Cesium carbonate → Tert-butyl 4-(6-fluoropyridin-3-yl)piperazine-1-carboxylate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A suspension of piperazine-1-carboxylic acid tert-butyl ester hydrochloride (0.75 mmol), 5-bromo-2-fluoropyridine (0.90 mmol), (R)-2,2′-bis(diphenylphosphino)-1, 1′-binaphthyl (0.038 mmol), palladium acetate (0.038 mmol) and cesium carbonate (1.8 mmol) in toluene is stirred at 80° C. for 7 h and then 100° C. for 4 h, and poured into water. The mixture is extracted with AcOEt. The organic layer is washed with water, dried over magnesium sulfate, and concentrated. The crude product is purified by silica gel column chromatography to give the product in 43% yield. Rf=0.61 (n-hexane:AcOEt=1:1)

Herkunft & Nachweise