4 



Dr. Hofmann on Kinone, 



[Nov. 19, 



IV. Note on Kinone/' By A. W. Hofmann, LL.D., F.R.S. 



Received June 23, 1863. 



The easy and perfect transformation of beta-plienylene-diamine into 

 kinone, which I have pointed out in a former communication, has induced 

 me to examine the action of oxidizing agents upon other derivatives of the 

 phenyl-series. 



Aniline, when submitted to the action of a mixture of peroxide of man- 

 ganese and sulphuric acid, furnishes very appreciable quantities of kinone, 

 which sublimes, the residue containing the sulphates of ammonium and 

 manganese. 



C^H^ + 0,=CeH^, + H3 N. 



Aniline. Kinone. 



This equation represents, however, only one phase of the reaction. The 

 result, in a measure, depends upon the mode of experimenting : one part 

 of aniline, four parts of peroxide of manganese, and four parts of sulphuric 

 acid diluted with its own bulk of water were found to be appropriate pro- 

 portions. But the amount of kinone is always limited, the greater portion 

 of the aniline undergoing further alterations. 



The experiment succeeds much better with benzidine. On heating the 

 mixture of this base with the oxidizing agents, torrents of kinone are in- 

 stantaneously evolved, which condense in the receiver into magnificent 

 yellow needles. The quantity of kinone thus obtained corresponds to the 

 amount of benzidine employed. 



C,,H,,N, + H,Q + 03=2 C^H^,+ 2 H3 N. 



Benzidine. Kinone. 



The transformation of aniline into kinone, very naturally suggested the idea 

 of examining the behaviour of these two bodies with one another. 



The reddish-brown liquid obtained by dissolving kinone in aniline very 

 rapidly solidifies into a crystalline mass. The crystalline product of the 

 reaction proved to be insoluble in water, alcohol, and ether, and several 

 solvents which I tried, so that purification by crystallization became im- 

 possible ; it was therefore found to be convenient to accomplish the re- 

 action in the presence of a large quantity of boiling alcohol. The brown 

 liquid deposits on cooling reddish brown almost metal-lustrous scales, 

 which by washing with cold alcohol become perfectly pure. 



The analysis of this substance shows that it has the following com- 

 position : — 



(Cell,), ] 



c,3H,,N,o=(cji,o,y' In,. 



H2 J 



The complementary product of the reaction was discovered without dif- 

 ficulty in the mother-liquor of the reddish-brown crystals. The saline 



