In the title compound, C24H36N2O2, the orientation of the 2-oxopropylidene substituent is determined by the formation of an intramolecular N—H...O hydrogen bond. The benzodiazepine seven-membered ring adopts a slightly twisted boat conformation. The molecules pack in a bilayer fashion with the dodecyl chains intercalated to form the inner portion, and the benzodiazepine moieties on the outer surfaces.