132244-31-6

73183-34-3

936902-12-4

5-Bromobenzoxazole (1 g, 5.05 mmol), pinacol ester of bisboronic acid (1.54 g, 6.06 mmol), potassium acetate (1.49 g, 15.15 mmol) and Pd(dppf)Cl2 (184.76 mg, 0.25 mmol) were used as raw materials, and the above reagents were added to a reaction flask under nitrogen protection, using 1,4-dioxane as solvent. The reaction mixture was stirred at 100 °C for 8 hours. After completion of the reaction, it was cooled to room temperature and the solvent was removed by distillation under reduced pressure. The crude product was purified by column chromatography to afford 1.03 g of the target product benzoxazole-5-boronic acid pinacol ester in white powder form in 83.4% yield.