反应详情

TFM (0.44 mL, 2.4 mmol) was added to a stirred solution of 1-oxide 50 (486 mg, 2.2 mmol) in DCM (20 mL) at 0° C. and the solution stirred at 20° C. for 16 h. H2O2 (70%, 1.1 mL, ca. 21.9 mmol) was added dropwise to a stirred solution of TFAA (3.1 mL, 21.9 mmol) in DCM (20 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 the solution of 1-oxide 50 prepared above and the resulting solution was stirred at 20° C. for 16 h. Dilute aqueous NH3 solution (40 mL) was added and the mixture stirred vigorously for 4 h, then the mixture extracted with DCM (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 (i) starting material 50 (254 mg, 52%); and (ii) 1,4-dioxide 51 (166 mg, 27%) as a red solid: mp (MeOH/DCM) 182-184° C.; 1H NMR δ 8.05 (s, 1H, H-9), 8.03 (s, 1H, H-5), 7.61 (br t, J=5.7 Hz, 1H, NH), 3.82 (br t, J=5.7 Hz, 2H, CH2O), 3.78 (br s, 1H, OH), 3.71-3.77 (m, 2H, CH2N), 3.10 (br t, J=7.5 Hz, 2H, H-6), 3.04 (br t, J=7.5 Hz, 2H, H-8), 2.20 (p, J=7.5 Hz, 2H, H-7), 1.97 (br p, J=6.0 Hz, 2H, CH2); 13C NMR δ 156.1, 149.5, 145.8, 137.8, 129.7, 115.7, 111.3, 60.2, 39.1, 33.4, 32.3, 31.5, 25.5. Anal. calcd for C13H16N4O3: C, 56.5; H, 5.8; N, 20.3. Found: C, 56.8; H, 5.9; N, 20.2%.