PREPARATION OF UNSATURATED CARBOXYLIC ACID

摘要

PURPOSE:To obtain the titled compound useful as a raw material for a variety of industrial products or as an intermediate for medicines or agricultural chemicals, in high purity and yield, by the reaction of a specific halogenocarboxylic acid with a base in the presence of a phenol as a catalyst. CONSTITUTION:A halogenocarboxylic acid expressed by formula I (R<1> and R<2> are H, halogen, alkyl, etc.;R<3> is H, halogen or lower alkyl; R<4> is H, alkenyl, alkyl, etc.;X<1> and X<2> are H or halogen) is reacted with a base in the presence of a phenol, e.g. a compound expressed by. formula III, IV or V (R<5> is 1-20C alkyl, phenoxy, heterocycle, etc.;m is an integer 3 or more and n is an integer 1-5), preferably in an amount of 0.1-10mol% based on the raw material compound as a catalyst and in the presence (absence) of a solvent, preferably at 10-100 deg.C, to give an unsaturated carboxylic acid expressed by formula II.