반응 #55201

반응 방정식

potassium hydroxide

triphenylphosphoranylideneacetic acid ethyl ester

4-(1-bromoethyl)-2',4'-difluorobiphenyl

ethyl acetate

→

3-(2',4'-difluoro-4-biphenylyl)butyric acid

용매

methanol

반응 조건

후처리

1. 1
   온도under reflux for 54 hours
2. 2
   여과The precipitate is filtered off
3. 3
   기타the filtrate is evaporated
4. 4
   기타Crude [1-(2',4'-difluoro-4-biphenylyl)ethyl]-triphenylphosphoranylideneacetic acid ethyl ester thus obtained
5. 5
   workup.DISSOLUTIONis dissolved in 500 ml
6. 6
   온도the mixture is heated
7. 7
   온도under reflux for one hour
8. 8
   workup.DISTILLATIONThe methanol is distilled off
9. 9
   workup.ADDITIONwater is added
10. 10
    세척the reaction mixture is washed with ether

실험 절차

69.7 g. of triphenylphosphoranylideneacetic acid ethyl ester and 29.7 g. of 4-(1-bromoethyl)-2',4'-difluorobiphenyl in 300 ml. of absolute ethyl acetate are heated under reflux for 54 hours. The precipitate is filtered off and the filtrate is evaporated. Crude [1-(2',4'-difluoro-4-biphenylyl)ethyl]-triphenylphosphoranylideneacetic acid ethyl ester thus obtained is dissolved in 500 ml. of methanol to which 150 ml. of 20% potassium hydroxide solution are added and the mixture is heated under reflux for one hour. The methanol is distilled off, water is added and the reaction mixture is washed with ether and acidified with hydrochloric acid to give 3-(2',4'-difluoro-4-biphenylyl)butyric acid, m.p. 109°-110°.

출처