4-(4-Fluoro­phen­oxy)benzoic acid

Hoong-Kun Fun; Jia Hao Goh; Sankappa Rai; Prakash Shetty; Arun M Isloor

doi:10.1107/S1600536809028232

. 2009 Jul 25;65(Pt 8):o1971. doi: 10.1107/S1600536809028232

4-(4-Fluorophenoxy)benzoic acid

Hoong-Kun Fun ^a,^*,^‡, Jia Hao Goh ^a, Sankappa Rai ^b, Prakash Shetty ^c, Arun M Isloor ^d

PMCID: PMC2977365 PMID: 21583647

Abstract

In the title compound, C₁₃H₉FO₃, the dihedral angle between the two benzene rings is 70.99 (5)°. In the crystal structure, molecules are linked into dimers by centrosymmetric O—H⋯O interactions, generating R ₂ ²(8) ring motifs. These dimers are linked into a two-dimensional array, parallel to the ab plane, by two different C—H⋯O interactions. A weak C—H⋯π interactions is also present.

Related literature

For general background to and applications of phenoxy benzoic acid derivatives, see: Forster et al. (1989 ▶); Holla et al. (2003 ▶); Ramu et al. (2000 ▶). For the stability of the temperature controller used for the data collection, see: Cosier & Glazer (1986 ▶).

Experimental

Crystal data

C₁₃H₉FO₃
M _r = 232.20
Triclinic,
a = 5.8850 (1) Å
b = 7.8526 (2) Å
c = 12.0250 (2) Å
α = 91.803 (1)°
β = 96.321 (1)°
γ = 106.027 (1)°
V = 529.75 (2) Å³
Z = 2
Mo Kα radiation
μ = 0.12 mm⁻¹
T = 100 K
0.38 × 0.22 × 0.14 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.958, T _max = 0.984
17124 measured reflections
4049 independent reflections
3329 reflections with I > 2σ(I)
R _int = 0.023

Refinement

R[F ² > 2σ(F ²)] = 0.045
wR(F ²) = 0.123
S = 1.04
4049 reflections
190 parameters
All H-atom parameters refined
Δρ_max = 0.48 e Å⁻³
Δρ_min = −0.26 e Å⁻³

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT (Bruker, 2005 ▶); 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 datablocks global, I. DOI: 10.1107/S1600536809028232/tk2506sup1.cif

e-65-o1971-sup1.cif^{(17KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809028232/tk2506Isup2.hkl

e-65-o1971-Isup2.hkl^{(198.4KB, 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
O2—H1O2⋯O3ⁱ	0.92 (2)	1.70 (2)	2.6204 (11)	175 (2)
C5—H5A⋯O3ⁱⁱ	0.980 (15)	2.403 (15)	3.3573 (12)	164.3 (14)
C9—H9A⋯O2ⁱⁱⁱ	0.969 (17)	2.588 (16)	3.3519 (13)	135.9 (11)
C2—H2A⋯Cg2^iv	0.981 (15)	2.928 (16)	3.9014 (10)	172.1 (13)

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) . Cg1 is the centroid of the C1–C6 benzene ring.

Acknowledgments

HKF and JHG thank Universiti Sains Malaysia (USM) for a Research Universiti Golden Goose Grant (No. 1001/PFIZIK/811012). JHG thanks USM for the award of a USM Fellowship. AMI is grateful to the Head of the Department of Chemistry and the Director, NITK, Surathkal, India, for providing research facilities.

supplementary crystallographic information

Comment

Phenoxy benzoic acids and its derivatives are known for their herbicidal and plant growth-regulating activities (Forster et al., 1989). These compounds are also used in the synthesis of various thiadiazoles and oxadiazole derivatives which show excellent anti-bacterial activity (Holla et al., 2003).The title compound, (I), which is used for peripheral neuropathic pain treatment, is a potent blocker of neuronal voltage-gated sodium channels that interacts selectively with inactivated states as opposed to resting states of the channels (Ramu et al., 2000).

In (I), Fig. 1, the two benzene rings are inclined to one another, with dihedral angle of 70.99 (5)°. In the crystal structure (Fig. 2), the molecules are linked into dimers by centrosymmetric O2—H1O2···O3 interactions (Table 1) to generate R²₂(8) ring motifs. These dimers are linked into a 2-D array, parallel to the ab plane, by intermolecular C—H···O interactions (Table 1). The crystal structure is further stabilized by weak C2—H2A···Cg2 (Table 1) and π···π interactions involving the C1-C6 benzene rings (centroid Cg1) [Cg1···Cg1 = 3.6427 (6)°; symmetry code: 1-x, 2-y, 1-z].

Experimental

4-Bromo-methylbenzoate (0.760 g, 3.57 mmol), sodium carbonate (0.750 g, 7.00 mmol), and tetrakis(triphenylphosphine)palladium(0) (0.400 g, 0.350 mmol) were added to a stirred solution of 4-fluorobenzene boronic acid (0.500 g, 3.57 mmol) in toluene and water (1:1) (20 ml). The reaction mixture was heated at reflux for 8 h; TLC indicated completion of reaction. Sodium hydroxide (0.284 g, 7.00 mmol) was added and stirring was continued for further 1 h. Mass analysis of crude reaction mixture shows the formation of desired compound. The reaction mixture was acidified to pH 3, extracted with ethylacetate and dried. The concentrated residue was purified by column chromatography to yield the pure product, which was recrystallized using hot dichloromethane to yield single crystals. The yield was 0.400 g, 50 %. M.p. 448-450 K.