208 
H 
a-amino-isobutyric anhydride (CH,),C—N—CO FRIEDMANN and I 
| | 
OC—N—C(CH,), 
H 
found something similar, with tnis understanding, however, that the 
nitration always took place with more difficulty, which can be attributed 
to sterical influence. 
At the same meeting, I also called attention to the fact previously 
noticed by me that the group NH placed in a ring. between two 
groups CO cannot be nitrated with absolute nitric acid, neither when 
it is placed between two saturated hydrocarbon groups. The expec- 
tation that one of the eleven isomers of the so-called glycocoll anhy- 
dride which Dr. JonNekees had prepared for me, namely dminodia- 
H 
cetic mide — H,C—N—CH, in which one NH-group is placed between 
| 
nee 
H 
two CQO-groups and the other one between two CH,-groups, would 
not be capable of direct nitration by absolute nitric acid, was not 
realised in so far that it appeared indeed to give a nitroderivative 
but with some properties differing from those observed up to the 
present with nitramines and nitramides, so that it was questionable 
whether the nitrogroup is attached to the nitrogen or to the carbon. 
Owing to the peculiar properties of the nitroderivative the chance 
of answering that question in a direct manner, for instance by 
reduction to hydrazine, was but a very slight one. 
Moreover, the starting material, the imide, is obtained with diffi- 
culty and then only in small yield so that a great economy is 
necessary in the research. Two indirect ways could, however, be 
pursued, namely by starting from substances in which either the 
hydrogen at the N, or that at the C is replaced by other groups 
and to test these compounds RN(CH,—CO),NH and HN(C(R),—CO), NH 
as to their behaviour on nitration. 
The last way is undoubtedly the best although even there 
we may meet with difficulties, for instance a difficult nitration owing 
to sterical hindrance as has already been demonstrated by ‘me 
and FRIEDMANN. 
Of the first process a few examples will be given here, namely 
acetyl and methyl derivatives, which, however, do not justify a 
final conclusion. The surmise that the NO,-group is placed at the N 
can be supported somewhat by the results of the nitration of the 
