52 



JIESSES. E. PEANEIiAND AND B. T. DUPPA'S 



In fact it was evident that the liquid with which we had now to do was the exact 

 counterpart of the one obtained in the corresponding reaction with ethyl iodide 

 described above, and that it consisted of the homologues produced in the ethylic reac- 

 tion, viz. ethylic methacetone carbonate and ethylic dimethacetone carbonate. To sepa- 

 rate these compounds, whose boiling-points were evidently nearly if not absolutely 

 identical, we availed ourselves of their different behaviour with boiling aqueous potash ; 

 ethylic dimethacetone carbonate, like ethylic diethacetone carbonate, being scarcely 

 affected by this treatment, whilst ethylic methacetone carbonate, like its ethylic homo- 

 logue, is rapidly decomposed. By thus boiling several ounces of the mixed ethers with 

 aqueous potash, a liquid was obtained which, by repeated rectification, was separated 

 into two products, the one boiling at about 80° C, and the other constantly at 184° C. 

 The latter was submitted to analysis, and yielded the following results : — 



I. '2001 grm. gave •4435 grm. carbonic acid and "1598 grm. water. 

 II. '1647 grm. gave -3652 grm. carbonic acid and -1317 grm. water. 



III. '3040 grm. gave "6728 grm. carbonic acid and •2399 grm. water. 



IV. ^2739 grm. gave •6052 grm. carbonic acid and •2218 grm. water. 

 V. ^331 9 grm. gave ^7388 grm. carbonic acid and "2721 grm. water. 



VI. -2548 grm. gave -5686 grm. carbonic acid and -2075 grm. water. 



These numbers approximate closely to those required by the formula of ethylic 



dimethacetone carbonate, 



IT 



q_ 



O 

 OQH. 



C4 



as shown by the following comparison :- 



Calcidated. 

 . y^ 



H 



14 



96 

 14 



48 



158 



60^76 



8^86 



30^38 



100-00 



Found. 

 ^ 



I. 



60-45 



8^87 



II. 



60-47 

 8-88 



III. 

 60-36 



8-77 



IV. 

 60-26 

 9-00 



V. 

 60-71 

 9^11 



VI. 



60-86 

 9-05 



Mean. 



60-52 

 8-95 



The production of ethylic dimethacetone carbonate from acetic ether is explained by 

 the following equations : — 



fH, 



2CJo +Na,=C4 



iOC^Hs 



■^^ — — 



Acetic ether. 



E3 



Naa 

 O 



+ C2H5OH+H, 



Alcohol. 



