Sodium hydride (60% dispersion in oil, 25 mg, 0.62 mmol) followed by methyl vinyl sulfone (1.30 g, 12.4 mmol) were added to a stirred solution of 1-{[2-(ethoxymethyl)-1H-imidazo[4,5-c]quinolin-1-yl]methyl}cyclohexanol (2.1 g, 6.2 mmol) in tetrahydrofuran (25 mL). The reaction mixture was heated at reflux for 2 hours and additional methyl vinyl sulfone (1 equivalent) and sodium hydride (60% dispersion in oil, spatula tip full) were added. The mixture was allowed to stir overnight at room temperature. Water (50 mL) was added and a precipitate formed that was removed by filtration. The filtrate was extracted with dichloromethane (2×50 mL). The organic layers were combined, washed with brine, dried over sodium sulfate, filtered, and concentrated under reduced pressure to afford an oil that was purified by flash chromatography (silica gel, eluted with 5% methanol in dichloromethane) to provide 0.45 g of 2-(ethoxymethyl)-1-({1-[2-(methylsulfonyl)ethoxy]cyclohexyl}methyl)-1H-imidazo[4,5-c]quinoline as a colorless oil.
