反应详情

温度

0 °C

H2O2 (70%, 0.5 mL, ca. 10 mmol) was added dropwise to a stirred solution of TFAA (1.4 mL, 10 mmol) in DCM (20 mL) at 0° C. The solution was stirred at 0° C. for 5 min, warmed to 20° C. for 10 min, then cooled to 0° C. and added to a stirred solution of 1-oxide 24 (246 mg, 1.0 mmol) and TFA (0.28 mL, 2.0 mmol) in DCM (20 mL) at 0° C. The solution was stirred at 0° C. for 1 h and then at 20° C. for 30 h, diluted with dilute aqueous NH3 solution (10 mL) and extracted with DCM (5×50 mL). The combined organic fraction was dried and the solvent evaporated. The residue was purified by chromatography, eluting with a gradient (0-4%) of MeOH/DCM, to give 1,4-dioxide 25 (106 mg, 40%) as a red solid: mp (MeOH/DCM) 187-188° C.; 1H NMR [(CD3)2SO] δ 7.99 (s, 1H, H-9), 7.92-7.98 (m, 2H, NH, H-5), 4.84 (t, J=6.0 Hz, 1H, OH)), 3.61 (q, J=6.0 Hz, 2H, CH2O), 3.46 (q, J=6.0 Hz, 2H, CH2N), 2.98-3.10 (m, 4H, H-6, H-8), 2.05-2.14 (m, 2H, H-7); 13C NMR [(CD3)2SO] δ 154.5, 149.4 144.9, 137.6, 129.0, 115.0, 110.9, 59.1, 43.1, 32.6, 31.7, 25.1. Anal. calcd for C12H14N4O3: C, 55.0; H, 5.4; N, 21.4. Found: C, 54.8; H, 5.4; N, 21.1%.

1. temperaturewarmed to 20° C. for 10 min
2. temperaturecooled to 0° C.
3. stirringThe solution was stirred at 0° C. for 1 h
4. waitat 20° C. for 30 h
5. extractionextracted with DCM (5×50 mL)
6. customThe combined organic fraction was dried
7. customthe solvent evaporated
8. customThe residue was purified by chromatography
9. washeluting with a gradient (0-4%) of MeOH/DCM