N-[2-Methoxy-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3-pyridinyl]-methanesulfonamide

1083327-58-5

73183-34-3

1083326-75-3

GENERAL STEPS: N-(5-bromo-2-methoxypyridin-3-yl)methanesulfonamide (3.35 g, 11.9 mmol) and pinacol ester of bisboronic acid (4.24 g, 16.7 mmol) were suspended in toluene (100 mL), degassed and displaced three times with nitrogen. Tris(dibenzylideneacetone)dipalladium (616 mg, 0.595 mmol) and triphenylphosphine (243 mg, 0.892 mmol) were then added. The mixture was heated to 45 °C and stirred for 45 min, then potassium acetate (3.74 g, 23.8 mmol) was added. The reaction mixture was heated to reflux and stirring was continued for 3 hours. After completion of the reaction, it was cooled to room temperature, diluted with ethyl acetate (100 mL) and filtered through diatomaceous earth. The filtrate was washed sequentially with water (70 mL x 3) and saturated brine (100 mL), dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (petroleum ether/ethyl acetate, v/v=2/1) to afford N-(2-methoxy-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridin-3-yl)methane sulfonamide as a white solid (2.90 g, 74%). Mass spectrum (ESI, cation mode) m/z: 328.9 [M + H]+; 1H NMR (600 MHz, CDCl3): δ 8.32 (d, J=1.4 Hz, 1H), 8.06 (d, J=1.3 Hz, 1H), 6.66 (br s, 1H), 4.05 (s, 3H), 3.02 (s, 3H), 1.33 (s. 12H).