Reaktion #1281645

Reaktionsgleichung

water

K2CO3

7-Hydroxy-8-methyl-3-(3,4-dimethoxyphenyl)

7-Hydroxy-8-methyl-3-(3,4-dimethoxyphenyl)-4H-1-benzopyran-4-one

epibromhydrine

→

7-(2,3-epoxypropoxy)-8-methyl-3-(3,4-dimethoxyphenyl)-4H-1-benzopyran-4-one

Lösungsmittel

dimethylformamide

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturAfter heating for 5 h at 60°
2. 2
   Filtrationthe precipitated product is filtered off
3. 3
   Sonstigerecrystallized from ethanol
4. 4
   SonstigeThe product is dried in vacuo to constant weight

Vorschrift

7-Hydroxy-8-methyl-3-(3,4-dimethoxyphenyl)-4H-1-benzoyran-4-one [see example 12] (3.12 g) is dissolved in dimethylformamide (15 ml) and K2CO3 (3.5 g) is added to the solution. While stirring, epibromhydrine (2.47 g) is dropped into the mixture. After heating for 5 h at 60°, the content of the reaction flask is poured into water (500 ml) and the precipitated product is filtered off and recrystallized from ethanol. The product is dried in vacuo to constant weight to yield 7-(2,3-epoxypropoxy)-8-methyl-3-(3,4-dimethoxyphenyl)-4H-1-benzopyran-4-one, m.p. 214°.

Quelle