5600-21-5

3977-29-5

5600-21-5

General procedure for the synthesis of 2-amino-4-chloro-6-methylpyrimidine from 2-amino-4-hydroxy-6-methylpyrimidine: 6 g of 2-amino-4-hydroxy-6-methylpyrimidine (IV) was mixed with 35 mL of freshly distilled phosphorous trichloride and the reaction was carried out by refluxing the mixture until it was homogeneous. Upon completion of the reaction, the excess phosphorous trichloride was removed under vacuum. The reaction mixture was cooled and the residue was mixed with ice water and the pH was adjusted with 25% ammonia to 8. The resulting suspension was filtered and the precipitate was washed with water. The crude product was recrystallized from 50% ethanol and dried to constant weight at constant temperature. A final 3.7 g of the target product (54% yield) was obtained with a melting point of 188°C (literature value 182-183°C [7]) and a thin-layer chromatographic Rf value of 0.79 (Expander D). Elemental analysis results: 41.74% C, 4.05% H, 29.35% N. Theoretically calculated values for the molecular formula C5H6ClN3: C 41.83%, H 4.21%, N 29.27%.