5-Ethyl-2-methyl-3-phenyl­sulfonyl-1-benzofuran

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

doi:10.1107/S1600536808012877

. 2008 May 7;64(Pt 6):o1016. doi: 10.1107/S1600536808012877

5-Ethyl-2-methyl-3-phenylsulfonyl-1-benzofuran

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

PMCID: PMC2961571 PMID: 21202541

Abstract

The title compound, C₁₇H₁₆O₃S, was prepared by the oxidation of 5-ethyl-2-methyl-3-phenylsulfanyl-1-benzofuran with 3-chloroperoxybenzoic acid. The phenyl ring makes a dihedral angle of 75.94 (8)° with the plane of the benzofuran fragment. The crystal structure is stabilized by π–π interactions between the furan rings of neighbouring molecules [centroid–centroid distance = 3.620 (4) Å]. In addition, the crystal structure exhibits C—H⋯π interactions.

Related literature

For the crystal structures of similar 3-phenylsulfonyl-1-benzofuran compounds, see: Choi et al. (2008a ▶,b ▶).

Experimental

Crystal data

C₁₇H₁₆O₃S
M _r = 300.36
Monoclinic,
a = 8.7009 (4) Å
b = 8.2019 (4) Å
c = 20.682 (1) Å
β = 97.301 (1)°
V = 1463.98 (12) Å³
Z = 4
Mo Kα radiation
μ = 0.23 mm⁻¹
T = 173 (2) K
0.40 × 0.20 × 0.20 mm

Data collection

Bruker SMART CCD diffractometer
Absorption correction: none
8693 measured reflections
3194 independent reflections
2264 reflections with I > 2σ(I)
R _int = 0.048

Refinement

R[F ² > 2σ(F ²)] = 0.056
wR(F ²) = 0.148
S = 1.03
3194 reflections
192 parameters
H-atom parameters constrained
Δρ_max = 0.42 e Å⁻³
Δρ_min = −0.49 e Å⁻³

Data collection: SMART (Bruker, 2001 ▶); cell refinement: SAINT (Bruker, 2001 ▶); 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/S1600536808012877/cf2194sup1.cif

e-64-o1016-sup1.cif^{(18.8KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808012877/cf2194Isup2.hkl

e-64-o1016-Isup2.hkl^{(156.7KB, 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
C15—H15C⋯Cg2ⁱ	0.98	2.80	3.592 (4)	139
C16—H16B⋯Cg2ⁱⁱ	0.98	3.21	3.903 (4)	128

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

supplementary crystallographic information

Comment

As a part of our ongoing studies on the synthesis and structure of 3-phenyl-sulfonyl-1-benzofuran analogues, the crystal structure of 5-bromo-2-methyl-3-phenylsulfonyl-1-benzofuran (Choi et al., 2008a) and 2,5,7-trimethyl-3-phenylsulfonyl-1-benzofuran (Choi et al., 2008b) have been described in the literature. Here we report the crystal structure of the title compound, 5-ethyl-2-methyl-3-phenylsulfonyl-1-benzofuran (Fig. 1).

The benzofuran unit is essentially planar, with a mean deviation of 0.007 Å from the least-squares plane defined by the nine constituent atoms. The phenyl ring (C9—C14) makes a dihedral angle of 75.94 (8)° with the plane of the benzofuran fragment. The crystal packing (Fig. 2) is stabilized by aromatic π-π stacking interactions between the furan rings of neighbouring molecules. The Cg1···Cg1ⁱ distance is 3.620 (4) Å (Cg1 is the centroid of the O1/C8/C1/C2/C7 furan ring, symmetry code as in Fig. 2). The molecular packing is further stabilized by C—H···π interactions (Table 1 and Fig. 2); one between a methyl H atom and the benzene ring of the benzofuran unit, i.e. C15—H15C···Cg2ⁱ, a second between a methylene H atom of the ethyl group and the benzene ring of the benzofuran unit, i.e. C16—H16B···Cg2ⁱⁱ, respectively. In both cases the benzene ring (Cg2) is involved (Cg2 is the centroid of the C2–7 benzene ring, symmetry code as in Fig. 2).

Experimental

3-Chloroperoxybenzoic acid (77%, 471 mg, 2.1 mmol) was added in small portions to a stirred solution of 5-ethyl-2-methyl-3-phenylsulfanyl-1-benzofuran (268 mg, 1.0 mmol) in dichloromethane (30 ml) at 273 K. After being stirred for 4 h at room temperature, 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 80%, m.p. 396- 397 K; R_f = 0.66 (hexane-ethyl acetate, 2:1 v/v)]. Single crystals suitable for X-ray diffraction were prepared by evaporation of a solution of the title compound in benzene at room temperature. Spectroscopic analysis: ¹H NMR (CDCl₃, 400 MHz) δ 1.26 (t, J = 7.68 Hz, 3H), 2.74 (q, J = 7.72 Hz, 2H), 2.79 (s, 3H), 7.14 (d, J = 8.44 Hz and 1.48 Hz, 1H), 7.32 (d, J = 8.44 Hz, 1H), 7.48–7.61 (m, 3H), 7.69 (s, 1H), 8.01 (d, J = 6.96 Hz, 2H); EI—MS 300 [M⁺].