Patent ID: 6255498
Filing Date: 2001-07-03
Classification: C07C,C07D

Abstract:
A process for preparing a compound having the structural formula (I) ##STR38##in which Ar.sup.1 and Ar.sup.2 are selected from the group consisting of aryl, aralkyl, heteroaryl and heteroaralkyl, optionally substituted with 1 to 3 substituents, and Q is O or S, the process comprising:(a) catalytically coupling a compound having the structure (II) ##STR39##to a compound having the structure (III) ##STR40##under reaction conditions effective to produce the diaryl-substituted dione or dithione intermediate (IV) ##STR41##(b) treating compound with a reducing agent, thereby providing compound (V) ##STR42##(c) effecting cyclization of compound (V), under acidic conditions, to produce cyclized intermediate (VI) ##STR43##as a racemic mixture of cis and trans isomers; and(d) isomerizing the cis isomer in the racemic mixture to give the trans isomer by dissolving the racemic mixture in a crystallization solvent, seeding the solvent with trans isomer, and cooling the mixture to promote crystallization, thereby effecting cis-trans isomerization.