公开(公告)号：US3859278A

公开(公告)日：1975-01-07

申请号：US38474773

申请日：1973-08-01

Applicant: STAMICARBON

Inventor： DE ROOY ABRAHAM H ,  GOETTSCH REIJER

IPC: C07D201/16 ,  C07D41/06

CPC classification number: C07D201/16

Abstract: Lactams are recovered from a solution of one or more lactams and sulfuric acid in an organic solvent after neutralization with ammonia or an ammonium salt and water without the simultaneous coproduction of solid ammonium sulfate according to the disclosed process. Ammonium hydrogen sulfate produced in the neutralization step is removed in the solution form, preferably concentrated to about 80 per cent by weight and the lactam is recovered from the organic solvent. Removing the ammonium hydrogen sulfate in the solution form rather than a solid avoids crystallization and deposition of the salt onto the surfaces of processing equipment.