Reaktion #159091

Reaktionsgleichung

NBS

Pyrrolidine-1,2-dicarboxylic acid 2-[2-(7-bromo-dibenzofuran-3-yl)-2-oxo-ethyl]ester 1-tert-butyl ester

tributyl(ethoxyvinyl)stannane

Water

→

Pyrrolidine-1,2-dicarboxylic acid 2-{2-[7-(2-bromo-acetyl)-dibenzofuran-3-yl]-2-oxo-ethyl}ester 1-tert-butyl ester

Ausbeute 75.3%

Lösungsmittel

dioxane

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturwas cooled to 0° C
2. 2
   Sonstigethe solvent was removed under reduced pressure
3. 3
   workup.ADDITIONThe mixture was diluted with EtOAc
4. 4
   Waschenwas washed with water and brine
5. 5
   Trocknendried with sodium sulfate
6. 6
   EinengenConcentration and purification by flash column chromatography (hexane/EtOAc)

Vorschrift

To the solution of Pyrrolidine-1,2-dicarboxylic acid 2-[2-(7-bromo-dibenzofuran-3-yl)-2-oxo-ethyl]ester 1-tert-butyl ester (250 mg, 0.5 mmol) and tributyl(ethoxyvinyl)stannane (188 μl, 0.55 mmol) in dioxane (3.3 ml) was added PdCl2(PPh3)2 (15 mg). The mixture was heated at 80° C. for 16 hours and was cooled to 0° C. Water (1.1 ml) was added, followed by slow addition of NBS (98 mg, 0.55 mmol) over 5 minutes period. The mixture was stirred at 0° C. for additional 40 minutes, and the solvent was removed under reduced pressure. The mixture was diluted with EtOAc, and was washed with water and brine and dried with sodium sulfate. Concentration and purification by flash column chromatography (hexane/EtOAc) gave Pyrrolidine-1,2-dicarboxylic acid 2-{2-[7-(2-bromo-acetyl)-dibenzofuran-3-yl]-2-oxo-ethyl}ester 1-tert-butyl ester (205 mg).

Quelle