Sciencemadness Discussion Board

Methylamine problem

carpen - 8-1-2014 at 03:30

Hi.

I'm a bit concerned due to a synthesis, that requires "Methylamine GAS". I know how to synthesize Methylamine.HCl, but how do one make Methylamine gas?

Best regards, carpen

turd - 8-1-2014 at 04:01

The principle is simple: you react MeNH2.HCl with a base, use a drying agent to expel the MeNH2 gas from the resulting aqueous solution, dry the gas and lead it into your stirred reaction/solvent taking care of suckback.

But since you have to ask such questions, you are not able to handle MeNH2 and there is no point in looking up the details. Besides, you are too inconsiderate to follow forum guidelines and too lazy to search the literature, so why should anybody bother to help you?

woelen - 8-1-2014 at 05:29

Mix solid methylamine.HCl with solid NaOH and add a few drops of water. A fairly vigorous reaction starts and gaseous CH3NH2 escapes from the mix. At the end of the reaction you need some heating. Be careful with this reaction, quite a lot of heat is produced and if it is done with too large quantities of reagents, then you get a lot of gas at once, running the risk of overpressure in your apparatus.

Lead the gas through a column with dry NaOH to absorb any water vapor which goes with the gas as well. Do not use CaCl2 as drying agent, because that absorbs CH3NH2 as well.

The chemical reaction itself is straightforward and very easy. The generation of a nice constant stream of CH3NH2 is not easy at all though, this requires some intelligent thought and engineering of your setup.

carpen - 8-1-2014 at 11:50

Thank you so much for your answer. Another question: If i use 10kg of solid Methylamine.hcl, how much solid NaOH, and water, should i use?

Appreciate it, thanks!

DraconicAcid - 8-1-2014 at 11:58

10 kg of methylamine hydrochloride is 148 moles of CH3NH3Cl, and will require 148 moles (5.9 kg) of sodium hydroxide. Please note that this will produce 148 moles of methylamine, which will occupy over three thousand litres at STP. You would have to be very, very careful to avoid overpressuring your system.

Why on earth would you want to deal with such large quantities when you have no idea what you're doing?

carpen - 8-1-2014 at 12:44

Quote: Originally posted by DraconicAcid  
10 kg of methylamine hydrochloride is 148 moles of CH3NH3Cl, and will require 148 moles (5.9 kg) of sodium hydroxide. Please note that this will produce 148 moles of methylamine, which will occupy over three thousand litres at STP. You would have to be very, very careful to avoid overpressuring your system.

Why on earth would you want to deal with such large quantities when you have no idea what you're doing?


Thank you! My question was only hypothetical, and i'm curious. Of course, I won't use 10kg of MA at the same time.

woelen - 8-1-2014 at 13:21

The use of 10 kg is insane. You definitely need some control mechanism in order to obtain a constant stream of methyl amine. If you simply mix the chemicals in larger than gram quantities and then add a little water, then you at once produce a LOT of gas and whatever reaction you do with the gas, it will not be capable of absorbing all that gas at once and you certainly will have overpressure in your system with the risk of blowing up the system.

carpen - 8-1-2014 at 13:51

The synthesis of a substance that i want to make I will have to dissolve 1,25kg MeNH2 gas in 12,5l MeOH (-20 degrees). So I guess I'll first have to react MA.hcl with natrium hydroxide in a pressure reaction vessel and lead the evolving gas through a condenser filled with a drying agent and bubble the gas into the methanol.

DraconicAcid - 8-1-2014 at 13:59

If I were to attempt a reaction such as this, I would dissolve/suspend the methylammonium chloride in a minimum of water (enough to make a slurry that could be stirred), and then slowly add a sodium hydroxide solution with an addition funnel. The solubility of the methylamine would prevent sudden pressure changes.

Magpie - 8-1-2014 at 14:10

If you could clarify the process conditions it would help us to assist you.

Surely you don't have to dissolve all of the 10 kg methylamine in the 5L of methanol all at once do you? Or are you going to meter in the methylamine gas into a reaction vessel containing the methanol over a certain period of time as it reacts with your substrate? If so, might we know the substrate?

[Edited on 8-1-2014 by Magpie]

ScienceSquirrel - 8-1-2014 at 14:11

If I had little experience I would start with 50g not 1.25kg of methylamine hydrochloride

Pyro - 8-1-2014 at 14:26

those amounts sound like cookery to me...

I would make a suspension of methylamine HCl in MeOH, then add NaOH dissolved in MeOH to it with stirring.

remember: methylamine smells like shit, well, fish actually. but you get what I mean so wear old clothes and gloves

[Edited on 8-1-2014 by Pyro]

plante1999 - 8-1-2014 at 14:27

Who would make kgs of methylamine without much if any chemistry knowledge.... I can't see basic household use for that...


Anyway, it may be possible to make it in-situe in the methanol using sodium hydroxide solution in methanol over methylamine hydrochloride.

turd - 8-1-2014 at 14:29

Quote: Originally posted by carpen  
I will have to dissolve 1,25kg MeNH2 gas in 12,5l MeOH (-20 degrees).

You are lying. You want to make us believe that you're planning to make a mole of MDMA according to https://www.erowid.org/archive/rhodium/chemistry/redamin.nab... but that at the same time you didn't find this document: https://www.erowid.org/archive/rhodium/chemistry/10pc-menh2.....

You neither have P2P nor MDP2P, you are just a transparent poseur. Yawn.

[Edited on 8-1-2014 by turd]

Pyro - 8-1-2014 at 14:36

who's to say he doesn't?
but hey, anything that contributes the the collection of information here is good.


carpen - 8-1-2014 at 14:39

--

[Edited on 8-1-2014 by carpen]

turd - 8-1-2014 at 14:47

Quote:
I wont do any kind of bloody cooking
Well, that's too bad, because as you might have noted this forum is dedicated to amateur experimentalism. It's not supposed to be a freaky role-playing game where one pretends to be a drug tycoon. :P

Anyway, the answer to your question is given in the link above.

[Edited on 8-1-2014 by turd]

ScienceSquirrel - 8-1-2014 at 15:36

Heading for Detritus.

Turner - 8-1-2014 at 15:51

Quote: Originally posted by turd  
Quote:
I wont do any kind of bloody cooking
Well, that's too bad, because as you might have noted this forum is dedicated to amateur experimentalism. It's not supposed to be a freaky role-playing game where one pretends to be a drug tycoon. :P

Anyway, the answer to your question is given in the link above.

[Edited on 8-1-2014 by turd]


I honestly can't take anything you post seriously with a username like that