PROCESS FOR PREPARING 5-METHYLISOXAZOLE-4-CARBOXYLIC-(4'-TRIFLUOROMETHYL)-ANILIDE

摘要

A process for preparing 5-methylisoxazole-4-carboxylic-(4'-trifluoromethyl)-anilide comprising: (a) reacting ethylacetoacetate, triethylorthoformate, and acetic anhydride to form ethyl ethoxymethyleneacetoacetic ester; (b) combining the ethyl ethoxymethyleneacetoacetic ester with sodium acetate or a salt of trifluoroacetic acid in the presence of hydroxylamine sulfate, to form ethyl-5-methylisoxazole-4-carboxylate; (c) reacting the ethy-15-methylisoxazole-4-carboxylate with a strong acid to form 5-methylisoxazole-4-carboxylic acid; (d) reacting the crystallized 5-methylisoxazole-4-carboxylic acid with thionyl chloride to form 5-methylisoxazole-4-carbonyl chloride; and (e) reacting the 5-methylisoxazole-4-carbonyl chloride with trifluoromethyl aniline and an amine base.