Reaktion #4268

Reaktionsgleichung

diethyl 2-methyl-2-propargyl-malonate

potassium hydroxide

→

2-Methyl-2-propargyl-malonic acid

Lösungsmittel

water ethanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturthe mixture is refluxed
2. 2
   Sonstigeis evaporated to dryness in vacuo
3. 3
   Extraktionextracted several times with methylene chloride
4. 4
   SonstigeThe combined extracts are dried
5. 5
   Sonstigeevaporated to dryness in vacuo
6. 6
   Sonstigea colourless product is obtained

Vorschrift

187 g (0.88 mol) of diethyl 2-methyl-2-propargyl-malonate are added to a solution of 101 g (1.8 mol) of potassium hydroxide in a mixture of 560 ml of water/ethanol (1:1) and the mixture is refluxed with stirring for 2 hours. After the reaction has ended (monitored by TLC) the mixture is evaporated to dryness in vacuo and the residue is then taken up with in water. The aqueous solution is acidified with 50% sulphuric acid and extracted several times with methylene chloride. The combined extracts are dried, evaporated to dryness in vacuo and a colourless product is obtained, m.p. 135° C.

Quelle