1-(2-Chloro­benz­yl)-3-methyl-2,6-diphenyl­piperidine

Chennan Ramalingan; Seik Weng Ng; Edward R T Tiekink

doi:10.1107/S1600536812029200

. 2012 Jun 30;68(Pt 7):o2300. doi: 10.1107/S1600536812029200

1-(2-Chlorobenzyl)-3-methyl-2,6-diphenylpiperidine

Chennan Ramalingan ^a,^‡, Seik Weng Ng ^b,^c, Edward R T Tiekink ^b,^*

PMCID: PMC3394076 PMID: 22798941

Abstract

In the title compound, C₂₅H₂₆ClN, the piperidine ring has a chair conformation with all ring substituents in equatorial positions. The dihedral angle formed between the chlorobenzene ring and the flanking phenyl rings are 74.91 (18) and 47.86 (17)°. The chloro substituent is anti to the piperidine N atom. In the crystal, centrosymmetrically related molecules aggregate via π–π interactions occurring between chlorobenzene rings [centroid–centroid distance = 3.778 (2) Å] and these are linked into linear supramolecular chains along the a axis by C—H⋯π interactions occurring between the phenyl rings.

Related literature

For the biological activity of piperidine derivatives, see: Ramalingan et al. (2004 ▶); Ramachandran et al. (2011 ▶). For a related structure, see: Ramalingan et al. (2012 ▶).

Experimental

Crystal data

C₂₅H₂₆ClN
M _r = 375.92
Triclinic,
a = 10.0878 (7) Å
b = 10.2837 (5) Å
c = 11.3583 (7) Å
α = 94.150 (5)°
β = 107.713 (6)°
γ = 111.065 (5)°
V = 1025.32 (11) Å³
Z = 2
Mo Kα radiation
μ = 0.20 mm⁻¹
T = 100 K
0.25 × 0.15 × 0.03 mm

Data collection

Agilent SuperNova Dual diffractometer with an Atlas detector
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2012 ▶) T _min = 0.495, T _max = 1.000
7033 measured reflections
4678 independent reflections
2850 reflections with I > 2σ(I)
R _int = 0.034

Refinement

R[F ² > 2σ(F ²)] = 0.074
wR(F ²) = 0.185
S = 1.03
4678 reflections
244 parameters
12 restraints
H-atom parameters constrained
Δρ_max = 0.72 e Å⁻³
Δρ_min = −0.47 e Å⁻³

Data collection: CrysAlis PRO (Agilent, 2012 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ▶) and DIAMOND (Brandenburg, 2006 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812029200/hb6872sup1.cif

e-68-o2300-sup1.cif^{(21.5KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812029200/hb6872Isup2.hkl

e-68-o2300-Isup2.hkl^{(229.1KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812029200/hb6872Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

Cg1 is the centroid of the C20–C25 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C17—H17⋯Cg1ⁱ	0.95	2.83	3.692 (4)	151

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors are grateful for facilities provided by the Chairman/Management of Kalasalingam University, and thank the Ministry of Higher Education (Malaysia) for funding structural studies through the High-Impact Research scheme (UM.C/HIR/MOHE/SC/3).

supplementary crystallographic information

Comment

Piperidine derivatives are an important class of heterocyclic compounds with potential applications in medicinal chemistry as these can be frequently recognized in the structures of various synthetic targets as well as naturally occurring alkaloids (Ramalingan et al., 2004; Ramachandran et al., 2011). The title compound, (I), was designed and synthesized to evaluate its biological properties. The crystal structure determination was undertaken in order to establish conformational details.

In (I), Fig. 1, the piperidine ring has a chair conformation and all ring-substituents occupy equatorial positions. The dihedral angle formed between the C1–C6 benzene ring and the flanking C14–C19 and C20–C25 phenyl rings are 74.91 (18) and 47.86 (17)°, respectively; the dihedral angle between the phenyl rings is 58.93 (18)°. In a comparable molecule, having an extra C-bound methyl group (Ramalingan et al., 2012), these substituents were found to occupy the same positions. The chloro substituent is anti to the piperidine-N atom.

In the crystal packing, centrosymmetrically related molecules aggregate viaπ—π interactions occurring between chlorobenzene rings [inter-centroid distance = 3.778 (2) Å for symmetry operation 2 - x, 1 - y, 1 - z]. These are linked into linear supramolecular chains along the a axis by C—H···π interactions whereby a phenyl-H17 atom associates with the C20—C25 ring, Fig. 2 and Table 1. Chains aggregate into layers in the ab plane without specific intermolecular interactions between them, Fig. 3.

Experimental

A starting material, 3-methyl-2,6-diphenylpiperidine, was synthesized from benzaldehyde, 2-butanone and ammonium acetate through a Mannich-type reaction (for a typical synthesis, see Ramalingan et al. (2004)) followed by standard Wolff-Kishner reduction using hydrazine hydrate in diethylene glycol. 1-(2-Chlorobenzyl)-3-methyl-2,6-diphenylpiperidine was then synthesized as follows. To a DMF solution (15 ml) of 3-methyl-2,6-diphenylpiperidine (1.26 g, 0.005 mol) was added potassium tert-butoxide (0.67 g, 0.006 mol). The mixture was stirred for 30 minutes and 2-chlorobenzyl bromide (0.78 ml, 0.006 mol) was added drop-wise. Stirring was continued overnight before aqueous work-up. Extraction with diethyl ether followed by column chromatography separation using n-hexane/ethyl acetate (100:4) as an eluent eventually provided the pure title compound as a white solid. Re-crystallization was performed by slow evaporation of its ethanolic solution which afforded colourless plates. M.pt: 352–353 K. Yield: 83%.