Methylamine

Methylamine is the chemical compound with a formula of CH₃NH₂. It is a derivative of ammonia, wherein one H atom is replaced by a methyl group. It is the simplest primary amine. It is usually sold as solutions in methanol (2M), ethanol (8M), THF (2M), and water (40%), or as the anhydrous gas in pressurized metal containers. It has a strong odour similar to rotten fish. Methylamine is used as a building block for the synthesis of other organic compounds. It is on the DEA watchlist for chemical precursors because of clandestine use in manufacture of the drug MDMA (ecstasy) and methamphetamine.

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Chemistry

Methylamine is a good nucleophile as it is highly basic and unhindered. Its use in organic chemistry is pervasive. For example, it is a precursor to CH₃NCS.^[1]

The hydrochloride salt of methylamine, methylammonium chloride, CH₃NH₃Cl, is a colourless powder that can be converted to the amine.

Although methylamine is a gas at room temperature, liquid methylamine can be used as a solvent analogous to liquid ammonia. It shares some of the properties of liquid ammonia, but is better for dissolving organic substances, same as methanol is better than water.^[2]

Production

Methylamine is prepared commercially by the reaction of ammonia with methanol with zeolite as catalyst.^[3]

CH₃OH + NH₃ → CH₃NH₂ + H₂O

It can also be readily prepared by the reaction of hydrochloric acid with hexamine or by the reaction of formaldehyde with ammonium chloride.^[4]

NH₄Cl + H₂CO → CH₂NH·HCl + H₂O

CH₂NH·HCl + H₂CO + H₂O → CH₃NH₂ + HCOOH

Methylamine serves as a buffering agent in the lumen of the chloroplast in plants, effectively siphoning off protons that are heading for ATP synthase.^{[citation needed]}

References

1. ^ Moore, M. L.; Crossley, F. S. (1955). "Methyl Isothiocyanate". Org. Synth.; Coll. Vol. 3: 599. 
2. ^ H. D. Gibbs. Liquid methylamine as a solvent, and a study of its chemical reactivity. J. Am. Chem. Soc. 1906, 28, 1395-1422.
3. ^ Corbin D.R.; Schwarz S.; Sonnichsen G.C. (1997). "Methylamines synthesis: A review". Catalysis Today 37 (2): 71-102. doi:10.1016/S0920-5861(97)00003-5.
4. ^ Marvel, C. S.; Jenkins, R. L. (1941). "Methylamine Hydrochloride". Org. Synth.; Coll. Vol. 1: 347.