Benzoyl chloride


Benzoyl chloride, also known as benzenecarbonyl chloride, is an organochlorine compound with the formula. It is a colourless, fuming liquid with an irritating odour, and consists of a phenyl ring with an acyl chloride substituent. It is mainly useful for the production of organic peroxides but is also used in other areas such as in the preparation of dyes, perfumes, pharmaceuticals, and resins.

Preparation

Benzoyl chloride is produced from benzotrichloride using either water or benzoic acid:
As with other acyl chlorides, it can be generated from the parent acid and standard chlorinating agents such as phosphorus pentachloride, thionyl chloride, and oxalyl chloride. It was first prepared by treatment of benzaldehyde with chlorine.
An early method for production of benzoyl chloride involved chlorination of benzyl alcohol.

Reactions

It reacts with water to produce hydrochloric acid and benzoic acid:
Benzoyl chloride is a typical acyl chloride. It reacts with alcohols to give the corresponding esters. Similarly, it reacts with amines to give the amide.
It undergoes the Friedel-Crafts acylation with aromatic compounds to give the corresponding benzophenones and related derivatives. With carbanions, it serves again as a source of the benzoyl cation synthon,.
Benzoyl peroxide, a common reagent in polymer chemistry, is produced industrially by treating benzoyl chloride with hydrogen peroxide and sodium hydroxide:

Modified benzoyl chlorides

Many substituted derivatives of benzoyl chloride are known. 4-Nitrobenzoyl chloride is a precursor to the anesthetic procaine. One example is 4-chlorobenzoyl chloride, a precursor to 4-chloro-4'-hydroxybenzophenone, which is used to make high performance polymers.

Safety

Benzoyl chloride is toxic and a serious skin irritant.