2-{(E)-[(2Z)-(3-Chloro-1-methyl-2,2-dioxo-3,4-dihydro-1H-2,1-benzothiazin-4-ylidene)hydrazinylidene]methyl}phenol

In the title compound, C16H14ClN3O3S, the thiazine ring adopts a sofa (half-chair) conformation, with an r.m.s. deviation from the mean plane of 0.23 angstrom. The S atom and S-bonded C atom exhibit the maximum deviations from the thiazine mean plane [-0.3976 (12) and 0.3179 (14) angstrom, respectively]. The conformations around the double bonds in the R2C=N-N=CHR unit are Z and E. An intramolecular O-H center dot center dot center dot N hydrogen bond with the hydroxy group as donor generates an S(6) ring motif. In the crystal, pairs of weak C-H center dot center dot center dot O interactions connect the molecules, forming inversion dimers.