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Acta Cryst. (2009). E65, o694    [ doi:10.1107/S1600536809007648 ]

2,6-Bis(2-chlorobenzylidene)cyclohexanone

D. Liu

Abstract top

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].

Comment top

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).

Related literature top

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

Experimental top

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%.

Refinement top

All H atoms were positioned geometrically and refined using a riding model with C—H = 0.93–0.97 Å and Uiso(H) = 1.2Ueq(C).

Computing details top

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 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The molecular structure of (I) showing the atomic numbering scheme and 30% probability displacement ellipsoids.
(I) top
Crystal data top
C20H16Cl2ODx = 1.358 Mg m−3
Mr = 343.23Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, PbcaCell parameters from 2653 reflections
a = 14.4004 (15) Åθ = 2.8–43.8°
b = 8.1553 (10) ŵ = 0.39 mm−1
c = 28.593 (3) ÅT = 298 K
V = 3358.0 (6) Å3Needle, colourless
Z = 80.42 × 0.32 × 0.17 mm
F(000) = 1424
Data collection top
Bruker SMART APEX CCD area-detector
diffractometer		2962 independent reflections
Radiation source: fine-focus sealed tube1762 reflections with I > 2σ(I)
graphiteRint = 0.064
phi and ω scansθmax = 25.0°, θmin = 1.4°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)		h = −14→17
Tmin = 0.854, Tmax = 0.937k = −8→9
13876 measured reflectionsl = −29→34
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.045Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.124H-atom parameters constrained
S = 1.06 w = 1/[σ2(Fo2) + (0.0353P)2 + 3.2692P]
where P = (Fo2 + 2Fc2)/3
2962 reflections(Δ/σ)max = 0.001
208 parametersΔρmax = 0.24 e Å−3
0 restraintsΔρmin = −0.32 e Å−3
Crystal data top
C20H16Cl2OV = 3358.0 (6) Å3
Mr = 343.23Z = 8
Orthorhombic, PbcaMo Kα radiation
a = 14.4004 (15) ŵ = 0.39 mm−1
b = 8.1553 (10) ÅT = 298 K
c = 28.593 (3) Å0.42 × 0.32 × 0.17 mm
Data collection top
Bruker SMART APEX CCD area-detector
diffractometer		2962 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)		1762 reflections with I > 2σ(I)
Tmin = 0.854, Tmax = 0.937Rint = 0.064
13876 measured reflectionsθmax = 25.0°
Refinement top
R[F2 > 2σ(F2)] = 0.045H-atom parameters constrained
wR(F2) = 0.124Δρmax = 0.24 e Å−3
S = 1.06Δρmin = −0.32 e Å−3
2962 reflectionsAbsolute structure: ?
208 parametersFlack parameter: ?
0 restraintsRogers parameter: ?
Special details top

