To a solution of 5-bromo-2-iodo-N-methyl-6-(N-methylmethylsulfonamido)benzofuran-3-carboxamide (800 mg, 1.6 mmol), 2-(3,6-dihydro-2H-thiopyran-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (371 mg, 1.6 mmol) and Cs2CO3 (1.07 g, 3.28 mmol) in 1,4-dioxane (20 mL) was added Pd(dppf)Cl2 (50 mg) and tri-o-tolylphosphine (50 mg) under nitrogen. The reaction mixture was heated at 100° C. for 4 h, concentrated in vacuo to remove 1,4-dioxane and purified by column chromatography (PE:EA=3:1) to give the compound 5-bromo-2-(3,6-dihydro-2H-thiopyran-4-yl)-N-methyl-6-(N-methylmethylsulfonamido)benzofuran-3-carboxamide (250 mg, yield: 33%). 1H-NMR (CDCl3, 400 MHz) δ 8.09 (s, 1H), 7.59 (s, 1H), 6.73 (s, 1H), 6.06 (brs, 1H), 3.38 (t, J=2.0 Hz, 2H), 3.30 (s, 3H), 3.05 (s, 3H), 3.00 (d, J=4.8 Hz, 3H), 2.87 (t, J=5.6 Hz, 2H), 2.70˜2.76 (m, 2H). MS (M+H)+: 459/461.
