High-performance liquid chromatographic enantioseparation of bicalutamide and its related compounds

Direct high-performance liquid chromatographic methods were developed for the enantioseparation of (R,S)-bicalutamide (1) and its analogs (+/-)-3-chloro-N-(4-cyano-3-(trifluoromethyl)phenyl)-2-hydroxy-2-methylpropanamide (2), (+/-)-N-(4-cyano-3-(trifluoro-methyl)phenyl)-2-methyloxirane-2-carboxamide (3), (+/-)-4-fluorophenylsulfonyl-2-hydroxy-2-methylpropionic acid (4) and (+/-)-3-hydroxy-N-(4-cyano-3-(trifluoromethyl)phenyl)-2-hydroxy-2-methylpropanamide (5). The methods involved the use of a cellulose-based Chiralcel OD-H, macrocyclic glycopeptide-based Chirobiotic T, TAG and R, beta-cyclodextrin-based Cyclobond I 2000SN and t-butyl carbamate-derivatized quinine-based columns. The conditions affording the best resolution were found by selection and variation of the mobile-phase compositions, and the differences in separation capability of the methods were noted. The sequence of elution of the enantiomers was determined in all cases.