Reacción #55973

Ecuación de reacción

2-acetylthiophene

diethyl-o-cyanobenzylphosphonate

sodium methylate

→

2-[2-(2-thienyl)-1-propenyl]benzonitrile

Disolventes

dimethyl formamide

dimethyl formamide

—

ice water

Condiciones de reacción

Tratamiento posterior

1. 1
   OtroThe starting material may be produced
2. 2
   workup.WAITat 100° for a further 2 hours
3. 3
   ExtracciónThe condensation product is extracted with ether
4. 4
   Lavadothe extract is washed with water until neutral,
5. 5
   Secadois dried over potassium carbonate
6. 6
   Concentraciónconcentrated by evaporation
7. 7
   OtroThe evaporation residue is chromatographed through 110 g of silica gel with a mixture of benzene/petroleum ether (1:4)

Procedimiento

The starting material may be produced as follows: (a) A solution of 10.0 g of 2-acetylthiophene and 21.0 g of diethyl-o-cyanobenzylphosphonate in 70 cc of anhydrous dimethyl formamide is added dropwise at 20°-30° in an atmosphere of nitrogen to a suspension of 4.5 g of pulverized sodium methylate in 100 cc of anhydrous dimethyl formamide, the reaction mixture is stirred at 40° for 2 hours, and at 100° for a further 2 hours, is cooled to room temperature and diluted with 600 cc of ice water. The condensation product is extracted with ether, the extract is washed with water until neutral, is dried over potassium carbonate and concentrated by evaporation. The evaporation residue is chromatographed through 110 g of silica gel with a mixture of benzene/petroleum ether (1:4). The 2-[2-(2-thienyl)-1-propenyl]benzonitrile (nD20 =1.6460, B.P. 165°-175°/0.1 mm Hg), isolated as main fraction, is used for the next reaction without further purification.

Fuente