Acetyl chloride → Imiquimod hydrochloride

Participants

Reaction Steps

A solution of acetyl chloride (0.15 mL, 2 mmol) in ethanol (2 mL) was added to a solution of 5-(2-aminophenyl)-1-(2-methylpropyl)-1H-imidazole-4-carbonitrile (0.13 g) in ethanol (5 mL). The mixture was heated at reflux for two hours and allowed to cool to ambient temperature. The volume of the mixture was decreased to 2 mL by concentrating under reduced pressure. A solid was present, and the remaining liquid was decanted away from the solid, which was washed with diethyl ether (2×2 mL) and dried overnight in a vacuum oven at room temperature to provide 0.035 g (23% for Example 19 and Example 20 combined) of 1-(2-methylpropyl)-1H-imidazo[4,5-c]quinolin-4-amine hydrochloride as a beige solid, mp>265° C.

Provenance & Evidence