Isopropyl 2-(5-bromo-3-methyl­sulfinyl-1-benzofuran-2-yl)acetate

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

doi:10.1107/S160053680803506X

. 2008 Nov 8;64(Pt 12):o2250. doi: 10.1107/S160053680803506X

Isopropyl 2-(5-bromo-3-methylsulfinyl-1-benzofuran-2-yl)acetate

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

PMCID: PMC2959940 PMID: 21581231

Abstract

In the title compound, C₁₄H₁₅BrO₄S, the O atom and the methyl group of the methylsulfinyl substituent lie on opposite sides of the plane of the benzofuran fragment. The crystal structure is stabilized by C—H⋯π interactions between a methyl H atom and the benzene ring of a neighbouring molecule, and by weak intermolecular C—H⋯O hydrogen bonds.

Related literature

For the crystal structures of similar alkyl 2-(3-methylsulfinyl-1-benzofuran-2-yl)acetate derivatives, see: Choi et al. (2007 ▶, 2008 ▶).

Experimental

Crystal data

C₁₄H₁₅BrO₄S
M _r = 359.23
Triclinic,
a = 7.947 (1) Å
b = 10.078 (1) Å
c = 10.868 (1) Å
α = 69.623 (2)°
β = 82.027 (2)°
γ = 67.409 (2)°
V = 753.33 (14) Å³
Z = 2
Mo Kα radiation
μ = 2.88 mm⁻¹
T = 298 (2) K
0.40 × 0.40 × 0.20 mm

Data collection

Bruker SMART CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1999 ▶) T _min = 0.321, T _max = 0.559
3979 measured reflections
2604 independent reflections
2123 reflections with I > 2σ(I)
R _int = 0.011

Refinement

R[F ² > 2σ(F ²)] = 0.031
wR(F ²) = 0.085
S = 1.02
2604 reflections
181 parameters
H-atom parameters constrained
Δρ_max = 0.46 e Å⁻³
Δρ_min = −0.46 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/S160053680803506X/sg2276sup1.cif

e-64-o2250-sup1.cif^{(18.3KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S160053680803506X/sg2276Isup2.hkl

e-64-o2250-Isup2.hkl^{(127.9KB, 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⋯O2ⁱ	0.93	2.50	3.392 (4)	160
C10—H10B⋯O2ⁱⁱ	0.97	2.40	3.365 (4)	173
C13—H13C⋯Cgⁱⁱⁱ	0.96	2.78	3.526 (4)	136

Open in a new tab

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

supplementary crystallographic information

Comment

This work is related to our previous communications on the synthesis and structure of alkyl 2-(3-methylsulfinyl-1-benzofuran-2-yl)acetate analogues, viz. ethyl 2-(5-bromo-3-methylsulfinyl-1-benzofuran-2-yl)acetate (Choi et al., 2007) and isopropyl 2-(5-methyl-3-methylsulfinyl-1-benzofuran-2-yl) acetate (Choi et al., 2008). Here we report the crystal structure of the title compound, isopropyl 2-(5-bromo-3-methylsulfinyl-1-benzofuran-2-yl) acetate (Fig. 1).

The benzofuran unit is essentially planar, with a mean deviation of 0.014 (2) Å from the least-squares plane defined by the nine constituent atoms. The molecular packing (Fig. 2) is stabilized by intermolecular C—H···π interactions between a methyl H atom of isoproyl group and the benzene ring of the benzofuran fragment, with a C13—H13C···Cgⁱⁱⁱ separation of 2.78 Å (Fig. 2 and Table 1; Cg is the centroid of the C2–C7 benzene ring, symmetry code as in Fig. 2). The molecular packing is further stabilized by two intermolecular C—H···O hydrogen bonds (Fig. 2 and Table 1)

Experimental

77% 3-chloroperoxybenzoic acid (370 mg, 1.65 mmol) was added in small portions to a stirred solution of isopropyl 2-(5-bromo-3-methylsulfanyl-1-benzofuran-2-yl)acetate (515 mg, 1.50 mmol) in dichloromethane (40 ml) at 273 K. After being stirred for 3 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 78%, m.p. 429–430 K; R_f = 0.74 (hexane-ethyl acetate, 1;2 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 (d, J = 6.24 Hz, 6H), 3.07 (s, 3H), 4.01 (s, 2H), 5.01–5.08 (m, 1H), 7.39 (d, J = 8.80 Hz, 1H), 7.48 (d, J = 8.76 Hz, 1H), 8.09 (s, 1H); EI—MS 360 [M+2], 358 [M⁺].