Reacción #357345

Ecuación de reacción

acetophenone

ethyl cyanoacetate

acetic

ammonium acetate

ethyl cyanoacetate

ammonium acetate

→

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

Disolventes

benzene

ethyl acetate

acetic acid

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturato reflux in a Dean-Stark apparatus
2. 2
   workup.WAITAfter an additional 10 hours
3. 3
   Lavadowashed with water (240 mL), brine (40 mL)
4. 4
   Otrodried (Na2S04)
5. 5
   FiltraciónAfter filtering
6. 6
   Concentraciónthe extract was concentrated in vacuo
7. 7
   workup.ADDITIONthe desired product, as a mixture of E and Z-isomers
8. 8
   Otrowas isolated by column chromatography on silica gel
9. 9
   Lavadoeluting with 5% ethyl acetate in petroleum ether
10. 10
    Otroaffording an oil that
11. 11
    Otroon standing at room temperature

Procedimiento

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.

Fuente