1-Ethyl-4-[1-(1-phenylethylidene)hydrazin-2-ylidene]-3,4-dihydro-1H2 lambda(6),1-benzothiazine-2,2-dione

In the title compound, C18H19N3O2S, the thiazine ring adopts an envelope conformation, with the S atom displaced by 0.732 (1) angstrom from the other atoms of the ring. The phenyl ring is oriented at a dihedral angle of 79.33 (7)degrees with respect to the fused benzene ring. The conformations about the two double bonds in the R2C=N-N C(CH3) Ar grouping are Z and E, respectively. In the crystal, inversion dimers linked by pairs of C-H center dot center dot center dot O interactions generate R-2(2) (8) and R-2(2) (12) loops, as parts of infinite chains along the a-axis direction.