反応手順
H2O2 (70%, 0.37 mL, ca. 7.3 mmol) was added dropwise to a stirred solution of TFAA (1.0 mL, 7.3 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 a stirred solution of 1-oxide 46 (240 mg, 0.7 mmol) and TFA (0.28 mL, 3.7 mmol) in DCM (20 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 47 (146 mg, 61%) as a red solid: mp (MeOH) 181-184° C.; 1H NMR δ 8.13 (s, 1H, H-9), 8.10 (s, 1H, H-5), 7.55 (br s, 1H, NH), 3.56-3.60 (m, 2H, CH2N), 3.03-3.07 (m, 4H, H-6, H-8), 2.81 (dd, J=6.1, 6.0 Hz, 2H, CH2N), 2.67-2.72 (m, 4H, 2×CH2N), 2.20 (p, J=7.5 Hz, 2H, H-7), 1.60-1.71 (m, 8H, 4×CH2); 13C NMR δ 155.6, 149.4, 145.7, 138.0, 129.6, 115.7, 111.5, 55.9, 55.1 (2), 39.0, 33.4, 32.3, 28.5 (2), 27.0 (2), 25.5. Anal. calcd for C18H25N5O2: C, 63.0; H, 7.3; N, 20.4. Found: C, 62.9; H, 7.2; N, 20.3%.
