3-Bromopyridine → Tert-butyl 4-(pyridin-3-YL)piperazine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

TRIS(DIBENZYLIDENEACETONE)DIPALLADIUM(0) (0.059 g, 0.06 mmol) and rac-2,2'-bis(diphenylphosphino)-1,1'-binaphthyl (0.080 g, 0.13 mmol) were mixed together and evacuated and purged with nitrogen 3 times. toluene (31.6 ml) was added and the resulting mixture heated to 90°C for 10 minutes then cooled to room temperature. sodium tert-butoxide (0.465 g, 4.84 mmol), 3-bromopyridine (0.310 ml, 3.22 mmol) and tert-butyl piperazine-1-carboxylate (0.6 g, 3.22 mmol) were added and the resulting mixture was heated at 85 °C for 64 hours. The reaction mixture was cooled to RT and filtered through celite and concentrated to give an orange solid. The crude product was purified by flash silica chromatography, elution gradient 30 to 50% EtOAc in heptane. Pure fractions were evaporated to dryness to afford tert-butyl 4-(pyridin-3-yl)piperazine-1-carboxylate (0.248 g, 29.2 %) as a yellow oil which crystallised on standing.

Provenance & Evidence