Synthesis
General method: 2-chloro-5-nitropyridine (1 eq.), hexafluoroisopropanol (HFIP, 10 eq.) and iron powder (5 eq.) were added to the reaction tube and mixed. Subsequently, 2N aqueous hydrochloric acid solution was slowly added to the reaction mixture. The reaction mixture was stirred at room temperature for 30 minutes and then neutralized with saturated aqueous sodium bicarbonate (NaHCO3). The organic layer was extracted three times with saturated aqueous sodium bicarbonate solution and combined. The organic layers were subsequently washed with brine, dried over anhydrous sodium sulfate (Na2SO4), filtered, and concentrated under reduced pressure. The crude product was purified by silica gel column chromatography to afford the target product 2-chloro-5-aminopyridine.
References
[1] Bulletin des Societes Chimiques Belges, 1988, vol. 97, # 1, p. 51 - 54
[2] Organic Letters, 2009, vol. 11, # 6, p. 1345 - 1348
[3] ACS Catalysis, 2014, vol. 4, # 6, p. 1777 - 1782
[4] New Journal of Chemistry, 2015, vol. 39, # 11, p. 8498 - 8504
[5] Tetrahedron Letters, 2017, vol. 58, # 37, p. 3646 - 3649
