Synthetical Researches on the Hydrocarbons. 507 



toluole, € 12 H 16 ' (NO 2 ) 2 . Oxidized with chromic acid, amyl- 

 toluole yields acetic acid and terephthalic acid, G 8 H 6 O 4 . 

 The same chemists have also prepared amylxylole, 



[G H 3 

 lG 5 R n 



Fittig and Konig have investigated the action of oxidation on 

 ethylbenzole, € 6 H 5 (G 2 H 5 ), which is isomeric with xylole, and 



of diethylbenzole, G 6 H 4 < p 2 tjs- The former, by chromic acid 



and also by nitric acid, yields benzoic acid, whereby it is distin- 

 guished from xylole ; the latter, when oxidized by chromic acid, 

 yields terephthalic acid, 



g6h4 {Sh^ +120=GSH4 {go'h +2G02+4H2 ° ; 



Diethylbenzole. Terephthalic acid. 



while if nitric acid be used, the action only extends to one atom 

 of ethyle, and there is formed a new acid which is isomeric with 

 xylylic acid, 



€ 6 H 4 |^5 + 60=€ 6 H 4 |^f25+ G ° 2 + 2H2G - 



Diethylbenzole. New acid. 



This new acid, which Fittig and Konig call ethylbenzoic acid, 

 crystallizes in laminse which melt at 110° C. 



Under the direction of Fittig*, Ahrens and Mattheides have 

 made an extensive series of comparative experiments on the de- 

 rivatives from the xylole of coal-tar and those from methyl- 

 toluole. The result of these investigations has shown that in 

 the nitro-compounds more especially there is a great difference, 

 and that this difference extends to the bases which result from 

 these nitro-compounds by reduction. The dibromo-compounds, 

 too, which have the same formula, G 8 H 8 Br 2 , exhibit a small 

 but distinct difference in fusing-point. When treated with oxi- 

 dizing agents, both yield identically the same products : — with 

 dilute nitric acid,toluylic acid; and with chromic acid, terephthalic 

 acid. It would seem that the difference of the two hydrocarbons 

 only appears when other bodies are substituted for the hydrogen. 



Fittig has described another hydrocarbon which is isomeric 

 with xylole. Mesitylenic acid, described below (p. 510), exhibits 

 the greatest analogy with benzoic acid, with which it is homolo- 

 gous. When mixed with three times its weight of caustic lime and 



* Zeitschrift fur Chemie, vol. iii. p. 523. 

 2L2 



