Reaktion #215036

Reaktionsgleichung

water

Ethyl cyanoacetate

sodium

1-bromo-3,3-dimethylallene

→

ethyl 2-cyano-3,3-dimethylpent-4-ynoate

Lösungsmittel

ethanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONafter the addition
2. 2
   workup.ADDITIONwas carefully added over about 30 minutes
3. 3
   TemperaturThe mixture was then heated at the reflux temperature for a period of 2.5 hours
4. 4
   Extraktionextracted with chloroform
5. 5
   WaschenThe extract was washed with water
6. 6
   Trocknendried over anhydrous magnesium sulphate
7. 7
   Einengenconcentrated by evaporation of the solvent
8. 8
   workup.DISTILLATIONThe residual oil was distilled

Vorschrift

Ethyl cyanoacetate (77.0 g.) was slowly added at 40° C. to a stirred solution of sodium (15.7 g.) in ethanol (400 ml.) and 15 minutes after the addition was completed 1-bromo-3,3-dimethylallene (100 g.) was carefully added over about 30 minutes. The mixture was then heated at the reflux temperature for a period of 2.5 hours and then kept at the ambient temperature for a further 20 hours. The mixture was then poured into an excess of water and extracted with chloroform. The extract was washed with water, dried over anhydrous magnesium sulphate and concentrated by evaporation of the solvent. The residual oil was distilled and ethyl 2-cyano-3,3-dimethylpent-4-ynoate was obtained as a colourless oil (boiling point 75°-76° C./0.1 mm Hg.).

Quelle