A 100 mL round-bottom flask was charged tert-butyl 4-[(4-bromo-2-methylphenyl)methyl]piperazine-1-carboxylate (1.90 g, 5.14 mmol, 1.00 equiv), (3-methylphenyl)boronic acid (2.12 g, 15.6 mmol, 3.00 equiv), potassium carbonate (2.15 g, 15.6 mmol, 3.00 equiv), Pd(PPh3)4 (0.600 g, 0.520 mmol, 0.10 equiv), dioxane (25 mL), water (2.5 mL) with an inert atmosphere of nitrogen. The resulting solution was stirred overnight at 80° C., diluted with water (50 mL), extracted with dichloromethane (3×40 mL) and the organic layers were combined, dried over Na2SO4, filtered and concentrated under reduced pressure. The residue was chromatographed on a silica gel column with ethyl acetate/petroleum ether (20/80) to provide in 2.00 g (95% yield) of tert-butyl 4-[[2-methyl-4-(3-methylphenyl)phenyl]methyl]piperazine-1-carboxylate as light yellow oil. LCMS (ESI, m/z): 381 [M+H]+.
