(1RS,6SR)-Ethyl 4-(4-chloro­phen­yl)-6-(4-fluoro­phen­yl)-2-oxocyclo­hex-3-ene-1-carboxyl­ate toluene hemisolvate

Grzegorz Dutkiewicz; B Narayana; K Veena; H S Yathirajan; Maciej Kubicki

doi:10.1107/S1600536811000158

. 2011 Jan 12;67(Pt 2):o334–o335. doi: 10.1107/S1600536811000158

(1RS,6SR)-Ethyl 4-(4-chlorophenyl)-6-(4-fluorophenyl)-2-oxocyclohex-3-ene-1-carboxylate toluene hemisolvate

Grzegorz Dutkiewicz ^a, B Narayana ^b, K Veena ^b, H S Yathirajan ^c, Maciej Kubicki ^a,^*

PMCID: PMC3051615 PMID: 21523018

Abstract

In the crystal structure of the title compound, C₂₁H₁₈ClFO₃·0.5C₇H₈, the toluene solvent molecules occupy special positions on centres of symmetry, and consequently are disordered across this site. The cyclohexene ring has a slightly distorted sofa conformation; the two benzene rings are inclined by 72.90 (7)° and their planes make dihedral angles of 30.09 (10) (chlorophenyl) and 88.13 (6)° (fluorophenyl) with the approximately planar part of the cyclohexenone ring [maximum deviation from plane through five atoms is 0.030 (2) Å, the sixth atom is 0.672 (3)Å out of this plane]. Weak intermolecular C—H⋯O and C—H⋯X (X = F, Cl) interactions join molecules into a three-dimensional structure. Also, a relatively short and directional C—Cl⋯F—C contact is observed [Cl⋯F = 3.119 (2) Å, C—Cl⋯F = 157.5 (2)° and C—F⋯Cl 108.3 (2)°]. The solvent molecules fill the voids in the crystal structure and are kept there by relatively short and directional C—H⋯π interactions.

Related literature

For biological applications of some cyclohexanones, see: Eddington et al. (2000 ▶). For asymmetry parameters, see: Duax & Norton (1975 ▶). For similar structures, see: in Anuradha et al. (2009 ▶); Fun et al. (2008 ▶, 2009 ▶, 2010 ▶); Badshah et al. (2009 ▶). For a description of the Cambridge Structural Database, see: Allen (2002 ▶).

Experimental

Crystal data

C₂₁H₁₈ClFO₃·0.5C₇H₈
M _r = 418.87
Triclinic,
a = 7.572 (2) Å
b = 11.259 (3) Å
c = 13.362 (3) Å
α = 69.42 (2)°
β = 86.58 (2)°
γ = 70.98 (2)°
V = 1006.3 (4) Å³
Z = 2
Mo Kα radiation
μ = 0.22 mm⁻¹
T = 100 K
0.3 × 0.25 × 0.1 mm

Data collection

Oxford Diffraction Xcalibur Eos diffractometer
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2009 ▶) T _min = 0.990, T _max = 1.000
8414 measured reflections
4154 independent reflections
2567 reflections with I > 2σ(I)
R _int = 0.030

Refinement

R[F ² > 2σ(F ²)] = 0.042
wR(F ²) = 0.085
S = 1.02
4154 reflections
341 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.24 e Å⁻³
Δρ_min = −0.28 e Å⁻³

Data collection: CrysAlis PRO (Oxford Diffraction, 2009 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SIR92 (Altomare et al., 1993 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811000158/dn2647sup1.cif

e-67-0o334-sup1.cif^{(29.5KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811000158/dn2647Isup2.hkl

e-67-0o334-Isup2.hkl^{(199.4KB, hkl)}

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

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

Cg is the centroid of the C1A–C3A,C1A′–C3A′ ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C45—H45⋯F64ⁱ	0.94 (2)	2.54 (2)	3.327 (3)	141.6 (15)
C5—H52⋯F64ⁱⁱ	0.938 (19)	2.54 (2)	3.432 (3)	159.3 (15)
C6—H6⋯Cl44ⁱⁱⁱ	1.003 (19)	2.84 (2)	3.846 (3)	176.3 (14)
C65—H65⋯O12^iv	0.94 (2)	2.59 (2)	3.519 (3)	173.6 (16)
C3—H3⋯Cg	0.918 (19)	2.78 (2)	3.627 (3)	155.0 (17)
C3—H3⋯Cg^v	0.918 (19)	2.78 (2)	3.627 (3)	155.0 (17)

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) ; (v) .

