178 Proceedings of the Royal Irish Academy. 



Dibenzylidene-diflavanone crystallizes from ligroi'n in almost colourless 

 needles, which are insoluble in water or dilute potash, scarcely soluble in 

 alcohol, ether, or ligroi'n, and readily soluble in warm chloroform. 



The crystals are coloured dark-red by concentrated sulphuric acid, in 

 which they dissolve to a cherry-red solution. 



7. Dvpiperonylidene-3' '. £ '. 3'. ^.' .-dimethylenedioxy-diflavoMone. 



^Ov. ^CH ^Ov. 



HC=0=CHCH C ^C CHCH=0=CH 



2 2 63 J || VI | | 6S * 2 



HC-OrCHCH:C C ^C C:CHCH=Q=CH 



Diacetoresorcinol (5 grammes) and piperonal (20 grammes) were dissolved 

 in a hot mixture of alcohol (200 cc.s.). Anhydrous hydrochloric acid was 

 passed into the solution until the latter was saturated with the gas. The 

 mixture was let stand in a stoppered flask for several days. The solid which 

 separated was filtered and washed with alcohol. By warming the yellow 

 product with chloroform it was separated into a more soluble yellow part and 

 a sparingly soluble much lighter-coloured one. The more soluble compound 

 was formed by the condensation of three molecules of piperonal with one 

 molecule of diacetoresorcinol and the less soluble by the condensation of four 

 molecules of piperonal with one of the ketone. When the latter was 

 recrystallized from boiling xylene, in which it was sparingly soluble, it melted 

 at 289° C, and gave on analysis the following results : — 



0T499 substance gave 0'3814 C0 2 and 0-0476 H 2 

 corresponding to C 69 - 4, H 3 - 56. 

 C„ H 26 0„ requires C 69.78 H 3-63. 



Dipiperonylideiie-dimethylenedioxy-diflavanone crystallizes from xylene in light 

 yellow prisms, which are scarcely soluble in alcohol, ether, ligroi'n, or benzene, 

 and sparingly soluble in boiling xylene or chloroform. 



The crystals are coloured deep blue by concentrated sulphuric acid, in 

 which they dissolve to a violet solution. 



No coloration was observed when ferric chloride was added to a suspension 

 of the substance in boiling alcohol. 



8. Piperonylidene-3. aceto-jfr. hydroxy- ho-c^ CH ^~c^°~^ch ch o c 



pipcronylidcac-1' . //->/„ f I, ykncdio.vy-fla- ch^ch c^cH-coi J ™ [chchVch 

 vpnone. 2 2 ej ^ch^-co^ 



The yellow more soluble compound obtained during the preparation of 

 dipiperonylidene-dimethylenedioxy-diflavanone was dissolved in hot chloro- 



