反应详情

2.5 g (11 mmol) of 5-(2-fluorobenzoyl)furan-2-carboxylic acid, 3.28 g (24 mmol) of benzhydrazide and 2 drops of glacial acetic acid in 50 ml of ethanol were heated under reflux for 10 h. The mixture was subsequently concentrated using a rotary evaporator and the residue was taken up in water, made alkaline using 2 N NaHCO3 solution and extracted with ethyl acetate. The aqueous phase was made acidic using 2 N hydrochloric acid and extracted with ethyl acetate. The combined organic phases were dried and concentrated using a rotary evaporator. The residue was dissolved in 25 ml of THF, 2.74 g (24.2 mmol) of potassium tert-butoxide were added and the mixture was stirred at reflux temperature for 1.5 h. After cooling, the mixture was concentrated using a rotary evaporator and the residue was taken up in 1 N aqueous sodium hydroxide solution and extracted with ethyl acetate. The precipitate that resulted when the aqueous phase was acidified was filtered off with suction, washed with water and dried in a vacuum drying cabinet at 40° C. This gave 1.88 g (75%) of the title compound. m.p.: 205° C. (decomp).

1. temperatureunder reflux for 10 h
2. concentrationThe mixture was subsequently concentrated
3. customa rotary evaporator
4. extractionextracted with ethyl acetate
5. extractionextracted with ethyl acetate
6. customThe combined organic phases were dried
7. concentrationconcentrated
8. customa rotary evaporator
9. dissolutionThe residue was dissolved in 25 ml of THF
10. temperatureat reflux temperature for 1.5 h
11. temperatureAfter cooling
12. concentrationthe mixture was concentrated
13. customa rotary evaporator
14. extractionextracted with ethyl acetate
15. customThe precipitate that resulted when the aqueous phase
16. filtrationwas acidified was filtered off with suction
17. washwashed with water
18. customdried in a vacuum
19. customdrying cabinet at 40° C