Reaktion #6334

Reaktionsgleichung

3

4-(2-carbethoxy-1-ethyl)-7-methoxy-2-oxo-2H-1-Benzopyran

AlCl3

EtSH

→

4

Ausbeute 27.1%

4-(2-carbethoxy-1-ethyl)-7-hydroxy-2-oxo-2H-1-Benzopyran

Ausbeute 27.1%

Lösungsmittel

dichloromethane

dichloromethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe ice bath was removed
2. 2
   SonstigeThe solvents were removed in vacuo
3. 3
   Sonstigethe residue thoroughly vacuum dried
4. 4
   ExtraktionThe residue was extracted into EtOAc as much as possible, then the extract
5. 5
   Sonstigechromatographed

Vorschrift

To a suspension of 726 mg (5.4 mmol) of AlCl3 in 10 mL of dichloromethane at 0° C. was added 4 mL of EtSH. The suspension became a clear solution within seconds. Then, 298 mg (1.08 mmol) of 3 in 4 mL of dichloromethane was added, turning the yellow solution red in color. The ice bath was removed, and the reaction stirred to room temperature for 3 h. The solvents were removed in vacuo, and the residue thoroughly vacuum dried. The residue was extracted into EtOAc as much as possible, then the extract was flash chromatographed using 30/70 EtOAc/hexane. The long- and short-wave UV active band gave 76.7 mg (27%) of 4.

Quelle