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

In the title compound, C14H15ClO4S, the S atom has a distorted trigonal-pyramidal coordination. The O atom and the methyl group of the methylsulfinyl substituent lie on opposite sides of the benzofuran ring system. The crystal structure is stabilized by intermolecular aromatic π–π interactions between the benzene rings of neighbouring molecules [centroid–centroid distance = 4.057 (3) Å], and by C—H⋯π interactions between a methyl H atom and the benzene ring of an adjacent molecule.

In the title compound, C 14 H 15 ClO 4 S, the S atom has a distorted trigonal-pyramidal coordination. The O atom and the methyl group of the methylsulfinyl substituent lie on opposite sides of the benzofuran ring system. The crystal structure is stabilized by intermolecular aromaticinteractions between the benzene rings of neighbouring molecules [centroid-centroid distance = 4.057 (3) Å ], and by C-HÁ Á Á interactions between a methyl H atom and the benzene ring of an adjacent molecule.

Related literature
For the crystal structures of similar compounds, see: Choi et al. (2008a,b Table 1 Hydrogen-bond geometry (Å , ).
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: NG2521).
The benzofuran unit is essentially planar, with a mean deviation of 0.012 (2) Å from the least-squares plane defined by the nine constituent atoms. The molecular packing is stabilized by aromatic π-π stacking interactions between the benzene rings of adjacent molecules. The Cg···Cg ii distance is 4.057 (3) Å ( Fig. 2; Cg is the centroid of C2-C7 benzene ring; symmetry code as in Fig. 2). The molecular packing is further stabilized by C-H···π interactions between a methyl H atom of isoproyl group and the benzene ring of the benzofuran uint, with a C13-H13B···Cg i separation of 2.78 Å ( Fig. 2 and Table 1; Cg is the centroid of the C2-C7 benzene ring).

Experimental
77% 3-chloroperoxybenzoic acid (173 mg, 0.77 mmol) was added in small portions to a stirred solution of isopropyl 2-(5chloro-3-methylsulfanyl-1-benzofuran-2-yl)acetate (209 mg, 0.7 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 (hexane-ethyl acetate, 1:2 v/v) to afford the title compound as a colorless solid [yield 83%, m.p. 422-423 K; R f = 0.52 (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 acetone at room temperature.  Fig. 1. The molecular structure of the title compound, showing displacement ellipsoids drawn at the 30% probability level.

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.
Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > 2sigma(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.