Reaktion #495742

Reaktionsgleichung

triphenylphosphine

4-bromobenzothiophene

tert-butyl cyanoacetate

t-BuOK

HCl

→

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

Lösungsmittel

DME

Reaktionsbedingungen

Aufarbeitung

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

Vorschrift

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.

Quelle