Water → HCID 57447006, compound

Participants

Reaction Steps

A solution of ethyl 4-[(3-aminoquinolin-4-yl)amino]butanoate (72.0 g, 263 mmol) in toluene (700 mL) was heated at reflux for 10 minutes and then cooled slightly. Trimethyl orthobutyrate (42 g, 280 mmol) and pyridinium p-toluenesulfonate (1.0 g, 4.0 mmol) were added, and the reaction was heated at reflux under a Dean-Stark trap for two hours while the distillate was periodically removed. The reaction was then stirred overnight at ambient temperature. Charcoal (5 g) was added, and the resulting mixture was heated at reflux for three hours and then filtered through a layer of CELITE filter agent. The filtrate was concentrated under reduced pressure to provide an oil that crystallized upon standing. The solid was dissolved in hot methanol (125 mL), and water (50 mL) was added. After one hour, the mixture was cooled in an ice bath to form a precipitate. The precipitate was isolated by filtration and dissolved in dichloromethane. A layer of water was present and was removed. The remaining solution was dried over potassium carbonate, filtered, and concentrated under reduced pressure to provide 53.2 g of ethyl 4-(2-propyl-1H-imidazo[4,5-c]quinolin-1-yl)butanoate.

Provenance & Evidence