Method of purifying 4-fluorophenol

摘要

A method of efficiently purifying crude 4-fluorophenol containing phenol as impurity. Phthalic acid or its anhydride, or a suitable derivative of phthalic acid, and a dehydrating agent such as sulfuric acid or a metal chloride are mixed with the crude 4-fluorophenol, and the mixture is kept in a liquid state usually with moderate heating to 30 DEG -180 DEG C. until completion of condensation reaction between phenol and the phthal-compound. After that pure 4-fluorophenol can easily be recovered by distillation or recrystallization.