Reaktion #357345

Reaktionsgleichung

acetophenone

ethyl cyanoacetate

acetic

ammonium acetate

ethyl cyanoacetate

ammonium acetate

→

2-Cyano-3-phenyl-but-2-enoic acid ethyl ester

Lösungsmittel

benzene

ethyl acetate

acetic acid

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturto reflux in a Dean-Stark apparatus
2. 2
   workup.WAITAfter an additional 10 hours
3. 3
   Waschenwashed with water (240 mL), brine (40 mL)
4. 4
   Sonstigedried (Na2S04)
5. 5
   FiltrationAfter filtering
6. 6
   Einengenthe extract was concentrated in vacuo
7. 7
   workup.ADDITIONthe desired product, as a mixture of E and Z-isomers
8. 8
   Sonstigewas isolated by column chromatography on silica gel
9. 9
   Wascheneluting with 5% ethyl acetate in petroleum ether
10. 10
    Sonstigeaffording an oil that
11. 11
    Sonstigeon standing at room temperature

Vorschrift

A mixture of acetophenone (50 mmol), ethyl cyanoacetate (50 mmol), acetic; acid (1.14 mL), ammonium acetate (400 mg), and benzene (50 mL) was heated to reflux in a Dean-Stark apparatus. After approximately 10 hours, additional ethyl cyanoacetate (50 mmol), acetic acid (1.14 mL), and ammonium acetate (400 mL) are added. After an additional 10 hours, the reaction was cooled to room temperature, diluted with ethyl acetate (30 mL), washed with water (240 mL), brine (40 mL), and dried (Na2S04). After filtering, the extract was concentrated in vacuo and the desired product, as a mixture of E and Z-isomers, was isolated by column chromatography on silica gel, eluting with 5% ethyl acetate in petroleum ether, affording an oil that solidified on standing at room temperature.

Quelle