(R)-1-{(2-oxo-1,2-dihydroquinolin-6-yl)[3-(trifluoro-methyl)phenyl]methyl}-1H-1,2,4-triazol-4-ium bromide

The metabolism of all-trans-retinoic acid is mediated by a cytochrome depen dent P-450 system. The title compound, C19H14F3N4O+. Br- (R111214), is an i nhibitor of P-450. The three planar ring systems, viz. the triazolyl, pheny l and quinolinone groups, are arranged in a propeller-like fashion around t he central CH group. The dihedral angles formed by the triazolyl/phenyl, tr iazolyl/quinolinone and phenyl/quinolinone planes are 55.8 (1), 79.85 (9) a nd 78.49 (9)degrees, respectively. The N-H . . .O hydrogen bonds, involving the triazolium N-H group and the quinolinone O atom, link the cations into infinite chains stretching along the c axis of the crystal.