1-Methyl-1H-2,1-benzothia­zin-4(3H)-one 2,2-dioxide

In the crystal structure of the title compound, C(9)H(9)NO(3)S, there is distorted tetra­hedral geometry around the S atom. The sulfonyl group is almost normal to the benzene ring, while the carbonyl O atom and methyl C atom are on opposite sides of this ring. The heterocyclic ring adopts a half-boat conformation with the S atom out of the plane. The mol­ecules are dimerized by hydrogen bonding involving the benzene ring and the sulfonyl group. These dimers are linked to each other in the same way. There is an intra­molecular hydrogen bond between a methyl C—H group and a sulfonyl O atom, and a π–π inter­action between the aromatic rings of two dimers at a centroid-to-centroid distance of 3.6373 (13) Å.