Potassium Carbonate → Tert-butyl 4-(2-fluoro-4-(methoxycarbonyl)phenyl)piperazine-1-carboxylate

Participants

Reaction Steps

Potassium carbonate (5.56 g, 40.3 mmol) and tert-butyl piperazine-1-carboxylate (6.92 g, 37.2 mmol) were combined, methyl 3,4-difluorobenzoate (5.33 g, 31.0 mmol) was added and the reaction mixture was stirred at 90° C. for 1d. The mixture was triturated with ethyl acetate (3×5 mL) and the combined organic extracts were filtered. This was concentrated down to about 5-10 mL and subjected to flash column chromatography on silica gel (120 g SiO2, hexanes:ethyl acetate 1:0 to 4:1) to afford tert-butyl 4-(2-fluoro-4-(methoxycarbonyl)phenyl)piperazine-1-carboxylate (4.702 g, 13.90 mmol, 44.9% yield) as a white solid. ESI-MS:m/z 339 (M+H)+.

Provenance & Evidence