反应详情

5-Fluorosalicylaldehyde (4.4 g), diethylbromomalonate (11.3 g) and methyl ethyl ketone (35 ml) were stirred together. Anhydrous potassium carbonate (8.7 g) was added and the mixture was heated at reflux for 4 hours. Excess dilute sulphuric acid was added and the mixture was extracted with diethyl ether. The combined extracts were washed with water, dried and evaporated to leave an oil which was treated with 10% w/v ethanolic KOH (60 ml) and heated at reflux for 45 minutes. The solvent was evaporated and the residue treated with excess dilute sulphuric acid and heated briefly on a steam bath. After cooling the crude acid was filtered off. Recrystallisation from ethylacetate/ethanol gave a fawn coloured product (1.1 g), m.p. 261°-266° (decomp), I.R. νmax 1685 cm-1.

1. temperaturethe mixture was heated
2. temperatureat reflux for 4 hours
3. extractionthe mixture was extracted with diethyl ether
4. washThe combined extracts were washed with water
5. customdried
6. customevaporated
7. customto leave an oil which
8. temperatureheated
9. temperatureat reflux for 45 minutes
10. customThe solvent was evaporated
11. additionthe residue treated with excess dilute sulphuric acid
12. temperatureheated briefly on a steam bath
13. temperatureAfter cooling the crude acid
14. filtrationwas filtered off
15. customRecrystallisation from ethylacetate/ethanol