反应详情

温度

85 °C

Referring to FIG. 20, under a nitrogen atmosphere, selenium dioxide (11 mg, 0.099 mmol) was added to a solution of 8a (22.1 mg, 0.089 mmol) in dioxane (2 mL) at 85° C. The reaction was stirred for 20 h at 85° C., then cooled, diluted with methanol, and vacuum filtered. The filtrate was collected and concentrated, leaving a yellow solid, which was purified by column chromatography (4:6 EtOAc/hexane) to provide 9a (13.7 mg, 0.0523 mmol, 59%) as a yellow solid: 1H NMR (CDCl3) δ 10.15 (1H, s), 8.35 (1H, d, J=8.4 Hz), 8.02 (1H, d, J=8 Hz), 8.00 (1H, d, J=9.6 Hz), 7.76 (1H, d, J=9.2 Hz), 5.43 (2H, s), 3.56 (3H, s); 13C NMR (CDCl3) δ 193.25, 154.14, 149.28, 140.47, 137.83, 137.55, 130.64, 125.26, 119.33, 117.34, 95.45, 57.24; FTIR (neat) 2858, 1715, 1529, 1263, 1197, 1155, 1061, 935, 918, 849, 806, 771, 658 cm−1; MS (ESI) m/z calculated for (C12H10N2O5+H)+ 263, found 263; HRMS (ESI) m/z calculated for (C12H10N2O5+H)+ 263.0668, found 263.0662.

1. temperaturecooled
2. filtrationfiltered
3. customThe filtrate was collected
4. concentrationconcentrated
5. customleaving a yellow solid, which
6. customwas purified by column chromatography (4:6 EtOAc/hexane)