Nitric Acid → 5-Fluoro-3-nitropyridin-2-amine

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Reaction Steps

Under ice cooling, to 5-fluoropyridine-2-amine (10.36 g) was added concentrated sulfuric acid (48 ml), followed by stirring for 10 minutes, and then fuming nitric acid (3.83 ml) was added dropwise over 30 minutes. Stirring was carried out at room temperature for 1 hour, and further at 55° C. for 90 minutes. Ice was poured thereinto, and neutralized with a 10 N aqueous sodium hydroxide solution, followed by concentration under reduced pressure. The residue was dissolved in dichloromethane (600 ml), followed by stirring for 30 minutes, and then the insolubles were filtered off to concentrate the filtrate under reduced pressure. The residue was purified by silica gel column chromatography to afford 5-fluoro-3-nitropyridine-2-amine (2.66 g).

Provenance & Evidence