反应详情

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).

1. customThe solution is evaporated
2. extractionextracted with chloroform
3. washthe organic phase is washed with dilute sodium hydroxide and with water
4. dry with materialdried with Na2SO4
5. customre-evaporated
6. customThe product is purified by column chromatography over silica gel 60 (eluent: ethylacetate/acetone)