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

The title compound, C(21)H(18)N(2)O(4), 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.