Reaction Steps
A solution of N1-(3-aminopropyl)-2-ethoxymethyl-1H-imidazo[4,5-c]quinoline-1,4-diamine (0.250 g, 0.795 mmol) in 10 mL of CH2Cl2 was cooled to 0° C. under an atmosphere of nitrogen. The reaction mixture was treated dropwise with phenyl isocyanate (0.091 mL, 0.835 mmol). After 16 h, the reaction mixture was quenched by 10% Na2CO3 solution, diluted with CHCl3 and the phases were separated. The organic portion was washed with brine, dried over Na2SO4, filtered and concentrated under reduced pressure to yield an off-white solid. Chromatography (SiO2, 95:5 CHCl3:MeOH) gave an off-white foam. The foam was triturated with diethyl ether and filtered to give 1-{3-[(4-amino-2-ethoxymethyl-1H-imidazo[4,5-c]quinolin-1-yl)amino]propyl}-3-phenylurea (0.115 g) as an off-white solid. mp 177–179° C.; 1H NMR (300 MHz, DMSO-d6) δ 8.46 (dd, J=8.1, 1.0 Hz, 1H), 8.39 (s, 1H), 7.58 (dd, J=8.4, 0.9 Hz, 1H), 7.44–7.35 (m, 3H), 7.25–7.18 (m, 3H), 6.99 (t, J=5.6 Hz, 1H), 6.90–6.85 (m, 1H), 6.60 (s, 2H), 6.16 (t, J=5.6 Hz, 1H), 4.76 (s, 2H), 3.60 (q, J=7.0 Hz, 2H), 3.26–3.18 (m, 4H), 1.76 (t, J=7.0 Hz, 2H), 1.15 (t, J=7.0 Hz, 3H); 13C NMR (125 MHz, DMSO-d6) δ 155.2, 151.8, 149.0, 144.8, 140.4, 132.0, 128.5, 126.9, 125.7, 123.7, 120.9, 120.8, 120.8, 117.6, 114.3, 65.4, 62.7, 49.7, 37.0, 28.1, 14.9; MS (APCI) m/z 434 (M+H)+; Anal. Calcd for C23H27N7O2: C, 63.72; H, 6.28; N, 22.62; Found: C, 63.45; H, 6.04; N, 22.28.
