2-(3-Nitrophenyl)-3-phenyl-2,3-dihydro-4H-1,3-benzothiazin-4-one

The title compound, C₂₀H₁₄N₂O ₃S, has three aromatic rings, viz. (i) a phenyl ring, (ii) a 3-nitrophenyl and (iii) a 1,3-benzothiazine fused-ring system. The dihedral angle between (i) and (ii) is 85.31(15)°, between (ii) and (iii) is 81.33(15)° and between (i) and (iii) is 75.73(15)°. The six-membered 1,3-thiazine ring has an envelope conformation with the C atom in the 2-position forming the flap. In the crystal, molecules are linked by weak C - H⋯O interactions, forming a three-dimensional network.