Methylamine hydrochloride is a very useful chemical, however most of it's use is associated with illicit substance manufacture. Because of this, it has become impossible to obtain and must be made - at least in the US. Fortunately, it's not too hard to make, and doesn't require any odd reagents. Due to it's hygroscopic nature, it's somewhat of a pain in the arse but completely managable. This page only contains information on the direct synthesis of the hydrochloride salt. Later I might provide information on preparing the gas (and then of course turning it into the hydrochloride salt), but for now I lack any motivation to do so since this method is quite easy. The first method given describes the hydrolysis of Hexamine with hydrochloric acid, the second method showing the same thing, but under vacuum (much much better yeilds and much easier).
C6H12N4 + 4HCl + 6H2O ----> 4NH4Cl + 6CH2O
NH4Cl + CH2O -----> CH2NH*HCl + H2O
CH2NH*HCl + CH2O + H2O ----> CH3NH2*HCl + HCOOH
C6H12N4 + 4HCl + 6H2O ----> 3CH3NH2*HCl + NH4Cl + 3HCOOH
Hexamine and hydrochloric acid at atmospheric pressure
|Hydrochloric acid (31.45%)||Heat source|
|Methanol||Filtration (vacuum preferred)|
|Chloroform (optional, but recommended)||Dessicator|
Into a 600ml beaker, place 70g of hexamine. In a graduated cylinder, prepare a solution of 180ml water, 220ml of Muriatic acid (31.45% hydrochloric acid), in that order. Add this to the 600ml beaker and mix thoroughly - until all the hexamine has dissolved. Beaking heating this on a hotplate. As it approaches 80 and 90, and effervesence will become apparent and will become vigorous. The effervesence is due to the formic acid decomposing into carbon dioxide. It's mainly carbon dioxide coming off, but some formic acid too, so do not breath the vapors. Continue heating until you're down to around 200ml of volume, then turn off the hotplate (but don't remove the beaker). Let it cool to room temp and filter the white crystals out. Evaporate the filtrate until more white crystals form, then filter again.
Dissolve all of the filtered materials in 100ml or so of methanol. Filter the insoluble white crystals out, rinsing with a small portion of methanol. Evaporate the filtrate and filter out any crystals **Optional: Place the crystals into a beaker and add 100ml of chloroform. Stir it well, crush up the big lumps, etc. This will dissolve any unreacted hexamine, as well as dimethylamine hydrochloride which surely has formed in some amount. Filter out the pure methylamine hydrochloride. Add more chloroform to the beaker to rinse out any remaining crystals, and pour this through the filter as well. Then place the crystals back into the beaker, and recrystallize from methanol**. If you skipped the optional step, simply recrystallize from methanol. Evaporate methanol on a boiling water bath, then place in a dessicator full of dry calcium chloride for a couple days. When dry, it should be a white, fluffy powder. Theoretical yeild is 101.34g, but yeilds are typically around 50g. The first time I attempted this, my yeild was around 36g, due to me trying to figure out the best method.