反应详情

A suspension of 39.0 g (246 mmol) of 5-amino-2-fluoropyridine-4-carboxylic acid hydrated with 0.15 equivalents of water, 52.01 g (500 mmol) of formamidine acetate, and 500 mL of 2-methoxyethanol was heated at reflux for 6 hours, then concentrated to a solid. The solids were treated carefully with 100 mL of 10% aqueous sodium bicarbonate while maintaining vigorous stirring. The resultant suspension was filtered, and the collected brown solids were washed well with water, then dried over P2O5 to afford 31.3 g (77%,) of product that was used directly in the next reaction. Recrystallization of a small sample from methanol gave product of mp 287° C. (dec).

1. temperaturewas heated
2. temperatureat reflux for 6 hours
3. concentrationconcentrated to a solid
4. additionThe solids were treated carefully with 100 mL of 10% aqueous sodium bicarbonate
5. temperaturewhile maintaining vigorous stirring
6. filtrationThe resultant suspension was filtered
7. washthe collected brown solids were washed well with water
8. dry with materialdried over P2O5
9. customto afford 31.3 g (77%,) of product that
10. customwas used directly in the next reaction
11. customRecrystallization of a small sample from methanol
12. customgave product of mp 287° C. (dec)