn't this exactly the same ratio like in Vogel's?

So if it is true that ethanol mainly serves the purpose of accelerating the reaction (thus enabling for less formaldehyde being necessary - without alc, the rxn is driven by excess HCHO), then the purpose behind adding NH4Cl would be to bring the molar ratio of "products used up in the reaction" to the same as in Vogel's...(again you can recalculate that yourself if u want)

(SHIT! I broke a long thermometer again!! This time 250°C/30cm measuring depth  >:(  :(  >:(  - seems like methylamine via EtOH-leuckart does hurt my thermometer collection very bad...)

Greetz A


armageddon

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*real* brain food
« Reply #182 on: August 27, 2004, 07:57:00 AM »
OK I think I made a mistake when doing the calculations for my above post... sorry!

Here's the correction to it:

200g hexamine = 1.42 mol => 4 * 1.42 mol NH4Cl + 6 * 1.42 mol HCHO
24.5g NH4Cl = 0.46 mol => total amount of NH4Cl is 5.68 + 0.46 = 6.12 mol

 this means 6.12 mol NH4Cl and 8.52 mol HCHO.
 now I got ~165ml C2H5OOCH from this; meaning 2.04 mol.
 So I can be sure that when EtCOOH is collected, 2.04 mol HCHO will have reacted.
 Now let's calculate the amount of HCHO being still available:

8.52 - 2.04 => 6.48 mol HCHO

And now the ratio between NH4Cl and HCHO after esterification:

6.48 mol / 6.12 mol = 1.06 => ratio is roughly 1:1, slight excess HCHO - but maybe there were losses during purifying the EtOOCH; then the ratio would be exactly 1:1...

Now for comparison reasons the ratio before esterification:

8.52 / 6.12 = 1.39 => ratio roughly 1.4:1, excess aldehyde - but of course the excess gets smaller when more NH4Cl is added; and numerous posts show that yields are quite good when doing so...




Now as you can see, the alcohol brings an excess of HCHO (how big excess depends on the amount of additonal NH4Cl) down to an equimolar amount compared to NH4Cl, while allowing for a slow temperature rise over a long time, in contrast to the standard method, involving brute heating to 105° from beginning on.

In other words: alcohol accelerates the reaction by pushing the equilibrium towards products - no big excess HCHO necessary to get things going! (at least not 50% excess like with the old hex method, but rather 1 : 1.4 like with the Org.Syn. method, which uses methanolic formaline.. Or even smaller excess, if more NH4Cl is used - just watch out for solubility problems  :) )
Alcohol further could avoid overalkylation through binding any free formic acid by esterification (at least the nitrous acid test for sec amines was negative for me), and, lemme rephrase: this reaction is a leuckart reductive methylation! (not my idea but some PhD's!) ..and with leuckart rxns, better results are obtained with slowly rising the temperature over a long time, not by heating with full power for x hours!

Think about it.


Greetz, A


Organikum

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If it makes you and some PhDs happy than the...
« Reply #183 on: August 27, 2004, 11:41:00 AM »
If it makes you and some PhDs happy than the reaction is a Leuckard. Or wet socks or nosedriller or whatever you like. It doesnt really matter, same as solubility of the NH4Cl doesnt matter as this is stated in the patent and was posted by me before: Not all NH4Cl goes into solution at once but dissolves whilst heating up/during the reaction. The importance of heating up SLOWLY was also emphasized by me already.

This thread is running in circles now, whatta nonsense and confusion.

And now dont come and say it does matter as because the right conditions were already presented without any mystic reactionpathway innards readings it doesnt. Period. You dont have to be a hen to know how to make a tasty omelette.

Ever heard about: "The urge to express oneself lengthy and self-opinionated under the influence" ? Yes? Read part two: "The strong wish not having oneself expressed lengthy and self-opinionated AFTER the influence is over".

Not to piss you off armer-geddon  ;)  I share my most private experiences here with you...  ;D .

COOL DOWN!

ORG


armageddon

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OK, no more experimental data then
« Reply #184 on: August 27, 2004, 05:25:00 PM »
You dont have to be a hen to know how to make a tasty omelette.

:)  - obviously some bees would like to be a chicken though; I just thought I could supply them with info on how to become one...  ;D


Not all NH4Cl goes into solution at once but dissolves whilst heating up/during the reaction

And sometimes, it goes completely into solution at once, but partly precipitates upon applying heat...


But you're right; the outlines for a successfull procedure were given long before in this thread - I just wanted to throw into discussion a few new thoughts about ratios, molarities etc. to provide thought food to those trying to find a mechanism that explains why alcohol is helpful (some bees are not content with knowing that it works nice but also want to know why it does - or maybe better said they want to know why they don't get good results?)

