反应详情

A mixture of 4-(3-amino-2,6-difluorophenyl)-pyridine (6.5 g), acetic anhydride (4.9 g) and ethanol (200 ml) was heated at reflux. After 1 hour, a further 3.3 ml acetic anhydride was added and a third portion (1.5 ml) after another 3.5 hours. Reflux was continued for a total of 6 hours after which time the solution was cooled and evaporated and the residue was partitioned between aqueous sodium bicarbonate and chloroform. The organic layer was washed with water, dried and evaporated to give the solid product of m.p. 148°-150° C. (6.8 g, 86% yield). NMR (CDCl3, 60 MHz): 8.8 (m, 2H), 8.05 (m, 2H), 7.4 (m, 2H), 6.9 (m, 1H), 2.2 (s, 3H).

1. temperaturewas heated
2. temperatureat reflux
3. waita third portion (1.5 ml) after another 3.5 hours
4. temperatureReflux
5. customwas continued for a total of 6 hours
6. temperaturewas cooled
7. customevaporated
8. customthe residue was partitioned between aqueous sodium bicarbonate and chloroform
9. washThe organic layer was washed with water
10. customdried
11. customevaporated
12. customto give the solid product of m.p. 148°-150° C. (6.8 g, 86% yield)