NMR-STUDIES OF DRUGS - USE OF LANTHANIDE SHIFT-REAGENTS IN POLAR-SOLVENT WITH THALIDOMIDE

The 200.1 MHz H-1 NMR spectra of thalidomide, 1underbar, have been stu died in CD3CN solution at ambient temperatures with the achiral shift reagent, uoro-2,2-dimethyl-3,5-octanedionato)europium(III), 2underbar, and the chiral reagent, ylhydroxy-methylene)-(+)-camphorato)europium( III), 3underbar. The use of sufficiently high LSR:1underbar molar rati os served to compensate for competitive binding of LSR by the polar so lvent, and permitted substantial lanthanide-induced shifts to be obser ved with 2underbar or 3underbar. With 3underbar, significant enantiome ric shift differences were produced for the methine NCH multiplets of each enantiomer to be fully separated from one another, offering the p otential for direct determination of enantiomeric excess of 1underbar.