Reaction Steps
Under a nitrogen atmosphere, tert-butyl 4-{2-[2-(4-amino-1H-imidazo[4,5-c]quinolin-1-yl)butoxy]ethyl}piperidine-1-carboxylate (1.00 g, 2.1 mmol) and 2N ethanolic hydrochloric acid (10 ml, 20 mmol) were combined and the solution was stirred at ambient temperature for 14 hours. The solvent was removed in vacuo and the resulting tan solid was dissolved in water. Saturated aqueous sodium carbonate was added until the pH reached 10. After extraction with dichloromethane (3×), the organic fractions were combined, washed with brine, dried (Na2SO4), filtered, and the majority of the solvent was removed in vacuo. Hexane was added to form a precipitate. Vacuum filtration yielded 0.5 g of 1-{1-[(2-piperidin-4-ylethoxy)methyl]propyl}-1H-imidazo[4,5-c]quinolin-4-amine as a tan powder. 1H-NMR (300 MHz, DMSO-d6): δ8.34 (bs, 1H), 8.19 (d, J=8.49 Hz, 1H), 7.61 (dd, J=8.31, 1.13 Hz, 1H), 7.45-7.39 (m, 1H), 7.25-7.19 (m, 1H), 6.55 (s, 2H), 5.25-5.15 (m, 1H), 4.00-3.80 (m, 2H), 3.5-3.3 (m, 2H), 2.8-2.64 (m, 2H), 2.22-2.11 (m, 2H), 2.09-1.99 (m, 2H), 1.8-1.63 (bs, 1H), 1.37-1.0 (m, 5H), 0.95-0.7 (m, 5H); 13C-NMR (75 MHz, DMSO-d6): δ152.8, 145.8, 140.6, 133.0, 127.8, 127.0, 126.9, 121.3, 121.0, 115.5, 71.8, 68.1, 58.4, 46.1, 36.3, 33.1, 32.7, 24.5, 9.9; MS (CI) m/e 368.2459 (368.2450 calcd for C21H30N5O).
