Crystal structures of two 2,3-diaryl-2,3-di­hydro-4H-1,3-benzo­thia­zin-4-ones

The syntheses and crystal structures of 2,3-bis­[3-(tri­fluoro­meth­yl)phen­yl]-2,3-di­hydro-4H-1,3-benzo­thia­zin-4-one (di-m-CF(3); C(22)H(13)F(6)NOS) (1) and 2,3-bis­(4-methyl­phen­yl)-2,3-di­hydro-4H-1,3-benzo­thia­zin-4-one (di-p-CH(3); C(22)H(19)NOS) (2) are reported. Each structure is racemic: the asymmetric unit of 2 consists of two mol­ecules. In both 1 and 2, the six-membered 1,3-thia­zine ring is close to an envelope conformation with the chiral C atom forming the flap. In 1, the 2-aryl group is pseudo-equatorial, while in 2 it is pseudo-axial. In 1, the pendant aryl rings form a V shape with an inter-centroid distance of 3.938 (3) Å and an acute dihedral angle of 48.3 (2)° between them. Both CF(3) groups are disordered over two orientations in 0.687 (19):0.313 (19) and 0.667 (16):0.33 (16) ratios. In each of the independent mol­ecules of 2, the aryl rings are almost orthogonal to each other [dihedral angles = 85.50 (12) and 86.07 (11)°]. In both structures, the chiral C atom and the O atoms participate in C—H⋯O-type hydrogen bonding between symmetry-related mol­ecules of 1 or the independent enanti­omers in 2, forming chains along the c-axis direction in 1 and the b-axis direction in 2. Additionally, in 1, π–π contacts of both face-to-face and edge-to-face type, as well as π-H⋯O and π-H⋯F inter­actions are observed. In 2, a racemic mixture of mol­ecules forms layers in the ac plane linked by weak π–π and C—H⋯π inter­actions.