In the title mol-ecule, C(23)H(17)NO(5)S, the heterocyclic thia-zine ring adopts a half-chair conformation, with the S and N atoms displaced by 0.383 (3) and 0.473 (3) Å, respectively, on opposite sides of the mean plane formed by the ring C atoms. The phenyl rings attached to carbonyl groups lie almost parallel to each other at a dihedral angle 7.43 (9)°, the distance between the centroids of the rings being 3.780 (1) Å. The C(thia-zine)-C=O and O=C-CH(2) groups make dihedral angles of 37.56 (16) and 1.93 (18)°, respectively, with the phenyl groups to which they are attached. The crystal structure features O-H⋯O and C-H⋯O hydrogen bonds and further consolidated by C-H⋯π inter-actions; an intra-molecular O-H⋯O hydrogen bond is also present.