Methyl o-bromobenzoate (2.15 g, 10 mmol), bis(pinacolato)diboron (3.05 g, 12 mmol), potassium acetate (3.92 g, 40 mmol), and [1,1'-bis(diphenylphosphino)ferrocene]palladium dichloride (0.49 g, 0.5 mmol) were sequentially added to 150 mL of dioxane under nitrogen atmosphere. The reaction mixture was heated to 85 °C and the reaction was stirred at this temperature for 12 hours. Upon completion of the reaction, the solvent dioxane was removed by distillation under reduced pressure. The residue was extracted with dichloromethane and the combined organic phases were washed three times with saturated aqueous sodium chloride solution. The organic phases were dried over anhydrous sodium sulfate and the dichloromethane was removed by distillation under reduced pressure to give the crude product. The crude product was purified by column chromatography, and the eluent was a mixed solvent of petroleum ether and dichloromethane (3:1, v/v) to give 2-methoxycarbonylphenylboronic acid pinacol ester as a white solid (1.25 g, 86% yield). The structure of the product was confirmed by 1H NMR, 13C NMR, mass spectrometry (MS) and elemental analysis.
