2,4,6,7-Tetramethyl-3-phenylsulfinyl-1-benzofuran

In the title compound, C18H18O2S, the O atom and the phenyl group of the phenylsulfinyl substituent lie on opposite sides of the planar benzofuran fragment. The phenyl ring is nearly perpendicular to the benzofuran system [88.56 (7)°] and is tilted slightly towards it. Molecules form pseudo-helices along the a axis. The crystal structure is stabilized by a C—H⋯π interaction between a methyl H atom and the phenyl ring of the phenylsulfinyl substituent, and by intra- and intermolecular C—H⋯O interactions.

In the title compound, C 18 H 18 O 2 S, the O atom and the phenyl group of the phenylsulfinyl substituent lie on opposite sides of the planar benzofuran fragment. The phenyl ring is nearly perpendicular to the benzofuran system [88.56 (7) ] and is tilted slightly towards it. Molecules form pseudo-helices along the a axis. The crystal structure is stabilized by a C-HÁ Á Á interaction between a methyl H atom and the phenyl ring of the phenylsulfinyl substituent, and by intra-and intermolecular C-HÁ Á ÁO interactions.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: FL2196).

Comment
Benzofuran ring systems have attracted considerable interest because of their various pharmacological properties (Howlett et al., 1999;Ward, 1997). This work is related to earlier communications on the synthesis and structure of similar benzofuran analogues (Choi et al., 2007(Choi et al., , 2008 In the title commmpound, the benzofuran unit is essentially planar, with a mean deviation of 0.008 Å from the leastsquares plane defined by the nine constituent atoms (Fig. 1). The phenyl ring (C9-C14) is almost perpendicular to the plane of the benzofuran system [88.56 (7)°] and is tilted slightly towards it.

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq S 0.60317 (5)