The asymmetric unit of the title compound, C16H20N2O2, consists of two independent mol-ecules differing slightly in the conformations of the seven-membered rings and the butyl substituents, where the benzene rings are oriented at a dihedral angle of 34.56 (3)°. In the crystal, pairwise inter-molecular C-H⋯O and complementary intra-molecular C-H⋯O hydrogen bonds form twisted strips extending parallel to (012). These strips are connected into layers parallel to (111) by additional inter-molecular C-H⋯O hydrogen bonds. The layers are further joined by C-H⋯π inter-actions. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (65.5%), H⋯C/C⋯H (16.0%) and H⋯O/O⋯H (15.8%) inter-actions.
Keywords: Hirshfeld surface; benzodiazepine; crystal structure; hydrogen bond; π-stacking.