반응 #8658

반응 방정식

Ethyl (2R/S) (+/−) 2-ethoxy-3-(4-hydroxyphenyl)propanoate

NaOH

→

(2S)-2-Ethoxy-3-(4-hydroxyphenyl)propanoic acid

수율 40.8%

용매

phosphate

반응 조건

후처리

1. 1
   기타100 mg of the lyophilised esterase preparation from Aspergillus oryzae
2. 2
   workup.ADDITIONwas added
3. 3
   기타Most of the water was evaporated in vacuo
4. 4
   workup.ADDITIONMethanol was added to the remaining slurry in order
5. 5
   기타the hydrolysis
6. 6
   기타The precipitate, which formed
7. 7
   여과was filtered off
8. 8
   기타the methanol was evaporated in vacuo
9. 9
   workup.DISSOLUTIONThe remaining oil was dissolved in water
10. 10
    추출followed by extraction of unreacted ester with tert-butyl methyl ether (TBME) (eeester=87%, determined as in Example 2)
11. 11
    추출the acid extracted with TBME
12. 12
    건조After drying over Na2SO4 and evaporation of the TBME

실험 절차

Ethyl (2R/S) (+/−) 2-ethoxy-3-(4-hydroxyphenyl)propanoate (5 g) was added to an aqueous 0.1 M phosphate buffer pH 7 (10 ml). 100 mg of the lyophilised esterase preparation from Aspergillus oryzae was added and the mixture was stirred for 18 hours at room temperature. During that time, the pH of the reaction mixture was kept constant at pH=6-8 by addition of NaOH. Most of the water was evaporated in vacuo. Methanol was added to the remaining slurry in order to stop the hydrolysis. The precipitate, which formed was filtered off and the methanol was evaporated in vacuo. The remaining oil was dissolved in water followed by extraction of unreacted ester with tert-butyl methyl ether (TBME) (eeester=87%, determined as in Example 2). The water phase was acidified to pH=3 and the acid extracted with TBME. After drying over Na2SO4 and evaporation of the TBME, 1.8 g (2S)-2-Ethoxy-3-(4-hydroxyphenyl)propanoic acid was obtained as an oil, which crystallized on standing (m.p.=105° C., eeacid=>99%, determined as in Example 2).

출처