反应详情

A solution of 5,6-diamino-1-methyluracil (2.5 g) in acetic anhydride (25 ml) was heated at reflux for 2 hours and then the acetic anhydride was evaporated under reduced pressure. The residue was dissolved in 10% aqueous sodium hydroxide solution (50 ml) and heated at reflux for 2 hours. After cooling to room temperature, the mixture was acidified to pH 4 by addition of concentrated hydrochloric acid. The precipitate was filtered, washed with water (15 ml), rinsed with acetone (15 ml) and dried under vacuum to provide 3,8-dimethylxanthine (1.8 g).

1. temperatureat reflux for 2 hours
2. customthe acetic anhydride was evaporated under reduced pressure
3. dissolutionThe residue was dissolved in 10% aqueous sodium hydroxide solution (50 ml)
4. temperatureheated
5. temperatureat reflux for 2 hours
6. additionthe mixture was acidified to pH 4 by addition of concentrated hydrochloric acid
7. filtrationThe precipitate was filtered
8. washwashed with water (15 ml)
9. washrinsed with acetone (15 ml)
10. customdried under vacuum