2-Amino-3-bromo-5-chloropyrazine

33332-29-5

76537-18-3

General procedure for the synthesis of 2-amino-3-bromo-5-chloropyrazine from 2-amino-5-chloropyrazine: 2-amino-5-chloropyrazine (3 g, 23 mmol), N-bromosuccinimide (4 g, 23 mmol), and dichloromethane (100 mL) were added to a 250 mL round-bottomed flask under nitrogen protection. The reaction mixture was heated and refluxed for 1 h before being cooled to room temperature and concentrated under reduced pressure. The crude product was purified by fast column chromatography using pentane/ethyl acetate (0 to 50%) as eluent to afford 2-amino-3-bromo-5-chloropyrazine (3 g, 62% yield).1H NMR (DMSO-d6) δ 6.8-6.9 (2H, broad single peak), 8.0 (1H, single peak). Mass spectrum (ES+): m/z 210, 212.