tert-Butyl piperazine-1-carboxylate → tert-Butyl 4-(6-(trifluoromethyl)pyridin-2-yl)piperazine-1-carboxylate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A 20 mL microwave vial was charged with 2-chloro-6-(trifluoromethyl)pyridine (860 mg, 4.74 mmol), rac-2,2'-Bis(diphenylphosphino)-1,1'-binaphthyl (295 mg, 0.47 mmol), Sodium tert-butoxide (546 mg, 5.68 mmol), tert-butyl piperazine-1-carboxylate (882 mg, 4.74 mmol) and a mixture of toluene (25 mL) and DMF (5 mL). The reaction mixture was degassed for 10 minutes with nitrogen, and then Tris(dibenzylideneacetone)dipalladium(0) (217 mg, 0.24 mmol) was added. The reaction mixture was stirred at 105°C in an oil bath 12h. The solution was diluted with EtOAc and washed with saturated NaHCO3 solution, brine, dried over anhydrous Na2SO4, filtered and concentrated under reduced pressure. The crude material was loaded on a 80g silica gel column and purified on a Teledyne Isco instrument, eluting with 0% to 100% ethyl acetate in heptane to provide tert-butyl 4-(6-(trifluoromethyl)pyridin-2-yl)piperazine-1-carboxylate (811 mg, 51.7 %) as a solid.

Herkunft & Nachweise