M. Friedel on the Synthesis of Acetone, 535 



€3H 4 + H* = G 3 H 6 0. 



Allylic alcohol. 



€ 3 H 4 + 2H 2 = G 3 H 8 9. 



Propylic alcohol. 



2G 3 H 4 9 + H 2 = G 6 H 10 9 2 . * 

 Acropinakone. 



Linnemann* has also found that pinakone exists in two iso- 

 meric modifications — a liquid one, which boils at 176° or 177°, 

 and dissolves in water, from which it soon separates as a crystal- 

 line hydrate ; the solid pinakone is a snow-white crystalline mass 

 which melts at 35° to 38°, gradually softening first, and boils at 

 171° to 172°. The distillate is a colourless thickish liquid, 

 which soon solidifies. Both these modifications unite with water 

 and form one and the same hydrate, G 6 H 4 9 2 + 6 Aq ; pinakone 

 forms besides, as Fittig has shown, several hydrates. 



Freund found some time agof that the synthesis of acetone 

 could be effected by the action of chloride of acetyle on zinc- 

 methyle; thus 



Zn ''GH 3 } + 2G 2 H 3 9Cl = Zn"Cl 2 + 2G 3 H 6 9. 



„. Chloride of Chloride Acetone. 



Zinc- ,t o ■ 



methyle. acet y le ' ofzmc ' 



Friedel J has now found that the synthesis of acetone can also 

 be accomplished by another reaction, in which he makes use of 

 chloracetene, G 2 H 3 CI, the interesting body obtained by Harnitz- 

 Harnitzsky§, by the action of phosgene gas on aldehyde. When 

 this substance acts upon methylate of sodium, chloride of sodium 

 is formed and acetone ; thus, 



G 2 H 3 C1 + G H 3 Na 9=NaCl + G 3 H 6 9. 

 A quantity of sodium corresponding to the chloracetene was dis- 

 solved in methylic alcohol and the excess evaporated. On gra- 

 dually adding chloracetene to the mixture, kept cool, a brisk 

 reaction was established, chloride of sodium was formed, and, 

 when the mass was distilled, a distillate was obtained consisting 

 of acetone mixed with a little methylic alcohol. As the boiling- 

 points of the two liquids are very close, separation could not be 

 effected by fractional distillation, and the mixture was accord- 

 ingly treated by permanganate of potash, by which methylic 

 alcohol is oxidized very much more readily than acetone. In this 



* Liebig's Annalen, (Suppl. 3) vol. iii. part 3. 

 t Phil. Mag. S. 4. vol. xx. p. 201. 

 X Comptes Rendus, May 1, 1865. 

 § Phil. Mag. S. 4. vol. xvii. p. 430. 



