A mixture of the 1-{[(3-nitroquinolin-4-yl)amino]methyl}cyclohexanol prepared above (87%, 7.00 g, 20.3 mmol) and 5% platinum on carbon (0.60 g) in toluene (160 mL) and ethanol (20 mL) was hydrogenated at 20-30 psi (1.4×105 to 2.1×105 Pa) on a Parr apparatus for 2 h. The mixture was filtered through CELITE filter agent, which was rinsed with toluene. The filtrate was concentrated to a golden oil. The oil was concentrated twice from toluene. To the oil was added CH2Cl2 (200 mL) and the resulting solution was cooled in an ice bath. Triethylamine (3.11 mL, 22.3 mmol) was added followed by dropwise addition of ethoxyacetyl chloride (88%, 2.96 g, 21.3 mmol). The solution was allowed to warm to rt and stir for 1 h, during which time a precipitate formed. The reaction mixture was concentrated to a yellow foam to which ethanol (200 mL) and triethylamine (11 mL) were added. The resulting solution was heated at reflux for 13 h. The solution was concentrated to a yellow solid, which was dissolved in CH2Cl2 (150 mL) and washed with water (50 mL) and brine (75 mL). The organic layer was dried over MgSO4, filtered, and concentrated to a solid that was crystallized from CDCl3/CH2Cl2 to yield 1-{[2-(ethoxymethyl)-1H-imidazo[4,5-c]quinolin-1-yl]methyl}cyclohexanol as pale orange crystals after drying (1.94 g, 28%).
