Synthesis
The general procedure for the synthesis of ethyl 5-amino-2-pyridinecarboxylate from ethyl 5-nitropyridinecarboxylate was as follows: a suspension of ethyl 5-nitropyridine-2-carboxylate (2.00 g, 10.2 mmol) and 10% Pd/C (200 mg) in ethanol (30 mL) was subjected to a hydrogen atmosphere, and the reaction was oscillated for 4 hr at a pressure of 40 psi. Upon completion of the reaction, the catalyst was removed by diatomaceous earth filtration and rinsed with ethanol. The filtrate was concentrated under reduced pressure to give 1.47 g (87% yield) of yellow solid product. The 1H NMR spectrum of this product was in agreement with literature reports (Min, RS; Aksenov, VS Chem. Heterocycl. Compd. (Engl. Transl.) 1988, 24, 885-886), and it could be used in subsequent reactions without further purification.
References
[1] Patent: US2005/38078, 2005, A1. Location in patent: Page/Page column 30
[2] Patent: WO2004/14904, 2004, A1. Location in patent: Page 54
[3] Journal of Organic Chemistry, 1984, vol. 49, # 20, p. 3681 - 3684
