2-(4-Chloro­phen­yl)-2-oxoethyl 2,4-di­fluoro­benzoate

Hoong-Kun Fun; Suhana Arshad; B Garudachari; Arun M Isloor; M N Satyanarayan

doi:10.1107/S1600536811020630

. 2011 Jun 11;67(Pt 7):o1599. doi: 10.1107/S1600536811020630

2-(4-Chlorophenyl)-2-oxoethyl 2,4-difluorobenzoate

Hoong-Kun Fun ^a,^*,^‡, Suhana Arshad ^a, B Garudachari ^b, Arun M Isloor ^b, M N Satyanarayan ^c

PMCID: PMC3151833 PMID: 21837007

Abstract

The asymmetric unit of title compound, C₁₅H₉ClF₂O₃, consists of two crystallographically independent molecules. The dihedral angle between the two terminal benzene rings in one molecule is 7.92 (14)°, while that in the other molecule is 73.50 (16)°. In the crystal, molecules are stacked into columns along the b axis by intermolecular C—H⋯O hydrogen bonds. A π–π interaction with a centroid-to-centroid distance of 3.747 (2) Å further stabilizes the crystal structure.

Related literature

For background to and applications of phenacyl benzoates, see: Rather & Reid (1919 ▶); Sheehan & Umezaw (1973 ▶); Ruzicka et al. (2002 ▶); Litera et al. (2006 ▶); Huang et al. (1996 ▶); Gandhi et al. (1995 ▶). For reference bond-length values, see: Allen et al. (1987 ▶).

Experimental

Crystal data

C₁₅H₉ClF₂O₃
M _r = 310.67
Monoclinic,
a = 16.0179 (17) Å
b = 7.9609 (8) Å
c = 24.0172 (18) Å
β = 115.939 (5)°
V = 2754.1 (5) Å³
Z = 8
Mo Kα radiation
μ = 0.31 mm⁻¹
T = 296 K
0.55 × 0.26 × 0.09 mm

Data collection

Bruker SMART APEXII DUO CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.850, T _max = 0.974
17424 measured reflections
6308 independent reflections
3353 reflections with I > 2σ(I)
R _int = 0.030

Refinement

R[F ² > 2σ(F ²)] = 0.054
wR(F ²) = 0.206
S = 1.03
6308 reflections
379 parameters
H-atom parameters constrained
Δρ_max = 0.33 e Å⁻³
Δρ_min = −0.32 e Å⁻³

Data collection: APEX2 (Bruker, 2009 ▶); cell refinement: SAINT (Bruker, 2009 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536811020630/is2722sup1.cif

e-67-o1599-sup1.cif^{(25.1KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811020630/is2722Isup2.hkl

e-67-o1599-Isup2.hkl^{(308.8KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811020630/is2722Isup3.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
C8A—H8AB⋯O3B	0.97	2.60	3.451 (4)	147
C8A—H8AA⋯O1Bⁱ	0.97	2.42	3.294 (3)	149
C5B—H5BA⋯O3Aⁱⁱ	0.93	2.50	3.376 (4)	158
C8B—H8BB⋯O3Aⁱⁱ	0.97	2.58	3.415 (3)	144
C14B—H14B⋯O1Aⁱⁱⁱ	0.93	2.59	3.216 (5)	125

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

Acknowledgments

The authors thank Universiti Sains Malaysia (USM) for Research University Grant No. 1001/PFIZIK/811160. SA thanks the Malaysian government and USM for the award of a research scholarship. AMI is grateful to the Department of Atomic Energy, Board for Research in Nuclear Sciences, Government of India, for a Young Scientist Award. BG thanks the Department of Information Technology, New Delhi, India, for financial support.

supplementary crystallographic information

Comment

Phenacyl benzoates derivatives are very important in identification of organic acids (Rather & Reid, 1919), they undergo photolysis in neutral and mild conditions (Sheehan & Umezaw, 1973; Ruzicka et al., 2002; Litera et al., 2006). They find applications in the field of synthetic chemistry for the synthesis of oxazoles, imidazoles (Huang et al., 1996), benzoxazepine (Gandhi et al., 1995). We hereby report the crystal structure of 2-(4-chlorophenyl)-2-oxoethyl 2,4-difluorobenzoate of potential commercial importance.

The asymmetric unit of the title compound (Fig. 1), consists of two crystallographically independent molecules A and B. Both terminal phenyl rings (C1–C6 and C10–C15) in molecules A and B make dihedral angles of 7.92 (14) and 73.50 (16)° to each other, respectively. The bond lengths (Allen et al., 1987) and angles are within normal ranges.

The crystal packing is shown in Fig. 2. The intermolecular C8A—H8AB···O3B hydrogen bond linked the molecule A with molecule B together. The molecules are linked into columns along the b axis by the intermolecular C8A—H8AA···O1B, C5B—H5BA···O3A, C8B—H8BB···O3A and C14B—H14B···O1A hydrogen bonds (Table 1). A π–π interaction further stabilizes the crystal structure [Cg1···Cg2ⁱⁱ = 3.747 (2) Å; Cg1 and Cg2 are centroids of C1B–C6B and C10B–C15B benzene ring, respectively].

Experimental

A mixture of 2,4-difluorobenzoic acid (1.0 g, 0.0063 mol) potassium carbonate (0.95 g, 0.0069 mol) and 2-bromo-1-(4-chlorophenyl)ethanone (1.41 g, 0.0063 mol) in dimethylformamide (10 ml) was stirred at room temperature for 2 h. On cooling, colourless needle-shaped crystals 2-(4-chlorophenyl)-2-oxoethyl 2,4-difluorobenzoate begin to separate. It was collected by filtration and recrystallized from ethanol. Yield: 1.65 g, 84.1%. M.p.: 376–377 K.