Methyl 2-(5-fluoro-3-methyl­sulfinyl-1-benzofuran-2-yl)acetate

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

doi:10.1107/S1600536809030451

. 2009 Aug 8;65(Pt 9):o2096. doi: 10.1107/S1600536809030451

Methyl 2-(5-fluoro-3-methylsulfinyl-1-benzofuran-2-yl)acetate

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

PMCID: PMC2969894 PMID: 21577512

Abstract

In the title compound, C₁₂H₁₁FO₄S, the O atom and the methyl group of the methylsulfinyl substituent lie on opposite sides of the plane of the benzofuran fragment [O—S—C—C and C—S—C—C torsion angles = 126.70 (13) and −123.55 (13)°, respectively]. The crystal structure is stabilized by weak non-classical intermolecular C—H⋯O hydrogen-bond interactions. The crystal structure also exhibits aromatic π–π stacking interactions between furan/benzene and benzene/benzene rings of adjacent benzofuran ring systems [centroid–centroid distances = 3.8258 (9) and 3.8794 (9) Å] and a weak intermolecular C—H⋯π ring interaction.

Related literature

For crystal structures of similar methyl 2-(5-halo-3-methylsulfinyl-1-benzofuran-2-yl)acetate derivatives. see: Choi et al. (2008a ▶,b ▶). For the pharmacological properties of benzofuran compounds, see: Howlett et al. (1999 ▶); Twyman & Allsop (1999 ▶).

Experimental

Crystal data

C₁₂H₁₁FO₄S
M _r = 270.27
Triclinic,
a = 7.7799 (5) Å
b = 8.5609 (6) Å
c = 10.5592 (7) Å
α = 73.834 (1)°
β = 80.178 (1)°
γ = 67.486 (1)°
V = 622.36 (7) Å³
Z = 2
Mo Kα radiation
μ = 0.28 mm⁻¹
T = 273 K
0.60 × 0.40 × 0.40 mm

Data collection

Bruker SMART CCD diffractometer
Absorption correction: none
5368 measured reflections
2667 independent reflections
2389 reflections with I > 2σ(I)
R _int = 0.014

Refinement

R[F ² > 2σ(F ²)] = 0.032
wR(F ²) = 0.089
S = 1.08
2667 reflections
165 parameters
H-atom parameters constrained
Δρ_max = 0.28 e Å⁻³
Δρ_min = −0.31 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/S1600536809030451/jj2003sup1.cif

e-65-o2096-sup1.cif^{(17.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809030451/jj2003Isup2.hkl

e-65-o2096-Isup2.hkl^{(130.9KB, 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
C3—H3⋯O4ⁱ	0.93	2.39	3.303 (2)	166
C9—H9A⋯O4ⁱⁱ	0.97	2.22	3.179 (2)	168
C9—H9B⋯O1ⁱⁱⁱ	0.97	2.54	3.489 (2)	166
C12—H12A⋯O3^iv	0.96	2.60	3.478 (2)	152
C11—H11A⋯Cg2^v	0.96	2.97	3.93	173

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) ; (v) . Cg2 is the centroid of the C2–C7 ring.

supplementary crystallographic information

Comment

Molecules containing the benzofuran skeleton have received considerable attention related to their pharmacological properties (Howlett et al., 1999; Twyman & Allsop, 1999). This work is related to our communications on the synthesis and crystal structures of methyl 2-(5-halo-3-methylsulfinyl-1-benzofuran-2-yl)acetate derivatives, viz. methyl 2-(5-chloro-3-methylsulfinyl-1-benzofuran-2-yl)acetate (Choi et al., 2008a), and methyl 2-(5-bromo-3-methylsulfinyl-1-benzofuran-2-yl)acetate (Choi et al., 2008b). Here we report the crystal structure of the title compound, methyl 2-(5-fluoro-3-methylsulfinyl-1-benzofuran-2-yl)acetate (Fig. 1).

The benzofuran unit is essentially planar, with a mean deviation of 0.006 (1) ° from the least-squares plane defined by the nine constituent atoms (Fig. 1). In the title compound, all of the bond angles and bond distances are in the normal range of related molecules (Choi et al., 2008a, b). The oxygen atom and the methyl group of the methylsulfinyl substituent lie on opposite sides of the plane of the benzofuran fragment [O4–S–C1–C8 and C12–S–C1–C8 torsional angles = 126.70 (13)° and -123.55 (13) °, respectively]. Crystal packing is stabilized by weak intermolecular C–H···O hydrogen bond interactions involving the S═O unit with the benzofurn ring (C3–H3···O4ⁱ) and a methylene H atom (C9–H9A···O4ⁱⁱ), between the furan ring and methylene H atom (C9–H9B···O1ⁱⁱⁱ) as well as between a methyl H atom of the methylsulfinyl substituent and the C═O unit (C12–H12A···O3^iv), respectively (Fig. 2, Table 1). Crystal packing also exhibits aromatic π–π stacking interactions between the furan/benzene and the benzene/benzene rings of neighbouring molecules [Cg1···Cg2^vii = 3.8258 (9)Å and Cg2···Cg2^vi = 3.8794 (9)Å, where Cg1 and Cg2 are centroids of the furan (C1/C2/C7/O1/C8) and benzene (C2-C7) rings, respectively, Fig. 3]. The molecular packing is further stabilized by a weak, intermolecular C–H···π ring interaction between a methyl H atom of the methoxy group and a benzene ring of a neighbouring molecule (C11–H11A···Cg2^v; = 3.927 (3)Å, Table 1).

Experimental

The 77% 3-chloroperoxybenzoic acid (247 mg, 1.1 mmol) was added in small portions to a stirred solution of methyl 2-(5-fluoro-3-methylsulfanyl-1-benzofuran-2-yl)acetate (254 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,1:2 v/v) to afford the title compound as a colorless solid [yield 79%, m.p. 370-371 K; R_f = 0.4 (hexane-ethyl acetate, 1;2 v/v )]. Single crystals suitable for X-ray diffraction were prepared by slow evaporation of a solution of the title compound in benzene at room temperature.