Isopropyl 2-(5-iodo-7-methyl-3-methyl­sulfinyl-1-benzofuran-2-yl)acetate

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

doi:10.1107/S1600536808038671

. 2008 Nov 26;64(Pt 12):o2431. doi: 10.1107/S1600536808038671

Isopropyl 2-(5-iodo-7-methyl-3-methylsulfinyl-1-benzofuran-2-yl)acetate

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

PMCID: PMC2960088 PMID: 21581399

Abstract

In the title molecule, C₁₅H₁₇IO₄S, the O atom and the methyl group of the methylsulfinyl substituent lie on opposite sides of the plane of the benzofuran fragment. In the crystal structure, intermolecular I⋯O [2.994 (3) Å] halogen bonding links the molecules into centrosymmetric dimers, which are further packed into ribbons along the c axis by intermolecular sulfinyl–sulfinyl interactions [S⋯O 3.128 (3) Å].

Related literature

For the crystal structures of similar isopropyl 2-(3-methylsulfinyl-1-benzofuran-2-yl)acetate derivatives, see Choi et al. (2008a ▶,b ▶). For a review of halogen bonding, see Politzer et al. (2007 ▶). For a review of carbonyl–carbonyl interactions, see Allen et al. (1998 ▶).

Experimental

Crystal data

C₁₅H₁₇IO₄S
M _r = 420.25
Monoclinic,
a = 17.615 (2) Å
b = 10.0905 (7) Å
c = 19.144 (1) Å
β = 99.177 (2)°
V = 3359.2 (5) Å³
Z = 8
Mo Kα radiation
μ = 2.04 mm⁻¹
T = 298 (2) K
0.40 × 0.30 × 0.20 mm

Data collection

Bruker SMART CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1999 ▶) T _min = 0.480, T _max = 0.667
6667 measured reflections
2897 independent reflections
2172 reflections with I > 2σ(I)
R _int = 0.030

Refinement

R[F ² > 2σ(F ²)] = 0.033
wR(F ²) = 0.064
S = 1.24
2897 reflections
192 parameters
H-atom parameters constrained
Δρ_max = 0.48 e Å⁻³
Δρ_min = −0.37 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/S1600536808038671/cv2478sup1.cif

e-64-o2431-sup1.cif^{(18.7KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808038671/cv2478Isup2.hkl

e-64-o2431-Isup2.hkl^{(142.3KB, hkl)}

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

Table 1. Selected interatomic distances (Å).

I⋯O4ⁱ	2.994 (3)
S⋯O4ⁱⁱ	3.128 (3)

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

supplementary crystallographic information

Comment

This work is related to our previous communications on the synthesis and structure of isopropyl 2-(3-methylsulfinyl-1-benzofuran-2-yl)acetate analogues, viz. isopropyl 2-(5-methyl-3-methylsulfinyl-1-benzofuran-2-yl)acetate (Choi et al., 2008a) and isopropyl 2-(5-bromo-3-methylsulfinyl-1-benzofuran-2-yl)acetate (Choi et al., 2008b). Here we report the crystal structure of the title compound, isopropyl 2-(5-iodo-7-methyl-3-methylsulfinyl-1-benzofuran-2-yl)acetate (Fig. 1).

The benzofuran unit is essentially planar, with a mean deviation of 0.030 (3) Å from the least-squares plane defined by the nine constituent atoms. The molecular packing (Fig. 2) is stabilized by intermolecular I···O halogen bonding (Politzer et al., 2007) of 2.994 (3) Å and a nearly linear C—I···O angle of 168.51 (9)°, which link the molecules into centrosymmetric dimers (Table 1). These dimers are further packed into ribbons along the c axis by sulfinyl–sulfinyl interactions (Table 1) interpreted as simliar to a type–II carbonyl–carbonyl interaction (Allen et al., 1998).

Experimental

77% 3-Chloroperoxybenzoic acid (123 mg, 0.55 mmol) was added in small portions to a stirred solution of isopropyl 2-(5-iodo-7-methyl-3-methylsulfanyl-1-benzofuran-2-yl)acetate (202 mg, 0.5 mmol) in dichloromethane (30 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 (ethyl acetate) to afford the title compound as a colorless solid [yield 81%, m.p. 396-397 K; R_f = 0.74 (ethyl acetate)]. Single crystals suitable for X-ray diffraction were prepared by evaporation of a solution of the title compound in acetone at room temperature. Spectroscopic analysis: ¹H NMR (CDCl₃, 400 MHz) δ 1.27 (d, J = 6.24 Hz, 6H), 2.46 (s, 3H), 3.06 (s, 3H), 4.00 (s, 2H), 5.03-5.09 (m, 1H), 7.49 (s, 1H), 8.10 (s, 1H); EI-MS 420 [M⁺].