Reaktion #640394

Reaktionsgleichung

potassium tert-butoxide

4-bromobenzothiophene

potassium tert-butoxide

tert-butyl cyanoacetate

hydrochloric acid

→

tert-butyl 2-(1-benzothiophen-4-yl)-2-cyanoacetate

Ausbeute 67.6%

Lösungsmittel

1,2-dimethoxyethane

ethyl acetate

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturwas then refluxed for 40 minutes
2. 2
   Temperaturwas then refluxed for 30 minutes
3. 3
   SonstigeThe organic layer was separated
4. 4
   Trocknendried over anhydrous magnesium sulfate
5. 5
   workup.DISTILLATIONby distilling off the solvent under reduced pressure
6. 6
   SonstigeThe resultant residue was purified

Vorschrift

To 1,2-dimethoxyethane (3 mL) solution of 0.30 g of 4-bromobenzothiophene were added 0.33 g of potassium tert-butoxide, 0.21 g of tert-butyl cyanoacetate, 0.01 g of dichlorobis(triphenylphosphine)palladium(II) and 0.01 g of triphenylphosphine, which was then refluxed for 40 minutes. Thereto were added 0.33 g of potassium tert-butoxide, 0.01 g of dichlorobis(triphenylphosphine)palladium(II) and 0.01 g of triphenylphosphine, which was then refluxed for 30 minutes. The reaction mixture was added to a mixed solution of water and ethyl acetate, and the pH was adjusted to 1 with 6 mol/L hydrochloric acid. The organic layer was separated, and dried over anhydrous magnesium sulfate, followed by distilling off the solvent under reduced pressure. The resultant residue was purified using silica gel column chromatography (eluent; hexane:ethyl acetate=5:1) to provide 0.26 g of tert-butyl 2-(1-benzothiophen-4-yl)-2-cyanoacetate as pale brown oily form.

Quelle