METHOD FOR PREPARING N-ACYL ORTHO-AMINOBENZAMIDE

Disclosed herein is a method of preparing N-acyl anthranilamide (I), including: reacting a substituted anthranilic acid (II) with pyrazolecarboxylic acid (III) under the action of a phosphorus reagent and a base to obtain an intermediate benzoxazinone (IV); and subjecting the intermediate benzoxazinone(IV) and a protonic acid salt of methylamine to a ring-opening reaction to obtain N-acyl anthranilamide (I), as shown in the following reaction scheme:where X is hydrogen, chloro or cyano group; and HY is hydrohalic acid, sulfuric acid, phosphoric acid or a carboxylic acid. The method has the advantages of simple operation, mild reaction conditions, less waste and high overall yield, and thus is suitable for industrial production.