3,5-Dimethoxy-4′-methylbiphenyl

The title compound, C15H16O2, crystallizes with three independent molecules in the asymmetric unit. The intramolecular torsion angle between the aromatic rings of each molecule are −36.4 (3), 41.3 (3) and −37.8 (3)°. In the crystal, the complicated packing of the molecules forms wave-like layers along the b and c axes. The molecules are connected via extensive methoxy–phenyl C—H⋯π interactions. A weak C—H⋯O hydrogen-bonding network also exists between methoxy O atoms and aromatic or methoxy H atoms.

The title compound, C 15 H 16 O 2 , crystallizes with three independent molecules in the asymmetric unit. The intramolecular torsion angle between the aromatic rings of each molecule are À36.4 (3), 41.3 (3) and À37.8 (3) . In the crystal, the complicated packing of the molecules forms wave-like layers along the b and c axes. The molecules are connected via extensive methoxy-phenyl C-HÁ Á Á interactions. A weak C-HÁ Á ÁO hydrogen-bonding network also exists between methoxy O atoms and aromatic or methoxy H atoms.

Experimental
A flame dried Schlenk-tube was charged with 4-methylphenylboronic acid (6.00 g, 44.13 mmol), potassium fluoride (5.13 g, 88.30 mmol), 1-chloro-3,5-dimethoxybenzene (5.08 g, 29.43 mmol), Pd(OAc) 2 (66 mg, 0.29 mmol, 1.0 mol%) and 2-(di-tert-butylphosphino)biphenyl (176 mg, 0.59 mmol, 2.0 mol%). The flask was sealed with a teflon screwcap, evacuated/backfilled with argon five times. Then dry, degassed THF (40 ml) was added via syringe. The reaction mixture was stirred at ambient temperature until the aryl chloride had been completely consumed as judged by GC analysis. The mixture was diluted with ether, filtered, and washed with 1 M NaOH. The aqueous layer was extracted with ether, the combined organic layer was washed with brine and dried with MgSO 4 . After evaporation the crude material was purified by flash column chromatography: silica gel/CH 2 Cl 2 . The solvent was evaporated and the product was re-crystallized from EtOH affording 6.40 g (95%) of a white crystalline solid. Crystals suitable for a single-crystal structure determination were obtained from a slow evaporation of ethanol.

Refinement
Hydrogen atoms were calculated to their positions as riding atoms (C host) using isotropic displacement parameters that were fixed to be 1.2 or 1.5 times larger than those of the attached non-hydrogen atom.

Figure 1
The molecular structure of the title compound showing 50% probability displacement ellipsoids and the atomic numbering.  Overlay of three crystallographically disctinct molecules of an asymmetric unit.    Extensive C-H···π and π-π interaction network shown along b-axis.

3,5-Dimethoxy-4′-methylbiphenyl
Crystal data Special details Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s 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 > σ(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.