OF ARTS AND SCIEN'CES. 69 



had undergone complete decomposition, as they contained bromine ; 

 the residue, however, furnished a considerable amount of the substi- 

 tuted tartronic ester mentioned above. The action therefore has a 

 certain resemblance to the conversion of the nitrate of tartaric acid 

 into tartronic acid. These easy conversions of the compound con- 

 taining the group NO.2 into the corresponding tartronic ester can be 

 best explained on the theory that this group is attached to the side- 

 chain by oxygen, but cannot be considered as a strict proof of this 

 {loint. Accordingly we have reduced with tin and hydrochloric acid 

 the substance CeIl2Br(N02)2CNOo(COOC2ll5)2 (selected because it 

 can be obtained more easdy than the trinitro compound), and have 

 found that it yields amraouic chioride and a substance having tlie for- 

 mula C6H3NH,(CHOHCONH)HCl, that is, the chloride of amidoxy- 

 oxindol ; there can be no doubt, therefore, that the group NO2 is 

 attached to the side-chain by one of its atoms of oxygen, and the 

 substances are nitrites and not nitromalonic esters. 



One of the most striking properties of the nitrite of bromtrinitro- 

 phenylmalonic ester is its slight stability. As has been already stated, 

 it decomposes rapidly, with change of color and evolution of gas, at 

 124°-12G°, but it is not necessary to heat to this temperature to bring 

 about the decomposition, as it also takes place slowly at 100°, and 

 partially even at 70°. Boiling with alcohol decomposes the substance 

 completely, and boiling water produces a similar but less complete 

 change. The nitrites of the corresponding dinitro compound and of 

 the trinitrophenylenedimalonic ester are much more stable. 



As has been stated above, the nitrite of bromtrinitrophenylmalonic 

 ester, if warmed for three hours with strong nitric acid, or heated 

 alone to its decomposition point, yields a product in which the radical 

 of the nitrous acid has been replaced by hydroxyl, and which, is there- 

 fore bromtrinitrophenyltartronic ester ; this substance melts at 156°, 

 and possesses marked acid properties. It is not necessary, however, 

 to make it from the nitrite, as the bromtrinitrophenylmalonic ester is 

 converted directly into it by warming for three hours with nitric acid. 

 This therefore is a case of the direct oxidation of a tertiary liydrogen 

 to hydroxyl,* and, as we have succeeded in isolating the intermediate 

 product, our work throws some light on the mechanism of the reaction, 

 showing that it consists in the case of nitric acid of the formation of 

 a nitrite, followed by its saponification to the hydroxyl compound. 



* Richard Meyer, Ann. Cliem , CCXIX. 234, CCXX 1 ; J. Bredt, Ber. d. 

 ch. G., XIV. 1780. 



