Process for recovering cobalt carbonyl catalysts used to produced N-acyl-alpha-amino acid derivatives by amidocarbonylation

US6162753A · kind A · utility

Assignee

• Aventis Research & Technologies GmbH & Co. · DE

Inventors

• Holger Geissler · Mainz, DE
• Peter Gross · Saarlouis, DE
• Sandra Bogdanovic · Frankfurt am Main, DE

Key dates

• Filing date: Jul 28, 1999
• Grant date: Dec 19, 2000
• Expiry date: Jul 28, 2019

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B01J2531/845
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

The present invention relates to a process for recovering cobalt carbonyl catalysts used in the preparation of N-acyl-alpha-amino acid derivatives by amidocarbonylation comprising the process steps: PA0 adding aqueous hydrogen peroxide solution to the reaction solution present after the preparation of the N-acyl-.alpha.-amino acid derivative, PA0 then separating the aqueous phase containing water-soluble cobalt(II) salt from the nonaqueous product-containing phase, PA0 subsequently adding an alkali metal salt of the N-acyl-alpha-amino acid derivative to the aqueous phase from the previous process step, PA0 then separating off the precipitated cobalt salt of the N-acyl-alpha-amino acid derivative, and PA0 finally converting the resulting cobalt salt of the N-acyl-alpha-amino acid derivative into the cobalt carbonyl catalyst in the presence of a mixture of carbon monoxide and hydrogen.