Method of purifying caprolactam

摘要

The invention is concerned with a method of purifying caprolactam as obtained by Beckmann transposition or by nitrosation of cyclohexyl compounds, characterized in that it comprises the following steps: (a) the caprolactam oil is treated with ammonia to obtain a pH in the 8 to 10 range; (b) the caprolactam in water-ammonia solution yielded by (a) is extracted with toluene; (c1) any caprolactam still in the toluene solution yielded by (b) is treated with NaOH; (C2) the aqueous phase left over from the extraction with toluene (b) is removed.