LIQUID-CHROMATOGRAPHIC SEPARATION OF THE ENANTIOMERS OF ANTIHISTAMINIC 3,3'-DI(1,3-THIAZOLIDIN-4-ONE) DERIVATIVES WITH 2 AND 4 STEREOGENIC CENTERS

The enantiomers of anti-inflammatory and antihistaminic -(1,2-ethanedi yl)bis(2-aryl-1,3-thiazolidin-4-one) derivatives possessing two stereo genic centres were separated on Chiralcel OD stationary phase without derivatization. The meso form was also well separated from the enantio mers. The good resolution afforded a milligram-scale separation and su bsequent measurement of the circular dichroism spectra of an enantiome ric pair. Addition of racemic alpha-mercaptopropionic acid to the N,N' -dibenzylideneethylenediamine yielded ten possible stereoisomers with four stereogenic centres. Two centres (2 and 2') bear the same groups; the other two (5 and 5') also bear the same groups, but these are dif ferent from the groups at 2 and 2'. In this situation four enantiomeri c pairs and two meso forms exist; all of them were separated and ident ified using a Chiralpak AD column.