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 ethylbenzoic acid and terephtalic 

 acid. 



d. Cymene (Parapropylmethylbenzene). 

 CH 3 

 C 3 H 7 . 



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 n H 16 = C 6 H 5 (C 5 H n ) = C 6 H 5 .CH 2 CH 2 .CH(CH 3 ) 2 . 



Is prepared like ethylbenzene. Liquid, that boils at 

 193. When oxidized, it yields benzoic acid. 



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

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

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