反应详情

温度

20 °C

H2O2 (70%, 0.15 mL, ca. 2.9 mmol) was added dropwise to a stirred solution of TFAA (0.40 mL, 2.9 mmol) in DCM (5 mL) at 0° C. The solution was stirred at 20° C. for 10 min, then cooled to 0° C., and added to a solution of 1-oxide 67 (60 mg, 0.29 mmol) and TFA (0.05 mL, 0.63 mmol) in CHCl3 (5 mL) at 0° C. Another aliquot of H2O2 (0.15 mL) was added after 24 h, and the solution stirred at 20° C. for another 24 h. The solution was made basic with dilute aqueous NH3 solution and extracted with CHCl3 (3×10 mL). The combined organic fraction was dried and the solvent evaporated. The residue was purified by chromatography, eluting with 5% EtOAc/DCM, to give (i) starting material 67 (18 mg, 30%) and (ii) 1,4-dioxide 68 (32 mg, 48%) as a yellow solid: mp 140-142° C.; 1H NMR δ 8.32 (s, 1H, H-9), 8.27 (s, 1H, H-5), 3.13-3.23 (m, 6H, H-6, H-8, CH2), 2.26 (q, J=7.5 Hz, 2H, H-7), 1.43 (t, J=7.5 Hz, 3H, CH3); 13C NMR δ 155.7, 155.1, 150.6, 139.1, 133.8, 115.9, 113.9, 33.4, 32.8, 25.6, 23.9, 9.31. Anal. calcd for C12H13N3O2.½CH3OH: C, 60.7; H, 6.1; N, 17.0. Found: C, 60.3; H, 5.7; N, 16.8%.

1. temperaturecooled to 0° C.
2. stirringthe solution stirred at 20° C. for another 24 h
3. extractionextracted with CHCl3 (3×10 mL)
4. customThe combined organic fraction was dried
5. customthe solvent evaporated
6. customThe residue was purified by chromatography
7. washeluting with 5% EtOAc/DCM