Dimethylamine

Dimethylamine or N-methylmethanamine or DMA is an organic compound and an amine. It is a colorless, liquefied and flammable gas with an ammonia and fish-like odor. Dimethylamine is generally used as a solution in water at concentrations up to around 40%.

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Chemistry

Dimethylamine is a secondary amine. The molecule consists of a nitrogen atom with two methyl substituents and one proton. Dimethylamine is a base and the pKa of the ammonium salt CH₃-NH₂⁺-CH₃ is 10.73, a value intermediate between methylamine (10.64) and trimethylamine (9.79). Dimethylamine reacts with acids to form salts. Dimethylamine hydrochloride is an odorless white solid with a melting point of 171.5 °C. Dimethylamine is produced by catalytic reaction of methanol and ammonia at elevated temperatures and high pressure.^[1]

Biochemistry

The German cockroach utilizes dimethylamine as a pheromone for communication.

DMA undergoes nitrosation under weak acid conditions to give dimethlynitrosamine. This animal carcinogen has been detected and quantified in human urine samples and it may also arise from nitrosation of DMA by nitrogen oxides present in acid rain in highly industrilized countries (Zhang et al. 1998).

Uses

Dimethylamine is used as dehairing agent in tanning, in dyes, in rubber accelerators, in soaps and cleaning compounds and as an agricultural fungicide. In industry dimethylamine is converted to dimethylformamide and the surfactant lauryl dimethylamine oxide. It is raw material in the production of many pharmaceuticals such as diphenhydramine and also that of the chemical weapon tabun.

See also

• Methylamine
• Trimethylamine

References

Zhang AQ, Mithchell SC, Smith RL (1998) Dimethylamine formation in the rat from various related amine precursors. Food Chem Toxicol 36(11):923-7