PRODUCTION OF CYANOBENZOYL HALIDE

PROBLEM TO BE SOLVED: To industrially obtain the subject high-purity compound scarcely causing environmental load, capable of readily detoxicating by-products and useful as an intermediate for medicines, etc., in a high yield by converting an aldehyde group into an acid halide group without damaging cyano group on the benzene ring of a cyanobenzaldehyde compound. SOLUTION: An aldehyde group is converted into an acid halide group with preferably a halogenating agent without damaging cyano group on the benzene ring of (A) a cyanobenzaldehyde compound to produce a cyanobenzoyl halide. Furthermore, the above halogenating agent is preferably chlorine and the acid halide group is preferably an acid chloride. The component A is preferably a compound represented by formula I (X is Cl or F; n is 0-4), especially m- cyanobenzaldehyde, etc. The objective compound is preferably a compound represented by formula II (Y is Cl or Br), especially m-cyanobenzoyl chloride, etc. The reaction is preferably carried out in the presence of a radical initiator.