3-Methoxypropanoyl chloride → tert-Butyl 4-[2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl]butylcarbamate

Participants

Reaction Steps

3-Methoxypropionyl chloride (15.4 g, 126 mmol) was added dropwise over a period of 20 minutes to a chilled (ice bath) solution of tert-butyl N-{4-[(3-aminoquinolin-4-yl)amino]butyl}carbamate (38 g, 115 mmol, U.S. Pat. No. 6,541,485, Example 2, Part B) in pyridine. The reaction mixture was stirred for 4 hours and then allowed to stand at ambient temperature over the weekend. Pyridine hydrochloride (3.9 g, 34 mmol) was added and the reaction mixture was heated at reflux overnight. The reaction mixture was concentrated under reduced pressure and the residue was diluted with dichloromethane (250 mL) and aqueous sodium bicarbonate (250 mL). The layers were separated. The separatory funnel was rinsed with a small amount of methanol to remove a residue coating the walls. The combined organics were concentrated under reduced pressure. The residue was purified by prep HPLC (COMBIFLASH system eluting first with a gradient of 0 to 5% methanol in dichloromethane containing 1% ammonium hydroxide and then with a gradient of 5 to 10% methanol in dichloromethane containing 1% ammonium hydroxide) to provide 18 g of tert-butyl N-{4-[2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl]butyl}carbamate.

Provenance & Evidence