公开(公告)号：CA914668A

公开(公告)日：1972-11-14

申请号：CA914668D

Applicant: STAMICARBON

Inventor： DASSEN BERNARDUS H N ,  BOESTEN WILHELMUS H J ,  DAHLMANS JOHANNES J

公开(公告)号：CA1322626C

公开(公告)日：1993-09-28

申请号：CA565465

申请日：1988-04-29

Applicant: STAMICARBON

Inventor： BOESTEN WILHELMUS H J ,  DASSEN BERNARDUS H N

IPC: C07K1/06 ,  C07K5/06 ,  C07K5/075

Abstract: AE 5682 The invention relates to a process for the preparation of aspartylphenylalanine methyl ester from N-formylaspartylalanine methyl ester by treatment with an acid, characterized in that N-formyl-aspartylalanine methyl ester is treated at 30-60.degree.C with at least 0.5 molar equivalent oxalic acid per mole of N-formyl-aspartylphenyl-alanine methyl ester in a solvent mixture in which N-formylaspartylphenylalanine methyl ester dissolves well and in which the oxalic acid salt of aspartylphenylalanine methyl ester is poorly soluble, after which the oxalic acid salt of aspartylphenylalanine methyl ester is removed by filtration, dissolved in water and subsequently neutralized with the aid of an inorganic base with formation of free aspartylphenylalanine methyl ester.

公开(公告)号：CA1292434C

公开(公告)日：1991-11-26

申请号：CA506281

申请日：1986-04-10

Applicant: STAMICARBON

Inventor： BOESTEN WILHELMUS H J ,  SCHOEMAKER HANS E ,  DASSEN BERNARDUS H N

IPC: C07B55/00 ,  C07B31/00 ,  C07C67/00 ,  C07C231/00 ,  C07C231/12 ,  C07C231/16 ,  C07C237/06 ,  C07C237/30 ,  C07C241/00 ,  C07C251/02 ,  C12P13/04 ,  C12P13/08 ,  C12P41/00 ,  C12P13/02

Abstract: AE 3631 The invention relates to a process for racemizing an optically active N-benzylidene amino-acid amide, characterized in that a solution of the N-benzylidene amino-acid amide is mixed in a water-miscible organic solvent with at least 0.05 mole strong base per litre solution. The invention further relates to a process for preparing an L-amino acid by enzymatic separation of the corresponding DL-amino-acid amide with an enzyme preparation from Pseudomonas putida, in which process also unconverted D-amino-acid amide is left behind in solution, characterized in that benzaldehyde is added to the solution, during which addition a precipitate of D-N-benzylidene aminoacid amide is being formed, this precipitate is subsequently, after being separated off, dissolved in an acetone-water mixture, 0.08-0.15 mole KOH/Litre solution is subsequently added, the resulting solution is stirred for 1-20 hours at 20-60.degree.C, sulphuric acid is then added until the pH of the solution is 5 and the resulting sulphuric acid salt of the DL-amino-acid amide is finally, after isolation at pH 8-10, converted into the DL-amino-acid amide and this DL-amino-acid is used again. 22772-1062

公开(公告)号：CA983240A

公开(公告)日：1976-02-10

申请号：CA174111

申请日：1973-06-15

Applicant: STAMICARBON

Inventor： OTTENHEYM JOHANNES H ,  DASSEN BERNARDUS H N

IPC: C22B3/00 ,  B01D15/00 ,  B01D15/04 ,  B01D53/64 ,  B01J20/24 ,  B01J45/00 ,  C02F1/28 ,  C02F1/42 ,  C02F1/52 ,  C02F1/62 ,  C09K3/00 ,  C22B3/24

Abstract: 1401891 Removing metals from solutions; gas separation STAMICARBON BV 14 June 1973 [17 June 1972 1 May 1973 17 May 1973] 28383/73 Headings C1A and C1C [Also in Division C3] Metal values are removed from solutions or gaseous mixtures containing them by contacting the solution or mixture with a reduced keratin, a Bunte salt of a keratin or a natural or synthetic polyamide having at least some of the amide groups replaced by thioamide groups, which binds the metal values to the contacting agent. The keratin may be in the form of wool or fowls' feathers and can be converted to the Bunte salt by reaction with an alkali metal or alkaline earth metal sulphite with a tetrathionate as oxidant. The amide groups of a natural or synthetic polyamide can be replaced by thioamide groups by reaction of the polyamide with phosphorus pentasulphide. The process may particularly be applied to aqueous effluents.