Reaktion #324019

Reaktionsgleichung

ethyl α,β-dibromo-β-(3-chloro-4-cyclohexyl)propionate

potassium hydroxide

→

3-chloro-4-cyclohexylpropiolic acid

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe mixture is refluxed on a steam bath for 6 hours
2. 2
   SonstigeThe alcohol is evaporated
3. 3
   workup.DISSOLUTIONthe residue is dissolved in water
4. 4
   WaschenThe ether layer is washed with water, saline
5. 5
   Trocknendried over sodium sulfate
6. 6
   SonstigeThe ether is removed
7. 7
   Sonstigeto give a residue which
8. 8
   Sonstigeis triturated with carbon tetrachloride
9. 9
   SonstigeRecrystallization
10. 10
    Sonstigetriturated with boiling carbon tetrachloride

Vorschrift

Powdered ethyl α,β-dibromo-β-(3-chloro-4-cyclohexyl)propionate (33.0 g.) is added portion-wise to 20% ethanolic potassium hydroxide (135 ml) at room temperature. The mixture is refluxed on a steam bath for 6 hours. The alcohol is evaporated and the residue is dissolved in water and covered with ether and is acidified with cold, dilute hydrochloric acid. The ether layer is washed with water, saline, and dried over sodium sulfate. The ether is removed to give a residue which is triturated with carbon tetrachloride. Recrystallization is carried out from acetic acid-water. This material is digested and triturated with boiling carbon tetrachloride to give 3-chloro-4-cyclohexylpropiolic acid.

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