تفاعل #95406

معادلة التفاعل

water

n-butyl-lithium

3,3-dimethylallyl-triphenyl-phosphonium bromide

trifluoroacetophenone

→

1,1,1-trifluoro-2-phenyl-5-methyl-hexa-2,4-diene

المردود 56.6%

المذيبات

hexane

tetrahydrofuran

ظروف التفاعل

المعالجة

1. 1
   أخرىThe deep red solution thus obtained
2. 2
   workup.STIRRINGwas stirred at 0° C. for a further 15 minutes
3. 3
   workup.STIRRINGThe mixture was subsequently stirred at room temperature until it
4. 4
   أخرى(about 12 hours)
5. 5
   استخلاصthe reaction mixture was extracted 5 times with 200 ml of petroleum ether each time
6. 6
   تجفيفThe petroleum ether phases were dried over magnesium sulphate
7. 7
   أخرىthe solvent was then stripped off in a rotary evaporator under a waterpump vacuum
8. 8
   workup.ADDITION150 ml of n-hexane were added to the residue and residual triphenyl-phosphine oxide
9. 9
   ترشيحwas filtered off
10. 10
    workup.DISTILLATIONThe solvent was subsequently distilled off from the filtrate under normal pressure
11. 11
    workup.DISTILLATIONthe oily residue was then distilled in vacuo

الإجراء التجريبي

65 ml of 15% strength solution of n-butyl-lithium in hexane were added dropwise to a suspension of 41.1 g (0.1 mol) of dry 3,3-dimethylallyl-triphenyl-phosphonium bromide in 300 ml of anhydrous tetrahydrofuran at 0° C. under nitrogen, while stirring. The deep red solution thus obtained was stirred at 0° C. for a further 15 minutes and 17.4 g (0.1 mol) of ≃,≃,≃-trifluoroacetophenone were then added dropwise at 0°-10° C. The mixture was subsequently stirred at room temperature until it was decolorized (about 12 hours). 600 ml of water were then added and the reaction mixture was extracted 5 times with 200 ml of petroleum ether each time. The petroleum ether phases were dried over magnesium sulphate and the solvent was then stripped off in a rotary evaporator under a waterpump vacuum. 150 ml of n-hexane were added to the residue and residual triphenyl-phosphine oxide was filtered off. The solvent was subsequently distilled off from the filtrate under normal pressure and the oily residue was then distilled in vacuo. 12.8 g (56.6% of theory) of 1,1,1-trifluoro-2-phenyl-5-methyl-hexa-2,4-diene were obtained as a slightly reddish liquid with a boiling point of 80°-85° C. under 3 mbar.

المصدر