反应详情

22.8 g (205 mmol) of calcium chloride and 8.4 g (114 mmol) of calcium hydroxide were dissolved in 50 g of water and stirred for 20 minutes. Then, 28.0 g (142 mmol) of methyl 4-bromo-3-hydroxybutanoate was added dropwise at room temperature over 5 minutes. The mixture was stirred at room temperature for 10 minutes and then cooled by ice, and 8.7 g (178 mmol) of sodium cyanide was added thereto. Then, the mixture was further stirred at an internal temperature of 25 to 33° C. for 4.5 hours. Then, concentrated hydrochloric acid was added dropwise, and ethyl acetate was used for extraction five times. The residue that was obtained by concentrating the organic layer under reduced pressure was dissolved in ethyl acetate and dried over anhydrous magnesium sulfate. The solution from which magnesium sulfate was removed through filtration was cooled with ice, and 20.0 g (198 mmol) of triethylamine and 26.6 g (172 mmol) of diethyl sulfate were added thereto. It was stirred for about 30 minutes while gradually heating to room temperature. It was further stirred at an internal temperature of 55 to 63° C. for 40 minutes. Then, the reaction solution was cooled by ice and 50 ml of saturated sodium hydrogen carbonate was added thereto, which was then stirred. This solution was separated, and solution layer was subjected again to extraction with ethyl acetate. Combined organic layers were washed with saturated saline solution dried over anhydrous magnesium sulfate, and concentrated. The residue was subjected to the distillation under reduced pressure and 15.7 g of ethyl 4-cyano-3-hydroxybutanoate was obtained. The purity of the obtained ethyl 4-cyano-3-hydroxybutanoate was 95% (gas chromatography in area percentage).

1. stirringThe mixture was stirred at room temperature for 10 minutes
2. additionwas added
3. stirringThen, the mixture was further stirred at an internal temperature of 25 to 33° C. for 4.5 hours
4. extractionethyl acetate was used for extraction five times
5. customThe residue that was obtained
6. concentrationby concentrating the organic layer under reduced pressure
7. dissolutionwas dissolved in ethyl acetate
8. dry with materialdried over anhydrous magnesium sulfate
9. customThe solution from which magnesium sulfate was removed through filtration
10. additionwere added
11. stirringIt was stirred for about 30 minutes
12. stirringIt was further stirred at an internal temperature of 55 to 63° C. for 40 minutes
13. additionwas added
14. stirringwhich was then stirred
15. customThis solution was separated
16. extractionsolution layer was subjected again to extraction with ethyl acetate
17. washCombined organic layers were washed with saturated saline solution
18. dry with materialdried over anhydrous magnesium sulfate
19. concentrationconcentrated
20. distillationThe residue was subjected to the distillation under reduced pressure