Reaktion #323524

Reaktionsgleichung

7-hydroxy-3-(4-hydroxyphenyl)-4H-1-benzopyran-4-one

ethyl 2-bromopropionate

potassium carbonate

→

7-(1-ethoxy- carbonylethyl)oxy-3-(4-hydroxyphenyl)-4H-1-benzopyran-4-one

Ausbeute 54.1%

Lösungsmittel

dimethylformamide

Reaktionsbedingungen

Aufarbeitung

1. 1
   Extraktionextracted with ethyl acetate
2. 2
   WaschenThe extract was washed with water
3. 3
   Einengenconcentrated
4. 4
   Sonstigethe residue was recrystallized from dichloroethane

Vorschrift

A mixture of 4.0 g of 7-hydroxy-3-(4-hydroxyphenyl)-4H-1-benzopyran-4-one, 3.42 g of ethyl 2-bromopropionate, 60 ml of dimethylformamide and 4.3 g of potassium carbonate was stirred well with heating at 80° C. for 2 hours, poured into ice water and extracted with ethyl acetate. The extract was washed with water and concentrated and the residue was recrystallized from dichloroethane to give 3.0 g of 7-(1-ethoxy- carbonylethyl)oxy-3-(4-hydroxyphenyl)-4H-1-benzopyran-4-one as white crystals. m.p. 172°-173° C.

Quelle