Benzenesulfonamide-3-boronic acid pinacol ester

89599-01-9

73183-34-3

486422-08-6

3-Bromobenzenesulfonamide (0.620 g, 2.63 mmol), potassium acetate (KOAc, 1.032 g, 10.52 mmol) and PdCl2(dppf)2 (0.100 g, 0.137 mmol) were used as raw materials, which were dissolved in dioxane (20 mL) under the protection of argon, and argon was blown up for 10 minutes to deoxygenate. Subsequently, bis(pinacolato)diboron (1.000 g, 3.94 mmol) was added to the reaction system, the reaction vessel was sealed, and the reaction was stirred at 110 °C for 24 hours. After completion of the reaction, the mixture was cooled to room temperature and filtered through diatomaceous earth. The filtrate was concentrated under reduced pressure and the residue was purified by silica gel column chromatography (eluent: petroleum ether/ethyl acetate, gradient from 4:1 to 1:1) to afford the target product 3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzenesulfonamide (0.663 g, 89% yield) as a white solid. The product was characterized by NMR (DMSO-d6, HMDSO): δ 8.14 (ddd, J = 2.0, 1.1, 0.5 Hz, 1H), 7.93 (ddd, J = 7.9, 2.0, 1.3 Hz, 1H), 7.85 (td, J = 1.2, 7.4 Hz, 1H), 7.59 (ddd, J = 7.9, 7.4, 0.5 Hz, 1H), 1.32 (s, 12H).LCMS (ESI) m/z: 284.0 [M + H]+.