Patent ID: 6333412
Filing Date: 2001-12-25
Classification: C07D

Abstract:
Process to prepare .epsilon.-caprolactam from a starting mixture containing a 6-aminocaproate ester in an amount higher than 0.5 wt % calculated on the amount of organic compounds in the starting mixture, in which in a first step (1) the 6-aminocaproate ester is converted into 6-aminocaproic acid and 6-aminocaproamide by reaction with water in the presence of ammonia at a temperature of between 50 and 250.degree. C., with a separate or simultaneous removal of alcohol(s), and in a subsequent step (2) the 6-aminocaproic acid and 6-aminocaproamide are cyclizised at an elevated temperature, characterized in that in step (1) the 6-aminocaproate ester is converted into 6-aminocaproic acid and 6-aminocaproamide in the presence of an amount higher than 3 wt. % and less than or equal to 25 wt. % NH.sub.3 (relative to the total amount of organic compounds, water and ammonia present in step (1)).