Abstract
In the title compound, C17H15NO5S, the benzene ring of the fused-ring system is twisted by 11.67 (6)degrees with respect to the thiazine ring. The atoms of the four-atom methyl ester group and the phenyl ring of the benzyl unit are inclined at 16.50 (7) and 44.52 (3)degrees with respect to the thiazine ring. An intramolecular O-H center dot center dot center dot O hydrogen bond gives rise to a six-membered S(6) ring motif. In the crystal, molecules are extended through a C-H center dot center dot center dot O interaction along the a axis. C-H center dot center dot center dot pi interactions are also observed.