反应详情

温度

85 °C

Referring to FIG. 20, under a nitrogen atmosphere, selenium dioxide (0.0604 g, 0.544 mmol) was added to a solution of 8c (0.1232 g, 0.5184 mmol) in p-dioxane (3 mL), and the resulting orange solution was stirred in a sealed flask for 2 h at 85° C. The black precipitate was removed by vacuum filtration and the filtrand was evaporated, leaving a residue, which was purified by column chromatography (2:8 EtOAc/hexane) to afford 9c (0.0724 g, 0.288 mmol, 56%) as a pale yellow solid (mp 118-121° C.): 1H NMR (CDCl3) δ 10.30 (1H, s), 8.30 (1H, d, J=8.0 Hz), 7.99, (1H, d, J=8.0 Hz), 7.81 (1H, d, J=9.6 Hz), 7.70 (1H, d, J=8.8 Hz), 5.45 (2H, s), 3.60 (3H, s); 13C NMR (CDCl3) δ 193.9, 154.7, 153.4, 145.6, 138.0, 127.2, 127.0, 121.3, 120.2, 116.5, 95.7, 57.0; FTIR (neat) 2931, 2835, 1713, 1615, 1303, 1159, 1043, 920, 775 cm−1; MS (ESI) m/z calculated for (C12H10ClNO3+H)+ 252 (35Cl) and 254 (37Cl), found 252 (35Cl) and 254 (37Cl); HRMS (ESI) m/z calculated for (C12H10ClNO3+H)+ 252.0427 (35Cl) and 254.0398 (37Cl), found 252.0418 (35Cl) and 254.0390 (37Cl).

1. customThe black precipitate was removed by vacuum filtration
2. customthe filtrand was evaporated
3. customleaving a residue, which
4. customwas purified by column chromatography (2:8 EtOAc/hexane)