Patent ID: 6162753
Filing Date: 2000-12-19
Classification: B01J

Abstract:
A process for recovering cobalt carbonyl catalysts used in the preparation of N-acyl-alpha-amino acid derivatives by amidocarbonylation comprising the process steps:a--amidocarbonylating N-acyl-alpha-amino acid derivatives in a solution forming a reaction solution,b--adding aqueous hydrogen peroxide solution to the reaction solution present after the preparation of the N-acyl-alpha-amino acid derivative forming an aqueous phase and non-aqueous product-containing phase,c--then separating the aqueous phase containing water-soluble cobalt(II) salt from the non-aqueous product-containing phase,d--subsequently adding an alkali metal salt of the N-acyl-alpha-amino acid derivative to the aqueous phase from the step c and forming a precipitated cobalt salt,e--then separating off the precipitated cobalt salt of the N-acyl-alpha-amino acid derivative to form a resulting cobalt salt, andf--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.