tert-Butyl piperazine-1-carboxylate → 4-(5-Nitro-2-trifluoromethoxy-phenyl)-piperazine-1-carboxylic acid tert-butyl ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of 0.048 g palladium(II)-acetate (0.214 mmol) and 0.133 g BINAP (0.214 mmol) in 7 mL toluene was heated to 60° C., stirred for 10 min. and the obtained suspension was added dropwise to a solution of 0.51 g 2-bromo-4-nitro-1-(trifluoromethoxy)benzene (1.783 mmol), 0.343 g tert.butyl-piperazine-1-carboxylate (1.842 mmol) and 0.232 g sodium tert-butoxide (2.414 mmol) in 8 mL of toluene. The thus obtained reaction mixture was treated at 130° C. for 1.5 h in a commercial microwave oven. The organic layer was washed with water, the aqueous phase was extracted with dichloromethane and the combined organic layers were extracted with saturated aqueous sodium chloride, dried over sodium sulfate, filtered, and the solvent was evaporated under reduced pressure. The crude product was further purified via silica gel chromatography using a ISCO Companion system (eluent cyclohexane-ethyl acetate 5-25%) to yield 0.413 g of product.

Herkunft & Nachweise