Author Topic: For the vindication of Eleusis - Methylamine  (Read 56807 times)

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Organikum

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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

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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

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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

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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

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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

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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

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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)