Reaktion #1165788

Reaktionsgleichung

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

potassium bicarbonate

ethyl iodide

DMF

→

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

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe solution is evaporated
2. 2
   Extraktionextracted with chloroform
3. 3
   Waschenthe organic phase is washed with dilute sodium hydroxide and with water
4. 4
   Trocknendried with Na2SO4
5. 5
   Sonstigere-evaporated
6. 6
   SonstigeThe product is purified by column chromatography over silica gel 60 (eluent: ethylacetate/acetone)

Vorschrift

33.0 g (140 mmol) of 5,7-dihydroxy-3-(2-hydroxyethyl)-4-methyl-2H-1-benzopyran-2-one (Example 49), 56.0 g (560 mmol) of potassium bicarbonate and 76.4 g (490 mmol) of ethyl iodide are stirred in 500 ml of DMF for 55 hours at 80° C. under nitrogen. The solution is evaporated, extracted with chloroform, and the organic phase is washed with dilute sodium hydroxide and with water, dried with Na2SO4 and re-evaporated. The product is purified by column chromatography over silica gel 60 (eluent: ethylacetate/acetone). Yield 19.5 g (48%); m.p. 117°-119° C. (from acetone/petroleum ether).

Quelle