Reacción #61517

Ecuación de reacción

4-Iodo-5-thiophen-2-yl-2H-pyrazole-3-carboxylic acid ethyl ester

copper cyanide

→

4-Cyano-5-thiophen-2-yl-2H-pyrazole-3-carboxylic acid ethyl ester

Disolventes

DMF

Condiciones de reacción

Tratamiento posterior

1. 1
   Otro20 ml of tetrahydrofuran and the solution was degassed with argon
2. 2
   OtroThe solvent was removed under reduced pressure
3. 3
   workup.DISSOLUTIONThe residue was dissolved in ethyl acetate
4. 4
   Lavadothis solution was washed with saturated aqueous sodium bicarbonate
5. 5
   SecadoThe organic phase was dried with sodium sulfate
6. 6
   Filtraciónfiltered
7. 7
   Otrothe solvent was removed under reduced pressure
8. 8
   OtroThe product was purified by silica gel chromatography
9. 9
   Lavadoeluting with n-heptane

Procedimiento

1.57 g (4.5 mmol) of 4-Iodo-5-thiophen-2-yl-2H-pyrazole-3-carboxylic acid ethyl ester, 0.81 g (9.0 mmol) of copper cyanide and 352 mg (2.3 mmol) of tetraethylammonium cyanide were dissolved in 10 ml of DMF and 20 ml of tetrahydrofuran and the solution was degassed with argon. 223 mg (0.2 mmol) of Tris(dibenzylideneacetone)dipalladium (0) and 374 mg (0.7 mmol) of 1,1′-bis-(diphenylphosphino) ferrocene were added at RT. The reaction was stirred at 120° C. for 5 h. The solvent was removed under reduced pressure. The residue was dissolved in ethyl acetate and this solution was washed with saturated aqueous sodium bicarbonate. The organic phase was dried with sodium sulfate, filtered and the solvent was removed under reduced pressure. The product was purified by silica gel chromatography eluting with n-heptane:ethyl acetate/1:1.

Fuente