To a dry reaction flask was added 6-bromo-1-methyl-3,4-dihydroquinolin-2(1H)-one (3 g, 12.5 mmol), pinacol ester of bisboronic acid (3.81 g, 15.0 mmol), potassium acetate (3.68 g, 37.5 mmol), and dioxane (48 mL). Dichloro[1,1'-bis(diphenylphosphino)ferrocene]palladium(II) dichloromethane complex (457 mg, 0.625 mmol) was added to the reaction system under argon protection. The reaction mixture was heated to 80 °C and stirred overnight. After completion of the reaction, the reaction mixture was diluted with ethyl acetate, filtered through diatomaceous earth and the filter cake was washed with ethyl acetate (2 x 150 mL). The organic phases were combined, washed with saturated brine, dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The residue was purified by silica gel column chromatography using 0 to 40% ethyl acetate-heptane gradient elution to afford the target product 1-methyl-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,4-dihydroquinolin-2(1H)-one (2.63 g, 73% yield) as an off-white solid. Mass spectrum (MS): 288.0 (M+H+).
