N-bromobutanimide → Tert-butyl 4-(5-bromo-3-chloropyrazin-2-yl)piperazine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

A 500 mL round bottom flask was charged with tert-butyl 4-(3-chloropyrazin-2-yl)piperazine-1-carboxylate (13.5 g, 45.3 mmol), N-bromosuccinimide (10.48 g, 58.9 mmol) and CHCl3 (150 mL). The resulting mixture was stirred at 20° C. overnight and it became a clear solution. The solvent was evaporated and the residue was purified by flash column chromatography on silica gel with 0-10% EtOAc in petroleum ether, to afford 16.1 g (94%) of the product as a white solid. 1H NMR (300 MHz, CDCl3) δ: 8.18 (s, 1H), 3.57 (m, 4H), 3.39 (m, 4H), 1.48 (s, 9H).

Provenance & Evidence