Synthesis
General procedure for the synthesis of 3-aminoisonicotinamide from 3-aminoisonicotinic acid: ammonium hydrochloride (4.98 g, 93.2 mmol) was mixed with 3-aminoisonicotinic acid (9.90 g, 71.7 mmol) to which was added 2-(3H-[1,2,3]triazolo[4,5-b]pyridin-3-yl)-1 ,1,3,3-tetramethylene diuronium hexafluorophosphate (V) ( 35.4 g, 93.2 mmol) and N-ethyl-N-isopropylpropan-2-amine (37.5 mL, 215.02 mmol) in a solution of DMF (100 mL). The reaction mixture was stirred at 40 °C for 72 h under nitrogen protection. After completion of the reaction, the solvent was removed by evaporation to give the crude product. The crude product was purified by fast silica gel column chromatography using a gradient elution with a dichloromethane solution of 5% methanol. The purified grades were collected and evaporated to dryness to give 3-aminoisonicotinamide (8.57 g, 87% yield) as a yellow gel.
References
[1] Synthesis (Germany), 2016, vol. 48, # 8, p. 1226 - 1234
[2] Bioorganic and Medicinal Chemistry, 2011, vol. 19, # 5, p. 1623 - 1642
[3] Patent: WO2013/12915, 2013, A1. Location in patent: Paragraph 00674-00676
[4] European Journal of Medicinal Chemistry, 2018, vol. 152, p. 235 - 252
[5] Patent: WO2007/117161, 2007, A1. Location in patent: Page/Page column 24-25
