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

In the title compound, C(10)H(11)NO(3)S, there is distorted tetra­hedral geometry around the S atom. The heterocyclic thia­zine ring adopts a half-chair conformation. The ethyl and sulfonyl groups form dihedral angles of 82.53 (13) and 88.91 (9)°, respectively, with the plane formed by the benzothia­zine ring, excluding the S atom; the S atom and the ethyl group lie on opposite sides of the ring. The mol­ecules are linked into dimers by inter­molecular C—H⋯O hydrogen bonds involving benzene C—H and carbonyl O atoms, thus forming eight-membered rings. The dimers are linked into chains via inter­actions of a similar type. There is an intra­molecular C—H⋯O hydrogen bond.