Methylamine Hydrochloride from HMTA, Eleusis' version [with comments by Rhodium]
140g of Hexamine is carefully dissolved in 400mL of Muriatic Acid (31.45% HCl) to which at least 100mL of (preferably) absolute ethanol has been
added. Add the hexamine slowly while stirring vigorously and with good ventilation as some nasty fumes are produced. Allow all to stir at room
temperature for at least 8 hours but preferably 16.
The solution will become turbid within several hours of the initial mixing. I *believe* this is the formation of a formaldehyde trimer of some sort
and I suspect that the original equation for the conversion of hexamine into methylamine fragments is therefore incorrect. [There is no trimer of any
sort formed, if enough water and formaldehyde is present. Eleusis uses 4 moles of amine to 6 methylenes, which is enough, but gives less yield.]
At any rate, filter off this white precipitate which is obviously not an amine salt due to it being fluffy even in Florida's humidity (almost all
simple amine salts are hygroscopic) [With the exception of ammonium chloride, and this is it].
Finally, remove the excess water, hydrochloric acid and freako volatile products by, ideally, heating the liquid at low to medium heat in a porcelain
saucepan. Stove-proof glass would be ideal, but stainless-steel, aluminum and copper are definitely not! [Rather use a RB flask, with a water
aspirator attached, smells considerably less].
The concentration can generally be left unattended for a couple of hours, but try to stick around and babysit it at least the first time so you will
have a good idea of how long it takes for your particular stove/pots/etc... [Or else it'll BURN!]
Also, the methylamine HCl will form a melt if heated too long at which point it will sublimate off. It will then appear as if it's taking forever for
the stuff to concentrate when in fact you are merely boiling your product away. After the concentrated slush has become sufficiently "thick", take it
off the heat every so often to see if it doesn't soldify, insuring that the water is mostly gone and that not too much sublimation has occured (some
is inevitable and even desireable). The yield of Methylamine HCl should be around 200g as white deliquescent crystals. Note, ACS-grade methylamine HCl
is colorless. We aren't using ACS-grade production techniques here, so don't expect ACS-grade product. However, the methylamine produced by this
method is eminently suitable for the many purposes normally intended and if allowed to sublimate some when heating, no adjustment for "purity" or
"water content" need be made in subsequent uses of it. [I can't understand how he can get 200g of product. 140g hexamine gives 80 grams of NH4Cl, and
HOPEFULLY more than 100g of methylamine].
If the crystals are opaque white and do not deliquesce quickly in air of average humidity (65% rh), they may be contaminated with some Hexamine or
some bizarre polymer. [Or ammonium chloride. Recrystallize from methanol, then wash with CHCl3].
Washing 100g of the crude product with 100mL of Chloroform by stirring in a beaker then filtering, repeated as many times as necessary, will remove
Hexamine. Methylamine HCl is insoluble in Chloroform whereas Hexamine is at the rate of 1g to 10mL. As a final note, I have been informed that
hexamine is available in some areas in the form of "fuel tablets" for small camping stoves. I have received mixed results from various individuals
using this so, as the saying goes, Caveat Emptor. |
and I'm out of
hexamine, so I need to get some more... The reaction yielded a considerable amount of ammonium chloride but I don't have any formaldahyde or
paraformaldahyde.
