| 摘要 |
An improved process for the preparation of N-acetyl-p-aminophenol. p-Aminophenol is acetylated in an aqueous medium to produce a crude aqueous reaction mixture and N-acetyl-p-aminophenol product is recovered by crystallization from an aqueous system comprising the reaction mixture. Crystals are separated from the crude mother liquor which contains residual N-acetyl-p-aminophenol and unreacted acetic acid. According to the improvement, residual N-acetyl-p-aminophenol and acetic acid are recovered from the crude mother liquor by liquid-liquid extraction with a water-immiscible organic solvent to produce an extract containing N-acetyl-p-aminophenol and acetic acid. The extract is distilled to strip off the solvent and acetic acid.
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