反应详情

温度

80 °C

To a solution of palladium acetate (18.00 mg, 0.08 mmol) in dry toluene (16 mL) under nitrogen was added BINAP (100 mg, 0.16 mmol). The reaction was heated to 80 °C and stirred for 10 min. To the reaction was then added tert- butyl piperazine-1-carboxylate (299 mg, 1.60 mmol), cesium carbonate (261 mg, 0.80 mmol), potassium carbonate (222 mg, 1.60 mmol), 18-crown-6 (42.4 mg, 0.16 mmol) and methyl 4-bromo-2-chlorobenzoate (400 mg, 1.60 mmol). The reaction was stirred at 80°C overnight, filtered through celite and washed with small amounts of DCM. The filtrate was concentrated under reduced pressure and purified by flash chromatography on silica gel, eluting with mixtures of EtOAc and heptane, to afford tert-butyl 4-(3-chloro-4-(methoxycarbonyl)phenyl)piperazine-1-carboxylate (517 mg, 91 %) as a solid.