Ryan and Duvink — Condensation of Aldehydes -with Ketones. 21 1 



ketone and aldehyde interacting slowly at the ordinary temperature, when 

 dissolved in alcoholic hydrochloric acid, to form the compound C25H20O. 



Piperonal and methylethylketone interacted under similar conditions to 

 form an analogously constituted piperonal derivative of methylethylketone. 



The preparation of the compound G J5 H a ,0 from methylethylketone, 

 a-benzylidene-methylethylketone and the compound Ci 8 Hi 8 02 may be repre- 

 sented by the equations : — 



CH 3 . CO . CfJU . OH, + 3C 6 H 5 . CHO = G»H»0 + 3H 2 



C 6 H 5 . CH : CH . CO . CH 2 . CH 3 + 2C 5 H 5 . CHO = C 2i H 2(1 + 2H 2 



C ls H 16 2 + C 5 H 6 . CHO = C 25 H 20 O + 2H 2 



The unsaturated nature of the compound C25EU0O was shown by the 

 formation of a dibromide C2 5 H2oOBr 2 ; but we were unable to establish the 

 presence of a keto radical in the substance, since the latter formed neither an 

 oxime nor a phenyl-hydrazone. 



Empirically the substance corresponds to a tribenzylidene derivative of 

 methylethylketone 



C 6 H 5 . CH : CH . CO. C. CH : CH . C 6 H 5 

 II 

 CH . C 6 H 5 ; 



but as it is difficult to see how such a- compound can be formed by normal 



reactions from benzaldehyde and methylethylketone, we shall postpone the 



consideration of its structure until further experimental facts have been 



accumulated, 



EXPEEDIENTAL PAJRT. 



A. Action of Benzaldehyde on Methylethylketone in the Presence of Alkali. 

 1. Equimolecidar Quantities of Benzaldehyde and Methylethylketone. 



A mixture of 130 grams of methylethylketone, and 140 grams of benzal- 

 dehyde, with a solution of 50 grams of sodium hydroxide in 1500 c.cs. of water, 

 was shaken on a machine for eight days. The oil which separated was 

 extracted with ether, and after evaporation of the latter the residue was 

 distilled in a current of steam. When the benzaldehyde ceased coming over, 

 the residue in the flask was subjected to further distillation in a current of 

 steam, previously heated in a coil to 180 c C, while the flask from which 

 the distillation was being conducted was heated to 180° C. in an oil-bath. 



The oil which now distilled solidified after short standing, and the solid, 

 when recrystallized from petroleum ether, melted at 3S°-39° C. 



Towards the end of the operation the distillate contained a small cp.iantity 

 of another compound which melted at 81°-83° C. 



a-Benzylidene-methylethylketonc crystallizes from petroleum ether in large 



