Hydrochloric Acid → 1-(3-aminopropyl)-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-4-amine

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Reaction Steps

Tert-Butyl 3-[4-amino-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl]propylcarbamate (5 g, U.S. Pat. No. 6,573,273, example 148) and hydrochloric acid in dioxane (100 mL of 4 M) were combined and stirred for 4 hours at ambient temperature. The reaction mixture was concentrated under reduced pressure. The residue was dissolved in methanol (30 mL). The pH was adjusted to pH 8 with 6 M sodium hydroxide. The solution was diluted with dichloromethane, ethyl acetate, triethylamine, and brine. The organic layer was concentrated under reduced pressure to provide an orange solid. This material was purified by prep HPLC (COMBIFLASH system eluting first with a gradient of 0 to 10% methanol in dichloromethane containing 1% ammonium hydroxide and then with a gradient of 9 to 30% methanol in dichloromethane containing 1% ammonium hydroxide) to provide 1.58 g of 1-(3-aminopropyl)-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-4-amine as a yellow solid.

Provenance & Evidence