反应详情

A mixture of 100 kg (438.5 mole) of 2,4-dihydroxy-phenyl-benzyl-ketone, 38 kg of dimethyl-formamide, 5.2 kg of morpholine and 75 kg (506 mole) of ethyl-orthoformate is stirred at 80°-90° C., while within one hour crystallization is initiated. 360 kg of chloroform are added to the suspension after 7 hours at 60° C. After cooling the crystalline substance is centrifuged, covered with chloroform, filtered and dried. 94.5 kg of 7-hydroxy-isoflavone are obtained, 7-ethoxy-isoflavone content: 0.1% by weight, yield: 90.5%.

1. temperatureAfter cooling the crystalline substance
2. filtrationfiltered
3. customdried