反应详情

温度

60 °C

To a stirred mixture of 100 ml of methyl-ethyl-ketone and 2.6 ml (30 millimoles) of 1,2-dibromo ethane heated to 60° C. 4.2 g (20 millimoles) of 6,7-dihydroxy-2,2-dimethyl-4-chromanone and a suspension of 8.3 g (60 millimoles) of potassium carbonate and 0.5 g of potassium iodide in 100 ml of methyl-ethyl ketone are added dropwise within 3 hours. The reaction mixture is heated to boiling for 5 hours. The inorganic salt is filtered off, washed twice with 20 ml of acetone each and the solvent is removed. The residue is crystallized from 70% ethanol. Thus 3.75 g of the desired compound are obtained, yield 80%. Mp.: 118°-119° C.

1. additionare added dropwise within 3 hours
2. temperatureThe reaction mixture is heated
3. filtrationThe inorganic salt is filtered off
4. washwashed twice with 20 ml of acetone each and the solvent
5. customis removed
6. customThe residue is crystallized from 70% ethanol