I could still think of *several* ways of varying the rxn parameters to learn more about possible mechanisms and stuff; but as you said, the outlines for a successful application of the patent were given, and it is up to everyone to make his own guesses about why it works the way it does.

Just thought I could help in doing so by providing more data (its always better to start from experimental data rather than from speculations when trying to find out about rxn mechanisms  :) ) - but as you think it isn't necessary...



Not to piss you off armer-geddon  I share my most private experiences here with you... .

COOL DOWN!


Probably you're right with that as well  :)  - well supervising a rxn for >12h isn't that exciting; so I tried to get some diversion by bragging about how it could possibly work - I still think my theory has some right points in it...




About the workup - I advise to use the following procedure:

after concentrating the remainder (orange syrup) to dryness and letting it cool/solidify, add small amount of IPA, crush up solid cake and decant IPA (save it). This contains methylamine HCl and most of the orange impurities.
Now add some 300ml IPA (for 200g hexamine used in the beginning) and reflux it for 30 minutes, then decant the IPA into other beaker and let slowly let cool to -7°C, filter precipitated MeAm crystals, rinse them with acetone, chloroform and again acetone, let dry for a short time and place in sealable container. The washes will form a 2-layer system in filtering flask - clear upper layer acetone and red bottom layer CHCl3.
Now place the mother liquor (without the washes!) into your flask with MeAm/NH4Cl-cake again, and reflux again for 30 minutes, then repeat the decanting/cooling/filtering/washing and add the so obtained crystals to the first crop. Repeat this 4-5x with same mother liquor, then extract one last time with small amount of fresh IPA.

Combine the small first, dirty extract with the remaining mother liquor and final IPA rinse and concentrate under vacuum, then cool, filter and rinse with tone/ChCl3. Recrystallize from ~250ml boiling IPA per 50g of raw product to get clear, colorless crystals of good purity.

The good thing is that you only have to deal with dirt and byproducts (by thoroughly washing/crushing up inside funnel) when crystallizing the contents of the first small extraction; the following xtractions (using same mother liquor) will contain substantially less impurities and result in clean crystallization of the product - but will account for the major amount of isolated MeAm...

A


armageddon

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again couldn't resist...
« Reply #185 on: August 28, 2004, 09:28:00 PM »
To those considering it being of interest - old thread, same topic:


"I know that the following reactions occur to produce the methylamine:

Hexamine + 4HCl __> 4NH4Cl + 6CH2O

CH2O + NH4Cl __> CH2NH + H2O + HCl

CH2NH + CH2O + HCl __> CH3NH3Cl + HCO2H

Now I know that CO2 is produced from the formic acid, but how?  Something must be reduced in order to oxidize the formic acid to CO2.  What is being reduced?  Another molecule of formic acid to formaldehyde?  The imine?

It seems that the sum of the last two reactions is overall reversible.  Therefore, formic acid must be removed to drive it to completion.  The most probable mechanism is that two molecules of formic acid react to form formaldehyde and carbonic acid.  This reaction is probably also reversible.  In order to drive the synthesis to completion, the carbonic acid must be removed by dehydration to CO2.  This would mean that the lower the pressure that the reaction runs under, the faster it will proceed.  This also means that theoretically, 1 mole of hexamine contains exactly the right composition to produce 4 mol of methylamine and 2 mol of CO2, with no excess of any reactant.


(

Post 374164 (missing)

(lab_bitch: "Stoichiometry of Methylamine Synth from Hexamine", Chemistry Discourse)







To those having access to libraries:

E. A. Werner, Methylation by Means of Formaldehyde. Part I., J. Chem. Soc., pp844-853 (1917)

H. I. Jones, The Preparation of Methylamine, J. Am. Chem. Soc.(?), pp1411-1515 (1918)







..and even the esterification concept isn't new - but its advantages wheren't realized back then, as the common practice was/is to push the reaction equilibrium to the right side through CO2 removal, rather than formic removal:

"The reason that your reference does not mention CO2 evolution probably arises from the fact that the procedure uses formalin, which contains ~10% methanol and removes the formic acid via its methyl ester before it can decompose."

(

Post 374511 (missing)

(terbium: "No gas is evolved.", Chemistry Discourse)



;D

A


LaBTop

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Stop whining.
« Reply #186 on: September 13, 2004, 04:56:00 PM »
1. Nobody owes any thread or post in all these forums, every member decides by his own free will to come here and to contribute. So who are you to say this thread is dead?
(Anyone of you out there perhaps think this is YOUR playground, but we think it's OUR playground, which means all of us, and we are not the easy intimidated kind of people.
We particularly don't like to be rapped over the knuckles about the way we moderate. So thread carefully around here. :o )
Btw, I just saw that the members can't see WHO rates them.  :) . You would like to know, but I won't tell,  ;) . Ask around if curious.

