SYNTHETICAL EESEAECHES ON ETHEES. 66 



action of zinc ethyl upon propionyl chloride. This body boils at 101° C. like ethylated 

 acetone, but, unlike the latter, does not form a crystalline compound with sodium bi- 

 sulphite. The origin of Moeley's propione*, obtained by the distillation of barium 

 propionate, renders its identity with ethyl-propionyl almost certain. Its boiling-point, 

 100° C, is nearly the same, and, like ethyl-propionyl, it also, as Fbeund has proved, 

 refuses to form a crystalline compound with sodium bisulphite. 



There are still two other compounds of this formula which have been sometimes 

 classed as ketones, but respecting which evidence is still wanting as to whether they 

 belong to the ketone or aldehyde family. These are Limpricht and Uslar's propione f, 

 which boils at 110° C, and methyl-butyral J, which boils at 111° C. The first forms a 

 crystalline compound with sodium bisulphite, but it is not known whether or not it 

 reduces ammoniacal solution of silver oxide. The behaviour of the second with either 

 of these reagents is unknown. 



The seven-carbon ketones to which diethylatcd acetone belongs, are capable of more 

 numerous modifications, of which however only two are known, viz. — 



T, , fCEtH, 



Diethylated acetone ... -I 



CEt2H 

 CMeO 



The isomerism of these bodies is evident from their origin, and from the difference of 6° 

 in their boiling-points, butyrone boiling at 144° C, whilst diethylated acetone boils at 

 137°-139°C. The rise in boiling-point by the successive replacement of the hydrogen of 

 methyl by alcohol radicals affords a valuable clue to the constitution of numerous organic 

 compounds, and attention has recently been called to this subject by Kolbe§, who has 

 shown that the successive replacement by alcohol radicals of the three atoms of hydrogen 

 in ammonia and in the methyl of methylic alcohol is attended with very different results 



as regards elevation of boiling-point ; thus the addition of C H, to aniline N< H j 



\ I H / 



/ [ ^7 HyX 



with the production of toluidine j^< H j raises the boiling-point about 19° C. ; but 



\ I H / 



if the addition of C Hg to aniline converts the latter into methyl-aniline I N< C H3 j, then 



\ I H / 

 the boiling-point rises only 10°, whilst the replacement of the third atom of hydrogen 

 appears to be attended with a rise of only about 5° C. This observation, so far as the 

 existence of the difference described is concerned, receives considerable support from 



* Ann. der Ch. und Pharm. Ixxviii. 187. t Ibid. xciv. 327. 



+ Ibid. lii. 295. § Ibid, cxxxii. 112. 



