4-Bromobiphenyl → 1-[2-(1-Biphenyl-4-ylpiperidin-4-yl)ethyl]-2-oxo-1,2,3,4-tetrahydroquinoline-5-carboxaldehyde

Participants

Reaction Conditions

Reaction Steps

Palladium acetate (34 mg, 0.15 mmol), tri-tert-butylphosphine tetrafluoroborate (66 mg, 0.23 mmol) and sodium tert-butoxide (218 mg, 2.27 mmol) were added to a toluene solution (10 ml) of 5-(1,3-dioxolan-2-yl)-1-(2-piperidin-4-ylethyl)-3,4-dihydro-1H-quinolin-2-one (500 mg, 1.52 mmol) and 4-bromobiphenyl (424 mg, 1.82 mmol), followed by stirring in an argon atmosphere at 100° C. for 7.5 hours. After cooling to room temperature, water was added to the reaction mixture, and extraction with ethyl acetate was performed. The extract was dried over sodium sulfate and concentrated under reduced pressure, and the residue was purified by basic silica gel column chromatography (n-hexane:ethyl acetate=2:1). The purified product was concentrated under reduced pressure, and the residue was dissolved in acetone (10 ml). p-Toluenesulfonic acid monohydrate (104 mg) and water (2 ml) were added, followed by heating under reflux for 15 minutes. The resulting mixture was cooled to room temperature and concentrated under reduced pressure. The residue was rendered basic by adding an aqueous solution of potassium carbonate, and washed for 10 minutes in an ultrasonic washing machine. The produced insoluble matter was collected by filtration, washed with water and dried to thereby obtain 213 mg (yield: 32.1%) of 1-[2-(1-biphenyl-4-ylpiperidin-4-yl)ethyl]-2-oxo-1,2,3,4-tetrahydroquinoline-5-carboxaldehyde as a colorless solid.

Provenance & Evidence