Chloroacetyl chloride is a chlorinated acyl chloride. It is a bifunctional compound, making it a useful building block chemical.
Industrially, it is produced by the carbonylation of methylene chloride, oxidation of vinylidene chloride, or the addition of chlorine to ketene.[3] It may be prepared from chloroacetic acid and thionyl chloride, phosphorus pentachloride, or phosgene.
Chloroacetyl chloride is bifunctional—the acyl chloride easily forms esters[4] and amides, while the other end of the molecule is able to form other linkages, e.g. with amines. The use of chloroacetyl chloride in the synthesis of lidocaine is illustrative:[5]
The major use of chloroacetyl chloride is as an intermediate in the production of herbicides in the chloroacetanilide family including metolachlor, acetochlor, alachlor and butachlor; an estimated 100 million pounds are used annually. Some chloroacetyl chloride is also used to produce phenacyl chloride, another chemical intermediate, also used as a tear gas.[3] Phenacyl chloride is synthesized in a Friedel-Crafts acylation of benzene, with an aluminium chloride catalyst:[6]
With anisole, it is used for the synthesis of venlafaxine.
Like other acyl chlorides, reaction with other protic compounds such as amines, alcohols, and water generates hydrochloric acid, making it a lachrymator.
There is no regulated permissible exposure limit set by the Occupational Safety and Health Administration. However, the National Institute for Occupational Safety and Health has set a recommended exposure limit at 0.05 ppm over an eight-hour work day.[7]