Tert-butyl 4-(4-bromo-3-methyl-1H-pyrazol-1-yl)piperidine-1-carboxylate (2.7 g), pinacol ester of biphenylboronic acid (4.98 g), 1,1'-bis(diphenylphosphino)ferrocene palladium(II) dichloride-CH2Cl2 adduct (0.634 g), and potassium acetate (2.31 g) were used as raw materials, in DMSO (40 ml) at 80 °C under The reaction was stirred for 4 hours. After completion of the reaction, the reaction mixture was cooled to room temperature, quenched with water (25 ml) and extracted with ethyl acetate (3 x 40 ml). The organic phases were combined, washed sequentially with water (3 x 30 ml) and brine (1 x 20 ml), dried with magnesium sulfate and concentrated. The residue was purified by rapid chromatography on silica gel, using a petroleum ether solution of 10% to 30% ethyl acetate as eluent, to afford the target product tert-butyl 4-(3-methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazol-1-yl)piperidine-1-carboxylate (0.937 g, 30.5% yield) as a white solid.NMR data (DMSO-d6): δ 1.24 (s, 12H), 1.41 (s, 9H), 1.71 (dd, 1H), 1.76 (dd, 1H), 1.89-1.96 (m, 2H), 2.22 (s, 3H), 2.85 (bs, 2H), 3.95-4.07 (m, 2H), 4.20-4.29 (m, 1H) , 7.82 (s, 1H).
