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:
<Chemistry id="chema01" num="0001"><Image id="ia01" he="13" wi="38" file="IMGA0001.TIF" imgContent="chem" imgFormat="TIFF" inline="no" /></Chemistry>wherein X is a p-toluenesulfonyl group, a methanesulfonyl group, a benzylsulfonyl group, a p-chlorobenzenesulfonyl group or a benzenesulfonyl group, R' is a hydrogen atom or a lower alkyl group, and R<Sup>2</Sup> is a hydrogen atom, an alkyl group or an alkali metal cation, or its optical isomer in the presence of a base.