反应详情

温度

90 °C

4.35 g of potassium carbonate was added to N,N-dimethylformamide (15 mL) solution of 1 g of 4-hydroxycarbazole and 4.72 g of ethyl 2-bromo-2-methylpropionate, and stirred at 90° C. for 4 hours. The reaction mixture was allowed to cool to room temperature, ice water was added thereto thereafter, and extracted twice with ethyl acetate. The combined extract was washed with brine and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated in vacuo. The residue was purified by NH silica gel chromatography (ethyl acetate:n-hexane=1:2), and ethyl 2-(9H-carbazole-4-yloxy)-2-methylpropionate was prepared. 5 N sodium hydroxide solution was added to the prepared ethanol 30 mL solution of ethyl 2-(9H-carbazole-4-yloxy)-2-methylpropionate, and stirred at 70° C. for 1 hour. The reaction mixture was allowed to cool to room temperature, 1 N hydrochloric acid was added thereafter to be acidified, and extracted twice with ethyl acetate. The combined extract was washed with brine and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated in vacuo. The filtrate was crystallized from diisopropylether, and isolated by filtration, washed with n-hexane, dried under reduced pressure, and 1.18 g of the subject compound was prepared as yellow crystal.

1. temperatureto cool to room temperature
2. extractionextracted twice with ethyl acetate
3. extractionThe combined extract
4. washwas washed with brine
5. dry with materialdried over anhydrous sodium sulfate
6. filtrationAfter filtration
7. concentrationthe filtrate was concentrated in vacuo
8. customThe residue was purified by NH silica gel chromatography (ethyl acetate:n-hexane=1:2), and ethyl 2-(9H-carbazole-4-yloxy)-2-methylpropionate
9. customwas prepared
10. stirringstirred at 70° C. for 1 hour
11. temperatureto cool to room temperature
12. extractionextracted twice with ethyl acetate
13. extractionThe combined extract
14. washwas washed with brine
15. dry with materialdried over anhydrous sodium sulfate
16. filtrationAfter filtration
17. concentrationthe filtrate was concentrated in vacuo
18. customThe filtrate was crystallized from diisopropylether
19. customisolated by filtration
20. washwashed with n-hexane
21. dry with materialdried under reduced pressure, and 1.18 g of the subject compound
22. customwas prepared as yellow crystal