PROCESS FOR PRODUCTION OF CARBOXYLIC ACID CHLORIDE COMPOUND

Disclosed is a process for production of a carboxylic acid chloride compound represented by the general formula (III), which comprises reacting a carboxylic acid compound represented by the general formula (I) with an acid chlorinating agent in the presence of an urea compound represented by the general formula (II). The process enables to produce the carboxylic acid chloride compound with a high purity or in high yield at a high reaction speed. The carboxylic acid chloride compound produced by the process is useful as an intermediate for the production of a D-penylalanine derivative which is used as a therapeutic agent for diabetes. (I) wherein the ring A represents a cyclohexane ring or a benzene ring; and R1 represents an alkyl group having 1 to 6 carbon atoms. (II) wherein R2 to R6 independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, or R5 and R6 may be bound to each other, and in this case,-R5-R6-represents an ethylene group or the like. (III) ® KIPO & WIPO 2009