3-Amino-2-chloro-4-methylpyridine

152362-01-1

133627-45-9

General procedure for the synthesis of 2-chloro-3-amino-4-methylpyridine from 2-chloro-4-methylnicotinamide: 61.5 g of calcium hypochlorite was added to the reaction mixture in batches, and after the addition was completed, stirring was continued for 30 minutes at a maintained reaction temperature of 50 °C. Subsequently, 50 mL of 40 wt% aqueous calcium oxide solution was added in batches, the temperature was controlled not to exceed 10 °C, and the reaction lasted for 2 to 3 hours. Upon completion of the reaction, the cooled reaction mixture was slowly added dropwise to 150 mL of water, and the temperature was controlled not to exceed 100 °C during the dropwise addition. After the dropwise addition, the reaction was continued at 70 to 80°C for 2 hours. After the reaction solution was cooled to 5°C, the pH was adjusted to 6.5~7 with concentrated hydrochloric acid. filtration was carried out and the filter cake was washed with ice water. The filter cake was resuspended in 75 mL of water, heated to 60-70°C, stirred for 30 minutes, and then slowly cooled to 0~5°C to precipitate crystals. It was filtered again and the filter cake was washed with ice water and finally dried under vacuum. This process yielded 41.5 g of 2-chloro-3-amino-4-methylpyridine with 99.9% HPLC purity.