5-Cyclo­pentyl-2-(4-fluoro­phen­yl)-3-methyl­sulfinyl-1-benzofuran

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

doi:10.1107/S1600536811036087

. 2011 Sep 14;67(Pt 10):o2591. doi: 10.1107/S1600536811036087

5-Cyclopentyl-2-(4-fluorophenyl)-3-methylsulfinyl-1-benzofuran

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

PMCID: PMC3201219 PMID: 22065539

Abstract

In the title compound, C₂₀H₁₉FO₂S, the cyclopentyl ring adopts an envelope conformation. The 4-fluorophenyl ring makes a dihedral angle of 27.10 (7)° with the mean plane of the benzofuran fragment. In the crystal, molecules are linked by weak intermolecular C—H⋯O hydrogen bonds and C—H⋯π interactions. In the cyclopentyl ring, one C atom is disordered over two orientations with site-occupancy factors of 0.617 (7) and 0.383 (7).

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 related 2-(4-fluorophenyl)-3-methylsulfinyl-1-benzofuran derivatives, see: Choi et al. (2010 ▶, 2011 ▶).

Experimental

Crystal data

C₂₀H₁₉FO₂S
M _r = 342.41
Orthorhombic,
a = 20.0254 (13) Å
b = 33.197 (2) Å
c = 10.0233 (7) Å
V = 6663.3 (8) Å³
Z = 16
Mo Kα radiation
μ = 0.21 mm⁻¹
T = 173 K
0.35 × 0.26 × 0.19 mm

Data collection

Bruker SMART APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.930, T _max = 0.961
16962 measured reflections
4136 independent reflections
3915 reflections with I > 2σ(I)
R _int = 0.034

Refinement

R[F ² > 2σ(F ²)] = 0.041
wR(F ²) = 0.106
S = 1.06
4136 reflections
223 parameters
96 restraints
H-atom parameters constrained
Δρ_max = 0.48 e Å⁻³
Δρ_min = −0.37 e Å⁻³
Absolute structure: Flack (1983 ▶), 1949 Friedel pairs
Flack parameter: 0.15 (7)

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) I. DOI: 10.1107/S1600536811036087/gk2398sup1.cif

e-67-o2591-sup1.cif^{(29.7KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811036087/gk2398Isup2.hkl

e-67-o2591-Isup2.hkl^{(203KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811036087/gk2398Isup3.cml

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

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

Cg is the centroid of the C1/C2/C7/O/C8 furan ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C20—H20B⋯O2ⁱ	0.98	2.29	3.262 (3)	169
C16—H16⋯Cgⁱ	0.95	2.53	3.365 (3)	146

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Symmetry code: (i) Inline graphic .

supplementary crystallographic information

Comment

Many compounds containing a benzofuran ring system have attracted much interest owing to their valuable 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 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 the substituent effect on the solid state structures of 2-(4-fluorophenyl)-3-methylsulfinyl-1-benzofuran analogues (Choi et al., 2010, 2011), we report herein the crystal structure of the title compound.

The title compound crystallizes ins the non-centrosymmetric space group Fdd2. The crystal studied was an inversion twin with a 0.85 (7) : 0.15 (7) domain ratio.

In the title molecule (Fig. 1), the benzofuran unit is essentially planar, with a mean deviation of 0.024 (2) Å from the least-squares plane defined by the nine constituent atoms. The cyclopentyl ring is in the envelope form. In the cyclopentyl ring, the C10 atom is disordered over two positions with site-occupancy factors, from refinement of 0.617 (7) (part A) and 0.383 (7) (part B). The dihedral angle formed by the 4-fluorophenyl ring and the mean plane of the benzofuran fragment is 27.10 (7)°. The crystal packing (Fig. 2) is stabilized by weak intermolecular C—H···O hydrogen bonds between a methyl H atom and the O atom of the sulfinyl group (Table 1; C20—H20B···O2ⁱ). The crystal packing (Fig. 2) is further stabilized by intermolecular C—H···π interactions between a 4-fluorophenyl H atom and the furan ring (Table 1; C16—H16···Cgⁱ, Cg is the centroid of the C1/C2/C7/O1/C8 furan ring).

Experimental

77% 3-chloroperoxybenzoic acid (224 mg, 1.0 mmol) was added in small portions to a stirred solution of 5-cyclopentyl-2-(4-fluorophenyl)-3-methylsulfanyl-1-benzofuran (293 mg, 0.9 mmol) in dichloromethane (30 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, 1:2 v/v) to afford the title compound as a colorless solid [yield 72%, m.p. 419-420 K; Rf = 0.67 (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.