1254319-51-1

73183-34-3

1313399-38-0

N-methyl-6-bromoisoindolin-1-one (723 mg, 3.41 mmol) and pinacol ester of bisboronic acid (1.04 g, 4.09 mmol) were added with potassium acetate (1.00 g, 10.2 mmol) and PdCl2 (dppf) catalyst (139 mg, 0.17 mmol) and the reaction system was sealed under nitrogen protection. DMSO (15 mL) was added to the reaction mixture and the reaction was stirred at 90 °C for 5 hours. After completion of the reaction, it was cooled to room temperature, the reaction mixture was diluted with water (250 mL) and extracted with dichloromethane (5 x 50 mL). The organic phases were combined, washed sequentially with water (2×100 mL) and brine (100 mL), dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to obtain the crude product. Purification by silica gel fast column chromatography (eluent 20% THF/dichloromethane) afforded the target product 2-methyl-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)isoindolin-1-one as a crystalline beige solid (262 mg, 28% yield).NMR [400 MHz, (CD3)2SO] δ 7.91 (br s, 1H), 7.85 (dd, J = 7.6, 1.0 Hz, 1H), 7.59 (dd, J = 7.5, 0.6 Hz, 1H), 4.49 (s, 2H), 3.07 (s, 3H), 1.32 (s, 12H). lRMS (APCI+) m/z Calculated value C15H21Br3O3 [M+H]+ 274, measured value 274.