7-Bromo-1-benzofuran → Tert-butyl 4-(7-benzo[b]furanyl)piperazine-1-carboxylate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

7-bromobenzofuran (2 g, 10.15 mmol), tert-Butyl 1-piperazinecarboxylate (1.891 g, 10.15 mmol), Tris(dibenzylideneacetone)dipalladium(0) (0.465 g, 0.51 mmol), 2-Dicyclohexylphosphino-2',4',6'-tri-iso-propyl-1,1'-biphenyl (0.484 g, 1.02 mmol) and sodium t-butoxide (1.856 mL, 21.32 mmol) were heated to 100 °C in toluene (10 mL) for 3h. The mixture was allowed to cool to ambient temperature. Ethylacetate was added and the mixture was filtered through Celite. The filtrate was concentrated and redissolved in ethylacetate. The organic mixture was washed with satd. aqueous Na2CO3 and brine. The organic phase was separated, dried over Na2CO3, filtered and the solvent removed by rotary evaporation. The crude product was redissolved in diethylether and loaded onto a silica gel column and eluted with 0-50% EtOAc in heptanes. The collected fractions were combined and the solvent removed by rotary evaporation to yield tert-butyl 4-(benzofuran-7-yl)piperazine-1-carboxylate (2.58 g, 84 %). MS (m+1) = 303. HPLC Peak RT = 5.97 minutes is product. Purity = 94%.

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