tert-Butyl piperazine-1-carboxylate → Tert-butyl 4-(2-methylpyridin-3-yl)piperazine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

RuPhos (0.543 g, 1.16 mmol) and palladium (II) acetate (0.131 g, 0.58 mmol) were suspended in toluene (15 mL) at ambient temperature. The resulting mixture was degassed and purged several times and warmed to 50°C under nitrogen for 20 mins. In a separate vessel were mixed 3-bromo-2-methylpyridine (2 g, 11.63 mmol), tert-butyl 4-(2-methylpyridin-3-yl)piperazine-1-carboxylate (2.67 g, 83 %), sodium tertbutoxide (1.676 g, 17.44 mmol) and toluene. The mixture was degassed and purged with nitrogen several times and warmed to 50°C. The catalyst solution was added to the reaction vessel and the resulting mixture degassed and purged wtih nitrogen. The reaction was heated at 100°C overnight. The reaction mixture was allowed to cool to ambient temperature and filtered through GF/F paper, washing with MeOH. The filtrate was concentrated to provide the crude material. This was purified by flash silica chromatography, elution gradient 20 to 70% EtOAc in heptane. Pure fractions were evaporated to dryness to afford tert-butyl 4-(2-methylpyridin-3-yl)piperazine-1-carboxylate (2.67 g, 83 %) as a pale yellow oil.

Provenance & Evidence