tert-Butyl piperazine-1-carboxylate → 1-Boc-4-(3-amino-6-bromopyrazin-2-YL)piperazine

Participants

Reaction Conditions

Reaction Steps

2-Amino-3,5-dibromopyrazine (1.26 g, 5.0 mmol) and piperazine-1-carboxylic acid tert-butyl ester (4.64 g, 25 mmol) were placed in a dry RBF and heated with stirring to 120° C. under dry nitrogen. Molten mixture was stirred at this temperature for 6 h and cooled to room temperature. The resulting slurry was diluted with EtOAc (20 mL) and stirred for 20 min. Amine salts were removed by filtration and washed with EtOAc (3×5 mL). Filtrate was washed with pH 4 buffer (35 mL) and brine (35 mL), dried over Na2SO4 (anhydrous), filtered, and concentrated in vacuo. The residue was purified by flash chromatography (hexanes/EtOAc 7:3) gives the title compound I-3r as an off white solid (1.64 g, 92% yield).

Provenance & Evidence