تفاعل #55201

معادلة التفاعل

potassium hydroxide

triphenylphosphoranylideneacetic acid ethyl ester

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

ethyl acetate

→

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

المذيبات

methanol

ظروف التفاعل

المعالجة

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

الإجراء التجريبي

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°.

المصدر