Synthesis
General procedure for the synthesis of 2-amino-5-bromo-4-methylpyridine from 2-amino-4-methylpyridine: 2-amino-4-methylpyridine (0.5 mmol, 1.0 eq.), p-toluenesulfonic acid (p-TSA, 0.4 mmol, 0.8 eq.), and brominated 1-butylpyridine (1.5 mmol, 3.0 eq.) were added to a 50 mL Schlenk tube ) were added to the mixture. Under air atmosphere, 2-dimethoxyethane (2 mL) was added as solvent. Subsequently, hydrogen peroxide (H2O2, 1.2 mmol, 2.4 eq.) was slowly added to the reaction system. The reaction mixture was stirred at 80 °C for 24 hours. Upon completion of the reaction, the mixture was purified by silica gel column chromatography (eluent: petroleum ether/ethyl acetate) to afford the target product 2-amino-5-bromo-4-methylpyridine.
References
[1] Journal of Medicinal Chemistry, 2010, vol. 53, # 22, p. 7958 - 7966
[2] Tetrahedron Letters, 2014, vol. 55, # 36, p. 5058 - 5061
[3] Journal of Heterocyclic Chemistry, 2004, vol. 41, # 4, p. 569 - 574
[4] Synthetic Communications, 1999, vol. 29, # 1, p. 103 - 110
[5] Bioorganic and Medicinal Chemistry, 2004, vol. 12, # 5, p. 1151 - 1175
