1193-22-2

1004-40-6

1193-22-2

Step 2: 2-mercapto-4-amino-6-hydroxypyridine (mass ratio 1:15) was added to 25% ammonia, followed by the addition of activated nickel and titanium dioxide, wherein the molar ratio of 2-mercapto-4-amino-6-hydroxypyridine, activated nickel and titanium dioxide was 1:4:1.5. The mixture was heated to 90°C and the reaction was carried out at reflux for 5 hours. Upon completion of the reaction, the activated nickel and titanium dioxide were removed by thermal filtration. The filtrate was cooled to room temperature and the solid product was precipitated. The solid was washed with 30 mL of water and dried at 40 °C to afford 4-amino-6-hydroxypyrimidine in 98.4% yield.