Patent ID: 8231765
Filing Date: 2012-07-31
Classification: C07D,Y10S

Abstract:
1. A process for the purification of lactams obtained from a hydrolysis reaction medium comprising an aminonitrile, a lactam, ammonia and a solvent used in the cyclizing hydrolysis of an aminonitrile, the process consisting in: a. removing ammonia and optionally solvent from the hydrolysis reaction medium; and b) recovering the lactam from the reaction medium by distilling said lactam at least once in the presence of a base and recovering: c. treating said distillation bottom product and recovering said lactam from said distillation bottom product, and d. recycling said recovered lactam from said distillation bottom product, wherein treating said distillation bottom product consists of evaporating a thin-layer of the lactam, crystallizing the lactam, or separating the lactam from impurities by extracting the lactam with water.