A carbamoyl chloride is the functional group with the formula R<sub>2</sub>NC(O)Cl. The parent carbamoyl chloride, H<sub>2</sub>NCOCl, is unstable, but many N-substituted analogues are known. Most examples are moisture sensitive, colourless, and soluble in nonpolar organic solvents. An example is dimethylcarbamoyl chloride (m.p. âÂÂ90 ðC and b.p. 93 ðC). Carbamoyl chlorides are used to prepare a number of pesticides, e.g. carbofuran and aldicarb.
Carbamoyl chlorides are prepared by the reaction of an amine with phosgene:
They also arise by the addition of hydrogen chloride to isocyanates:
In this way, carbamoyl chlorides can be prepared with N-H functionality.
In a reaction that is typically avoided, hydrolysis of carbamoyl chlorides gives carbamic acids:
Owing to the influence of the amino group, these compounds are less hydrolytically sensitive than the usual acid chlorides. A related but more useful reaction is the analogous reaction with alcohols: