Reaktion #511577

Reaktionsgleichung

ethyl 2-(5-bromothiophene-2-carbonyl)-3-phenylacrylate

aluminum trichloride

→

ethyl 2-bromo-6-oxo-4-phenyl-5,6-dihydro-4H-cyclopenta[b]thiophene-5-carboxylate

Ausbeute 78.8%

Lösungsmittel

nitroethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   Extraktionextracted with ethyl acetate
2. 2
   WaschenThe organic phase was washed with brine
3. 3
   Trocknendried (MgSO4)
4. 4
   Einengenconcentrated
5. 5
   Sonstigeto give a brown oil
6. 6
   SonstigeThe crude product was purified by silica gel flash chromatography

Vorschrift

A solution of ethyl 2-(5-bromothiophene-2-carbonyl)-3-phenylacrylate (1.3 g, 3.56 mmol) and aluminum trichloride (0.563 g, 4.27 mmol) in nitroethane (20 ml) was heated at 83° C. for 2.75 hours. The reaction mixture was poured into 1N HCl-ice solution, and extracted with ethyl acetate. The organic phase was washed with brine, dried (MgSO4) and concentrated to give a brown oil. The crude product was purified by silica gel flash chromatography using 0-5% ethyl acetate in hexanes to give ethyl 2-bromo-6-oxo-4-phenyl-5,6-dihydro-4H-cyclopenta[b]thiophene-5-carboxylate as a viscous foam (1.024 g, 78.8% yield). LCMS m/z 366, 368 (M+1); 388.9, 386.9 (M+23); HPLC: Rt 3.438, 3.718 min.

Quelle