反应详情

温度

130 °C

In 80 ml of N,N-dimethyl formamide 4.2 g (20 millimoles) of 6,7-dihydroxy-2,2-dimethyl-4-chromanone are dissolved, whereupon 4.1 g (30 millimoles) of potassium carbonate and 4.2 g (2.5 ml, 25 millimoles) of isopropyl iodide are added. The reaction mixture is heated at 130° C. for 6 hours, poured into 200 ml of water and extracted with 100 ml of carbon tetrachloride. To the aqueous layer 50 ml of an 5% sodium hydroxide solution are added and the mixture is cooled below 5° C. The mixture is acidified with concentrated hydrochloric acid, the precipitated crystalline substance is filtered off and crystallized from methanol. Thus 4.5 g of the desired compound are obtained, yield 90%, mp.: 138°-139° C.

1. additionare added
2. extractionextracted with 100 ml of carbon tetrachloride
3. additionTo the aqueous layer 50 ml of an 5% sodium hydroxide solution are added
4. temperaturethe mixture is cooled below 5° C
5. filtrationthe precipitated crystalline substance is filtered off
6. customcrystallized from methanol