4-Methyl-2,3-dihydro-1H-1,5-benzodiazepin-2-one monohydrate.

The seven-membered fused-ring in the title compound, C(10)H(10)N(2)O·H(2)O, adopts a boat conformation (with the two phenyl-ene C atoms representing the stern and the methyl-ene C atom the prow). In the crystal, two benzodiazepinone mol-ecules are linked about a center of inversion by diazepine-carbonyl N-H⋯O hydrogen bonds. The dimers are further linked by water-diazepine O-H⋯N hydrogen bonds, forming a linear chain.