Synthesis
Synthesis of 5-amino-2-fluoropyridine. A mixture of 5-nitro-2-chloropyridine (2.0 g, 12.6 mmol) and anhydrous potassium fluoride (2.2 g, 38 mmol) in a combination of sulfalone ( 6 mL) and benzene (4 mL) was stirred at RT for 20 min. The benzene was then removed by distillation. The resulting mixture was heated at 150 C for 12h. The mixture was cooled to RT whereupon water (60 mL) was added. The desired product was separated from the solution via steam distillation. Extraction of the distillate with diethyl ether (2 á 1 0 mL) followed by drying (Na2SO4) and concentration gave the compound. 5-nitro-2-fluoropyridine, water white oil (1.3 g, 73%).
References
[1] Chemistry Letters, 1993, # 3, p. 509 - 512
[2] Bioorganic and Medicinal Chemistry Letters, 2004, vol. 14, # 6, p. 1411 - 1416
[3] Patent: US6355636, 2002, B1. Location in patent: Page column 64
[4] Patent: EP1171440, 2004, B1. Location in patent: Page 53
[5] Tetrahedron, 1980, vol. 36, p. 1931 - 1936
