ethyl carbamate

Ethyl carbamate (also called urethane) is a substance first prepared in the nineteenth century. Structurally it is an ester of carbamic acid, i. e., ethyl carbamate as shown. Urethane itself is: (NH₂-COOC₂H₅) and is not a component of polyurethanes.

This ethyl ester is a white crystalline substance produced by the action of ammonia on ethyl chloroformate or by heating urea nitrate and ethyl alcohol.

Other carbamates include methyl carbamate (urethylane, m. p. 52-54°C), butyl carbamate, and phenyl carbamate (m. p. 149-152°C), which can also be prepared from the corresponding chloroformate and ammonia.

Ethyl carbamate forms a white, crystalline solid at standard temperature and pressure that is odorless and has a cooling saline taste. It sublimes readily at 103˚C and 54 torr. Solubility data includes 2.0 g/mL H₂O, 1.2 g/mL ethanol, 1.11 g/mL chloroform, and 0.67 g/mL ether. The aqueous solution is neutral.