反应详情

A 20% solution of sodium ethoxide in ethanol (29.7 g) was combined at 0C with diethyl malonate (14.0 g) and then with 4-(5-fluoro-2-methylphenyl)-3-buten-2-one (13.4 g) in portions. The reaction mixture was stirred at room temperature for 30 minutes, and then stirred with heating for 2 hours. After allowing to stand to cool, the solvent was distilled off, and the residue was combined with water and the aqueous layer was washed with ethyl acetate and then concentrated. 2M Sodium hydroxide (46 ml) was added and the mixture was heated under reflux for 1 hour. After allowing to stand to cool, 2.5M sulfuric acid (46 ml) was added over 10 minutes, and the mixture was heated under reflux for 30 minutes. After allowing to stand to cool, the precipitated crystal was recovered by a filtration and washed successively with water and isopropyl ether to obtain 5-(5-fluoro-2-methylphenyl)cyclohexane-1,3-dione (8.6 g) as a colorless crystal.

1. stirringstirred
2. temperaturewith heating for 2 hours
3. temperatureto cool
4. distillationthe solvent was distilled off
5. washthe aqueous layer was washed with ethyl acetate
6. concentrationconcentrated
7. addition2M Sodium hydroxide (46 ml) was added
8. temperaturethe mixture was heated
9. temperatureunder reflux for 1 hour
10. temperatureto cool
11. addition2.5M sulfuric acid (46 ml) was added over 10 minutes
12. temperaturethe mixture was heated
13. temperatureunder reflux for 30 minutes
14. temperatureto cool
15. filtrationthe precipitated crystal was recovered by a filtration
16. washwashed successively with water and isopropyl ether