Ethyl 2-(3,4-dimethyl-5,5-dioxo-1H,4H-benzo[e]pyrazolo­[4,3-c][1,2]thia­zin-1-yl)acetate

In the title mol­ecule, C(15)H(17)N(3)O(4)S, the heterocyclic thia­zine ring adopts a twist-boat conformation, which differs from that in related compounds, with adjacent S and C atoms displaced by 0.981 (4) and 0.413 (5) Å, respectively, on the same side of the mean plane formed by the remaining ring atoms. The mean plane of the benzene ring makes a dihedral angle of 23.43 (14)° with the mean plane of the pyrazole ring. In the crystal, mol­ecules are connected by weak C—H⋯O hydrogen bonds to form a three-dimensional network. The H atoms of the methyl group attached to the pyrazole ring were refined over six sites with equal occupancies.