Reaction Steps
A solution of N-(2-ethoxymethyl-1H-imidazo[4,5-c]quinolin-1-yl)(1-ethylpropyl)amine (1.01 g, 3.23 mmol) in 30 mL of CH2Cl2 was treated with MCPBA (1.04 g, 4.20 mmol, 77% max). After 1.5 h the reaction mixture was treated with 15 mL of concentrated NH4OH solution and p-toluenesulfonyl chloride (0.65 g, 3.39 mmol). After 30 min, the reaction mixture was diluted with CH2Cl2 and water and the phases were separated. The organic portion was washed with 2% Na2CO3 solution and water. The combined aqueous washes were back extracted with CHCl3 (2×). The combined organic portions were washed with brine, dried over Na2SO4, filtered and concentrated under reduced pressure to yield a light yellow foam. Chromatography (SiO2, 97:3 CHCl3:MeOH) gave a white foam. The foam was triturated with CH2Cl2/hexanes and filtered to give 2-ethoxymethyl-N1-(1-ethylpropyl)-1H-imidazo[4,5-c]quinoline-1,4-diamine (0.652 g) as a white solid. mp 125–128° C.; 1H NMR (300 MHz, CDCl3) δ 8.66 (dd, J=8.3, 1.1 Hz, 1H), 7.77 (dd, J=7.6, 0.8 Hz, 1H), 7.55–7.48 (m, 1H), 7.33–7.26 (m, 1H), 5.66, (d, J=3.0 Hz, 1H), 5.41 (s, 2H), 4.87 (s, 2H), 3.64 (q, J=7.0 Hz, 2H), 3.32–3.23 (m, 1H), 1.70–1.56 (m, 2H), 1.55–1.41 (m, 2H), 1.27 (t, J=7.1 Hz, 3H), 0.94 (t, J=7.5 Hz, 6H); 13C NMR (75 MHz, CDCl3) δ 151.5, 149.1, 145.4, 135.0, 132.4, 128.1, 126.9, 124.1, 122.2, 122.0, 115.9, 67.2, 66.2, 64.0, 24.5, 15.5, 10.2; MS (APCI) m/z 328 (M+H)+; Anal. Calcd for C18H25N5O: C, 66.03; H, 7.70; N, 21.39; Found: C, 65.64; H, 7.89; N, 21.02.
