Benzoyl chloride

Benzoyl chloride, also known as benzenecarbonyl chloride, is a colourless, fuming liquid, C6H5COCl, with an irritating odour. In the laboratory it may be prepared by distilling benzoic acid (C6H5COOH) with phosphorus pentachloride in anhydrous conditions. This replaces the hydroxy group of benzoic acid with a chlorine atom. This chlorination can also be accomplished using thionyl chloride. On a larger scale it is prepared by chlorinating benzaldehyde.

This substance is used as an intermediate chemical in the preparation of dyes, perfumes, peroxides, pharmaceuticals, and resins. It is also used in photography; as gasoline gum inhibitors, and in the manufacture of synthetic tannins. It was formerly employed as an irritant gas in chemical warfare.

Reactions
Like all other acyl chlorides, benzoyl chloride can also react with alcohols and amines to give the corresponding esters and amides, just as any acyl chloride can.

Benzoyl chloride is easily hydrolyzed; it reacts with water to produce hydrochloric acid and benzoic acid.


 * PhCOCl + H2O &rarr; PhCOOH + HCl