4-Hydroxyphenyl acetic acid.

摘要

A process for the preparation of 4-hydroxyphenyl acetic acid of the formula I, an important raw material for the preparation of pharmaceutically active substances, from sodium-4-hydroxymandalate monohydrate comprising reducing the sodium-4-hydroxymandalate monohydrate with a reducing agent consisting of stoichiometric quantity of a phosphorus (III) compound and catalytic or stoichiometric quantity of sulphur dioxide or equivalent salt thereof in a solvent at 60-120 DEG C and at ambient to 5 atmospheres pressures.