1872.] 



History of the Ethylene Bases. 



429 



was not unlikely to be generated from ethylenediamine sulphocyanhydrate 

 by atomic interchange within the molecule. 



Ethylenediamine sulphocyanhydrate. — I first endeavoured to prepare 

 this salt by decomposing the chlorhydrate with silver sulphocyanide, 

 but no action takes place between the two salts even under pressure. It 

 can, however, be readily obtained by saturating free sulphocyanhydric acid 

 with ethylenediamine. The compound crystallizes in large transparent 

 prisms which soon become opaque. The crystals, which are anhydrous, are 

 exceedingly soluble in water, somewhat less so, but still very soluble, in 

 alcohol, insoluble in ether. The formula 



C 4 H 10 N 4 S 2 =(C 2 H 4 ) H 4 N 2 , (HCNS) 2 

 was verified by the analysis of the substance dried at 100°. 



On heating the sulphocyanhydrate, it immediately undergoes profound 

 decomposition. Even below its melting-point, which lies at 145°, the salt 

 becomes changed into the ethylene sulpho-urea already described, am- 

 monium sulphocyanide being simultaneously separated. 



(C 2 HJ H 4 N a , (HCNS) 2 = (CS)(C 2 H 4 ) H 2 N 2 +H 3 N, HCNS. 



This transformation is perfectly analogous to that which, as I pointed 

 out many years ago*, aniline sulphocyanhydrate undergoes under the 

 influence of heat when it is changed into sulphocarbanilide and ammonium 

 sulphocyanide. No indication of the formation of a mustard-oil could be 

 observed. I must not leave unmentioned that experiments made in my 

 laboratory by M. Jul. Strakosch, with the view of preparing the mustard- 

 oil of benzidine, have had no better results. New methods, then, must be 

 sought for the production of the mustard-oils corresponding to diamines. 



2. Ethylenediamides. 



In order to complete the history of ethylenediamine I may here be allowed 

 to append some further observations, partly new and partly old, which have 

 not yet been published. 



Action of benzoyl chloride on ethylenediamine. — The reaction, which is 

 a very energetic one, takes place precisely in the manner indicated by 

 theory. The hot liquid solidifies on cooling to a crystalline mixture of 

 ethylenediamine chlorhydrate, and a new compound to which the name 

 ethylene dibenzoyldiamide belongs. After washing away the ethylene- 

 diamine salt, the residue only requires to be crystallized once or twice from 

 alcohol in order to obtain it in fine needles of perfect purity. These 

 dissolve very sparingly in cold, more readily in boiling alcohol, but are 

 insoluble in water. The composition of the new substance is 



C 10 H I8 N a O=(C,H s O) 2 N 2 ; 



it is formed according to the equation 



2[(C, HJ H 4 N 2 ] + 2C, H, O Cl= (C, H 4 ) (C, H, 0), II., N. + 

 (C 2 H. 1 )II 1 N 2 ,(IIC1) 2 . 

 * Ann. Chem. Pharm. vol. lxx. p. 143. 



2 i 2 



