Methylammonium Acetate - Synthesis of Crystal

Quote: Originally posted by chemrox

you could conceivably do this by heating the solution to release MeNH2 running it through a drierite/molecular sieve column hence through GAA. Have you checked the water solubility? You might get away with mixing the two ingredients MeNH2 and GAA but you will have too look up the product to see what its solubility is.

Quote: Originally posted by Praxichys

There is quite a bit of info in this thread: http://www.sciencemadness.org/talk/viewthread.php?tid=8182

Quote: Originally posted by swami.me

I am new to organic synthesis. I would like to synthesize Methylammonium Acetate crystals by reacting acetic acid and methyl amine solution (40% in water) at 0C. But I wasn't sure how to get dry crystals.

Quote: Originally posted by Nicodem

Quote: Originally posted by swami.me   I am new to organic synthesis. I would like to synthesize Methylammonium Acetate crystals by reacting acetic acid and methyl amine solution (40% in water) at 0C. But I wasn't sure how to get dry crystals. It is not called to synthesize crystals, but to grow crystals. This is done by numerous techniques. The most common are the crystallization from a hot solution by slow cooling and the slow evaporation techniques. For some compounds it is best to use seeds. As for how difficult it is, it depends on how large crystals you want to grow. You can try letting a solution of methylammonium acetate in ethanol or 2-propanol evaporate from an open beaker in a dry place (I think methylammonium acetate is hygroscopic). It might give you mm size crystals.

Quote: Originally posted by PlatinumLab

Swami, I find it quite odd that someone with very minimal chemistry knowledge is needing to do XRD and FTIR, on Methylamine, a known drug precursor no less. However if that is your simply your intention, Nicodem's technique should do just fine, or even simply gently heating your solution to evaporate, very gently. Both of these will take quite a long time, but small crystals should result. If your goal is to just isolate the powder form, there are tons of other techniques that are much faster.

Its definitely for drug use.

Enuf jokes!! I fabricate solar cells based on CH3NH3PbI3 perovskite structures. I get this by the reaction of

Pb(Ac)2 + 3 CH3NH3I ---> CH3NH3PbI3 + 2 CH3NH3(CH3COO)

It is important for me to study the byproduct to understand the perovskite formation mechanism. I am weak in Synthesis but not weak in material characterization.

If you need any more info on my work, I would be glad to show you my papers.

Quote: Originally posted by swami.me

Thanks for correcting me. I really don't need large crystals. I need the material in crystalline form as I need to do powder XRD and FTIR of MAAc. I will try method suggested by you if I end up with amorphous material.

If that's all you need the reference material for, then crystal size makes no difference.

Using toluene for forming an ammonium acetate is not commonly the best choice, especially if you want a crystalline product.

Generating methylamine gas from its aqueous solution requires heating. NaOH itself is not enough. It will increase the ionic power, heat up the mix to some degree and reduce hydration of methylamine, thus liberating some. But you need to apply heat as well, or else you will only release a small part of methylamine.

You could also do this without gassing. Just add 1.2 eq. of 40% aq. methylamine to acetic acid in 2-propanol. Rotavap, add more solvent, rotavap again, repeat until you get crystallization. This may or may not work, but it is simple enough to try. Just don't use toluene at reflux like reported here.

Procedure from EP808826:



[Edited on 24/1/2016 by Nicodem]