反应详情

温度

0 °C

H2O2 (70%, 0.12 mL, ca. 2.4 mmol) was added dropwise to a stirred solution of TFAA (0.34 mL, 2.4 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 172 (70 mg, 0.2 mmol) and TFA (95 μL, 1.2 mmol) in DCM (10 mL) at 0° C. The solution was stirred at 20° C. for 6 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 173 (38 mg, 52%) as a red solid: mp (MeOH/EtOAc) 139-142° C.; 1H NMR δ 8.06 (d, J=8.9 Hz, 1H, H-5), 7.51 (d, J=8.9 Hz, 1H, H-6), 7.38 (br s, 1H, NH), 3.59-3.66 (m, 2H, CH2N), 3.49-3.55 (m, 2H, CH2), 2.83-2.92 (m, 2H, CH2), 2.61-2.65 (m, 2H, CH2N), 2.32 [s, 6H, N(CH3)2], 1.80-1.88 (m, 4H, 2×CH2).

1. temperaturewarmed to 20° C. for 10 min
2. temperaturecooled to 0° C.
3. stirringThe solution was stirred at 20° C. for 6 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