Triethylamine → HCID 58869073, compound

Participants

Reaction Steps

Isopropyl isocyanate (0.67 mL, 6.85 mmol) and triethylamine (2.38 mL, 17.1 mmol) were added to a solution of 1-[4-(hydroxyamino)butyl]-2-propyl-1H-imidazo[4,5-c]quinolin-4-amine hydrochloride (prepared as described in Parts A-D of Example 43, 2.00 g, 5.71 mmol) in dichloromethane (50 mL). The reaction mixture was stirred at room temperature for 2 hours, then 10% aqueous sodium hydroxide (2 equivalents) was added. After the mixture was stirred for 1 hour at room temperature, the layers were separated and the organic layer was washed with saturated aqueous sodium bicarbonate and brine. The organic layer was dried over magnesium sulfate, filtered, and concentrated. The crude product was purified by flash chromatography (silica gel, eluted with 3% methanol in dichloromethane). The appropriate fractions were combined and concentrated under reduced pressure. The resulting solid was slurried in 1:1 saturated aqueous sodium bicarbonate/water and was isolated by filtration, washed with water, and dried overnight in a vacuum oven at 80° C. to provide 0.327 g of N-[4-(4-amino-2-propyl-1H-imidazo[4,5-c]quinolin-1-yl)butyl]-N-hydroxy-N′-isopropylurea as beige needles, mp 158-160° C.

Provenance & Evidence