POLYPEPTID! 6 1 



pared in 1907 by Bergell. Starting from chloracetamide he obtained 

 chloracetonitrile by heating it with phosphoric anhydride : 



Cl . CH, . CO . NH, - H,0 + Cl . CH, . CN. 

 Dichlorodiacetamide resulted in the interaction of this compound 



with chloracetic acid, 



Cl.CHj.CN + HOOC.CH,C1-CI.CH,.CO NH OC.CHjCl, 

 and on treating it with ammonia, diglycinimide hydrochloride was 

 obtained, 



Cl.CHj.CO NH OC.CH,C1 + 3NH,= 

 NH 4 C1 + NH,.CH,.CO NH OC.CH,.NH,.HC1, 



from which the free base was prepared by means of silver oxide as a 

 crystalline substance of a basic character. 



Bergell continued his work on this substance in conjunction with 

 Feigl. Diglycinimide was stable to acids and to the weak alkalies, 

 magnesia and sodium bicarbonate, but it was converted by caustic 

 alkalies and by baryta into ammonia and an acid of the constitution 



XHj.COOH 

 NH/ 



\CH,.COOH 



which was identical with iminp diacetic acid, prepared in 1862 by 

 Heintz. Its formation probably took place through the intermediate 

 ring compound, 



/CO CH, V 



NH/ J>NH. 



\CO CH,/ 



Diglycinimide did not give rise to ammonia and glycine as was 

 expected ; but its benzoyl derivative was converted on hydrolysis into 

 hippuric acid, ammonia and glycine : 



C 6 H B . CO . NH . CH, . CO NH OC . CH, . NH, + aH,O = 

 C,H 8 . CO . NH . CH, . COOH + NH S + HOOC . CH, . NH* 



In order to introduce another glycyl residue into diglycinimide, the 

 chloracetyl derivative was prepared, from which by the action of am- 

 monia glycyl-diglycinimide, 



NH,. CH, . CO . NH . CH, . CO NH OC . CH, . NH^ 



did not result ; but ammonia was lost and a compound probably of 

 the formula 



CH, . CO . NH , CH, . CO NH OC . CH, . NH 



was obtained. 



The homologous alanyl glycine imide, 



CH, . CH . (NHJCO NH CO . CH, . NH* 



was obtained by the action of ammonia at a low temperature upon 



