PYROGLUTAMATE SALTS AND THEIR USE IN THE OPTICAL RESOLUTION OF INTERMEDIATES FOR THE SYNTHESIS OF DEXTROCETIRIZINE AND LEVOCETIRIZINE
摘要
<p>The present invention relates to (S)-2-[4-(4-chlorobenzhydryl)piperazin-1-yl]- ethoxyacetamide - (S)-pyrrolidone-5-carboxylic acid salt; (R)-2-[4-(4-chlorobenzhydryl)piperazin-1-yl]-ethoxyacetamide - (S)-pyrrolidone-5-carboxylic acid salt; (S)-2-[4-(4-chlorobenzhydryl)piperazin-1-yl]-ethoxyacetamide - (R)-pyrrolidone-5-carboxylic acid salt; or (R)-2-[4-(4-chlorobenzhydryl)piperazin-1-yl]-ethoxycetamide - (R)-pyrrolidone-5-carboxylic salt. The present invention relates also to a process for preparing (S)-2-[4-(4-chlorobenzhydryl)piperazin-1-yl]-ethoxyacetamide (I) and (R)-2-[4-(4-chlorobenzhydryl) piperazin-1-yl]-ethoxyacetamide (II) by chemical resolution of a mixture. These compounds are respectively intermediates for the synthesis of dextrocetirizine and levocetirizine.</p>
