反应详情

温度

20 °C

H2O2 (70%, 0.27 mL, ca. 5.6 mmol) was added dropwise to a stirred solution of TFAA (0.77 mL, 5.6 mmol) in DCM (10 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 161 (144 mg, 0.56 mmol) and TFA (0.1 mL, 1.2 mmol) in CHCl3 (10 mL) at 0° C. The solution was stirred at 20° C. for 22 h, diluted with dilute aqueous NH3 solution until basic and extracted with CHCl3 (3×20 mL). The combined organic fraction was stirred with Et3N for 45 min, dried and the solvent evaporated. The residue was purified by chromatography, eluting with EtOAc/pet. ether, to give (i) starting material 161 (35 mg, 24%) and (ii) 1,4-dioxide 162 (92 mg, 60%) as a yellow solid: mp 152-155° C.; 1H NMR δ 8.29 (s, 1H, H-9), 8.24 (s, 1H, H-5), 3.77-3.82 (m, 2H, CH2O), 3.29-3.38 (m, 2H, H-6, H-8), 3.20 (q, J=7.5 Hz, 2H, CH2), 2.73-2.90 (m, 3H, H-6, H-7, H-8), 1.84 (q, J=6.6 Hz, 2H, CH2), 1.43 (t, J=7.5 Hz, 3H, CH3), 1.34 (t, J=4.9 Hz, 1H, OH); 13C NMR δ 155.8, 154.3, 149.8, 139.2, 133.8, 115.9, 113.9, 61.3, 39.6, 39.1, 37.8, 37.5, 23.9, 9.3. Anal. calcd for C14H17N3O3: C, 61.1; H, 6.2; N, 15.3. Found: C, 60.8; H, 6.3; N, 14.9%.

1. temperaturecooled to 0° C.
2. stirringThe solution was stirred at 20° C. for 22 h
3. extractionextracted with CHCl3 (3×20 mL)
4. stirringThe combined organic fraction was stirred with Et3N for 45 min
5. customdried
6. customthe solvent evaporated
7. customThe residue was purified by chromatography
8. washeluting with EtOAc/pet. ether