Under argon protection, 2,3,6-trifluoropyridine (5 g, 37.59 mmol) was dissolved in 1,4-dioxane (20 mL) and stirred until completely dissolved. Subsequently, ammonia (20 mL) was slowly added to the solution. The reaction mixture was stirred continuously at 100 °C for 16 hours. The progress of the reaction was monitored by thin layer chromatography (TLC) and after confirming complete consumption of 2,3,6-trifluoropyridine, the reaction was quenched with cold water (500 mL). The reaction mixture was extracted with dichloromethane (2 x 500 mL) and the organic phases were combined. The organic phase was dried with anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to afford 3,6-difluoropyridin-2-amine (3 g, 62% yield) as an off-white solid, which could be used for subsequent reactions without further purification.TLC conditions: 10% ethyl acetate/hexane (Rf: 0.5).
