公开(公告)号：US3937789A

公开(公告)日：1976-02-10

申请号：US425171

申请日：1973-12-14

Applicant: Ivo Donati ,  Werner Muench ,  Mario Fidecicchi

Inventor： Ivo Donati ,  Werner Muench ,  Mario Fidecicchi

IPC: C01C1/242 ,  C07D201/16

CPC classification number: C07D201/16 ,  C01C1/242

Abstract: A process is disclosed in which the heat generated, during neutralization,y ammonium sulfate of a solution of .xi.-caprolactam in sulfuric acid, is used to effect evaporation of water present, and the temperature is kept at about 40.degree.C to 50.degree.C, under subatmospheric pressure, so that substantial hydrolysis of the caprolactam is avoided while a substantial portion of the water present in the neutralization mixture is evaporated at the subatmospheric pressure, and the ammonium sulfate is crystallized substantially free from entrained caprolactam. The caprolactam is then separated from the aqueous phase.