Reacción #495742

Ecuación de reacción

triphenylphosphine

4-bromobenzothiophene

tert-butyl cyanoacetate

t-BuOK

HCl

→

benzo[b]thiophen-4-yl-cyano-acetic acid tert-butyl ester

Disolventes

DME

Condiciones de reacción

Tratamiento posterior

1. 1
   TemperaturaThe reaction was refluxed for 40 min
2. 2
   TemperaturaThe resulting mixture was refluxed for 1.5 h under argon
3. 3
   Otrothe reaction mixture was partitioned between water and EtOAc
4. 4
   OtroThe organic layer was separated
5. 5
   Secadodried over MgSO4
6. 6
   Filtraciónfiltered
7. 7
   Concentraciónconcentrated under reduced pressure
8. 8
   OtroThe crude was purified by chromatography on silica gel (elution with heptane/DCM: 9/1 to 1/1)

Procedimiento

To a solution of 4-bromobenzothiophene (1 eq.) in DME were added tert-butyl cyanoacetate (1.1 eq.) and t-BuOK (2 eq.). The reaction was refluxed for 40 min. Thereto were added dichlorobis(triphenylphosphine)palladium(II) (0.02 eq.) and triphenylphosphine (0.06 eq.). The resulting mixture was refluxed for 1.5 h under argon and then cooled to 20° C. Aqueous HCl (6N) was added dropwise until pH=1 and the reaction mixture was partitioned between water and EtOAc. The organic layer was separated, dried over MgSO4, filtered and concentrated under reduced pressure. The crude was purified by chromatography on silica gel (elution with heptane/DCM: 9/1 to 1/1) to afford benzo[b]thiophen-4-yl-cyano-acetic acid tert-butyl ester.

Fuente