Sciencemadness Discussion Board

looking for a good proceedure for methylamine

LD5050 - 10-3-2017 at 11:45

I just found a bunch of hexamine fuel tabs in some old camping equipment I have and I would like to make some methylamine from it. Does anyone know of where I can find a good write-up ? I have found a few but they seem to contradict each other. Is there a tried and true method floating around anywhere?

gluon47 - 10-3-2017 at 12:54

I've always used the write up on erowid to prepare methylamine (link), just substituting their crude makeshift equipment for proper laboratory glassware.

It's poorly written and layed out, but has always worked just fine for me.

LD5050 - 10-3-2017 at 14:18

Yes I saw this one but thought I couldn't trust it because how it was written and the equipment used. If I'm going to make it I would like to at least have something pretty pure if I'm going to take the time and make it. You said you got good results tho?

JJay - 10-3-2017 at 14:31

Everyone knows that it is impossible to make methylamine. Didn't you watch Breaking Bad? :P

I have not personally made methylamine and have no plans to, but there are dozens of procedures on the various drug-making sites on how to do it. I remember noticing that in the procedures I read, people using procedures involving hexamine paid much less attention to temperature control than people using more more formal procedures involving formaldehyde and ammonium chloride. I'm pretty sure that this is due to laziness rather than any good reason and that temperature control is critical for controlling the degree of methylation, but I can't say for sure.

Tsjerk - 10-3-2017 at 14:39

I can confirm temp control is very important, plus a lot of patience to evaporate enough water while you have no clue how far too go. I didn't like the reaction at all and gave up.

Melgar - 10-3-2017 at 16:37

The trouble with using hexamine is that you also get dimethylamine and trimethylamine, it's slow, and you end up with methylamine hydrochloride in solution, which isn't necessarily the form that you want. Aluminum/galinstan alloy in nitromethane mixed with a suitable hydrogen donor (water + methanol, usually) will reduce the nitromethane to methylamine gas pretty easily. You just need to use a suck-back prevention device, and possibly a desiccant.

edit: for the record, the only reason I've done this so much is to test the reducing power of this aluminum alloy I've been experimenting with, and both nitromethane and methylamine have very distinctive odors.

[Edited on 3/11/17 by Melgar]

LD5050 - 10-3-2017 at 16:55

Since the hexamine method doesn't produce pure methylamine and has many side products could one just maybe drip a NaOH solution into the methylamine/side product mix and drive off the gas into water and then acidify the water ( I think) to form pure methylamine HCL?

Melgar - 10-3-2017 at 18:31

No. The side products are volatile amines also.

LD5050 - 10-3-2017 at 18:53

If I go with the hexamine route I can recrystallize with iso propyl alcohol and wash with chloroform to obtain pretty pure methylamine?

Tsjerk - 10-3-2017 at 18:59

Both formaldehyde and ammonium chloride should be easy to get, I would go that way.

For the heating I would try to make something automated that you don't have to babysit and can not overheat, otherwise, as said, you will need a lot of patience with the constant danger of burning your reaction mixture.

Maybe that frying pan suggested in the link isn't that bad of an idea, set it to 110 and wait. According to www.sigmaaldrich.com/catalog/product/aldrich/m0505 methylamine hydrochloride doesn't decompose way beyond that, but you don't want to evaporate your formaldehyde. I would put something aircooled column-like over the outlet, to condense as much formaldehyde back into the pot. https://www.tedpella.com/msds_html/18508msd.htm

LD5050 - 10-3-2017 at 19:35

Is there a way to get the formaldehyde out of the campa chem? It says it is a mix of MeOH and formaldehyde but I cant find the percentages I'm having trouble finding the MSDS on it. It's a liquid and a really dark blue color. I picked it up one day randomly because I remembered reading some people use to extract the formaldehyde from it but I can find much on it anymore.

JJay - 10-3-2017 at 19:41

I've been meaning to try getting formaldehyde out of Campa Chem but have never gotten around to it.

I think you could evaporate the liquid off at low temperature to produce paraformaldehyde and then heat it to produce formaldehyde gas. There is also a variety of Campa Chem that consists of paraformaldehyde and some dyes.

Formaldehyde solutions are widely used by non-chemists for things like preserving biological specimens, so they are easy to buy.

AvBaeyer - 10-3-2017 at 19:44


You can easily hydrolyze N-methylformamide with 6M hydrochloric acid to get N-methylamine hydrochloride. Though N-methylformamide may not be cheap, neither is time and failed touchy preps from hexamine. I have posted somewhere on the site the hydrolysis of N,N-dimethylformamide to obtain dimethylamine hydrochloride.

Here is one current listing for methylformamide:
http://www.ebay.com/itm/N-Methylformamide-99-7-for-proteomic...

AvB

cubalibre - 11-3-2017 at 05:04

This topic was extensively discussed on this forum.
See https://www.sciencemadness.org/whisper/viewthread.php?tid=12...

It however lacks to discuss the risks involved when mixing formaldehyde and HCl i.e. read: https://www.ncbi.nlm.nih.gov/pubmed/6951075
Maybe hydrolysis should be done using H2SO4 instead of HCl to prevent forming BCME.

LD5050 - 11-3-2017 at 06:36

What about making ammonium methylsulfate from sulfamic acid and heating it to high temperature? This makes methylamine but does it also create dimethylamine? I guess I want to try to make as little dimethyamine as possible seeing as how this is the hardest to remove from the final product.

