Hydrogen Peroxide → N1-(1,4-Dioxido-7,8-dihydro-6H-indeno[5,6-e][1,2,4]triazin-3-yl)-N2,N2-dimethyl-1,2-ethanediamine

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Reaction Conditions

Reaction Steps

H2O2 (70%, 0.54 mL, ca. 10.8 mmol) was added dropwise to a stirred solution of TFAA (1.5 mL, 10.8 mmol) in DCM (10 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 22 (294 mg, 1.1 mmol) and TFA (0.17 mL, 2.2 mmol) in CHCl3 (15 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 23 (173 mg, 55%) as a red solid: mp (MeOH/EtOAc) 150-153° C.; 1H NMR δ 8.12 (s, 1H, H-9), 8.10 (s, 1H, H-5), 7.40 (br s, 1H, NH), 3.62-3.67 (m, 2H, CH2N), 3.03-3.13 (m, 4H, H-6, H-8), 2.63 (t, J=6.0 Hz, 2H, CH2N), 2.31 [s, 6H, N(CH3)2], 2.17-2.23 (m, 2H, H-7); 13C NMR δ 155.6, 149.5, 145.8, 138.0, 129.7, 115.7, 111.6, 57.5, 45.2 (2), 38.8, 33.6, 32.4, 25.6; MS m/z 289 (M+, 0.5%), 272 (5), 58 (100); HRMS calcd for C14H19N5O2 (M+) m/z 289.1539, found 289.1536. The hydrochloride salt was crystallised from MeOH/EtOAc. Anal. calcd for C14H20CIN5O2.½CH3OH: C, 49.7; H, 6.8; N, 19.3. Found: C, 49.4; H, 7.0; N, 19.8%.

Provenance & Evidence