反应详情

To a mixture of 3-bromo-2,6-dimethylpyridine (2.0 g), t-Boc-piperazine (2 g), palladium(II) acetate (0.12 g), rac-2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (0.31 g) and sodium tert-butoxide (1.34 g) was added toluene (35 mL), and the mixture was stirred with heating under reflux for 9 hr. Water was added to the reaction mixture, and the mixture was extracted with ethyl acetate. The organic layer was washed with saturated brine, and the solvent was evaporated. The obtained residue was purified by column chromatography (chloroform:methanol) to give 4-(2,6-dimethylpyridin-3-yl)piperazine-1-carboxylic acid tert-butyl ester (3.06 g). The obtained 4-(2,6-dimethylpyridin-3-yl)piperazine-1-carboxylic acid tert-butyl ester (2.16 g) was dissolved in chloroform (21 mL), 4N hydrogen chloride/ethyl acetate solution (10 mL) was added, and the mixture was stirred at room temperature overnight. The reaction mixture was neutralized with aqueous potassium carbonate solution, the mixture was extracted with ethyl acetate, and the solvent was evaporated to give the title compound (2.01 g).

1. extractionthe mixture was extracted with ethyl acetate
2. customthe solvent was evaporated