PRODUCTION OF CYANOBENZOIC ACID ALKYL ESTER

摘要

PROBLEM TO BE SOLVED: To obtain a cyanobenzoic acid alkyl ester useful as a synthetic intermediate for pharmaceuticals under mild condition in high selectivity and yield by using phthalonitrile as a raw material available on an industrial scale at a low cost. SOLUTION: The objective ester of formula I (COOR is positioned at meta or para-position relative to nitrile group; X is C1 or F; (n) is 0-4; R is a 1-5C alkyl) optionally having substituents on the benzene ring is produced by selectively hydrating one nitrile group of (A) a phthalonitrile optionally having substituents on the benzene ring in the presence of (B) a base in (C) an aliphatic alcohol solvent to obtain (D) the corresponding cyanobenzoic acid amide and reacting the component D with an aliphatic alcohol in the presence of an acid to convert exclusively the amide group into an alkyl ester group. The component A is preferably isophthalonitrile, etc., of formula II (two nitrile groups are meta- or para-positions with each other).