62 Proceedings of the Royal Irish Academy. 



Experimental Part. 

 Condensation of Benmldehyde with Dimethyl-acetylacetone. 



Benzaldehyde (45 c.c) was added to dimethyl-acetylacetone (10 c.c.) and 

 the mixture was saturated at a low temperature with gaseous hydrochloric 

 acid. The flask was tightly stoppered and allowed to stand at C C. for four 

 days. A reddish crystalline mass formed which on exposure to the air 

 became nearly colourless owing to loss of hydrochloric acid. It was washed 

 with absolute alcohol, and on recrystallisation from a mixture of chloroform 

 and alcohol about 20 grams of the condensation product were obtained- 

 It contained chlorine, and crystallised in colourless prisms which turned 

 slightly red at 14S° C, and melted with decomposition at 170 : C. 



Analyses : — 



0-2841 substance gave 0-7990CO, and 04522HA 



0-1858 „ „ 0-5236CO, „ 04018HA 



corresponding to C 76-7 H 5 - 9, 



C76-9 H6-1. 



0.-.H :3 OXl requires C 76-9 H5-9. 



The chlorinated product was boiled with pyridine for 3 hours under a 

 reflux condenser, and the solvent was then distilled. The residue was 

 dissolved in chloroform, washed with dilute hydrochloric acid, and the 

 residue was filtered through a dry filter. On addition of alcohol to the 

 filtrate, about 16 grams of colourless crystals were obtained. The product 

 was free from chlorine, melted at 16S-169-5°C, and gave on analysis 

 the following results : — 



0-3596 substance gave 11128CO, and 0-2114H.O, 

 0-2398 0-7415 CO, „ 01397HA 



0-2368 0-7323CO : 01394H 2 O, 



corresponding to C 844 H 6 - 6, 



C 84-3 H 6-5, 



C 84-3 H 6-6. 



C^H^O, requires C847 H61 



a-a.'-Diphenyl-ii-methyl-fi'-beniylidtne-tetrahydro-'Y-j)yrone crystallises in 

 colourless prisms, which are sparingly soluble in alcohol or ligroin, and 

 easily soluble in chloroform or ether. It is insoluble in alkali, and under- 

 goes no change on boiling for several hours with either dilute or concentrated 

 potash. Its solution in alcohol gives no coloration with ferric chloride. In 

 concentrated sulphuric acid the crystals are coloured orange, and dissolve to 

 a yellow solution. 



