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

In the title compound, C13H12BrClO4S, the O atom and the methyl group of the methylsulfinyl substituent lie on opposite sides of the plane of the benzofuran fragment. There is a mean deviation of 0.016 (4) Å from the least-squares plane defined by the nine constituent benzofuran atoms. The crystal structure is stabilized by aromatic π–π interactions between the benzene rings of neighbouring molecules [centroid–centroid distance = 3.689 (7) Å]and by a weak C—H⋯π interaction between an H atom of the methylene group bonded to the carboxylate O atom and the benzene ring of an adjacent molecule. In addition, the crystal structure exhibits weak non-classical intermolecular C—H⋯O hydrogen bonds. The chloroethyl group is disordered over two positions, with refined site-occupancy factors of 0.767 (6) and 0.233 (6).

In the title compound, C 13 H 12 BrClO 4 S, the O atom and the methyl group of the methylsulfinyl substituent lie on opposite sides of the plane of the benzofuran fragment. There is a mean deviation of 0.016 (4) Å from the least-squares plane defined by the nine constituent benzofuran atoms. The crystal structure is stabilized by aromaticinteractions between the benzene rings of neighbouring molecules [centroidcentroid distance = 3.689 (7) Å ]and by a weak C-HÁ Á Á interaction between an H atom of the methylene group bonded to the carboxylate O atom and the benzene ring of an adjacent molecule. In addition, the crystal structure exhibits weak non-classical intermolecular C-HÁ Á ÁO hydrogen bonds. The chloroethyl group is disordered over two positions, with refined site-occupancy factors of 0.767 (6) and 0.233 (6).
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: SJ2602).
The benzofuran unit is essentially planar, with a mean deviation of 0.016 (4) Å from the least-squares plane defined by the nine constituent atoms. The chloroethyl group is disordered over two positions with site-occupancy factors of 0.767 (6) (for atoms labelled A) and 0.233 (7) (for atoms labelled B). The molecular packing (Fig. 2) is stabilized by aromatic π-π interactions between the benzene rings of neighbouring molecules, with a Cg···Cg iii distance of 3.689 (7) Å (Cg is the centroid of the C2-C7 benzene ring; symmetry codes as in Fig. 2). The crystal packing is further stabilized by an intermolecular C-H···π interaction between an H atom of the methylene group bonded to the carboxylate O atom and the benzene ring of a neighbouring molecule, with a C11-H11B···Cg i distance of 3.07 Å (Table 1 and Fig. 2; symmetry code as in Fig. 2, Cg i is the centroid of the C2···C7 benzene ring). Additionally, the crystal structure exhibits weak, non-classical, intermolecular C-H···O hydrogen bonds; the first between a benzene H atom and the S═O unit, the second between a benzene H atom and the C═O unit, the third between an H atom of the methylene group bonded to the carboxylate C atom and the furan O atom, and the fourth between an H atom of the methylene group bonded to the carboxylate C atom and the S═O unit, respectively (Table 1 and Fig. 3; symmetry codes as in Fig. 3).

Refinement
All H atoms were positioned geometrically and refined using a riding model, with C-H = 0.93 Å for the aryl, 0.97 Å for the methylene, and 0.96 Å for the methyl H atoms.Uiso(H) = 1.2Ueq(C) for the aryl and methylene H atoms, and 1.5Ueq(C) for methyl H atoms. The chloroethyl group is disordered over two positions, with site-occupancy factors, from refinement, supplementary materials sup-2 of 0.767 (6) (C11A-C12A-ClA) and 0.233 (7) (C11B-C12B-ClB). Both sets of C and Cl atoms were restrained using the commands ISOR (0.01), EADP, and the C-C and C-Cl distances (A & B) were restrained to 1.46 (3) and 1.55 (3) Å, respectively, using the command DFIX. Despite this the atomic displacement parameters for the C atoms of the disordered chhloroethyl group were large, reflecting additional disorder and the room temperature data collection. Fig. 1. The molecular structure of the title compound with the atom numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. H atoms are presented as a small spheres of arbitrary radius.

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.