Appearance Colorless gas
Boiling point -6 °C
Melting point -93 °C
Density 700 kg/m³
Molar mass 31.0571 g/mol
Lewis dot structure of ch3nh2 methylamine
Methylamine is an organic compound with a formula of CH3NH2. This colorless gas is a derivative of ammonia, but with one hydrogen atom being replaced by a methyl group. It is the simplest primary amine. It is sold as a solution in methanol, ethanol, tetrahydrofuran, or water, or as the anhydrous gas in pressurized metal containers. Industrially, methylamine is transported in its anhydrous form in pressurized railcars and tank trailers. It has a strong Odor similar to fish. Methylamine is used as a building block for the synthesis of many other commercially available compounds.
- Lewis dot structure of ch3nh2 methylamine
- Industrial production
- Laboratory methods
- Reactivity and applications
- Biological chemistry
Methylamine is prepared commercially by the reaction of ammonia with methanol in the presence of an aluminosilicate catalyst. dimethylamine and trimethylamine are co-produced; the reaction kinetics and reactant ratios determine the ratio of the three products. The product most favoured by the reaction kinetics is trimethylamine.CH3OH + NH3 → CH3NH2 + H2O
In this way, an estimated 115,000 tons were produced in 2005.
Methylamine was first prepared in 1849 by Charles-Adolphe Wurtz via the hydrolysis of methyl isocyanate and related compounds. An example of this process includes the use of the Hofmann rearrangement, to yield methylamine from acetamide and bromine gas.
Reactivity and applications
Methylamine is a good nucleophile as it is highly basic and unhindered, but as an amine it is considered a weak base. Its use in organic chemistry is pervasive. Some reactions involving simple reagents include: with phosgene to methyl isocyanate, with carbon disulfide and sodium hydroxide to the sodium methyldithiocarbamate, with chloroform and base to methyl isocyanide and with ethylene oxide to methylethanolamines. Liquid methylamine has solvent properties analogous to those of liquid ammonia.
Representative commercially significant chemicals produced from methylamine include the pharmaceuticals ephedrine and theophylline, the pesticides carbofuran, carbaryl, and metham sodium, and the solvents N-methylformamide and N-methylpyrrolidone. The preparation of some surfactants and photographic developers require methylamine as a building block.
The LD50 (mouse, s.c.) is 2.5 g/kg.
The Occupational Safety and Health Administration (OSHA) and National Institute for Occupational Safety and Health (NIOSH) have set occupational exposure limits at 10 ppm or 12 mg/m3 over an eight-hour time-weighted average.