反应详情

To a solution of 6.28 g (0.040 mole) of 2-fluoro-4-methoxyphenylhydrazine in 200 mL of toluene was added with stirring 6.82 g (0.040 mole) of ethyl 2-cyclohexanonecarboxylate. This mixture was heated at reflux under a nitrogen atmosphere while water was removed with a Dean-Stark trap. When all water had been removed, the reaction mixture was cooled, and the solvent was evaporated under reduced pressure, leaving a residue, which was then dissolved in acetic acid. This solution was heated at reflux for approximately sixteen hours, after which the solvent was evaporated under reduced pressure, leaving a residue. This residue was dissolved in toluene, which was also evaporated under reduced pressure. The residue was dissolved in ethyl acetate and placed on a silica gel column and eluted with ethyl acetate. An attempt to crystallize the product by dissolving it in diethyl ether after the ethyl acetate had been evaporated was unsuccessful. After the solvent had been evaporated from this product, it was again heated at reflux in acetic acid for 24 hours and allowed to cool to room temperature, where the solution stirred for an additional 48 hours. The solvent was evaporated under reduced pressure, leaving a residue weighing 4.32 g. Two additional fractions weighing 0.80 g and 2.75 g had been recovered by extracting the reaction mixture before the solvent was evaporated. The NMR spectrum of the residue showed it to be a mixture of 2-(2-fluoro-4-methoxyphenyl)-4,5,6,7-tetrahydro-1H-indazol-3-one and the 2-fluoro-4-methoxyphenylhydrazone of 2-cyclohexanonecarboxylic acid.

1. temperatureThis mixture was heated
2. customwas removed with a Dean-Stark trap
3. customWhen all water had been removed
4. temperaturethe reaction mixture was cooled
5. customthe solvent was evaporated under reduced pressure
6. customleaving a residue, which
7. temperatureThis solution was heated
8. temperatureat reflux for approximately sixteen hours
9. customafter which the solvent was evaporated under reduced pressure
10. customleaving a residue
11. customwhich was also evaporated under reduced pressure
12. dissolutionThe residue was dissolved in ethyl acetate
13. washeluted with ethyl acetate
14. customAn attempt to crystallize the product
15. dissolutionby dissolving it in diethyl ether after the ethyl acetate
16. customhad been evaporated
17. customAfter the solvent had been evaporated from this product, it
18. temperaturewas again heated
19. temperatureat reflux in acetic acid for 24 hours
20. customThe solvent was evaporated under reduced pressure
21. customleaving a residue
22. customhad been recovered
23. extractionby extracting the reaction mixture before the solvent
24. customwas evaporated
25. additiona mixture of 2-(2-fluoro-4-methoxyphenyl)-4,5,6,7-tetrahydro-1H-indazol-3-one