反应详情

温度

5 °C

In 100 ml of acetone 4.2 g (20 millimoles) of 6,7-dihydroxy-2,2-dimethyl-4-chromanone are dissolved and to the solution thus obtained 4.1 g (30 millimoles) of potassium carbonate and 4.5 g (2 ml, 30 millimole) of methyl iodide are added under stirring. The reaction mixture is refluxed for 4 hours. The inorganic salt is filtered off, washed twice with 20 ml of acetone each and the solvent is removed. The residue is suspended in 100 ml of chloroform and extracted twice with 50 ml of a 4% sodium hydroxide solution each. The aqueous-alkaline phase is separated, cooled to 5° C. and acidified with 37% hydrochloric acid under constant stirring. The precipitated product is filtered off, washed twice with 20 ml of water each and dried to constant weight. The product is purified by recrystallization from anhydrous ethanol. Thus 4.0 g of the desired compound are obtained, yield 90%. Mp.: 134°-136° C.

1. additionare added
2. temperatureThe reaction mixture is refluxed for 4 hours
3. filtrationThe inorganic salt is filtered off
4. washwashed twice with 20 ml of acetone each and the solvent
5. customis removed
6. extractionextracted twice with 50 ml of a 4% sodium hydroxide solution each
7. customThe aqueous-alkaline phase is separated
8. filtrationThe precipitated product is filtered off
9. washwashed twice with 20 ml of water each and
10. customdried to constant weight
11. customThe product is purified by recrystallization from anhydrous ethanol