2,5,7-Trimethyl-3-phenyl­sulfonyl-1-benzofuran

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

doi:10.1107/S1600536808008477

. 2008 Apr 2;64(Pt 5):o794. doi: 10.1107/S1600536808008477

2,5,7-Trimethyl-3-phenylsulfonyl-1-benzofuran

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

PMCID: PMC2961306 PMID: 21202286

Abstract

The title compound, C₁₇H₁₆O₃S, was prepared by the oxidation of 2,5,7-trimethyl-3-phenylsulfanyl-1-benzofuran with 3-chloroperoxybenzoic acid. The phenyl ring exhibits a dihedral angle of 81.16 (4)° with the plane of the benzofuran fragment. The crystal structure is stabilized by π–π interactions between the furan and benzene rings of neighbouring molecules [centroid–centroid distance = 3.874 (2) Å] and by C—H⋯π interactions between a phenyl H atom of the phenylsulfonyl substituent and the furan ring of adjacent molecules. In addition, the crystal structure exhibits intra- and intermolecular C—H⋯O interactions.

Related literature

For the crystal structures of similar substituted benzofuran compounds, see: Choi et al. (2007a ▶,b ▶).

Experimental

Crystal data

C₁₇H₁₆O₃S
M _r = 300.36
Monoclinic,
a = 9.2468 (7) Å
b = 8.4238 (7) Å
c = 18.963 (2) Å
β = 91.535 (2)°
V = 1476.6 (2) Å³
Z = 4
Mo Kα radiation
μ = 0.23 mm⁻¹
T = 173 (2) K
0.40 × 0.40 × 0.10 mm

Data collection

Bruker SMART CCD diffractometer
Absorption correction: none
8704 measured reflections
3212 independent reflections
2544 reflections with I > 2σ(I)
R _int = 0.041

Refinement

R[F ² > 2σ(F ²)] = 0.037
wR(F ²) = 0.104
S = 1.03
3212 reflections
193 parameters
H-atom parameters constrained
Δρ_max = 0.30 e Å⁻³
Δρ_min = −0.38 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/S1600536808008477/zl2106sup1.cif

e-64-0o794-sup1.cif^{(19KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808008477/zl2106Isup2.hkl

e-64-0o794-Isup2.hkl^{(157.6KB, 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
C12—H12⋯Cg1ⁱ	0.95	2.81	3.747 (3)	169
C16—H16C⋯O3ⁱⁱ	0.98	2.48	3.403 (2)	158
C17—H17A⋯O2	0.98	2.42	3.135 (3)	129

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Symmetry codes: (i) Inline graphic ; (ii) . Cg1 is the centroid of the O1/C8/C1/C2/C7 furan ring.

supplementary crystallographic information

Comment

This work is related to earlier communications on the synthesis and structure of substituted benzofuran analogues, viz. 2,5-dimethyl-3-methylsulfinyl-1-benzofuran (Choi et al., 2007a) and 2,5-dimethyl-3-phenylsulfinyl-1-benzofuran (Choi et al., 2007b). Herein we report the molecular and crystal structure of the title compound, 2,5,7-trimethyl-3-phenylsulfonyl-1-benzofuran (Fig. 1).

The benzofuran unit is almost planar, with a mean deviation of 0.009 Å from the least-squares plane defined by the nine constituent atoms. The phenyl ring (C9—C14) is almost perpendicular to the plane of the benzofuran ring system [81.16 (4) °] and is tilted slightly towards it. The crystal packing (Fig. 2) is stabilized by aromatic π—π stacking interactions between the furan and the benzene rings from neighbouring molecules. The Cg1···Cg2ⁱⁱ distance is 3.874 (2)Å (Cg1 and Cg2 are the centroids of the O1/C8/C1/C2/C7 furan ring and the C2—C7 benzene ring, respectively, symmetry code as in Fig. 2). The molecular packing is further stabilized by C—H···π interactions between a phenyl H atom of the phenylsulfonyl substituent and the furan ring of the benzofuran unit, with a C12—H12···Cgⁱ separation of 2.81 Å (Fig. 2 and Table 1; Cg1 is the centroid of the O1/C8/C1/C2/C7 furan ring, symmetry code as in Fig. 2). Additionally, intra- and intermolecular C—H···O interactions in the structure were observed (Fig. 2 and Table 1; 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 2,5,7-trimethyl-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 81%, m.p. 399–400 K; R_f = 0.61 (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 2.41 (s, 6H), 2.80 (s, 3H), 6.92 (s, 1H), 7.47–7.52 (m, 4H), 8.01 (d, J = 7.68 Hz, 2H); EI—MS 300 [M⁺].