2,6-Bis(2-chloro­benzyl­idene)cyclo­hexanone

Deyun Liu

doi:10.1107/S1600536809007648

. 2009 Mar 6;65(Pt 4):o694. doi: 10.1107/S1600536809007648

2,6-Bis(2-chlorobenzylidene)cyclohexanone

Deyun Liu ^a,^*

PMCID: PMC2968786 PMID: 21582435

Abstract

In the title molecule, C₂₀H₁₆Cl₂O, the central cyclohexanone ring adopts an envelope conformation. The two aromatic rings form a dihedral angle of 30.0 (1)°. The crystal packing exhibits weak intermolecular C—H⋯O hydrogen bonds and short Cl⋯O contacts [3.213 (3) Å].

Related literature

For general background, see: Tanaka & Toda (2000 ▶). For a similar crystal structure, see: Brinda et al. (2007 ▶).

Experimental

Crystal data

C₂₀H₁₆Cl₂O
M _r = 343.23
Orthorhombic,
a = 14.4004 (15) Å
b = 8.1553 (10) Å
c = 28.593 (3) Å
V = 3358.0 (6) Å³
Z = 8
Mo Kα radiation
μ = 0.39 mm⁻¹
T = 298 K
0.42 × 0.32 × 0.17 mm

Data collection

Bruker SMART APEX CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.854, T _max = 0.937
13876 measured reflections
2962 independent reflections
1762 reflections with I > 2σ(I)
R _int = 0.064

Refinement

R[F ² > 2σ(F ²)] = 0.045
wR(F ²) = 0.124
S = 1.06
2962 reflections
208 parameters
H-atom parameters constrained
Δρ_max = 0.24 e Å⁻³
Δρ_min = −0.32 e Å⁻³

Data collection: SMART (Siemens, 1996 ▶); cell refinement: SAINT (Siemens, 1996 ▶); data reduction: SAINT (Siemens, 1996 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809007648/cv2518sup1.cif

e-65-0o694-sup1.cif^{(16.8KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809007648/cv2518Isup2.hkl

e-65-0o694-Isup2.hkl^{(145.5KB, hkl)}

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

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C20—H20⋯O1ⁱ	0.93	2.51	3.352 (4)	151

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Symmetry code: (i) Inline graphic .

Acknowledgments

This project was supported by the Foundation of Liaocheng Vocational and Technical College.

supplementary crystallographic information

Comment

Development of new solid phase (solvent-free) reactions and transferring solution phase reactions to solid phase are subjects of recent interest in the context of generating libraries of molecules for the discovery of biologically active leads and also for the optimization of potent drug candidates (Tanaka & Toda, 2000).

In this paper, we describe the synthesis of the title compound, (I), starting from the fragrant aldehydes and cyclohexanone in the presence of NaOH under solvent-free conditions. This method can be considered as a general method for the synthesis of benzylidene cyclohexanones.

In (I) (Fig. 1), all bond lengths and angles are normal and correspond to those observed in 4-methyl-2,6-bis(2-naphthylmethylene) cyclohexan-1-one (Brinda et al., 2007). The central cyclohexanone ring adopts an envelope conformation, the dihedral angles between the rings C8-C13 and C15-C20 is 30.0 (1)°.

The crystal packing exhibits short Cl···O contacts (Table 1) and weak intermolecular C—H···O hydrogen bonds (Table 2).

Experimental

2-Chlorobenzaldehyde (2 mmol) and cyclohexanone (1.0 mmol), NaOH (2.0 mmol) were mixed in 50 ml flash under sovlent-free condtions After stirring 15 min at 293 K, tthe resulting mixture was washed with water for several times for removing NaOH, and recrystalized from ethanol, and afforded the title compound as a crystalline solid. Elemental analysis: calcd. for C₂₀H₂₆Cl₂O: C 69.98, H 4.70%; found: C 69.93, H 4.65%.