Ryan and O'Nkill — Studies in the Diflavone Group. 55 



by concentrated sulphuric acid, in which they dissolved to an orange-yellow 

 solution which had a blue fluorescence. Pure diflavone which was got by 

 acting on dibenzoyraeeto-resorcinol-diniethylether with hydriodic acid is 

 coloured only a faint yellow by concentrated sulphuric acid, and its faint 

 yellow solution in the acid has a beautiful blue fluorescence. 



Dibenzoylaceto-resm-mwl-dirnsthylether. 



CO CH CO C H 

 2 6 5 



A mixture of 10 grams of diacetoresorcinol-diruethylether and 100 c.c. of 

 methyl benzoate was heated in a round flask under a reflux condenser until 

 the solid had all dissolved. The solution was cooled and 4'2 grams of sodium 

 wire were added gradually to it. When the energetic reaction had subsided 

 the mixture was heated to 120° C. in an oil-bath for fifteen minutes, and then 

 after addition of dry ether to the cold mixture it was lefrstaud in -a stoppered 

 flask for several hours. 



The sodium derivative of the diketone separated as a brownish solid. 

 The latter was disolved in water, and separated from the ethereal solution of 

 the excess of methyl benzoate. 



On addition of hydrochloric acid to the ac|ueous solution a yellow solid 

 was precipitated. The solid was filtered, washed with water and alcohol, 

 dried and reerystallised from boiling benzene. About five grams of the dike- 

 tone were obtained. When dried at 110° C. it melted at 200-201° C. and 

 gave on analysis the following results : — 



0-1971 substance gave 0-525-4 C0 3 and 0'0920 H 2 

 corresponding to C 72 - 7, H 5-2 

 C 25 H, 2 5 requires C 72-6, H 5-1. 



Dibenzoylaceto-resorcinol-dimethylether crystallises from benzene in 

 light yellow plates which are sparingly soluble in alcohol, ether, or ligroin, 

 and readily soluble in chloroform. It dissolves slowly in aqueous potash. 

 A hot alcoholic solution of the diketone develops a dark reddish-brown 

 coloration on the addition of ferric chloride. 



The crystals are turned red" by concentrated sulphuric acid in which they 

 dissolve to an orange solution. 



In attempting to convert the diketone into diflavone we experienced 

 many difficulties, due to the variable behaviour of hydriodic acid towards the 

 substance ; and it was only after numerous experiments under varvino- 

 conditions that the difficulties were finally overcome. 



While hydriodic acid 'sp. g. T5) scarcely affects the diketone, the acid of 

 specific gravity 1'7 converts the substance on short heating (1 hour) into 



K.T.A. PROC, VOL. XXXII., SECT. B. [J] 



