BENZENE. 271 



Dibromdiphenyl, C 12 H 8 Br 2 , is produced by the ac 

 tion of bromine on diphenyl under water. Large, 

 colorless prisms, that fuse at 164, and can be distilled 

 without decomposition. Insoluble in cold alcohol, diffi 

 cultly soluble in boiling alcohol, easily in benzene. 



Dinitrodiphenyl, C 12 H 8 (N0 2 ) 2 , is formed by pour 

 ing cold fuming nitric acid on diphenyl. Fine, color 

 less needles, difficultly soluble in alcohol. Fuses at 

 213. A compound of the same composition, isodini- 

 trodiphenyl, is formed at the same time with dinitrodi- 

 phenyl ; it is more easily soluble in alcohol, and forms 

 large colorless crystals that fuse at 93.5. 



Diamidodiphenyl (Benzidine), C 2 H 8 (OTI 2 ) 2 . Is 



obtained by the reduction of dinitrodiphenyl with am 

 monium sulphide or tin and hydrochloric acid. Is 

 further formed by the treatment of the isomeric hy- 

 drazobenzene (p. 269) with acids ; by heating azoben- 

 zene with concentrated hydrochloric acid at 115; by 

 treating monobromanilin with sodium ; and, together 

 with anilin, by conducting sulphuretted hydrogen into 

 an alcoholic solution of nitrobenzene in the presence of 

 copper or lead. Colorless laminae of a silvery lustre, 

 fusing at 118, but slightly soluble in cold water, more 

 readily in hot water, and easily in alcohol. Sublimable, 

 but undergoing partial decomposition. Benzidine sul 

 phate, C 12 H 12 N 2 .H 2 S0 4 , is almost insoluble in water and 

 alcohol. 



Carbazol, C 12 H 9 ISr (probably Imidodiphenyl 

 C C H 4 \ 

 O 6 II 4 ( ^&quot;B-)* -^ s obtained as a secondary product in 



the process for the purification of crude anthracene on 

 the large scale. Can be artificially prepared by con 

 ducting the vapor of anilin or diphenylamine through 

 red-hot tubes. Crystals, that resemble those of anthra 

 cene ; fusing point, 238 ; boiling point, 338. By 

 the action ofliydriodic acid on carbazol, there is formed 

 a base carbazolin, C 12 H 15 N, that crystallizes in large, 

 white needles, fuses at 96, and boils at 286. 



