N-(2-Chlorophenyl)-4-hydroxy-2H-1,2-benzothiazine-3-carboxamide 1,1-dioxide

In the title compound, C15H11ClN2O4S, there are two independent molecules in the asymmetric unit, in which the heterocyclic thiazine rings in both molecules adopt half-chair conformations. The conformations about the C-C and C-N bonds in the central C-C-N-C chain in both molecules are all EZ. There are strong intramolecular O-H center dot center dot center dot O and N-H center dot center dot center dot N hydrogen bonds resulting in graph-set patterns S(6) and S(5) for the oxo and amino rings, in addition to intramolecular N-H center dot center dot center dot Cl interactions. In the crystal structure, molecules are linked by intermolecular O-H center dot center dot center dot O and N-H center dot center dot center dot O hydrogen bonds into chains along [100].