PARADIETHYLBENZENE, ETC. 289 



c. Paradiethylbenzene. 

 C 6 H 4 (C 2 H 5 ) 2 . 



Is obtained by the decomposition of a mixture of 

 bromethylbenzene and ethyl bromide with sodium. 

 Colorless liquid; boiling point, 178-179. Subjected 

 to oxidation, it yields efhylbenzoic acid and terephtalic 

 acid. 



d. Cymene (Parapropylmethylbenzene). 



C 3 IF. 



Is contained in the oil of Roman cumin (the vola 

 tile oil of the seed of Cuminum cyminum), and sev 

 eral other volatile vegetable oils. Is produced to 

 gether with toluene, xylene, mesitylene, and other 

 hydrocarbons by the distillation of camphor over zinc 

 chloride or phosphoric anhydride; terpine (which see), 

 heated with bromine, loses water and hydrogen, and is 

 converted into cymene. Can be most readily ob 

 tained in a pure condition by gently heating camphor 

 with phosphorus pentasulphide. Liquid, that boils at 

 178. When oxidized, it yields toluic and terephtalic 

 acids. 



e. Isobutylbenzene. 

 C 6 H 5 .C 4 H 9 . 



Is obtained in the same way as ethylbenzene. Colorless 

 liquid, boiling at 159-161. Yields benzoic acid by 

 oxidation. 



6. Hydrocarbons containing a larger number of Carbon- 

 atoms. 



Amylbenzene. 

 C 11 !! 16 = C 6 H 5 (C 5 H U ) = C 6 II 5 .CII 2 CH 2 .CII(CH 3 ) 2 . 



Is prepared like ethylbenzene. Liquid, that boils at 

 193. When oxidized, it yields benzoic acid. 



An isomeric amylbenzene (dicthylized toluene), C 6 I1 5 . 

 CII(C 2 II 5 ) 2 , is produced by the action of zinc ethyl on 



