110 Dr. A. W. Hofmann on the Aromatic Cyanates. [Nov. 24, 



density was determined in aniline vapour. The numbers obtained con- 

 firmed the formula already established by analysis. 



C 7 H B NO=C° H jN. 



Theory. Expt. 



Specific gravity of vapour compared with hydrogen 59*50 58*90 



„ „ „ compared with air 4*13 4*09 



With respect to the behaviour of the body with other substances, I 

 can refer to my former paper. With water it yields carbonic acid and 

 diphenylcarbamide ; in contact with alcohol the urethane is reproduced ; 

 it combines immediately with ammonia and its derivatives, forming an 

 inconceivable number of ureas. But, besides other combinations, it ex- 

 hibits a remarkable reaction. I may mention that the possession of a 

 considerable quantity of phenylic cyanate has given me an opportunity 

 of again observing the behaviour of this body towards triethylphosphine, 

 formerly described*. If a glass rod, moistened with the phosphorus 

 base, be dipped into a considerable quantity of phenylic cyanate, in a few 

 moments it becomes very hot, and the whole solidifies to a mass of beau- 

 tiful crystals. 



The principal product formed in this reaction is a body insoluble in 

 water, and not very soluble in boiling alcohol, from which it crystallizes on 

 cooling in fine prisms, which in an analysis formerly published gave 

 numbers corresponding to cyanurate of phenyl, and may therefore be re- 

 garded as phenylic cyanurate. I must, however, leave it an open question, 

 whether this substance is identical with the phenylic cyanurates, obtained 

 the one by the action of chloride of cyanogen on phenolf , the other from 

 triphenylmelamine 



Now that the necessary material can be obtained, there is no difficulty 

 in a complete investigation of this body, as well as the by-products formed 

 by the reaction in question. 



We may here find room for some observations on the homologues of the 

 phenylic cyanurate. 



Tolyl Series. 



Tolylur ethane. — Chlorocarbonic ether acts with the greatest violence on 

 toluidine, so that it is advisable to conduct the reaction in the presence qj 

 ether. 



c!h! }0 + 2 [^;}x] = C ° ^ }0 + *gr} N, HC. 



The ethereal solution, filtered from the toluidine hydrochlorate, on evapora- 

 tion leaves the tolylurethane as an aromatic oil, which, when cooled by a 



* Hofmann, Ann. Chem. Pharm. Suppl. vol. i. p. 57. 



t Hofmann, Berichte Deutsch. Chem. Gresell. Jahrg. iii. S. 275. 



% Hofmann, Berichte Deutsch. Chem. Gresell. Jahrg. iii. S. 274. 



