A monoclinic polymorph of chloro­thia­zide

Abstract

Accessible from basic aqueous solutions, a new monoclinic polymorph of the diuretic chloro­thia­zide is described.

A new polymorph of the diuretic chloro­thia­zide, 6-chloro-1,1-dioxo-2H-1,2,4-benzo­thia­zine-7-sulfonamide, C₇H₆ClN₃O₄S₂, is described. Crystallized from basic aqueous solution, this monoclinic polymorph is found to be less thermodynamically favoured than the known triclinic polymorph and to feature only N—H⋯O type inter­molecular hydrogen bonds as opposed to the N—H⋯O and N—H⋯N type hydrogen bonds found in the P1 form.