4-(2,5-Dihexyl­oxyphen­yl)benzoic acid

Hong Li; Lu Zhang; Yan-Qi Liu; Duo-Bin Mao; Wen-Ye Zhang

doi:10.1107/S1600536808032170

. 2008 Oct 11;64(Pt 11):o2094. doi: 10.1107/S1600536808032170

4-(2,5-Dihexyloxyphenyl)benzoic acid

Hong Li ^a,^*, Lu Zhang ^a, Yan-Qi Liu ^a, Duo-Bin Mao ^a, Wen-Ye Zhang ^a

PMCID: PMC2959701 PMID: 21580958

Abstract

In the title compound, C₂₅H₃₄O₄, one n-hexyl chain of the hexyloxy group adopts a fully extended all-trans conformation, and the other n-hexyl chain displays disorder with site occupancies of 0.470 (3) and 0.530 (3). The dihedral angle between the benzene rings is 44.5 (3)°. In the crystal structure, intermolecular O—H⋯O hydrogen bonds form dimers via crystallographic inversion centres.

Related literature

For a review of applications of Suzuki–Miyura cross-coupling reactions in organic syntheses, see: Kotha et al. (2002 ▶). For the structure of 1,4-dibromo-2,5-bis(hexyloxy)benzene, see: Li et al. (2008 ▶). For the syntheses of related compounds, see: Maruyama & Kawanishi (2002 ▶); Zhang et al. (2006 ▶).

Experimental

Crystal data

C₂₅H₃₄O₄
M _r = 398.52
Monoclinic,
a = 7.2936 (12) Å
b = 14.689 (2) Å
c = 22.137 (4) Å
β = 95.283 (3)°
V = 2361.7 (7) Å³
Z = 4
Mo Kα radiation
μ = 0.07 mm⁻¹
T = 295 (2) K
0.35 × 0.15 × 0.06 mm

Data collection

Bruker SMART CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.975, T _max = 0.996
15777 measured reflections
4359 independent reflections
1432 reflections with I > 2σ(I)
R _int = 0.087

Refinement

R[F ² > 2σ(F ²)] = 0.061
wR(F ²) = 0.194
S = 0.97
4359 reflections
257 parameters
H-atom parameters constrained
Δρ_max = 0.16 e Å⁻³
Δρ_min = −0.14 e Å⁻³

Data collection: SMART (Bruker, 2004 ▶); cell refinement: SAINT (Bruker, 2004 ▶); data reduction: SAINT; 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 datablocks global, I. DOI: 10.1107/S1600536808032170/si2116sup1.cif

e-64-o2094-sup1.cif^{(26.2KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808032170/si2116Isup2.hkl

e-64-o2094-Isup2.hkl^{(213.6KB, 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
O1—H1⋯O2ⁱ	0.82	1.82	2.632 (4)	174

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Symmetry code: (i) Inline graphic .

Acknowledgments

This work was supported by the Doctoral Foundation of Zhengzhou University of Light Industry.

supplementary crystallographic information

Comment

Palladium-catalyzed Suzuki coupling reaction has become an extremely powerful method in synthesis for the formation of carbon-carbon bond (Kotha et al., 2002). For example, 1,4-Dibromide-2,5-bis(hexyloxy)benzene was reacted with 4-carboxyphenylboronic acid in the presence of Pd(PPh₃)₄ to give coupling product 2,5-bis(hexyloxy)-1,4-di(4'-carboxyphenyl)benzene (Zhang et al., 2006). In the above reaction, we obtained the title compound as a side product.

A view of the molecular structure of the title compound is given in Fig.1. The dihedral angle between benzene rings is 44.5 (3)°. One n-hexyl chain of the hexyloxyl group has the same fully extended all - trans conformation as the 1,4-Dibromide-2,5-bis(hexyloxy)benzene (Li, et al., 2008), while the other n-hexyl chain displays disorder with site occupancies 0.470 (3) and 0.530 (3). In the crystal structure, centrosymmetric dimers arise from pairs of O—H···O hydrogen bonds involving the carboxylic acid groups (Fig.2, Table 1).

Experimental

1,4-Dibromo-2,5-bis(hexyloxy)benzene was prepared as described in the literature (Maruyama & Kawanishi 2002). The title compound was obtained as a side-product from the Suzuki coupling reaction of 1,4-Dibromo-2,5-bis(hexyloxy)benzene and 4-carboxyphenylboronic acid as described in the literature (Zhang et al., 2006) and recrystallized from ethanol at room temperature to give the desired crystals suitable for single-crystal X-ray diffraction.