1867,] Aromatic Monamines into Acids richer in Carhon, 337 



odour, recalling that of benzoiiitrile, and exhibits an inclination to crys- 

 tallize ; it is readily proved to be a mixture. If this substance be boiled 

 for some time with a concentrated soda-solution in alcohol, it partly 

 dissolves with evolution of ammonia. When the fluid is allowed to cool, 

 after ammonia has ceased to be evolved and the alcohol distilled ofiP, its 

 surface is found to be covered with oily drops, which after a time become a 

 crystalline solid. This solidification is instantly produced by treating the 

 oil with a sm.all quantity of concentrated hydrochloric acid. When a few 

 drops of strong nitric acid are added to the hydrochloric fluid in which the 

 crystals are floating, and the mixture is then gently heated, a deep blue 

 colour is produced. This reaction is characteristic of diphenylamine, with 

 which the crystalline body perfectly accords in every respect. It cannot 

 be doubted that diphenylamine is produced from phenylformamide as a 

 product complementary to hydrocyanic acid ; 1 molecule of phenylform- 

 amide and 1 molecule of aniline contain the elements of 1 molecule of 

 diphenylamine, 1 molecule of hydrocyanic acid, and 1 molecule of water. 

 CHOI C.H^] C,H,] 



C3H, In+ h In = c,H, In + chn + h,o. 



H J ^ HI H J 



It still remains to give an account of the fluid substance formed together 

 with diphenylamine, which had disappeared with evolution of ammonia 

 when the mixture was heated with soda-solution. Had not both its odour 

 and its behaviour with soda pointed to henzonitrile, all doubt of the for- 

 mation of this body would have been removed, when upon addition of 

 hydrochloric acid to the filtered sodic liquid an abundant quantity of the 

 purest benzoic acid was separated, the nature of which was, moreover, fixed 

 by an analysis of the silver-salt. 



The formation of henzonitrile is easily explained. It is produced by a 

 secondary transformation of phenylformamide, from which 1 molecule of 

 water separates, 



CHOI 



In ^ C.H.N + H,0. 

 H J 



The transition of phenylformamide into henzonitrile is only in part 

 accomplished during the distillation of the mixture of aniline and oxalic 

 acid. The greater portion of the nitrile is evidently formed during the 

 treatment of the crude product of the distillation with hydrochloric acid. 



The conversion of anihne into benzoic acid, an acid richer in carbon than 

 this base, claims some interest, inasmuch as the development of the 

 manufacture of coal-tar colours places the aromatic monamines at our 

 disposal in abundant quantity, and at the cheapest price. It was by no 

 means improbable that some of the acids, already known, might in this 

 manner be more easily prepared than heretofore, nor was it doubtful that 

 the formation of many new compounds could be accomplished by this 

 process. 



2 E 2 



