1-Ethyl-4-{2-[1-(4-methylphenyl)ethylidene]hydrazinylidene}-3,4-dihydro-1H-2λ6,1-benzothiazine-2,2-dione

In the title compound, C19H21N3O2S, the dihedral angle between the aromatic rings is 6.7 (2)° and the C=N—N=C torsion angle is 178.0 (2)°. The conformation of the thiazine ring is an envelope, with the S atom displaced by 0.802 (2) from the mean plane of the other five atoms (r.m.s. deviation = 0.022 ). In the crystal, molecules are linked by C—H...O interactions, generating C(5) chains propagating in [010]. A weak C—H...π interaction is also observed.