4-(2-Nitro­benz­yl)-3-phenyl-3,4-di­hydro-2H-1,4-benzoxazin-2-ol

The title compound, C₂₁H₁₈N₂O₄, crystallizes with two independent mol­ecules (A and B) in the asymmetric unit. In both mol­ecules the oxazine ring has an envelope conformation with the hydroxyl-substituted C atom as the flap. The nitro­benzyl ring and the phenyl ring are almost normal to the mean plane of the benzooxazine ring system with dihdral angles of 85.72 (15) and 82.69 (15)°, respectively, in mol­ecule A, and 85.79 (15) and 87.72 (15)°, respectively, in mol­ecule B. The main difference in the conformation of the two mol­ecules concerns the dihedral angle between the nitro­benzyl ring and the phenyl ring, viz. 79.67 (18) in mol­ecule A and 71.13 (18)° in mol­ecule B. In the crystal, the A and B mol­ecules are linked by an O—H...O hydrogen bond. These units are then linked via C—H...O hydrogen bonds, forming sheets lying parallel to (010). Further C—H...O hydrogen bonds link the sheets to form a three-dimensional network. There are also O—H...π and C—H...π inter­actions present, reinforcing the three-dimensional structure.