Ryan and O'Neill — Studies in the Diflavone Group. 177 



either zinc chloride or aluminium chloride into dibenzylidene-diacetoresorcinol, 

 we thought it necessary to examine the compound in detail. 



The melting-point of a mixture of resorcinol-dicinnamate (MP 122-124°C.) 

 and cinnamic anhydride (MP 135° C.) was indefinite, lying between 110° and 

 130° C. 



We hydrolysed the substance by heating it on the water-bath with 

 moderately concentrated potash. The alkaline solution was acidified, cooled, 

 and filtered from the separated cinnamic acid. The filtrate was neutralised 

 with sodium bicarbonate, and extracted with ether. When the residue, which 

 was left on evaporating the ether, was dissolved in water, it gave a dark 

 violet coloration with ferric chloride indicating the presence of resorcinol. 



Eesorcinol-dicinnamate was heated to 140° C. with one-fourth of its 

 weight of anhydrous zinc chloride for half an hour, but from the tarry 

 product of the reaction no dibenzylidene-diacetoresorcinol could be isolated. 

 Variations in the quantity of zinc chloride and in the length of heating did 

 not enable us to prepare the desired compound. 



Similarly by heating resorcinol-dicinnamate in xylene solution with 

 anhydrous aluminium chloride, we did not succeed in converting the ester 

 into dibenzylidene-diacetoresorcinol. 



B. Condensation of Hydroxy-ketones with Aldehydes in the Presence of 



Hydrochloric Acid. 



6. Bibenzylidene-diftavanone. ss \ II "V" | 



CHCH:C C JE 



A mixture of 5 grammes of diacetoresorcinol, 25 ccs. of benzyaldehyde, 

 and 200 ccs. of alcohol on saturating with anhydrous hydrochloric acid 

 became hot, and turned a red colour as the diacetoresorcinol dissolved. The 

 solution was cooled, again saturated with hydrochloric acid, and then let stand 

 in a stoppered flask for a week. It was heated on the water-bath for a short 

 time, cooled, and filtered. The brown residue was dissolved in chloroform, and 

 the solution after washing with dilute potash was filtered. The chloroform 

 solution was concentrated, mixed with an equal volume of alcohol, and let 

 stand in a dish. The solid which separated was recrystallized a few times 

 from boiling ligroin. 



When dried at 110° C, it melted at 268° C, and gave on analysis the 

 following results : — 



0-2765 substance gave 0-8450CO, and 01254H,O, 

 corresponding to C 83'4 H 5 - 0, 



C 38 H 2( A requires C83'5 H4-8. 



[2 02] 



