Crystal structure of 4,4'-bis-[3-(piperidin-1-yl)prop-1-yn-1-yl]-1,1'-biphen-yl

The title compound, C₂₈H₃₂N₂, (I), is one of a second generation of compounds designed and synthesized based on a very potent and selective α9α10 nicotinic acetyl-choline receptor antagonist ZZ161C {1,1'-[[1,1'-biphen-yl]-4,4'-diylbis(prop-2-yne-3,1-di-yl)]bis-(3,4-di-methyl-pyridin-1-ium) bromide}, which has shown analgesic effects in a chemotherapy-induced neuropathy animal model. Compound (I) was synthesized by the reaction of 4,4'-bis-(3-bromo-prop-1-yn-1-yl)-1,1'-biphenyl with piperidine at room temperature in aceto-nitrile. The single-crystal used for X-ray analysis was obtained by dissolving (I) in a mixture of di-chloro-methane and methanol, followed by slow evaporation of the solvent. In the crystal of (I), the biphenyl moiety has a twisted conformation, with a dihedral angle of 25.93 (4)° between the benzene rings. Both piperidine head groups in (I) are in the chair conformation and are oriented so that the N-atom lone pairs of each piperidine group point away from the central biphenyl moiety.