| 摘要 |
PURPOSE:To recover the titled compound useful as an intermediate of pharmaceuticals, agricultural chemicals, etc. in high yield and purity, by treating crude 4-fluorophenol with phthalic acid compound in the presence of a dehydration agent thereby removing the impurity phenol from the fluorophenol. CONSTITUTION:A phthalic acid anhydride compound is added to crude 4-fluorophenol, and heated at 30-180 deg.C in the presence of a dehydration agent until the phenol existing as an impurity becomes completely undetectable by gas chromatography, and the product is distilled or extracted with an organic acid, concentrated, and then distilled or recrystallized to obtain pure 4-fluorophenol. The phthalic acid compound is e.g. phthalic acid anhydride, tetrachlorophthalic acid anhydride, o-sulfobenzoic acid anhydride, etc., and the dehydration agent is e.g. sulfuric acid, zinc chloride, tin tetrachloride, etc.
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