3-Aminoquinoline → 3-Fluoroquinoline

Participants

Reaction Steps

Quinolin-3-amine (4 g, 27.7 mmol) was added to HBF4 (26 mL, 48% aqueous solution) portionwise at room temperature, and the mixture was stirred at room temperature until it became homogeneous. The mixture was then cooled to 0° C., and a solution of NaNO2 (2.4 g, 34.8 mmol) in H2O (8 mL) was added dropwise, when the reaction mixture became heterogeneous. The mixture was stirred at 0° C. for 1 hour, then the mixture was filtered, and the filtered cake was washed with cold EtOH, then Et2O. The resulting solid was dried under vacuum, then suspended in toluene in a round bottom flask and was refluxed for 1.5 hours. The resulting mixture was cooled to room temperature, and then poured into cold water. The organic layer was dried over Na2SO4, and then concentrated in vacuo to obtain the desired product (1.6 g). LC-MS: m/z 148.1 (M+H)+

Provenance & Evidence