反应详情

In a mixture of 7.0 mL of tert-butanol and 1.75 mL of N,N-dimethylformamide was dissolved 1.75 g of 2-(6-methoxy-1-benzofuran-5-yl)-1-ethanol, and 2.2 g of 1-chloroacetylpiperidine and 1.54 g of potassium tert-butoxide were added to the solution under ice-cooling, after which the resulting mixture was stirred at the same temperature for 30 minutes and then at the room temperature for 2 hours. Water and ethyl acetate were added to the reaction mixture and the pH was adjusted to 1 with 6 mol/L hydrochloric acid, after which the organic layer was separated. The organic layer was washed with water and then a saturated aqueous sodium chloride solution, dried over anhydrous magnesium sulfate, and then distilled under reduced pressure to remove the solvent. The residue was dissolved in 10.5 mL of a 90% aqueous ethanol solution, followed by adding thereto 0.91 g of sodium hydroxide, and the resulting mixture was heated under reflux for 3 hours. After the reaction mixture was cooled, water and ethyl acetate were added thereto and the pH was adjusted to 1 with 6 mol/L hydrochloric acid, after which the organic layer was separated. The organic layer was washed with water and then a saturated aqueous sodium chloride solution, dried over anhydrous magnesium sulfate, and then distilled under reduced pressure to remove the solvent. Diisopropyl ether was added to the residue, and the crystals precipitated were collected by filtration, washed with diisopropyl ether and then dried to obtain 1.42 g of 2-[2-(6-methoxy-1-benzofuran-5-yl)ethoxy]acetic acid as yellow crystals.

1. additionwere added to the solution under ice-
2. temperaturecooling
3. waitat the room temperature for 2 hours
4. customafter which the organic layer was separated
5. washThe organic layer was washed with water
6. dry with materiala saturated aqueous sodium chloride solution, dried over anhydrous magnesium sulfate
7. distillationdistilled under reduced pressure
8. customto remove the solvent
9. dissolutionThe residue was dissolved in 10.5 mL of a 90% aqueous ethanol solution
10. additionby adding
11. temperature0.91 g of sodium hydroxide, and the resulting mixture was heated
12. temperatureunder reflux for 3 hours
13. temperatureAfter the reaction mixture was cooled
14. additionwater and ethyl acetate were added
15. customafter which the organic layer was separated
16. washThe organic layer was washed with water
17. dry with materiala saturated aqueous sodium chloride solution, dried over anhydrous magnesium sulfate
18. distillationdistilled under reduced pressure
19. customto remove the solvent
20. additionDiisopropyl ether was added to the residue
21. customthe crystals precipitated
22. filtrationwere collected by filtration
23. washwashed with diisopropyl ether
24. customdried