M. Saytzeff on Anisic Acid. Ill 



The bromine in the acid may be replaced by hydrogen, by 

 adding sodium-amalgam to its aqueous solution. 



C l8 H 8 Br 2 O 4 + 2Na + 2H = C ,8 H 10 O 4 +2NaBr. 



Bibromocinnamic New acid, 



acid. 



To the product of the action, dilute sulphuric acid is added 

 until a distinct acid reaction is set up ; a compact mass of crys- 

 talline structure separates out after continued standing, which, 

 when recrystallized, forms large lustrous needles. This new 

 acid has an intensely acid taste, is insoluble in water, but 

 readily so in alcohol and ether. At a gentle heat it melts 

 readily to a colourless liquid, which forms, on cooling, a crystal- 

 line mass. From the formula of this new acid, C 18 H 10 O 4 , it is 

 either the missing link between toluic and cuminic acids in the 

 benzoic acid series, or it is isomeric with this acid. Schmitt 

 assigns to it the name cymolic acid, as the corresponding hydro- 

 carbon bears the name cymole. 



Anteriorly to the publication of Schmitt's paper, Erlenmeyer, 

 led by theoretical considerations as to its constitution, had inves- 

 tigated* the action of nascent hydrogen on cinnamic acid. To 

 an aqueous solution of cinnamic acid a large excess of sodium- 

 amalgam was added ; and after the action was over, hydrochloric 

 acid in excess was added, whereby a substance was separated in 

 clear drops which solidified on agitation. This was an acid, and 

 was converted into the ether by passing hydrochloric acid gas 

 through its alcoholic solution. The ether thus obtained was 

 found to boil at 243°, and had the composition € u H 14 2 ; from 

 which it follows that the composition of the acid is € 9 H 10 O 2 , 

 and is thus isomeric and probably identical with Schniitt's acid. 

 Erlenmeyer assigns to it the name homotoluic acid; and is en- 

 gaged on a further investigation of its derivatives. 



Saytzeff has investigated the action of hydriodic acid on anisic 

 acidf. When anisic acid is heated with hydriodic acid in a closed 

 tube at 125° to 130° C. for twelve to sixteen hours, the decom- 

 position is tolerably complete ; a quantity of iodide of methyle 

 is formed, which on opening the tube can be distilled off in the 

 water-bath. 



When the residue in the tube, after expelling the iodide of 

 methyle, is heated in an open porcelain dish in order to get rid 

 of excess of hydriodic acid, a strongly coloured acid crystallizes 

 out, on cooling, which, by treatment with animal charcoal and 

 recrystallization, can be obtained colourless. 



The acid forms monoklinometric prisms, which are easily 



* Liebig's Annalen, vol. cxxi. p. 376. f Ibid. August 1863. 



