2-Amino-5-bromo-4-chloro-3-nitropyridine

Synthesis

General procedure for the synthesis of 2-amino-5-bromo-4-chloro-3-nitropyridine from 2-amino-3-nitro-4-chloropyridine: 4-chloro-3-nitropyridin-2-amine (2 g, 11.5 mmol) and N-bromosuccinimide (2.5 g, 13.8 mmol) were dissolved in acetonitrile (125 mL) and heated to react for 1 hr at 80 °C. Upon completion of the reaction, the mixture was cooled to room temperature and the solvent was removed by distillation under reduced pressure. The product was purified by fast column chromatography (silica gel, dichloromethane/ethyl acetate gradient elution, 0-5% ethyl acetate) to afford 2-amino-5-bromo-4-chloro-3-nitropyridine (2.9 g, 99% yield). Mass spectrum (electrospray ionization): calculated value C5H3BrClN3O2, 250.9; measured value m/z 251.8 [M + H]+. 1H NMR (400 MHz, DMSO-d6) δ 8.42 (s, 1H), 7.37 (br s, 2H).

References

[1] Patent: WO2018/67786, 2018, A1. Location in patent: Page/Page column 111
[2] Journal of Medicinal Chemistry, 2012, vol. 55, # 20, p. 8721 - 8734,14
[3] Journal of Medicinal Chemistry, 2012, vol. 55, # 20, p. 8721 - 8734
[4] Patent: WO2013/190320, 2013, A1. Location in patent: Paragraph 00119