PYROGLUTAMATS AND THEIR APPLICATION FOR THE SEPARATION OF OPTICAL ISOMERS OF INTERMEDIATE PRODUCTS OF SYNTHESIS OF DEXSTROCETHIRISIN AND LEVOCETIRISIN

摘要

The application describes a salt of (S) -2- [4- (4-chlorobenzhydryl) piperazin-1-yl] ethoxyacetamide with (S) -pyrrolidone-5-carboxylic acid; a salt of (R) -2- [4- (4-chlorobenzhydryl) piperazin-1-yl] ethoxyacetamide with (S) -pyrrolidone-5-carboxylic acid; a salt of (S) -2- [4- (4-chlorobenzhydryl) piperazin-1-yl] ethoxyacetamide with (S) -pyrrolidone-5-carboxylic acid and a salt of (R) -2- [4- (4-chlorobenzhydryl) piperazine -1-yl] ethoxyacetamide with (R) -pyrrolidone-5-carboxylic acid. The application also describes a method for producing (S) -2- [4- (4-chlorobenzhydryl) piperazin-1-yl] ethoxyacetamide (I) and (R) -2- [4- (4-chlorobenzhydryl) piperazin-1-yl ] ethoxyacetamide (II) by chemical separation of the mixture. These compounds are intermediates for the synthesis of dextrocetirizine and levocetirizine, respectively.