Process for preparing 2-(4-hydroxyphenoxy) alkanoic acid compounds

摘要

A process for preparing a 2-(4-hydroxyphenoxy) alkanoic acid, its ester or alkali metal salt, or an optical isomer thereof, which comprises condensing hydroquinone or an alkali metal salt of hydroquinone with a compound having the formula: <IMAGE> (I) wherein X is a p-toluenesulfonyl group, a methanesulfonyl group, a benzylsulfonyl group, a p-chlorobenzenesulfonyl group or a benzenesulfonyl group, R1 is a hydrogen atom or a lower alkyl group, and R2 is a hydrogen atom, an alkyl group or an alkali metal cation, or its optical isomer in the presence of a base.