(2E)-1-(2,6-Dichloro-3-fluoro­phen­yl)-3-(4-meth­oxy­phen­yl)prop-2-en-1-one

A S Praveen; Jerry P Jasinski; James A Golen; H S Yathirajan; B Narayana

doi:10.1107/S1600536812011841

. 2012 Mar 24;68(Pt 4):o1163. doi: 10.1107/S1600536812011841

(2E)-1-(2,6-Dichloro-3-fluorophenyl)-3-(4-methoxyphenyl)prop-2-en-1-one

A S Praveen ^a, Jerry P Jasinski ^b,^*, James A Golen ^b, H S Yathirajan ^a, B Narayana ^c

PMCID: PMC3344105 PMID: 22606108

Abstract

There are two independent molecules in the asymmetric unit of the title compound, C₁₆H₁₁Cl₂FO₂. The F atom equally populates both meta positions of the 6-dichloro-3-fluorophenyl ring in each molecule, resulting in 0.5 occupancy for both the F and H atoms in these positions. The dihedral angle between the mean planes of the benzene rings are 77.5 (2) and 89.8 (8)°in the two molecules. In the crystal, weak C—H⋯F and C—H⋯O interactions involving the half-occupied H and F atoms are observed. Weak π–π stacking interactions [centroid—centroid distance = 3.150 (2) Å] also contribute to the crystal stability.

Related literature

For the pharmacological importance of chalcones, see: Dominguez et al. (2001 ▶); Li et al. (1995 ▶); Mei et al. (2001 ▶); Sarojini et al. (2006 ▶). For related structures, see: Betz et al. (2012 ▶); Yathirajan et al. (2007 ▶). For standard bond lengths, see: Allen et al. (1987 ▶).

Experimental

Crystal data

C₁₆H₁₁Cl₂FO₂
M _r = 325.15
Monoclinic,
a = 11.9035 (6) Å
b = 10.4472 (5) Å
c = 23.7435 (12) Å
β = 92.296 (4)°
V = 2950.3 (3) Å³
Z = 8
Mo Kα radiation
μ = 0.45 mm⁻¹
T = 173 K
0.24 × 0.20 × 0.17 mm

Data collection

Oxford Diffraction Xcalibur Eos Gemini diffractometer
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2010 ▶) T _min = 0.900, T _max = 0.927
15257 measured reflections
7015 independent reflections
5165 reflections with I > 2σ(I)
R _int = 0.023

Refinement

R[F ² > 2σ(F ²)] = 0.061
wR(F ²) = 0.145
S = 1.06
7015 reflections
401 parameters
4 restraints
H-atom parameters constrained
Δρ_max = 0.67 e Å⁻³
Δρ_min = −0.57 e Å⁻³

Data collection: CrysAlis PRO (Oxford Diffraction, 2010 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis RED (Oxford Diffraction, 2010 ▶); 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 datablock(s) global, I. DOI: 10.1107/S1600536812011841/bt5846sup1.cif

e-68-o1163-sup1.cif^{(35.2KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812011841/bt5846Isup2.hkl

e-68-o1163-Isup2.hkl^{(343.3KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812011841/bt5846Isup3.cml

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
C2—H2A⋯F1Aⁱ	0.95	2.79	3.657 (7)	153
C4—H4A⋯F1ⁱⁱ	0.95	2.75	3.410 (5)	127
C11—H11A⋯O3ⁱⁱ	0.95	2.56	3.451 (3)	156

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Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

ASP thanks the University of Mysore for research facilities. JPJ acknowledges the NSF–MRI program (grant No. CHE1039027) for funds to purchase the X-ray diffractometer.

supplementary crystallographic information

Comment

Many Chalcones are known to exhibit various biological properties such as antimalarial (Li et al., 1995), antifungal (Dominguez et al., 2001) and antibacterial activity (Mei et al., 2001). They are also finding application as organic nonlinear optical materials (NLO) for their SHG conversion efficiency (Sarojini et al., 2006). Crystal structures of some related chalcones, viz., (2E)-1-(2,4-dichlorophenyl)-3-(2-hydroxy-3-methoxyphenyl)prop-2-en-1-one (Yathirajan et al., 2007) and (2E)-1-(2,6-dichloro-3-fluorophenyl)-3-(4-fluorophenyl)prop-2-en-1-one (Betz et al., 2012) have been reported. As part of our ongoing studies on chalcones, the title compound (I), C₁₆H₁₁C_l2FO₂, was synthesized and its crystal structure is reported.

In (I) two molecules crystallize in the asymmetric unit (Fig. 1). In the 2,6-dichloro-3-fluorophenyl ring, the fluorine atom equally populates both meta positions of the phenyl ring in each molecule (C2 & C4; C18 & C20) resulting in 0.5 occupancy for both the fluorine and hydrogen atoms (H2A & H4A; H18A & H20A) in these positions. The dihedral angle between the mean planes of the benzene rings in each molecule is 77.5 (2)° and 89.8 (8)°, respectively. Bond lengths are in normal ranges (Allen et al., 1987). Crystal packing is enhanced by weak C—H···F and C—H···O intermolecular interactions (Table 1) from both half-occupied H and F atoms supporting parallel chains along the b axis (Fig. 2) aa well as weak π–π stacking interactions (Table 2).

Experimental

To a stirred solution of 1-(2,6-dichloro-3-fluorophenyl)ethanone (1 g, 4.8 mmol) and 4-methoxybenzaldehyde (0.65 g, 4.8 mmol) in ethanol (10 ml), powdered KOH (0.40 g, 7.2 mmol) was added at 273 K. The reaction mixture was stirred at room temperature for 3 h. After completion of the reaction, the reaction mixture was poured to ice cold water and acidified with 1.5 N HCl (pH ₃). The solid precipitated was filtered and dried to afford 1.4 g of the title compound, (I,) in 89% yield. X-ray quality crystals were obtained by slow evaporation of a tetrahydrofuran solution (m.p.: 361–362 K).