2. The subject of this thread has been beaten all over the bushes, it's time to make room for some eventual additional practical input.
About the simple addition of an alcohol to a just as simple reaction.
Which has been discussed ad infinitum by now.

3. I assure you all that the more experienced members here are the ones who have been ROTFL, reading all this nitpicking about some theoretical wanking, after the first good posts.

Just imagine you are a nervous, underground chemist or cook ( a big part of this board is meant for them!), who needs the least possible attention from his surrounding neighbours, let alone the law.
Ofcourse that person will choose the Abolt or BondDoubleBond beaker way, but will do it in f.ex. a bottle in a warm water or oil bath, so the smelly byproducts can be lead through a hose to 2 washbotles in line, in a box outside a window even; the first one bigger and empty, the last one smaller and filled 3/4 with tap water. That way you can eat your breakfast beside the ongoing reaction, and won't smell a thing. (see btw my red remarks in the Biffman post)
No suspicious glassware, nothing out of the ordinary.

And a professional would ofcourse do it his/her way, and not bother at all to ask you backyard rocket scientists how to do things, but use TFSE, books, the WWW and his/her logic. LT/


armageddon

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sick and tired
« Reply #187 on: September 13, 2004, 05:43:00 PM »
I surely don't want to know who gives out those unrealistic and offensive ratings out of personal dislike.

Nor do I whine.

I just see that some bees are allowed to openly throw with dirt in this thread, while others (although nobody gives 'em a scientifically acceptable explanation on why) are flamed for their efforts and aren't allowed to post defensive statements although not offending anyone.

I further don't see what practical experience could be added anymore, everything important was said in the first few posts as LT said. (>220 posts, about one "simple rxn with simple EtOH addition")

And I want to remark that the "BondDoubleBond beaker way" doesn't exist. This shit is solely abolts idea. And beakers are not the type of vessel if you want to stay undetected. They are open vessels. And your neighbours won't care if you own real glassware or baking dishes, they will just detect eventual smells. More likely if beakers are used.


Left to say:

Big "FUCK YOU" to the moderators, I'm off.....

Greetz from your "backyard rocket scientist" being not able of doing scientific research and only posting insignificant stuff...


abolt

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This shit is solely abolts idea.
« Reply #188 on: September 14, 2004, 08:50:00 AM »
This shit is solely abolts idea. And beakers are not the type of vessel if you want to stay undetected. They are open vessels. And your neighbours won't care if you own real glassware or baking dishes, they will just detect eventual smells. More likely if beakers are used.

Well.........the thread is titled "for the vindication of elusius", a guy who told us all years ago that Methylamine could be made easily, with simple equipment.

For those of you who are challenged with the english language, I will provide the meaning of the word "vindication":

vindication (noun) - The defense, such as evidence or argument, that serves to justify a claim or deed.

The "Methylamine in a beaker" post merely "vindicated" the earlier work of Elusius. ;)

Other comments Deleted, out of respect for LT.


LaBTop

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Abolt,
« Reply #189 on: September 14, 2004, 01:57:00 PM »
Why must you insult him this way?
To my feeling, he's trying hard to defend his particular view on the subject, but both of you slipped off to namecalling.
This is totally unnescessairy.
The argument one uses, doesn't loose any importance in the eyes of the beholders, without all the insults.

This was the last time we warned you all not to use personal insults in the chemistry forums.
Any one caught from now on, will get banned for a few days, to cool off.
And my last banning spray is years ago, so save me from that macho behavior, pretty please. LT/


Organikum

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Why "vindication" ?
« Reply #190 on: September 14, 2004, 03:27:00 PM »
I named this thread "For the vindication of Eleusis" because it was told that the addition of alcohol would be absolutely wrong. See Rhodiums page the "Methylamine FAQ" for example.

The patent and the following trials showed that this is not true, therefor the naming.
I disapprove the use of open beakers for this as the fumes are
- dangerous
- smelly
- unhealthy

This was already cleared at start of this thread in a short discussion with Terbium.

LaBTop, you will rarely find me critisizing rating in the chemistry forums and this here was and will stay an exception. If you dont like it - I cant help it. Of course I dont own this thread, nobody does, but nevertheless I felt a certain responsibility for it as I had started it and I believed it contained something useful for many here. Is this wrong? I doubt it.

I am with Terbium:
"Baseline doesnt exist"
Thats sad. What about reestablishing one?
Just a suggestion.

regards
ORG


armageddon

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-
« Reply #191 on: September 14, 2004, 06:50:00 PM »