in ON THE SYNTHESIS OF ALBUMINS 121 



up chains of amino-acids, as by the action of acid-chlorides or acid- 

 azides, the acid radical enters the more strongly basic amino-group, 

 while the hydrazin-remainder is preserved as such, and the azide of 

 the resulting product is at once ready to unite with other amino- 

 acids. 



In addition to glycocoll Curtius has also coupled other amino-acids 

 (such as alanin, aspartic acid, amino-butyric acid) by means of his 

 azide-method. Thus, along with Lambotte, he first condensed hippur- 

 azide with alanin, and then adding other alanyl-remainders obtained 

 hippuryl-dialanyl-alanin : 



C 6 H 5 CO NH . CH 2 CO . (NHCH(CH 3 )CO) 2 . NHCH(CH 3 )COOH. 



To remove the glycin remainder derived from the hippurazid, and thus 

 to obtain glycyl-free alanyl-chains Curtius and Linden used Emil 

 Fischer's benzoyl-alanin : C 6 H 5 CO . NHCH(CH 3 )COOH ; and they 

 also added two glycin-remainders to benzoyl-alanin, and obtained thus 

 benzoylalanyl-glycyl-glycin 



C 6 H 5 CO NHCH(CH 3 )CO NHCH 2 CO NHCH 2 COOH. 



Curtius senior with Hans Curtius have obtained from aspartic acid, by 

 substituting for the Schotten-Baumann's reaction, the interaction of an 

 azide and an ammo-acid-ester dissolved in an indifferent medium, 

 namely ether, the following branched compounds : 

 The slightly soluble, dibasic hippuryl-aspartic acid : 



C 6 H 5 CO . NHCH 2 CO . NHCHCOOH 



CH 2 COOH. 



The very soluble 4-basic hippuryl-asparagyl-aspartic acid : 

 C 6 H 5 CO NH . CH 2 CO NHCHCO NHCH. COOH 



CH 2 . COOH 

 CH 2 CO . NHCH . COOH 

 CH 2 . COOH. 



From the normal 4-acid hydrazide of the last compound on the 

 addition of nitrous acid there resulted, owing to an internal splitting off 

 of hydrazin, the formation of a dibasic hydrazi-azide : 



