Crystal structures of three substituted 3-aryl-2-phenyl-2,3-di­hydro-4H-1,3-benzo­thia­zin-4-ones

Three ring-substituted 3-aryl analogs of 2-phenyl-2,3-di­hydro-4H-1,3-benzo­thia­zin-4-one, namely 3-(4-meth­oxy­phen­yl)-2-phenyl-4H-1,3-benzo­thia­zin-4-one, C21H17NO2S, (I), 2-phenyl-3-[4-(tri­fluoro­meth­yl)phen­yl]-2,3-di­hydro-4H-1,3-benzo­thia­zin-4-one toluene hemisolvate, C21H14F3NOS·0.5C7H8, (II), and 3-(3-bromo­phen­yl)-2-phenyl-2,3-di­hydro-4H-1,3-benzo­thia­zin-4-one toluene hemisolvate, C20H14BrNOS·0.5C7H8, (III), were synthesized and their crystal structures determined. The hemisolvates differ in that in (II), the asymmetric unit comprises two molecules of the benzo­thia­zinone compound and a toluene solvent mol­ecule, whereas in (III), the unit comprises one benzo­thia­zinone mol­ecule and a half-occupancy toluene solvent mol­ecule. All crystals are of racemic mixtures of the chiral 2-C atom of the thia­zine moiety, which in all structures has a screw-boat puckering, with the puckering amplitude values within the range 0.575–0.603 Å. In all three structures, the benzene plane of the benzo­thia­zine system makes a dihedral angle in the range 78.60 (5) to 98.40 (5)° with the unsubstituted benzene plane and in the range 70.50 (1) to 121.00 (5)° with the substituted benzene plane. The CF3 substituent group in one of the mol­ecules of (II) shows positional disorder, with an occupancy ratio of 0.57 (3):0.43 (3). In the crystals of (I) and (II), weak inter­molecular C—H⋯O inter­actions are present, giving in (I), mol­ecules arranged in a plane parallel to (010), and in (II), chains along a. In addition, all three structures show weak C—H⋯π inter­actions involving various aromatic rings.