3-Cyclo­hexyl­sulfinyl-5-iodo-2-methyl-1-benzofuran

Hong Dae Choi; Pil Ja Seo; Byeng Wha Son; Uk Lee

doi:10.1107/S160053681101124X

. 2011 Mar 31;67(Pt 4):o1026. doi: 10.1107/S160053681101124X

3-Cyclohexylsulfinyl-5-iodo-2-methyl-1-benzofuran

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

PMCID: PMC3099997 PMID: 21754042

Abstract

There are two independent molecules, A and B, in the asymmetric unit of the title compound, C₁₅H₁₇ClO₂S, in each of which the cyclohexyl ring adopts a chair conformation. The benzofuran units in each molecule are essentially planar, with mean deviations from a least-squares plane defined by the nine constituent ring atoms of 0.006 (2) Å for A and 0.011 (2) Å for B. In the crystal, molecules are linked by weak intermolecular C—H⋯O and C—H⋯π interactions and by two I⋯O contacts [I⋯O = 3.079 (2) and 3.017 (2) Å].

Related literature

For the pharmacological 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 structural studies of the related 5-bromo-3-cyclohexylsulfinyl-2-methyl-1-benzofuran, see: Choi et al. (2011 ▶). For a review of halogen bonding, see: Politzer et al. (2007 ▶).

Experimental

Crystal data

C₁₅H₁₇IO₂S
M _r = 388.25
Monoclinic,
a = 14.1817 (2) Å
b = 12.1347 (2) Å
c = 18.1258 (3) Å
β = 101.136 (1)°
V = 3060.55 (8) Å³
Z = 8
Mo Kα radiation
μ = 2.22 mm⁻¹
T = 173 K
0.20 × 0.17 × 0.13 mm

Data collection

Bruker SMART APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.663, T _max = 0.758
30319 measured reflections
7599 independent reflections
6386 reflections with I > 2σ(I)
R _int = 0.034

Refinement

R[F ² > 2σ(F ²)] = 0.031
wR(F ²) = 0.077
S = 1.04
7599 reflections
345 parameters
H-atom parameters constrained
Δρ_max = 2.47 e Å⁻³
Δρ_min = −1.61 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 datablocks global, I. DOI: 10.1107/S160053681101124X/nk2093sup1.cif

e-67-o1026-sup1.cif^{(26.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S160053681101124X/nk2093Isup2.hkl

e-67-o1026-Isup2.hkl^{(371.8KB, hkl)}

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

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

Cg is the centroid of the C16/C17/C22/O3/C23 furan ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C24—H24A⋯O4ⁱ	0.98	2.50	3.425 (4)	156
C29—H29A⋯Cgⁱ	0.99	2.63	3.552 (4)	155

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Symmetry code: (i) Inline graphic .

supplementary crystallographic information

Comment

Many compounds containing a benzofuran ring system exhibit interesting pharmacological 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 compounds occur in a wide range of natural products (Akgul & Anil, 2003; Soekamto et al., 2003). As a part of our ongoing study of the substituent effect on the solid state structures of 3-cyclohexylsulfinyl-5-halo-2-methyl-1-benzofuran analogues (Choi et al., 2011), we report herein on the molecular and crystal structures of the title compound.

The asymmetric unit of the title compound is shown in Fig. 1. There are two independent unique molecules [labeled A & B] in which the benzofuran unit is essentially planar, with a mean deviation of 0.006 (2) Å for A and 0.011 (2) Å for B, respectively, from the least-squares plane defined by the nine constituent atoms. The cyclohexyl rings of both molecules adopt a chair conformation [endocyclic torsion angles are within a 51.5–59.0 (4)° range for A and 54.0–58.3 (4)° range for B, respectively].

In the crystal packing (Fig. 2), the B molecules are linked by weak intermolecular C—H···O hydrogen bonds between a methyl H atom and the O atom of the S═O unit (Table 1; C24—H24A···O4ⁱ), and by intermolecular C—H···π interactions between a cyclohexyl H atom and the furan ring (Table 1; C29—H29A···Cgⁱ, Cg is the centroid of the C16/C17/C22/O3/C23 furan ring). Adjacent A and B molecules are linked by two I···O halogen bondings; the first one between the iodine and the O atom of the S═O unit [I1···O4ⁱⁱ = 3.079 (2) Å; C4—I1···O4ⁱⁱ =168.88 (9)°], and the second one between the iodine and the O atom of S═O unit [I2···O2 = 3.017 (2) Å; C19—I2···O2 = 175.89 (9)°] (Politzer et al., 2007).

Experimental

7% 3-chloroperoxybenzoic acid (224 mg, 1.0 mmol) was added in small portions to a stirred solution of 3-cyclohexylsulfanyl-5-iodo-2-methyl-1-benzofuran (335 mg, 0.9 mmol) in dichloromethane (40 mL) at 273 K. After being stirred at room temperature for 4h, the mixture was washed with saturated sodium bicarbonate solution and the organic layer was separated, dried over magnesium sulfate, filtered and concentrated at reduced pressure. The residue was purified by column chromatography (hexane-ethyl acetate, 2:1 v/v) to afford the title compound as a colorless solid [yield 76%, m.p. 412–413 K; R_f = 0.60 (hexane–ethyl acetate, 2:1 v/v)]. Single crystals suitable for X-ray diffraction were prepared by slow evaporation of a solution of the title compound in ethyl acetate at room temperature.