反应详情

温度

0 °C

H2O2 (70%, 0.47 mL, ca. 9.3 mmol) was added dropwise to a stirred solution of TFAA (1.3 mL, 9.3 mmol) in DCM (10 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 241 (270 mg, 0.9 mmol) and TFA (0.36 mL, 4.7 mmol) in DCM (15 mL) at 0° C. The solution was stirred at 20° C. for 4 h, diluted with dilute aqueous NH3 solution (10 mL) and extracted with CHCl3 (4×50 mL). The combined organic fraction was dried and the solvent evaporated. The residue was purified by chromatography, eluting with a gradient (0-10%) of MeOH/DCM, to give 1,4-dioxide 242 (71 mg, 22%) as a red solid: mp (MeOH/EtOAc) 152-154° C.; 1H NMR δ 7.99 (s, 1H, H-5), 7.61 (s, 1H, H-10), 7.27 (br s, 1H, NH), 4.30 (br dd, J=5.3, 5.2 Hz, 2H, H-8), 3.62 (br t, J=5.9 Hz, 2H, CH2N), 3.05 (br t, J=6.3 Hz, 2H, H-6), 2.62 (t, J=6.0 Hz, 2H, CH2N), 2.31 [s, 6H, N(CH3)2], 2.05-2.12 (m, 2H, H-7); 13C NMR δ 154.7, 148.7, 136.2, 133.2, 130.1, 117.4, 105.2, 67.1, 57.6, 45.1 (2), 38.8, 26.1, 21.3. Anal. calcd for C14H19N5O3.½H2O: C, 52.7; H, 6.5; N, 22.0. Found: C, 53.0; H, 5.9, 21.6%.

1. temperaturewarmed to 20° C. for 10 min
2. temperaturecooled to 0° C.
3. stirringThe solution was stirred at 20° C. for 4 h
4. extractionextracted with CHCl3 (4×50 mL)
5. customThe combined organic fraction was dried
6. customthe solvent evaporated
7. customThe residue was purified by chromatography
8. washeluting with a gradient (0-10%) of MeOH/DCM