5-Aminoquinoline → 5-Fluoroquinoline

Participants

Reaction Steps

To a solution of quinolin-5-amine (2 g, 13.9 mmol) in 10 mL of 48% HBF4 at 0° C. was added sodium nitrite (933 mg, 13.5 mmol) portionwise. This was stirred for 1 hour and then poured into 1:1 ethyl acetate diethyl ether mixture (50 mL). The resulting suspension was filtered and the solid was dried. This solid was added portionwise to refluxing xylene (30 mL) and stirred for 3 hours, then allowed to cool. The xylene was decanted off and the residue was dissolved in 1N HCl (50 mL). After neutralization with NaHCO3, the mixture was extracted with ethyl acetate (3×50 mL). The extracts were dried over sodium sulfate, filtered and the volatiles were removed under reduced pressure. The residue was purified by silica gel chromatography (3% EtOAc/PE) to afford 800 mg of title compound as colorless oil. LC-MS: m/z 148.2 (M+H)+

Provenance & Evidence