公开(公告)号：DE19500040A1

公开(公告)日：1996-07-04

申请号：DE19500040

申请日：1995-01-03

Applicant: BASF AG

Inventor： SCHNURR WERNER DR ,  WULFF-DOERING JOACHIM DR ,  FISCHER ROLF DR ,  BAEZNER RUDOLF DR

IPC: B01J23/755 ,  C07B61/00 ,  C07C253/30 ,  C07C255/24 ,  B01J23/78

Abstract: Aliphatic alpha,omega-aminonitriles are prepared by partial hydrogenation of aliphatic alpha,omega-dinitriles at elevated temperatures in the presence of a catalyst in the gas phase by a process which comprises carrying out the hydrogenation with a catalyst based on at least one metal selected from the group consisting of nickel, cobalt, ruthenium and rhodium and with the proviso that the catalyst is not a powder.

公开(公告)号：DE4434172A1

公开(公告)日：1996-03-28

申请号：DE4434172

申请日：1994-09-24

Applicant: BASF AG

Inventor： KRATZ DETLEF DR ,  WITZEL TOM DR ,  BAEZNER RUDOLF DR ,  KRONER MATTHIAS DR ,  PRESLER UWE DR

IPC: C07C227/06 ,  C07C229/24 ,  C07C227/04

Abstract: A process is disclosed for preparing D,L-aspartic acid by heating aqueous solutions of ammonium salts of the maleic acid. The molar ratio of maleic acid to ammonia ranges from 1:1 to 1:50. The process is carried out at temperatures from 60 to 250 DEG C and pressures of at least 1 bar. The pressure applied during the reaction is adjusted to ensure that the reaction mixture is almost completely present in liquid phase. Excess ammonia is removed and the reaction solution is acidified so as to release D,L-aspartic acid, which is then isolated.