Ryan and Algak — Studies in the Diflavone Group. 189 



Isomeric Forms of Dianisylidene-diacetoresorcinol. 

 3. a-Dianisylidene-diacetoresorcinol (I). 



This compound is apparently identical with that obtained by Eijkmann, 

 Bergenia, and Henrard [loc. cit.) by the condensation of diacetoresorcinol with 

 anisaldehyde in the presence of alcoholic sodium hydroxide. 



About 35 c.cs. of 50 per cent, aqueous sodium hydroxide were added, 

 drop by drop, to a solution of 10 grams of diacetoresorcinol, and 20 c.cs. of 

 anisaldehyde in 300 c.cs. of boiling alcohol. After addition of the sodium 

 hydroxide the mixture was further heated for about twenty minutes, when 

 a considerable quantity of an orange- coloured solid separated, which was 

 filtered and washed with cold alcohol. The solid was then shaken with 

 dilute hydrochloric acid, its colour changing from orange to yellow. It was 

 re-crystallized first from chloroform and alcohol, and afterwards from a small 

 quantity of acetone. 



The yield was seven grams. 



The substance crystallized from acetone in orange, somewhat elongated 

 hexagonal crystals, which melted at 205-206° C, and gave on analysis the 

 following results : — 



0-1618 substance gave 0-4325 CO, and 0-0775 H 2 

 corresponding to C 72-89, H 5-32 

 C 26 H 23 6 requires C 72-55, H 5-11 



u-Dianisylidene-diacetoresorcinol is almost insoluble in cold alcohol, slightly 

 soluble in cold acetone, and soluble in cold chloroform. 



Concentrated sulphuric acid colours the crystals dark red, and dissolves 

 them to a bright red solution. 



A solution of the substance in hot alcohol is coloured brownish-red by 

 ferric chloride. 



4. fi-Dianisylidene-diacdoresorcinol. 



Anisaldehyde (21 c.cs.), diacetoresorcinol (17'5 grams), and sodium hydrate 

 (6 grams) were mixed in a flask with 1200 c.cs. of water, and the mixture 

 was allowed to stand in a warm place, with occasional shaking, for six months. 

 A crystalline, yellow solid gradually separated. The solid was filtered, washed 

 with dilute hydrochloric acid, and crystallized from a mixture of chloroform 

 and alcohol. After re-crystallization from a mixture of chloroform and 

 acetone, it was obtained in the form of yellow diamond-shaped crystals, 



