Methyl 3-[(1,1-dioxo-1λ⁶,2-benzothiazol-3-yl)amino]-5-nitrothiophene-2-carboxylate

Abstract

The title nitro­thio­phene compound, C13H9N3O6S2, crystallizes with two independent mol­ecules in the asymmetric unit; the mol­ecular structure of each is stabilized by an intra­molecular N—H⋯O hydrogen bond. The two mol­ecules adopt flattened but slightly different conformations, viz. the dihedral angle between the thio­phene ring and the essentailly planar 1,2-benzisothia­zole fragment (r.m.s. deviations = 0.0227 and 0.0108 Å, respectively) is 15.62 (11)° in one mol­ecule and 5.46 (11)° in the other. In the crystal, mol­ecules are arranged into layers parallel to (-111) with weak Car—H⋯O inter­actions formed within the layer. N—H⋯O hydrogen bonds also occur. There are π–π stacking inter­actions between the mol­ecules in neighbouring layers, the distance between the centroids of the 1,2-benzisothia­zole benzene rings being 3.8660 (16) Å. Moreover, dipolar S=O⋯C=O inter­actions with an O⋯C distance of 2.893 (3) Å are observed between the symmetry-independent mol­ecules in different layers. The title compound showed weak inhibition of HLE (human leukocyte elastase).