Crystal structure of 2,5-dimethyl-3-(2-methylphenylsulfonyl)-1-benzofuran

The title compound, C17H16O3S, crystallized with two independent molecules (A and B) in the asymmetric unit. The dihedral angle between the benzofuran ring system [r.m.s. deviation of 0.013 (1) for A and 0.009 (1) Å for B] and the 2-methylphenyl ring is 83.88 (5) for A and 86.94 (5)° for B. In the crystal, the B molecules are linked into a chain along the b-axis direction by C—H⋯O hydrogen bonds. The A molecules are connected on either side of this chain by further C—H⋯O hydrogen bonds. These chains are linked via C—H⋯π interactions, forming sheets parallel to (100). There are also very weak π–π interactions present [centroid–centroid distance = 3.925 (11) Å] involvingthe 2-methylphenyl rings of neighbouring A and B molecules.

In the title molecules (A and B; Fig. 1 In the crystal, the B molecules are linked into a chain along the b axis direction by C-H···O hydrogen bonds (Table 1 and Fig. 2). The A molecules are connected on either side of this chain by further C-H···O hydrogen bonds (Table 1).

S3. Refinement
All H atoms were positioned geometrically and refined using a riding model, with C-H = 0.95 Å for aryl, and 0.98 Å for methyl H atoms and with U iso (H) = 1.5U eq (C) for methyl H atoms and = 1.2U eq (C) for other H atoms.
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Figure 1
The molecular structure of the two independent molecules (A and B) of the title compound, with atom labelling.
Displacement ellipsoids are drawn at the 50% probability level.

Figure 2
A view of the C-H···O interactions (dashed lines) in the crystal structure of the title compound -see Table 1 for details.

Figure 3
A view of the C-H···π and π-π interactions (dashed lines) in the crystal structure of the title compound -see Table 1 for details. H atoms non-participating in hydrogen-bonding have been omitted for clarity [Symmetry codes: (i) x, -y + 3/2, z -1/2; (ii) x, -y + 3/2, z + 1/2]. 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.