Crystal structure of 2-chloro-1-(3-ethyl-2,6-di-phenyl-piperidin-1-yl)ethanone.

In the racemic title compound, C21H24ClNO, the dihedral angle between the planes of the benzene rings is 86.52 (14)° and those between the benzene rings and the piperidine ring are 61.66 (14) and 86.39 (14)°. The piperidine ring adopts a twisted boat conformation. No directional inter-actions could be detected in the crystal.

Crystal structure of 2-chloro-1-(3-methyl-2,6-di-phenyl-piperidin-1-yl)ethanone.

In the title compound, C20H22ClNO, the piperidine ring has a twist-boat conformation. There is an intra-molecular C-H⋯π inter-action involving the two phenyl rings which are inclined to one another by 84.91 (7)°. In the crystal, mol-ecules are linked via C-H⋯O hydrogen bonds, forming helical chains along [010]. The chains are linked by C-H⋯π inter-actions, forming sheets parallel to (100).

3,5-Dimethyl-2,6-di-phenyl-piperidine.

In the title compound, C19H23N, the piperidine ring has a chair conformation. The phenyl rings are inclined to one another by 52.76 (16)°. One of the methyl substituents on the piperidine ring is axial while the other is equatorial, like the phenyl rings. In the crystal, mol-ecules are linked via C-H⋯π inter-actions, forming zigzag chains along [001].

r-2,c-6-Di-phenyl-piperidine.

In the title compound, C17H19N, the piperidine ring adopts a chair conformation. The phenyl rings substituted at the 2- and 6-positions of the piperidine ring subtend dihedral angles of 81.04 (7) and 81.10 (7)° with the best plane of the piperidine ring. The crystal packing features C-H⋯π inter-actions.

2-Chloro-1-(3,3-dimethyl-2,6-di-phenyl-piperidin-1-yl)ethanone.

In the title compound, C21H24ClNO, the piperidine ring adopts a chair conformation. The two phenyl rings are inclined to one another by 20.7 (1)°, and are inclined to the mean plane of the four planar atoms of the piperidine ring by 87.64 (10) and 70.8 (1)°. The mol-ecular structure features short intra-molecular C-H⋯Cl and C-H⋯O contacts. In the crystal, there are no significant inter-molecular inter-actions present.

3-Ethyl-cis-2,6-di-phenyl-piperidine.

In the title compound, C19H23N, the piperidine ring adopts a chair conformation. The phenyl rings at the 2,6-positions of the piperidine ring occupy equatorial orientations. The crystal structure features C-H⋯π inter-actions.