Reaktion #352089

Reaktionsgleichung

gallic acid ethyl ester

caesium carbonate

1,2-dibromoethane

→

title compound

5-Hydroxy-1,4-benzodioxane-7-carboxylic acid ethyl ester

Lösungsmittel

dimethylformamide

dimethylformamide

Reaktionsbedingungen

Aufarbeitung

1. 1
   Einengenis concentrated by evaporation
2. 2
   Sonstigethe residue is partitioned between diethyl ether and water
3. 3
   TrocknenThe organic phases are dried over sodium sulfate
4. 4
   Einengenconcentrated by evaporation

Vorschrift

A solution of 0.2 ml of 1,2-dibromoethane in 4 ml of dimethylformamide is added dropwise, four times at 2 hour intervals, to a solution, stirred at 100° C., of 2 g of gallic acid ethyl ester and 6.5 g of caesium carbonate in 80 ml of dimethylformamide. After being stirred for a further 2 hours at 100° C. the reaction mixture is concentrated by evaporation and the residue is partitioned between diethyl ether and water. The organic phases are dried over sodium sulfate and concentrated by evaporation. The title compound is obtained from the residue by FC (50 g of silica gel, methylene chloride-methanol=8:2): Rf (methylene chloride/methanol=8:2)=0.39.

Quelle