Methyl 5-chloro-4-hy-droxy-2,2-dioxo-1-2λ,1-benzo-thia-zine-3-carboxyl-ate: structure and Hirshfeld surface analysis.

The title compound, CHClNOS, which has potential analgesic activity, crystallizes in space group 2/. The benzo-thia-zine ring system adopts an inter-mediate form between sofa and twist-boat conformations. The coplanarity of the ester substituent to the bicyclic fragment is stabilized by an O-H⋯O intra-molecular hydrogen bond. In the crystal, hydrogen bonds of type N-H⋯O(SO) link the mol-ecules into zigzag chains extending along the -axis direction. Neighbouring chains are linked by both O-H⋯Cl and C-H⋯Cl inter-actions. A Hirshfeld surface analysis was used to compare different types of inter-molecular inter-actions, giving contributions of O⋯H/H⋯O = 42.0%, C⋯H/H⋯C = 17.3%, Cl⋯H/H⋯Cl = 14.2%, H⋯H = 11.1%.