General procedure for the synthesis of 2,3-diamino-5-trifluoromethylpyridine from 2-amino-3-bromo-5-trifluoromethylpyridine: In an autoclave reactor, 40 g of 2-amino-3-bromo-5-trifluoromethylpyridine, 2.2 g of copper(II) acetylacetonate, 6.6 g of acetylacetonate, 59 g of cesium carbonate, and 105 mL of N-methyl pyrrolidinone (NMP) were added in sequence. Under cooling in an ice bath, 25 mL of 28% ammonia solution was slowly added. After sealing the reactor, the reaction system was warmed to 110 °C and the reaction was stirred at this temperature for 12 hours. Upon completion of the reaction, the mixture was cooled to room temperature in an ice bath, diluted with water and extracted with ethyl acetate. The organic layers were combined, dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was purified by silica gel column chromatography to give 15 g of 2,3-diamino-5-trifluoromethylpyridine.1H-NMR (CDCl3) δ of 2,3-diamino-5-trifluoromethylpyridine: 7.93 (1H, d), 7.04 (1H, d), 4.71 (2H, brs), 3.46 (2H, brs).
