General procedure for the synthesis of 5-amino-2-nitropyridine from 2-nitro-5-chloropyridine: To a solution of 5-chloro-2-nitropyridine (3 g, 19 mmol) in ethanol (EtOH, 30 mL) was added saturated ammonia (NH3-H2O, 20 mL). The reaction mixture was placed in an autoclave and the reaction was stirred at 50 psi pressure and 150 °C overnight. The progress of the reaction was monitored by thin layer chromatography (TLC) and after confirming the completion of the reaction, the reaction mixture was cooled to room temperature. The resulting solid product was collected by filtration and washed with petroleum ether (PE, 100 mL) to afford 5-amino-2-nitropyridine (0.7 g, yield: 26%) as a yellow solid. Mass spectrometry (MS) analysis showed: m/z 140.1 ([M+H]+).
