42373-30-8

4-Aminonicotinaldehyde acts as a reagent used in the preparation of 2,3-disubstituted 1,6-naphthyridines as a potential diurectic agents.

Synthesis of Example 25C 4-Aminonicotinaldehyde: Example 25B (870 mg, 4.2 mmol) was dissolved in a 3N aqueous hydrochloric acid solution (10 mL), heated to reflux and held overnight. Upon completion of the reaction, it was extracted three times with ether to remove impurities. Subsequently, the pH of the aqueous layer was adjusted to greater than 7 with solid K2CO3 and extracted six times with a 20% isopropanol/chloroform mixture to collect the product. The organic phases were combined, dried with anhydrous Na2SO4, filtered and concentrated to afford the target compound 4-amino-3-pyridinecarboxaldehyde (450 mg, 87% yield).

[1] Patent: US2003/187026, 2003, A1
[2] Patent: US2003/199511, 2003, A1. Location in patent: Page/Page column 24
[3] Journal of Organic Chemistry, 1983, vol. 48, # 20, p. 3401 - 3408
[4] Synthesis, 1999, # 6, p. 959 - 964
[5] Patent: WO2013/13817, 2013, A1. Location in patent: Page/Page column 144