1016641-53-4

67927-44-0

73183-34-3

1016641-53-4

6-Bromo-3-methylbenzo[d]oxazol-2(3H)-one (1 eq., 17 mmol, 3.8 g), pinacol ester of bisboronic acid (1.1 eq., 18 mmol, 4.7 g), and potassium acetate (2 eq., 33 mmol, 3.3 g) were mixed with trans dichlorobis(triphenylphosphine)palladium(II) (0.03 eq., 0.5 mmol, 0.41 g) in dioxane (180 mL). The reaction mixture was stirred at 100 °C for 7 hours under argon protection. Upon completion of the reaction, water was added and the aqueous layer was extracted with dichloromethane. The organic layers were combined, dried with anhydrous magnesium sulfate and concentrated under reduced pressure. The crude product was purified by silica gel column chromatography using dichloromethane as eluent to afford the white powdery product 3-methyl-6-pinacolboronic acid ester benzo[d]oxazol-2(3H)-one (3.7 g, 81% yield, 81% liquid chromatographic purity).