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 F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Cl11.01278 (6)1.01596 (12)0.34622 (3)0.0568 (3)
Cl20.72695 (8)0.83897 (15)0.07162 (3)0.0783 (4)
O10.86474 (15)0.7337 (3)0.22424 (7)0.0515 (7)
C10.7861 (2)0.7354 (4)0.24087 (10)0.0342 (8)
C20.7724 (2)0.7802 (4)0.29170 (10)0.0347 (8)
C30.6741 (2)0.8022 (5)0.30951 (11)0.0472 (9)
H3A0.67260.89540.33060.057*
H3B0.65670.70580.32730.057*
C40.6032 (2)0.8289 (5)0.27104 (11)0.0455 (9)
H4A0.61450.93340.25590.055*
H4B0.54130.83130.28440.055*
C50.6099 (2)0.6916 (4)0.23542 (11)0.0399 (8)
H5A0.60060.58700.25090.048*
H5B0.56150.70460.21220.048*
C60.7032 (2)0.6928 (4)0.21178 (10)0.0335 (7)
C70.8490 (2)0.8002 (4)0.31767 (10)0.0412 (8)
H70.90510.78610.30200.049*
C80.8563 (2)0.8412 (5)0.36743 (11)0.0458 (9)
C90.9282 (2)0.9410 (5)0.38404 (11)0.0485 (9)
C100.9346 (3)0.9856 (6)0.43068 (13)0.0654 (12)
H100.98171.05550.44060.078*
C110.8710 (3)0.9260 (7)0.46211 (14)0.0806 (15)
H110.87530.95500.49350.097*
C120.8011 (3)0.8238 (7)0.44739 (14)0.0836 (15)
H120.75850.78320.46890.100*
C130.7935 (3)0.7809 (6)0.40090 (12)0.0626 (12)
H130.74610.71080.39150.075*
C140.7172 (2)0.6681 (4)0.16580 (11)0.0399 (8)
H140.77760.68120.15490.048*
C150.6467 (2)0.6227 (4)0.13110 (10)0.0382 (8)
C160.6448 (2)0.6917 (4)0.08648 (11)0.0444 (9)
C170.5785 (3)0.6500 (5)0.05364 (12)0.0561 (10)
H170.57850.70020.02440.067*
C180.5126 (3)0.5339 (5)0.06440 (13)0.0610 (11)
H180.46720.50620.04260.073*
C190.5141 (3)0.4588 (5)0.10758 (13)0.0588 (11)
H190.47070.37810.11460.071*
C200.5795 (2)0.5029 (4)0.14024 (11)0.0461 (9)
H200.57910.45150.16930.055*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cl10.0448 (5)0.0640 (7)0.0615 (6)−0.0018 (5)−0.0062 (5)−0.0015 (5)
Cl20.1071 (9)0.0832 (8)0.0447 (5)−0.0501 (7)−0.0081 (6)0.0118 (5)
O10.0311 (14)0.086 (2)0.0376 (13)−0.0010 (13)0.0065 (11)0.0017 (12)
C10.0311 (19)0.037 (2)0.0346 (17)0.0016 (15)0.0042 (15)0.0061 (14)
C20.0328 (19)0.038 (2)0.0338 (17)−0.0009 (15)0.0062 (14)0.0039 (14)
C30.038 (2)0.060 (3)0.0431 (19)−0.0041 (18)0.0083 (16)−0.0082 (17)
C40.0317 (19)0.051 (2)0.054 (2)0.0072 (16)0.0020 (16)−0.0050 (18)
C50.0316 (19)0.046 (2)0.0419 (18)−0.0017 (16)0.0002 (15)0.0013 (16)
C60.0296 (18)0.037 (2)0.0336 (17)0.0031 (14)0.0025 (14)0.0066 (14)
C70.032 (2)0.054 (2)0.0376 (18)0.0038 (16)0.0037 (15)0.0027 (16)
C80.045 (2)0.058 (2)0.0338 (18)0.0056 (18)−0.0014 (16)−0.0029 (17)
C90.050 (2)0.055 (3)0.040 (2)0.0114 (19)−0.0070 (17)−0.0024 (17)
C100.068 (3)0.078 (3)0.050 (2)0.011 (2)−0.011 (2)−0.014 (2)
C110.085 (4)0.120 (4)0.036 (2)0.017 (3)−0.008 (2)−0.015 (3)
C120.076 (3)0.134 (5)0.041 (2)0.001 (3)0.010 (2)0.007 (3)
C130.058 (3)0.091 (3)0.039 (2)−0.003 (2)0.0029 (19)0.006 (2)
C140.0346 (19)0.045 (2)0.0405 (19)−0.0006 (16)0.0013 (15)0.0063 (16)
C150.0365 (19)0.044 (2)0.0337 (17)0.0016 (16)0.0025 (15)−0.0040 (15)
C160.058 (2)0.041 (2)0.0345 (18)−0.0080 (18)0.0020 (16)−0.0019 (15)
C170.077 (3)0.060 (3)0.0318 (18)−0.007 (2)−0.0099 (19)−0.0037 (18)
