Ryan and O'Neill — Studies in the Diflavone Group. 51 



of diacetoresorcinol were obtained. After solution in chloroform and 

 repreeipitation by alcohol it crystallised in colourless prisms which melted 

 at 183° C, and in alcoholic solution gave a red colour with ferric chloride. 



It can be readily converted into its dimethylether by means of aqueous 

 alkali and dimethyl sulphate. 



Diacetoresorcinol-dimethylether C 6 H 2 (0 CH 3 ) 3 (CO CH 3 ) 2 . 



Diacetoresorcinol (20 grams) was added to a solution of potash (23 grams) 

 in water (50 c.c), and the mixture was heated in a large flask on a sand bath. 

 Dimethyl sulphate (38 c.c.) was added in about five instalments, and when the 

 reaction was completed the contents of the flask were cooled, diluted with 

 200 c.c. of water, and made slightly alkaline by addition of potash. The solid, 

 which separated, was filtered, washed with water and alcohol, and finally 

 recrystallised from chloroform and alcohol. 



About 14 grams of the dimethylether were obtained. It crystallised in 

 colourless prisms, which melted at 171° C. It was insoluble in dilute alkali, 

 and its solution in alcohol gave no coloration with ferric chloride. Eijkman, 

 Bergenia, and Henrard (toe. cit.) obtained it by the action of alkali and 

 methyl iodide on diacetoresorcinol. 



The dimethylether condenses readily with benzaldehyde to form the 

 dimethylether of dihydroxy-dichalkone. 



o.o. Dihydroxy-dichalkone- dimethylether 

 Dibenzylidene-diacetoresorciiiol-dimethylethe,r. 



On addition of 1 c.c. of fifty per cent sodium hydrate to a warm solution 

 of 2 grams of diacetoresorcinol-dimethylether and 2 c.c. of benzaldehyde in 

 25 c.c. of alcohol, and on warming the mixture for a short time on the water- 

 bath, a yellow crystalline compound separated. The solid was filtered, washed 

 with dilute alcohol, dried and recrystallised from boiling benzene. The 

 yield was nearly quantitative. When dried at 105°O, the substance melted at 

 156-157 c O, and gave on analysis the following results : — 



01558 substance gave 0-4498 C0 2 and 0'0838 H 2 



corresponding to C 78'7, H 5"9 



C 26 H 22 4 requires C 78-4, H 5-53. 



Dihydroxy-dichalkone-dimethylether crystallises from benzene in light 

 yellow prisms which are insoluble in water, dilute potash, petroleum ether or 

 ligroin, scarcely soluble in cold alcohol or ether, and readily soluble in 

 chloroform. 



