Reaktion #1165787

Reaktionsgleichung

5,7-dihydroxy-3-(2-hydroxyethyl)-4-methyl-2H-1-benzopyran-2-one

potassium carbonate

methyl iodide

→

3-(2-hydroxyethyl)-5,7-dimethoxy-4-methyl-2H-1-benzopyran-2-one

Lösungsmittel

ethanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   FiltrationThe solution is filtered
2. 2
   Sonstigeevaporated
3. 3
   Extraktionextracted with chloroform
4. 4
   Waschenthe organic phase is washed with water
5. 5
   Trocknendried with Na2SO4
6. 6
   Sonstigere-evaporated

Vorschrift

Alternative method: 100.0 g (423 mmol) of 5,7-dihydroxy-3-(2-hydroxyethyl)-4-methyl-2H-1-benzopyran-2-one (Example 49), 175.5 g (1270 mmol) of potassium carbonate and 150.2 g (1058 mmol) of methyl iodide are stirred under reflux for 4 hours in 1800 ml of ethanol. The solution is filtered, evaporated, extracted with chloroform, and the organic phase is washed with water, dried with Na2SO4 and re-evaporated. Yield 49.3 g (44%); m.p. 148°-150° C. (from isopropanol/TBME).

Quelle