5-Bromo-3-ethyl­sulfinyl-2-(4-fluoro­phenyl)-1-benzofuran

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

doi:10.1107/S1600536810000590

. 2010 Jan 9;66(Pt 2):o323. doi: 10.1107/S1600536810000590

5-Bromo-3-ethylsulfinyl-2-(4-fluorophenyl)-1-benzofuran

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

PMCID: PMC2979841 PMID: 21579753

Abstract

In the title compound, C₁₆H₁₂BrFO₂S, the 4-fluorophenyl ring is rotated out of the benzofuran plane, as indicated by the dihedral angle of 5.94 (5)°. The crystal structure exhibits aromatic π–π interactions between the benzene ring and the 4-fluorophenyl ring of an adjacent molecule [centroid–centroid distance = 3.632 (2) Å], and a Br⋯O halogen bond with a Br⋯O distance of 3.101 (1) Å.

Related literature

For the crystal structures of similar 2-(4-fluorophenyl)-5-halo-3-methylsulfinyl-1-benzofuran derivatives, see: Choi et al. (2009 ▶, 2010a ▶,b ▶). For the biological activity of benzofuran compounds, see: Aslam et al. (2006 ▶); Galal et al. (2009 ▶); Howlett et al. (1999 ▶). For natural products with benzofuran rings, see: Akgul & Anil (2003 ▶); Soekamto et al. (2003 ▶). For a review of halogen bonding, see: Politzer et al. (2007 ▶).

Experimental

Crystal data

C₁₆H₁₂BrFO₂S
M _r = 367.23
Triclinic,
a = 7.2806 (5) Å
b = 9.4999 (6) Å
c = 10.8334 (6) Å
α = 101.360 (3)°
β = 98.783 (3)°
γ = 104.771 (3)°
V = 693.87 (8) Å³
Z = 2
Mo Kα radiation
μ = 3.12 mm⁻¹
T = 100 K
0.30 × 0.26 × 0.18 mm

Data collection

Bruker SMART APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.457, T _max = 0.606
12298 measured reflections
3202 independent reflections
3040 reflections with I > 2σ(I)
R _int = 0.033

Refinement

R[F ² > 2σ(F ²)] = 0.024
wR(F ²) = 0.068
S = 1.01
3202 reflections
190 parameters
H-atom parameters constrained
Δρ_max = 0.48 e Å⁻³
Δρ_min = −0.47 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/S1600536810000590/si2236sup1.cif

e-66-0o323-sup1.cif^{(18.1KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810000590/si2236Isup2.hkl

e-66-0o323-Isup2.hkl^{(157.1KB, hkl)}

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

supplementary crystallographic information

Comment

Benzofuran ring systems have drawn considerable attention due to their diverse biological activities (Aslam et al., 2006; Galal et al., 2009; Howlett et al. 1999) and these compounds are occurring in natural products (Akgul & Anil, 2003; Soekamto et al., 2003). As a part of our continuing studies of the effect of side chain substituents on the solid state structures of 2-(4-fluorophenyl)-5-halo-3-methylsulfinyl-1-benzofuran analogues (Choi et al., 2009, 2010a,b), we report the crystal structure of the title compound (Fig. 1).

The benzofuran unit is essentially planar, with a mean deviation of 0.007 (1) Å from the least-squares plane defined by the nine constituent atoms. The dihedral angle formed by the plane of the benzofuran and the 4-fluorophenyl ring is 5.94 (5)°. The crystal packing (Fig. 2) is stabilized by aromatic π–π interactions between the benzene ring and the 4-fluorophenyl ring of an adjacent molecule. The Cg1-Cg2ⁱ distance is 3.632 (2) Å (Cg1 and Cg2 are the centroids of the C2-C7 benzene ring and the C9-C14 4-fluorophenyl ring, respectively). The crystal packing (Fig. 2) is further stabilized by a Br···O halogen bond between the bromine and the oxygen of the S═O unit [Br···O2ⁱⁱ = 3.101 (1) Å; C–Br···O2 = 168.51 (6)°] (Politzer et al., 2007).

Experimental

77% 3-Chloroperoxybenzoic acid (208 mg, 0.93 mmol) was added in small portions to a stirred solution of 5-bromo-3-ethylsulfanyl-2-(4-fluorophenyl)-1-benzofuran (298 mg, 0.85 mmol) in dichloromethane (30 mL) at 273 K. After being stirred at room temperature for 3h, the mixture was washed with saturated sodium bicarbonate solution and the organic layer was separated, dried over magnesium sulfate, filtered and concentrated in vacuum. The residue was purified by column chromatography (hexane-ethyl acetate, 2:1 v/v) to afford the title compound as a colorless solid [yield 83%, m.p. 428-429 K; R_f = 0.58 (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 tetrahydrofuran at room temperature.