2-(5-Cyclo­hexyl-3-isopropyl­sulfanyl-1-benzofuran-2-yl)acetic acid

Hong Dae Choi; Pil Ja Seo; Uk Lee

doi:10.1107/S1600536811055152

. 2012 Jan 14;68(Pt 2):o397. doi: 10.1107/S1600536811055152

2-(5-Cyclohexyl-3-isopropylsulfanyl-1-benzofuran-2-yl)acetic acid

Hong Dae Choi ^a, Pil Ja Seo ^a, Uk Lee ^b,^*

PMCID: PMC3275074 PMID: 22347019

Abstract

In the title compound, C₁₉H₂₄O₃S, the cylohexyl ring adopts a chair conformation. In the crystal, molecules are linked via pairs of O—H⋯O hydrogen bonds, forming inversion dimers. These dimers are further stabilized by weak intermolecular C—H⋯π interactions, and by slipped π–π interactions between the furan rings of adjacent molecules [centroid–centroid distance = 3.557 (2) Å, interplanar distance = 3.301 (2) Å and slippage = 1.325 (2) Å].

Related literature

For the biological activity of benzofuran compounds, see: Aslam et al. (2009 ▶); Galal et al. (2009 ▶); Khan et al. (2005 ▶). For natural products with benzofuran rings, see: Akgul & Anil (2003 ▶); Soekamto et al. (2003 ▶). For the crystal structure of related compound, see: Seo et al. (2011 ▶).

Experimental

Crystal data

C₁₉H₂₄O₃S
M _r = 332.44
Triclinic,
a = 9.1261 (2) Å
b = 9.5308 (2) Å
c = 10.5577 (2) Å
α = 72.228 (1)°
β = 79.702 (1)°
γ = 85.724 (1)°
V = 860.19 (3) Å³
Z = 2
Mo Kα radiation
μ = 0.20 mm⁻¹
T = 173 K
0.36 × 0.27 × 0.23 mm

Data collection

Bruker SMART APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.931, T _max = 0.955
16313 measured reflections
4297 independent reflections
3683 reflections with I > 2σ(I)
R _int = 0.028

Refinement

R[F ² > 2σ(F ²)] = 0.036
wR(F ²) = 0.098
S = 1.05
4297 reflections
214 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.33 e Å⁻³
Δρ_min = −0.24 e Å⁻³

Data collection: APEX2 (Bruker, 2009 ▶); cell refinement: SAINT (Bruker, 2009 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶) and DIAMOND (Brandenburg, 1998 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536811055152/ff2049sup1.cif

e-68-0o397-sup1.cif^{(26.8KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811055152/ff2049Isup2.hkl

e-68-0o397-Isup2.hkl^{(210.5KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811055152/ff2049Isup3.cml

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

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

Cg1 is the centroid of the C2–C7 benzene ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—H3O⋯O2ⁱ	0.87 (2)	1.81 (2)	2.6745 (14)	179 (2)
C15—H15B⋯Cg1ⁱⁱ	0.99	2.77	3.578 (2)	140

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

Acknowledgments

This work was supported by the Blue-Bio Industry Regional Innovation Center (RIC08-06-07) at Dongeui University as a RIC program under the Ministry of Knowledge Economy and Busan City.

supplementary crystallographic information

Comment

Substituted benzofuran derivatives have drawn much interest owing to their valuable biological properties such as antibacterial and antifungal, antitumor and antiviral, and antimicrobial activities (Aslam et al., 2009, Galal et al., 2009, Khan et al., 2005). These benzofuran derivatives occur in a wide range of natural products (Akgul & Anil, 2003; Soekamto et al., 2003). As a part of our ongoing study of 2-(5-cyclohexyl-1-benzofuran-2-yl)acetic acid derivatives containing 3-methylsulfanyl (Seo et al., 2011) substituent, we report herein the crystal structure of the title compound.

In the title molecule (Fig. 1), the benzofuran unit is essentially planar, with a mean deviation of 0.032 (1) Å from the least-squares plane defined by the nine constituent atoms. The cyclohexyl ring has the chair conformation. In the crystal structure, the carboxyl groups are involved in intermolecular O—H···O hydrogen bonds (see, Fig. 2 & Table 1), which link the molecules into centrosymmetric dimers. These dimers are further stabilized by weak intermolecular C—H···π interactions (see, Fig. 2 & Table 1; Cg1 is the centroid of the C2–C7 benzene ring). Additionally, the crystal packing (Fig. 2) shows a weak slipped between the furan rings of adjacent molecules, with a Cg2···Cg2ⁱⁱ distance of 3.557 (2) Å and an interplanar distance of 3.301 (2) Å resulting in a slippage of 1.325 (2) Å (Cg2 is the centroid of the C1/C2/C7/O1/C8 furan ring).

Experimental

Ethyl 2-(5-cyclohexyl-3-isopropylsulfanyl-1-benzofuran-2-yl)acetate (396 mg, 1.1 mmol) was added to a solution of potassium hydroxide (336 mg, 6 mmol) in water (10 ml) and methanol (15 ml), and the mixture was refluxed for 5h, then cooled. Water was added, and the solution was extracted with dichloromethane. The aqueous layer was acidified to pH=1 with concentrated hydrochloric acid and then extracted with chloroform. The organic layer was separated, dried over magnesium sulfate, filtered and concentrated at reduced pressure. The residue was purified by column chromatography (ethyl acetate) to afford the title compound as a colorless solid [yield 84%, m.p. 423–424 K; R_f = 0.55 (ethyl acetate)]. Single crystals suitable for X-ray diffraction were prepared by slow evaporation of a solution of the title compound in acetone at room temperature.