4-Methyl-3-phenyl-2,4-dihydropyrazolo[4,3-c][1,2]benzothiazine 5,5-dioxideThis paper is dedicated to Dr Hamid Latif Siddiqui who passed away to heaven on July 26, 2012.

Abstract

In the title molecule, C16H13N3O2S, the heterocyclic thiazine ring adopts a twist chair conformation with the S atom and an adjacent C atom displaced by 0.946 (5) and 0.405 (6) Å, respectively, on the same side of the mean plane formed by the remaining ring atoms. The mean planes of the benzene rings make dihedral angles of 16.61 (10) and 15.32 (10)° with the mean plane of the pyrazole ring. The molecular structure is consolidated by intramolecular C—H...N interactions and the crystal packing is stabilized by N—H...O and C—H...N hydrogen bonds. The crystal studied was an inversion twin with the refined ratio of the twin components being 0.53 (11):0.47 (11).