The general procedure for the synthesis of 2-methyl-4-pyridylboronic acid pinacol ester from 4-bromo-2-methylpyridine (0.500 g, 2.906 mmol) and pinacol ester of bis(diphenylphosphine) (0.812 g, 3.997 mmol) is as follows: in an inert atmosphere, 4-bromo-2-methylpyridine, pinacol ester of bis(boronic acid), potassium acetate (0.854 g, 8.720 mmol) and [1,1'-bis(diphenylphosphino)ferrocene]palladium(II) dichloride (0.021 g, 0.029 mmol) were dissolved in degassed 1,4-dioxane (5 mL) in a 50 mL sealed tube. The reaction mixture was stirred at 80 °C for 4 hours. Upon completion of the reaction, the solvent was removed by rotary evaporation and the crude product was purified by silica gel column chromatography (eluent: ethyl acetate/ether = 30:70) to afford 2-methyl-4-pyridinylboronic acid pinacol ester (0.250 g, 39% yield) as an off-white solid. m/z 220.1 [M + H]+ was shown by LCMS analysis.
