OF ARTS AND SCIENCES. 127 



does not contain a trace of phenylisocj'anide. This is further 

 shown by its behavior towards water, whereby pyruvic anilide, 



C 6 H 5 N=C 



OH 



)co, 

 en/ 



appears as the chief product, and no isonitrile is formed. The 

 imidechloride is, however, an extremely unstable substance, and 

 its preparation requires the greatest care; the phenylisocyanide 

 used must be twice distilled at reduced pressure, and even then it 

 may happen, especially if it is heated too long with the acetyl- 

 chloride, that on attempting to distil under diminished pressure 

 complete decomposition takes place. The imidechloride cannot 

 be kept long, but decomposes on standing in a desiccator into 

 phenylisocyanide and acetylchloride, the former substance at the 

 same time undergoing marked polymerization. As shown below, 

 the substance is decomposed by water into pyruvic anilide; on 

 pouring it into a small quantity of alcohol, marked evolution of 

 heat is noticed, and, on cooling, colorless leaflets of diphenyl- 

 formamidine hydrochloride (mpt. 255°) separate out. The free 

 base* obtained therefrom melts at 138°. This substance has such 

 marked properties, and was obtained so often in the work on iso- 

 nitriles, that an analysis was considered superfluous. The hydro- 

 chloride is especially characteristic; it dissolves in hot dilute 

 hydrochloric acid, and crystallizes out almost completely on cool- 

 ing (0°) in bulky hair-like needles, melting at 255°. 



Very noteworthy is the totally different behavior of the imide- 

 chloride towards water and alkalies; for whereas it reacts with the 

 former, giving pyruvic anilide, according to the equation, 



C 6 H 5 N=C C1 C 6 H 5 N=C OH 



I + H 2 == I + HC1, 



CH 3 -CO CH 3 -CO 



it is split on pouring into dilute sodic hydrate, chiefly into the 

 components, as follows: 



C 6 H 5 N=CC1 OH 



I + H 2 = C 6 H 5 NO + CH 3 CO + HC1, 

 CH3-CO 



* Hofmann, Jahresber. 1858, p. 354. 