C180.062 (3)0.070 (3)0.051 (2)−0.014 (2)−0.010 (2)−0.015 (2)
C190.054 (2)0.066 (3)0.056 (2)−0.018 (2)0.004 (2)−0.009 (2)
C200.049 (2)0.053 (2)0.0370 (18)−0.0034 (19)0.0034 (16)0.0057 (17)
Geometric parameters (Å, °) top
Cl1—C91.739 (4)C9—C101.385 (5)
Cl2—C161.738 (3)C10—C111.372 (6)
O1—C11.228 (3)C10—H100.9300
C1—C61.496 (4)C11—C121.374 (6)
C1—C21.511 (4)C11—H110.9300
C2—C71.340 (4)C12—C131.379 (5)
C2—C31.514 (4)C12—H120.9300
C3—C41.517 (4)C13—H130.9300
C3—H3A0.9700C14—C151.467 (4)
C3—H3B0.9700C14—H140.9300
C4—C51.517 (4)C15—C161.395 (4)
C4—H4A0.9700C15—C201.400 (4)
C4—H4B0.9700C16—C171.381 (5)
C5—C61.504 (4)C17—C181.376 (5)
C5—H5A0.9700C17—H170.9300
C5—H5B0.9700C18—C191.378 (5)
C6—C141.345 (4)C18—H180.9300
C7—C81.465 (4)C19—C201.374 (5)
C7—H70.9300C19—H190.9300
C8—C91.400 (5)C20—H200.9300
C8—C131.405 (5)
Cl1···O1i3.213 (3)
C9—Cl1—O1i165.55 (13)C10—C9—Cl1117.4 (3)
O1—C1—C6121.2 (3)C8—C9—Cl1120.8 (3)
O1—C1—C2119.7 (3)C11—C10—C9119.6 (4)
C6—C1—C2119.1 (3)C11—C10—H10120.2
C7—C2—C1117.0 (3)C9—C10—H10120.2
C7—C2—C3124.7 (3)C10—C11—C12120.2 (4)
C1—C2—C3118.3 (3)C10—C11—H11119.9
C2—C3—C4113.7 (3)C12—C11—H11119.9
C2—C3—H3A108.8C11—C12—C13120.5 (4)
C4—C3—H3A108.8C11—C12—H12119.8
C2—C3—H3B108.8C13—C12—H12119.8
C4—C3—H3B108.8C12—C13—C8121.1 (4)
H3A—C3—H3B107.7C12—C13—H13119.4
C3—C4—C5109.8 (3)C8—C13—H13119.4
C3—C4—H4A109.7C6—C14—C15126.6 (3)
C5—C4—H4A109.7C6—C14—H14116.7
C3—C4—H4B109.7C15—C14—H14116.7
C5—C4—H4B109.7C16—C15—C20116.0 (3)
H4A—C4—H4B108.2C16—C15—C14122.0 (3)
C6—C5—C4110.7 (3)C20—C15—C14121.9 (3)
C6—C5—H5A109.5C17—C16—C15122.4 (3)
C4—C5—H5A109.5C17—C16—Cl2118.3 (3)
C6—C5—H5B109.5C15—C16—Cl2119.3 (3)
C4—C5—H5B109.5C18—C17—C16119.6 (3)
H5A—C5—H5B108.1C18—C17—H17120.2
C14—C6—C1117.4 (3)C16—C17—H17120.2
C14—C6—C5124.9 (3)C17—C18—C19119.7 (3)
C1—C6—C5117.7 (3)C17—C18—H18120.2
C2—C7—C8128.7 (3)C19—C18—H18120.2
C2—C7—H7115.7C20—C19—C18120.2 (4)
C8—C7—H7115.7C20—C19—H19119.9
C9—C8—C13116.6 (3)C18—C19—H19119.9
C9—C8—C7121.0 (3)C19—C20—C15122.0 (3)
C13—C8—C7122.4 (3)C19—C20—H20119.0
C10—C9—C8121.9 (4)C15—C20—H20119.0
Symmetry codes: (i) −x+2, y+1/2, −z+1/2.
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
C20—H20···O1ii0.932.513.352 (4)151
Symmetry codes: (ii) −x+3/2, y−1/2, z.
Table 1
Selected geometric parameters (Å) top
Cl1···O1i3.213 (3)
Symmetry codes: (i) −x+2, y+1/2, −z+1/2.
Table 2
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
C20—H20···O1ii0.932.513.352 (4)151
Symmetry codes: (ii) −x+3/2, y−1/2, z.
Acknowledgements top

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

references
References top

Brinda, Mudakavi, R., Chopra, D., Murthy, M. S. & Row, T. N. G. (2007). Acta Cryst. E63, o4494.

Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.

Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.

Siemens (1996). SMART and SAINT. Siemens Analytical X-ray Systems, Inc., Madison, Wisconsin, USA.

Tanaka, T. & Toda, F. (2000). Chem. Rev. 100, 1025–1074.