4-Aminopyridine-3-carboxylic acid (4-aminonicotinic acid) and its ester are sometimes found as a partial structure in natural products, 1 and their derivatives behave as NAD analogs. 2 4-Aminopyridines (4APs) having a functional group at the vicinal position are also excellent precursors for [c]-fused pyrido compounds such as pyridopyrimidine, imidazopyridine, pyrazolopyridine and naphthyridine, those are widely used for medicines or their synthetic intermediates. 3 ...
[Cook, David C.; Jones, Ronald H.; Kabir, Humayun; Lythgoe, David J.; McFarlane, Ian M.; Pemberton, Clive; Thatcher, Alan A.; Thompson, David M.; Walton, John B. Organic Process Research and Development, 1998 , vol. 2, # 3 p. 157 - 168]