Acknowledgments

BN thanks the UGC and DST for financial assistance under the SAP and FIST programmes. HSY thanks the UOM for sabbatical leave.

supplementary crystallographic information

Comment

Cyclohexenone derivatives, prepared either from natural sources or entirely via synthetic routes, are known to possess a wide variety of biological activities, e.g. they were reported to have anticonvulsant, antimalarial, anti-inflammatory and cardiovascular effects (Eddington et al., 2000). In the course of our studies on chalcone derivatives, we have synthesized some cyclohexene derivatives. Structures of some similar compounds have been reported earlier (for instance, ethyl 6-(4-chlorophenyl)-4-(4-methoxyphenyl)- 2-oxocyclohex-3-ene-1- carboxylate, Fun et al., 2009, ethyl 4-(4-methoxyphenyl)-2-oxo-6- phenylcyclohex-3-ene-1-carboxylate, Fun et al., 2008, ethyl 4-(4-bromophenyl)-6-(4-ethoxyphenyl)- 2-oxocyclohex-3-enecarboxylate, Badshah et al., 2009). Here we report the crystal structure of (1RS,6SR) ethyl 4-(4-chlorophenyl)-6-(4-fluorophenyl)-2-oxocyclohex-3-ene-1-carboxylate toluene solvate (I, Scheme 1).

The overall conformation of I (Fig. 1) can be characterized by the dihedral angles between the phenyl rings, of 72.90 (7)°, and between these rings and the plane of cyclohexene ring which are equal to 30.09 (10)° for chlorophenyl ring and 88.13 (6)° for fluorophenyl ring. These values are similar to those found in the structures of related compounds, for instance in methyl 4,6-bis(4-fluorophenyl)-2-oxocyclohex- 3-ene-1-carboxylate (Fun et al., 2010) the dihedral angles between fluorophenyl rings in two symmetry-independent molecules are 79.7 (2)° and 73.7 (2)°, and the angles between the cyclohexene plane and the fluorophenyl rings are 14.9° and 73.7° in one molecule and 29.9° and 84.0° in the second. In the structure of ethyl 6 - r-(2-chlorophenyl)-2-oxo-4- phenylcyclohex-3-ene-1 - t-carboxylate (Anuradha et al., 2009) appropriate angles are 81.73 (12)°. 12.75 (14)° and 74.16 (8)°.

The cyclohexene ring adopts slightly distorted sofa conformation, the asymmetry parameter ΔC_s³ (Duax & Norton, 1975) is 6.2°. This is also confirmed by least-squares calculations: five atoms C1 - C5 are almost coplanar, maximum deviation is 0.030 (2) Å, while the sixth atom, C6, is by 0.672 (3)Å out of this mean plane.

In the crystal structure the molecules are joined by weak C—H···O, C—H···F and C—H···Cl interactions (Fig. 2). The solvent - toluene molecules are disordered over the centre of symmetry. They occupy the voids in the crystal structure and are kept there by means of relatively short and linear C—H···π interactions (H···Cg 2.78 Å, C—H···Cg 155°). An inteeresting feature of the structure is the presence of linear C—Cl···F—C contacts (F···Cl 3.12 Å, C—Cl···F 157.5 (2)°, C—F···Cl 108.3 (2)°). In the CSD (Allen, 2002) there are 196 cases of such contacts shorter than 3.2 Å, and the same directional preferences are observed.

Experimental

A mixture of ((2E)-1-(4-chlorophenyl)-3-(4-fluorophenyl)prop-2-en-1-one (0.01 mol) and ethyl acetoacetate (0.01 mol) were refluxed for 2 hr in 10–15 ml of ethanol in the presence of 0.8 ml 10% NaOH. The crystals were obtained by a slow evaporation from toluene solution. C₂₁H₁₈ClFO₃.C₇H₈: C: 72.26 (72.33); H:5.59 (5.64); m.p. 346 K.