tert-Butyl piperazine-1-carboxylate → tert-Butyl 4-(2-(ethoxycarbonyl)benzofuran-4-yl)piperazine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

ethyl 4-bromobenzofuran-2-carboxylate (7.7 g, 28.61 mmol), tert-butyl piperazine-1-carboxylate (5.33 g, 28.61 mmol), Tris(dibenzylideneacetone)dipalladium(0) (1.310 g, 1.43 mmol), 2-Dicyclohexylphosphino-2',4',6'-tri-iso-propyl-1,1'-biphenyl (1.364 g, 2.86 mmol) and CESIUM CARBONATE (12.12 g, 37.20 mmol) in dioxane (40 mL) was heated under argon to 95 °C overnight. The mixture was allowed to cool. The mixture was diluted with EtOAc and the mixture was filtered through a pad of Celite. The filterate was collected and the solvent was removed by rotary evaporation. The crude product was added to a silica gel column and was eluted with 0-50% EtOAc in heptane. The collected fractions were combined and the solvent was removed to yield tert-butyl 4-(2-(ethoxycarbonyl)benzofuran-4-yl)piperazine-1-carboxylate (4.92 g, 45.9 %). MS (m+1) = 375.8. HPLC Peak RT = 3.27 minutes is product. Purity = 96%.

Provenance & Evidence