Melgar - 11-3-2017 at 15:19

If you have hexamine, that's a condensation product between ammonia and formaldehyde, so putting it in hydrochloric acid will hydrolyze it back. You just need to have enough acid to neutralize the ammonia that's evolved. The acid also catalyzes the Cannizzaro reaction with formaldehyde, if I remember correctly, and produces formic acid, which is an effective reducing agent for the imine that's being formed.

Formaldehyde can be obtained easily from trioxane, paraformaldehyde, even the plastic polyoxymethylene, just by heating in acid.

RebekAbrin - 12-3-2017 at 05:07

There's a way to synthesize via ammonia chloride reacts with formaldehyde.You could find it on the book SECRETS OF METHAMPHETAMINE MANUFACTURE by uncle fester,and also you can find this book in PDF on google.:)

RebekAbrin - 12-3-2017 at 05:14

By the way,the product made by this way is the hydrochloride salt of methylamine,if you wanna make the methylamine gas then add sodium hydroxide solution to the methylamine hydrochloride.And if you wanna make methylamine solution,thus pass the gas into water with a pipe.

Tsjerk - 12-3-2017 at 09:43

Thank you very much for that elaboration RebekAbrin...

On topic of para-formaldehyde as an intermediate for the purification of formaldehyde:

If you evaporate everything low boiling, which is there to prevent polymerization (methanol), and than freeze and thaw a couple of times you will get the solid para-formaldehyde. There is no need to make formaldehyde gas from this except if you really need it as a gas, just boiling in water will get it dissolved again.

You can even use para-formaldehyde a "pure" form of formaldehyde, as it will form free formaldehyde in any heated reaction.

PirateDocBrown - 12-3-2017 at 19:00

Just steal some from a passing train.

Seriously, I have made it myself from sulfamic acid, which is cheap and widely available. You will always get some dimethylamine as a side product, no matter which route you take.

Melgar - 13-3-2017 at 22:48

Quote: Originally posted by PirateDocBrown  
You will always get some dimethylamine as a side product, no matter which route you take.

Not if you reduce nitromethane. :P

PirateDocBrown - 13-3-2017 at 23:40

Quote: Originally posted by Melgar  
Quote: Originally posted by PirateDocBrown  
You will always get some dimethylamine as a side product, no matter which route you take.

Not if you reduce nitromethane. :P


That's a good point, but what would you use as a reducing agent?

Melgar - 14-3-2017 at 05:39

Quote: Originally posted by PirateDocBrown  

That's a good point, but what would you use as a reducing agent?

Aluminum, activated with a metal or alloy that's liquid at room temperature. Mercury works, of course, but I use a eutectic gallium/indium alloy. You generally need to add methanol, because it allows mixing with nitromethane, and some water as a hydrogen donor.

JJay - 14-3-2017 at 23:12



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PirateDocBrown - 17-3-2017 at 22:21

Quote: Originally posted by Melgar  
Quote: Originally posted by PirateDocBrown  

That's a good point, but what would you use as a reducing agent?

Aluminum, activated with a metal or alloy that's liquid at room temperature. Mercury works, of course, but I use a eutectic gallium/indium alloy. You generally need to add methanol, because it allows mixing with nitromethane, and some water as a hydrogen donor.


That's very clever!

I've also gone the NH4Cl/CH2O route, in a steam distillation setup, so the water carries over the MeNH2. Of the two, I'd have to say I much prefer the reforming of sulfamic acid via ammonium methylsulfate.

Corrosive Joeseph - 17-3-2017 at 22:32

RoundBottoms re-post of "Chromic's Methylamine HCl" always looked very doable as well...............

https://www.thevespiary.org/talk/index.php?PHPSESSID=738fea2...


/CJ

Melgar - 18-3-2017 at 23:00

Quote: Originally posted by PirateDocBrown  
That's very clever!

I've also gone the NH4Cl/CH2O route, in a steam distillation setup, so the water carries over the MeNH2. Of the two, I'd have to say I much prefer the reforming of sulfamic acid via ammonium methylsulfate.

Even better: if someone needed methylamine for (heaven forbid) a reductive amination, they could do this reaction in one pot, with an excess of methanol or ethanol, then as soon as the reaction started smelling of methylamine, add the substrate that needed to be aminated. This could work with other nitro compounds as well, I'd imagine.

byko3y - 7-11-2017 at 23:35

Any1 have idea how to make anhydrous MeNH2 gas in good yield starting from anhydrous MeNH3Cl or some other salt? I didn't expect the task to be so hard, but that's true: you can't just add NaOH, heat the solution and expect the yield to be high - most of the MeNH2 will be left behind in the NaOH solution.
Any ideas?

Melgar - 8-11-2017 at 06:00

MeNH2 is very water-soluble, which is the problem. Best advice I can give is to use KOH instead of NaOH. It's a stronger base, and is better at forcing solutes out of an aqueous solution. Extract with ether or something, then dry, if you need it anhydrous.

KOH is also better at getting an organic layer to form when NaOH can't do it.

I get the feeling that the formaldehyde + NH3 + HCl route is basically a combination of the Cannizzaro reaction and the Leuckart reaction. If you didn't have much formaldehyde and did have formic acid, the Cannizzaro reaction could perhaps be skipped, even, making for a faster reaction. Lowering the pH would speed the reaction up too, since it wouldn't depend on the Cannizzaro reaction for formic acid. Assuming my logic is correct, anyway.