3-Hy­droxy-4-phenyl-1-(prop-2-en-1-yl)-2,3,4,5-tetra­hydro-1H-1,5-benzodiazepin-2-one

The asymmetric unit of the title compound, C₁₈H₁₈N₂O₂, contains three independent mol­ecules. In each, the seven-membered diazepine ring adopts a boat conformation with the hy­droxy-substituted C atom at the prow and fused-ring C atoms at the stern. In the crystal, the mol­ecules are linked by O—H...O and N—H...O hydrogen bonds. The allyl group of one mol­ecule is equally disordered over two positions.