| 摘要 |
PROBLEM TO BE SOLVED: To obtain a cyanobenzoic acid alkyl ester useful as a synthetic intermediate for pharmaceuticals in high selectivity and yield on an industrial scale at a low cost by using phthalonitrile as an industrially available inexpensive raw material. SOLUTION: The objective ester of formula I (COOR is positioned at meta or para-position relative to nitrile group; X is Cl or F; (n) is 0-4; R is a 1-5C alkyl) is produced by reacting (A) a phthalonitrile optionally having substituents on the benzene ring with (B) an aliphatic alcohol in the presence of an acid to convert one nitrile group to an alkylimino ether group and exclusively converting the above imino ether group into an alkyl ester group by reacting with water. Preferably, the component A is isophthalonitrile or terephthalonitrile of formula II (two nitrile groups are positioned at meta or para-positions with each other) and the component B is an alcohol expressed by ROH, concretely, methanol, etc.
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