Synthesis, characterization, crystal structure and Hirshfeld surface analysis of a hexahydroquinoline derivative: tert-butyl 4-([1,1′-biphenyl]-4-yl)-2,6,6-trimethyl-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate

The title compound, C29H33NO3, crystallizes with three molecules (A, B and C) in the asymmetric unit. They differ in the twist of the phenyl and benzene rings of the 1,1′-biphenyl ring with respect to the plane of the 1,4-dihydropyridine ring. In all three molecules, the 1,4-dihydropyridine ring adopts a distorted boat conformation. The cyclohexene ring has an envelope conformation in molecules A and B, while it exhibits a distorted half-chair conformation for both the major and minor components in the disordered molecule C. In the crystal, molecules are linked by C-H⋯O and N-H⋯O hydrogen bonds, forming layers parallel to (100) defining R 1 4(6) and C(7) graph-set motifs. Additional C-H⋯π interactions consolidate the layered structure. Between the layers, van der Waals interactions stabilize the packing, as revealed by Hirshfeld surface analysis. The greatest contributions to the crystal packing are from H⋯H (69.6% in A, 69.9% in B, 70.1% in C), C⋯H/H⋯C (20.3% in A, 20.6% in B, 20.3% in C) and O⋯H/H⋯O (8.6% in A, 8.6% in B, 8.4% in C) interactions.