Potassium Carbonate → 4-Boc-1-(5-bromo-2-pyridyl)piperazine

Participants

Reaction Conditions

Reaction Steps

29.2 g (157 mmol) of 1,1-dimethylethyl 1-piperazine-carboxylate, 37 g (157 mmol) of 2,5-dibromopyridine and 21.7 g (157 mmol) of potassium carbonate suspended in 27 ml of dimethyl sulfoxide (DMSO) are introduced into an autoclave. The mixture is then heated at 150° C. for 21 hours. The reaction mixture is allowed to cool to room temperature, it is taken up in ethyl acetate and water and the insoluble material is then separated out by filtration. The aqueous phase is separated out and extracted twice with ethyl acetate, the combined organic phases are washed with saturated aqueous sodium chloride solution and dried over sodium sulfate, and the filtrate is concentrated under reduced pressure. The residue obtained is purified by chromatography on silica gel, eluting with a 99/1 mixture of dichloromethane and methanol. 44 g of product are thus obtained in the form of a white solid.

Provenance & Evidence