Synthesis
The general procedure for the synthesis of 3-amino-6-cyanopyridine from 2-cyano-5-nitropyridine was as follows: to a solution of 5-nitropyridine-2-carbonitrile (7.0 g, 46.9 mmol) in methanol (150 mL) was added 10% palladium carbon catalyst (2.0 g) and ammonium carbamate (7.0 g, 115 mmol). The reaction mixture was heated under reflux conditions for 16 hours. Upon completion of the reaction, the mixture was filtered to remove the catalyst and the filtrate was concentrated under reduced pressure. The concentrated residue was dissolved in water (150 mL) and subsequently extracted with ethyl acetate (150 mL × 3). The organic layers were combined, dried over anhydrous sodium sulfate, and then concentrated under reduced pressure to give 5.1 g of 5-aminopyridine-2-carbonitrile in 91.3% yield.
References
[1] Patent: WO2015/22301, 2015, A1. Location in patent: Page/Page column 28
[2] Journal of Medicinal Chemistry, 1994, vol. 37, # 1, p. 18 - 25
[3] Organic Process Research and Development, 2004, vol. 8, # 1, p. 62 - 71
[4] Patent: CN106810494, 2017, A. Location in patent: Paragraph 0030; 0031
[5] Patent: WO2017/184547, 2017, A1. Location in patent: Paragraph 00384
