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

Abstract

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.

Keywords

• crystal structure