UNUSUAL EXAMPLES OF THE LIQUID-CHROMATOGRAPHIC RESOLUTION OF RACEMATES - RESOLUTION OF PI-DONOR ANALYTES ON A PI-DONOR CHIRAL STATIONARY-PHASE

A a-basic chiral stationary phase (CSP) derived from (S)-1-(6,7-dimeth yl-1-naphthyl)isobutylamine was used for the resolution of the enantio mers of pi-basic 3,5-dimethylanilide derivatives of non-steroidal anti -inflammatory drugs related to alpha-arylpropionic acids. The separati on factors are large enough for analytical purposes, baseline resoluti on being obtained. From the resolution of 3,5-dimethylanilide, N-methy l-3,5-dimethylanilide, N-alkylamide and N,N-dialkylamide derivatives o f naproxen, it was concluded that the pi-basic aryl derivatizing group plays a role as a hydrogen bond acceptor in the chiral recognition pr ocess and the amide NH hydrogen of analytes is essential for chiral re cognition.