Crystal structure of rac-2,3-di­phenyl-2,3,5,6-tetra­hydro-4H-1,3-thiazin-4-one 1-oxide

In the title compound, C16H15NO2S [alternative name: rac-2,3-diphenyl-1,3-thia­zinan-4-one 1-oxide], the thia­zine ring exhibits an envelope conformation, with the S atom forming the flap. The sulfoxide O atom is in a pseudo-axial position on the thia­zine ring and is trans to the phenyl group on C-2. The phenyl rings form a dihedral angle of 89.47 (19)°. In this racemate crystal, homochiral mol­ecules form slabs parallel to (010) of thickness b/2 which then stack with alternating chirality in the b-axis direction. The stacking is aided by edge-to-face inter­actions between the phenyl rings of racemic mol­ecules. Within each of the single-enanti­omer slabs, the mol­ecules are held by C—H⋯O-type inter­actions, with an H⋯O distance of 2.30 Å, forming infinite chains along the c-axis direction, as well by the edge-to-face inter­actions between phenyl rings of neighboring mol­ecules in the a-axis direction.