N-(2-Chloro-phen-yl)-4-hydr-oxy-2H-1,2-benzothia-zine-3-carboxamide 1,1-dioxide.

In the title compound, C(15)H(11)ClN(2)O(4)S, there are two independent mol-ecules in the asymmetric unit, in which the heterocyclic thia-zine rings in both mol-ecules adopt half-chair conformations. The conformations about the C-C and C-N bonds in the central C-C-N-C chain in both mol-ecules are all EZ. There are strong intra-molecular O-H⋯O and N-H⋯N hydrogen bonds resulting in graph-set patterns S(6) and S(5) for the oxo and amino rings, in addition to intra-molecular N-H⋯Cl inter-actions. In the crystal structure, mol-ecules are linked by inter-molecular O-H⋯O and N-H⋯O hydrogen bonds into chains along [100].