1-(2-Chlorobenzyl)-3,5-dimethyl-2,6-diphenylpiperidine

Two independent molecules (A and B) comprise the asymmetric unit of the title compound, C26H28ClN, with the inverted form of B almost superimposable upon A. Each piperidine ring has a chair conformation and the chloro substituent is anti to the piperidine N atom. Each of two aromatic rings, the benzyl residue and one methyl group substituents occupies an equatorial position, and the second methyl substituent occupies an axial position. The dihedral angle formed between the chlorobenzene ring and the flanking phenyl rings in molecule A are 84.24 (9) and 24.85 (8)°; the equivalent angles for molecule B are 79.97 (9) and 28.33 (9)°. In the crystal, the A and B molecules are connected by C—H⋯Cl and C—H⋯π interactions, forming a supramolecular chain along [101].

Two independent molecules (A and B) comprise the asymmetric unit of the title compound, C 26 H 28 ClN, with the inverted form of B almost superimposable upon A. Each piperidine ring has a chair conformation and the chloro substituent is anti to the piperidine N atom. Each of two aromatic rings, the benzyl residue and one methyl group substituents occupies an equatorial position, and the second methyl substituent occupies an axial position. The dihedral angle formed between the chlorobenzene ring and the flanking phenyl rings in molecule A are 84.24 (9) and 24.85 (8) ; the equivalent angles for molecule B are 79.97 (9) and 28.33 (9) . In the crystal, the A and B molecules are connected by C-HÁ Á ÁCl and C-HÁ Á Á interactions, forming a supramolecular chain along [101].
Cg1 is the centroid of the C35-C40 ring. The crystal structure determination of the title compound was undertaken in order to establish conformational details for a molecule designed and synthesized for the evaluation of its biological properties. The motivation for the biological trial arises as piperidine derivatives are an important class of heterocyclic compounds with potent pharmacological/biological activities (Ramalingan et al., 2004;Ramachandran et al., 2011).
Two independent molecules comprise the asymmetric unit of (I), Fig. 1. The inverted molecule of the N2-containing molecule is virtually super-imposable upon that of the N1-containing molecule, Fig. 2. The r.m.s. bond and angle fits are 0.0045 Å and 0.617°, respectively (Spek, 2009). Each piperidine ring has a chair conformation and the two aromatic rings, the benzyl residue and one methyl substituent occupy equatorial positions, as found in a related structure lacking one C-bound methyl group (Ramalingan et al., 2012), with the additional methyl substituent occupying an axial position.
In the crystal, the independent molecules are connected to each other by C-H···Cl and C-H···π interactions, Table 1, to form a supramolecular chain along [101], Fig. 3. These assemble into the three-dimensional architecture without specific intermolecular interactions between them, Fig. 4.

Figure 1
The molecular structure of (I) showing displacement ellipsoids at the 70% probability level.

Figure 2
Superimposition of the two independent molecules in (I); the N2-containing molecule has been inverted. The ring-C,N,Csequences have been superimposed, and the N1-and N2-containing molecules are shown as red and blue images, respectively.  A view in projection down the a axis of the unit-cell contents for (I). The C-H···Cl and C-H···π interactions are shown as orange and purple dashed lines, respectively.

1-(2-Chlorobenzyl)-3,5-dimethyl-2,6-diphenylpiperidine
Special details Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.