3-[(3-Benzoyl-4-hydroxy-1,1-dioxo-2H-1λ6,2-benzothiazin-2-yl)methyl]benzonitrile

There are two independent molecules in the asymmetric unit of the title compound, C23H17N2O4S, with significant differences in their conformations, e. g. the benzene rings of the benzothiazine and benzonitrile units are inclined at 28.19 (10) and 17.89 (7)degrees in the two molecules, with the centroids of the rings separated by 3.975 (2) and 3.637 (2) angstrom, respectively. Moreover, the N-C-C-C torsion angles involving the benzoyl group are 14.3 (5) and 8.2 (5)degrees in the two molecules, showing different degrees of rotation of this group. In both molecules, the heterocyclic thiazine rings adopt half-chair conformations, with the S and N atoms displaced by 0.427 (6) and 0.365 (6) angstrom, respectively, in one molecule and by 0.356 (6) and 0.432 (6) angstrom, respectively, in the other, on opposite sides of the mean planes formed by the remaining ring atoms. The crystal structure is stabilized by intermolecular C-H center dot center dot center dot O hydrogen bonds and further consolidated by intramolecular O-H center dot center dot center dot O hydrogen bonds.