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

Abstract

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.