Reaktion #82820

Reaktionsgleichung

5-(4-cyanophenyl)-3-formyl-1,2,4-oxadiazole

malonic acid

piperidine

→

3-{(E)-2-carboxyvinyl}-5-(4-cyanophenyl)-1,2,4-oxadiazole

Ausbeute 49.5%

Lösungsmittel

pyridine

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturwas refluxed for 1 hour
2. 2
   Sonstigethe mixture was evaporated in vacuo
3. 3
   workup.DISSOLUTIONThe residue was dissolved in ethyl acetate
4. 4
   Waschenwashed with water and brine
5. 5
   Trocknendried over magnesium sulfate
6. 6
   Sonstigeevaporated in vacuo
7. 7
   SonstigeThe residue was recrystallized from ethanol

Vorschrift

A mixture of 5-(4-cyanophenyl)-3-formyl-1,2,4-oxadiazole (2.0 g), malonic acid (4.18 g) and piperidine (0.50 ml) in pyridine (20 ml) was refluxed for 1 hour. After cooling to room temperature, the mixture was evaporated in vacuo. The residue was dissolved in ethyl acetate, acidified to pH 2.0 with 4N hydrochloric acid washed with water and brine, dried over magnesium sulfate, and evaporated in vacuo. The residue was recrystallized from ethanol to give 3-{(E)-2-carboxyvinyl}-5-(4-cyanophenyl)-1,2,4-oxadiazole (1.2 g).

Quelle