( 604 ) 



of the nitrate with acetic anhydride) he obtained a mononitroderivdtive, 

 of which he proved the structure by acting on it with methyl- 

 alcoholic potassium hydroxide, which yielded a properly crystallised 



acid, namely N0 2 NH CH 2 CO NH CH a CO, H. 

 nitraminoacetylaminoacetic arid 



The reaction therefore took place as in all other cases where 

 N0 2 and CO are both linked to a nitrogen atom; by absorbing the 

 elements of water H and OH the group CO leaves the nitrogen 

 whilst N0 2 remains attached to it. 



After the departure of Mr. Donk, who did not wish to prosecute 

 this matter, Dr. Friedmann took it up and obtained the dinitro-compound 

 from glycocol anhydride by treatment with excess of nitric acid and 

 acetic anhydride. By the action of ammonia on dinitroglycocol anhydride 

 nitroaminoacetamide was obtained, and by means of sodium hydroxide 

 nitraminoacetic acid was formed in such a quantity that the formation 

 of two molecules was no longer doubtful. The position of the two nitro- 

 groups on the nitrogen atoms has. therefore been sufficiently proved. 



CH 8 -CH— NH— CO 



when evaporated with nitric acid also 

 CO— NH— CH-CH, 



A lanin e-anhyt h 'ü U ■ 

 save a nitrate onlv, which on treatment with acetic anhydride 

 yielded a dinitroalanine anhydride. 



These results, which formed a first deviation from the rule previously 

 laid down, incited to further research. For it was shown plainly 

 that besides the placing of the group NH between CO and a saturated 

 hydrocarbon residue, the other part of the molecule may also influence 

 the reaction in such a manner that a direct nitration is prevented, 

 even on warming, although nitro-compounds actually exist. 



The question, therefore, arose as to the behaviour of those isomers 

 of glycocol anhydride, which possess the same atom-groups, but 

 arranged in another order. 



There may be eleven cyclic compounds which consist of two 

 groups of NH, two groups of CO and two groups of CH S , of whom 

 however three only are described in the literature, namely : 

 CH.— NH— CO CH,— CH 2 CO CO— NH -CH, 



I I and ' 



CO — NH— CH 2 NH— CO— NH CO— NH— CH 2 



glycocol anhydride hydro-uracil ethyleneoxamide 



The last one, however, only in an impure condition, as described 

 by Hoffmann in 1872, and which we have not yet succeeded in 

 obtaining in a pure state. 



This substance had a special importance. It has the two groups 



