To a mixture of C3 (10 g, 29 mmol), [4-(benzyloxy)-2-methylphenyl]boronic acid (10.4 g, 43.0 mmol) and cesium carbonate (28 g, 86 mmol) in 1,4-dioxane (400 mL) was added [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (2.2 g, 3.0 mmol). The reaction mixture was heated at reflux for 4 hours, then filtered. The filtrate was concentrated, and the residue was purified by silica gel chromatography (Gradient: 10% to 20% ethyl acetate in petroleum ether) to provide the product as a light yellow solid. Yield: 10 g, 21 mmol, 72%. 1H NMR (400 MHz, CDCl3) δ 7.34-7.49 (m, 5H), 7.00 (d, half of AB quartet, J=8.3 Hz, 1H), 6.91-6.97 (m, 2H), 5.50 (AB quartet, JAB=9.2 Hz, ΔνAB=4.1 Hz, 2H), 5.10 (s, 2H), 3.73-3.79 (m, 2H), 3.03 (s, 3H), 2.15 (s, 3H), 1.65 (s, 3H), 1.00-1.06 (m, 2H), 0.03 (s, 9H).
