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

Participants

Reaction Conditions

Reaction Steps

tert-butyl piperazine-1-carboxylate (0.692 g, 3.72 mmol), ethyl 4-bromobenzofuran-2-carboxylate (1 g, 3.72 mmol), 2-Dicyclohexylphosphino-2',4',6'-tri-iso-propyl-1,1'-biphenyl (0.177 g, 0.37 mmol), Tris(dibenzylideneacetone)dipalladium(0) (0.170 g, 0.19 mmol) and CESIUM CARBONATE (1.574 g, 4.83 mmol) were 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 (0.990 g, 71.1 %). 1H NMR in CDCl3 is consistent with desired product MS (m+1) = 375.6. HPLC Peak RT = 3.27 minutes is product. Purity = 95%.

Provenance & Evidence