Author Topic: For the vindication of Eleusis - Methylamine  (Read 22796 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

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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

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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

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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

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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

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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

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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

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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

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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.