ABSTRACT
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 34.56â (3)°. In the crystal, pairwise inter-molecular C-Hâ¯O and complementary intra-molecular C-Hâ¯O hydrogen bonds form twisted strips extending parallel to (012). These strips are connected into layers parallel to (111) by additional inter-molecular C-Hâ¯O hydrogen bonds. The layers are further joined by C-Hâ¯π inter-actions. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from Hâ¯H (65.5%), Hâ¯C/Câ¯H (16.0%) and Hâ¯O/Oâ¯H (15.8%) inter-actions.