Benzoyl

Benzoyl refers to the benzoyl group, the acyl substituent derived from benzoic acid, with the formula C6H5CO-. In structural terms, it consists of a phenyl ring attached to a carbonyl carbon. When the benzoyl group is bound to another atom or moiety via the carbonyl carbon, the resulting compounds are benzoyl esters, amides, or related derivatives. The benzoyl group is commonly introduced into molecules by benzoylating agents such as benzoyl chloride, and its chemistry includes various acylation reactions that install the group onto alcohols, amines, or aromatics. The carbonyl carbon is electrophilic, enabling condensation and acyl-transfer processes.

Common benzoyl derivatives include benzoyl chloride (PhCOCl), used to form esters and amides; benzoyl peroxide, a radical initiator in polymer chemistry and an ingredient in some acne treatments; and benzamide, the amide formed when the benzoyl group attaches to nitrogen. The benzoyl group also participates in Friedel–Crafts type acylation, where benzoyl chloride reacts with arenes in the presence of a Lewis acid to yield aryl ketones such as benzophenone after hydrolysis.

Applications of benzoyl chemistry span organic synthesis, pharmaceuticals, and specialty polymers. Benzoyl groups are employed to protect or modify functional groups, to form organized benzoyl esters and amides, and to serve as intermediates in the preparation of dyes, fragrances, and film-forming agents. Safety considerations include the corrosive and lachrymogenic nature of benzoyl chloride and the oxidizing and potentially explosive character of benzoyl peroxide, necessitating appropriate handling, ventilation, and protective equipment.