反应详情

温度

20 °C

Hydrogen peroxide (70%; 0.30 mL, ca. 6.1 mmol) was added dropwise to a stirred solution of trifluoroacetic anhydride (0.85 mL, 6.1 mmol) in DCM (15 mL) at 5° C. The solution was stirred at 20° C. for 10 min, then cooled to 5° C., added to a solution of 1-oxide 29 (160 mg, 0.61 mmol) and trifluoroactic acid (0.10 mL, 1.31 mmol) in DCM (15 mL) at 5° C. The solution was stirred at 20° C. for 16 h, diluted with dilute aqueous NH3 solution (40 mL) and extracted with CHCl3 (4×40 mL). The combined organic fraction was dried (Na2SO4) and the solvent evaporated. The residue was purified by column chromatography, eluting with a gradient (0-8%) MeOH/CH2Cl2 to give 1,4-dioxide 30 (55 mg, 32%) as a bright yellow solid, mp (MeOH, EtOAc) 146-149° C.; 1H NMR δ 8.33 (d, J=9.6 Hz, 1 H, H-8), 7.78 (d, J=2.6 Hz, 1 H, H-5), 7.42 (dd, J=9.6, 2.6 Hz, 1 H, H-7), 4.30 (t, J=5.4 Hz, 2 H, OCH2), 3.21 (q, J=7.5 Hz, 2 H, CH2), 2.83 (t, J=5.4 Hz, 2 H, NCH2), 2.37 [s, 6 H N(CH3)2], 1.43 (t, J=7.4 Hz, 3 H, CH3); 13C δ 164.9, 157.1, 141.5, 129.7, 124.7, 123.4, 98.0, 67.9, 57.7, 45.8 (2), 24.1, 9.3. Anal. Calcd for C13H18N4O3.¼MeOH: C, 55.6; H, 6.7; N, 19.6. Found: C, 55.5; H, 6.4; N, 19.5%.

1. temperaturecooled to 5° C.
2. stirringThe solution was stirred at 20° C. for 16 h
3. extractionextracted with CHCl3 (4×40 mL)
4. dry with materialThe combined organic fraction was dried (Na2SO4)
5. customthe solvent evaporated
6. customThe residue was purified by column chromatography
7. washeluting with a gradient (0-8%) MeOH/CH2Cl2