ETHYLBENZENE. 285 



3. Paraxylene. Prepared, like toluene, by the de- 

 composition of a mixture of parabromtoluene or para- 

 dibrombenzene, and methyl iodide with metallic 

 sodium. Colorless liquid, boiling at 136. At a low 

 temperature, solid and crystalline. Fusing point, 15. 

 Dilute nitric acid oxidizes it to paratoluic acid ; chro- 

 mic acid to terephtalic acid. 



Dibromparaxylene, C 6 H 2 Br 2 (CH 3 ) 2 , ' resembles di- 

 brommetaxylene in all its properties, and melts like 

 this at n. Tollylenebromide, C 6 H 4 (CH 2 Br) 2 , is formed 

 by the action of bromine on boiling paraxylene. Color- 

 less, lamellar crystals ; fusing point, 145-147. 



Dinitroparaxylene, C 8 H 8 (N0 2 ) 2 . Is formed by the 

 action of fuming nitric acid on paraxylene. Two iso- 

 meric modifications are produced at the same time, of 

 which the one forms long, thin needles, more difficultly 

 soluble in alcohol, fusing at 123.5 ; the other large, 

 monoclinate crystals, more easily soluble in alcohol, 

 fusing at $Z.Trinitroparaxylene, C 8 H 7 (K0 2 ) 3 . Long, 

 colorless needles. Fusing point, 137. Moderately 

 easily soluble in hot alcohol, but sparingly in cold. 



b. Ethylbenzene. 

 C 6 H 5 .CH 2 .CH 3 . 



Is obtained by the action of sodium on a mixture of 

 brombenzene and ethyl bromide, which is diluted 

 with ether. Colorless liquid, boiling at 134 ; specific 

 gravity, 0.866. Oxidized either with dilute nitric acid 

 or chromic acid, it yields benzoic acid. 



Bromethylbenzene, C 6 H 4 Br.C 2 H 5 . Colorless liquid, 

 boiling at 199. Benzene-ethyl bromide, C 6 H 5 .CH 2 . 

 CH 2 Br, and chloride, C 6 IP.CH 2 .CH 2 C1, are produced by 

 the action of bromine or chlorine on ethylbenzene with 

 the aid of heat. Liquids that cannot be distilled with- 

 out undergoing decomposition. The chloride is con- 

 verted into benzene-ethyl cyanide, C 6 H 5 .CH 2 .CH 2 .GN", by 

 boiling with potassium cyanide and alcohol. 



