Patent ID: 6291681
Filing Date: 2001-09-18
Classification: C07D

Abstract:
A process for the production of 2-oxo-1,3-dibenzyl-cis-4,5-imidazolidinedicarboxylic acid or 2-oxo-1,3-dibenzyl-cis-4,5-imidazolidinedicarboxylic acid anhydride starting from a meso-2,3-bis(benzylamino)succinic acid dialkali metal salt, comprising:a) reacting meso-2,3-bis(benzylamino)succinic acid dialkali metal salt with phenyl chloroformate in a monophasic solvent system consisting of an about 2:1 to 1:1 mixture of a water-miscible ether and aqueous alkali metal hydroxide solution at a temperature not exceeding about 40.degree. C.,b) converting the resulting 2-oxo-1,3-dibenzyl-cis-4,5-imidazolidinedicarboxylic acid dialkali metal salt by acidification into 2-oxo-1,3-dibenzyl-cis-4,5-imidazolidinedicarboxylic acid, andc) isolating the 2-oxo-1,3-dibenzyl-cis-4,5-imidazolidinedicarboxylic acid or converting the 2-oxo-1,3-dibenzyl- cis-4,5-imidazolidinedicarboxylic acid in step b) into 2-oxo-1,3-dibenzyl-cis-4,5-imidazolidinedicarboxylic acid anhydride by heating with acetic anhydride in an aromatic hydrocarbon as the organic solvent; and isolating the 2-oxo-1,3-dibenzyl-cis-4,5-imidazolidinedicarboxylic acid anhydride.