Crystal structure and Hirshfeld surface analysis of the hydro-chloride salt of 8-{4-[(6-phenyl-pyridin-3-yl)meth-yl]piperazin-1-yl}-3,4-di-hydro-quinolin-2(1 H)-one

Abstract

The amine 8-{4-[(6-phenyl-pyridin-3-yl)meth-yl]piperazin-1-yl}-3,4-di-hydro-quinolin-2(1H)-one was crystallized as the hydro-chloride salt, 4-(2-oxo-1,2,3,4-tetra-hydro-quinolin-8-yl)-1-[(6-phenyl-pyridin-3-yl)meth-yl]piperazin-1-ium chloride, C₂₅H₂₇N₄ ⁺·Cl^- (I·HCl). The conformation of the organic cation is half-moon in shape enclosing the chloride anion. The piperidine ring of the 3,4-di-hydro-quinolin-2(1H)-one moiety has a screw-boat conformation, while the piperazine ring has a chair conformation. In the biaryl group, the pyridine ring is inclined to the phenyl ring by 40.17 (7) and by 36.86 (8)° to the aromatic ring of the quinoline moiety. In the crystal, the cations are linked by pairwise N-H⋯O hydrogen bonds, forming inversion dimers enclosing an R ² ₂(8) ring motif. The Cl^- anion is linked to the cation by an N-H⋯Cl hydrogen bond. These units are linked by a series of C-H⋯O, C-H⋯N and C-H⋯Cl hydrogen bonds, forming layers lying parallel to the ab plane.

Keywords: Hirshfeld surface analysis; crystal structure; di­hydro­quinolin-2(1H)-one; dopamine D2 receptor; hydrogen bonding; hydro­chloride; mol­ecular salt; piperazine; serotonin 5-HT1a receptor.