4-(N-Boc-amino)phenylboronic acid pinacol ester

73183-34-3

131818-17-2

330793-01-6

Anhydrous dioxane (100 mL) was added to a 250 mL round-bottom flask using pinacol ester of bisboronic acid (10.5 g, 41.5 mmol) and N-tert-butoxycarbonyl-4-bromoaniline (7.75 g, 28.5 mmol). Pd(dppf)Cl2 (0.79 g, 1.1 mmol) and potassium acetate (7.0 g, 71.4 mmol) were subsequently added. The reaction mixture was stirred at 110 °C for 12 h under argon protection. After completion of the reaction, it was cooled to room temperature, filtered and the filtrate was concentrated by rotary evaporator. The residue was purified by silica gel column chromatography (eluent: petroleum ether/ethyl acetate, 10:1) to afford N-Boc-4-aminophenylboronic acid pinacol ester (3.26 g, 36% yield) as a white solid.1H NMR (400 MHz, DMSO-d6) δ 9.53 (s, 1H), 7.56 (d, J = 8.5 Hz, 2H), 7.47 (d, J = 8.5 Hz, 2H), 1.48 (s, 9H), 1.29 (s, 12H).