Ethyl Acetate → 1-(3,5-Dimethylpyridin-2-yl)piperazine hydrochloride

Participants

Reaction Steps

To a mixture of 4-(5-bromo-3-methylpyridin-2-yl)piperazine-1-carboxylic acid tert-butyl ester (25 g), methylboronic acid (8.4 g), [1,1′-bis(diphenylphosphino)ferrocene]palladium(II)dichloride dichloromethane complex (1:1, 2.9 g) and potassium fluoride (16 g) was added tetrahydrofuran (140 mL), and the mixture was stirred with heating under reflux for 8 hr. The reaction mixture was cooled, water was added, 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 (hexane:ethyl acetate) to give 4-(3,5-dimethylpyridin-2-yl)piperazine-1-carboxylic acid tert-butyl ester (16 g). The obtained 4-(3,5-dimethylpyridin-2-yl)piperazine-1-carboxylic acid tert-butyl ester (16 g) was dissolved in chloroform (100 mL), 4N hydrogen chloride/ethyl acetate (50 mL) was added, and the mixture was stirred at room temperature overnight. To the reaction mixture was added ethyl acetate (200 mL), and the precipitate was collected by filtration to give the title compound (10 g).

Provenance & Evidence