2 PROCEEDINGS OF THE AMERICAN ACADEMY 



tribromdiuitrobenzol, which we are obliged to publish now, although 

 in some respects the work is not so finished as we could wish, because 

 the departure of one of us from Cambridge will prevent us from con- 

 tinuing the investigation together. 



The most important of these results can be summarized briefly as 

 follows. Sodium malouic ester under the conditions used by us 

 removes from tribromdiuitrobenzol only two atoms of bromine, one 

 of which is replaced by the radical of malonic ester, the other by 

 hydrogen, so that the formula of the product is 



C 6 H 2 Br(N0 2 ) 2 CH(COOC 2 fL) 2 . 



This substance shows marked acid properties, and, although of a pale 

 yellow color itself, forms salts most of which are dark blood-red ; of 

 these the sodium salt was analyzed, and its formula proved to be 



C 6 H 2 Br(N0 2 ) 2 CNa(COOC 2 H 5 ) 2 . 



The yellow copper salt was also analyzed, but proved to be a some- 

 what complex basic salt. The bromine contained in the substance is 

 easily removed by treatment with aniline, the product being 



C 6 H 2 C c H 5 NH(N0 2 ) 2 CH(COOC 2 H 5 ) 2 , 



which also gives a blood-red sodium salt with a formula similar to 

 that of the salt derived from the original substance, but the acid prop- 

 erties of the anilido compound are much less pronounced. When 

 heated with strong hydrochloric acid the bromdinitrophenylmalonic 

 ester gives ethylchloride and a new substance melting at 170°, the 

 analysis of which led to the formula C ( .H 2 Br(NO. ) ),,C ; ,H 5 2 , but the 

 determination of its constitution must be postponed till a later paper. 



Action of Sodium Malonic Ester on Tribromdiuitrobenzol. 



If .in alcoholic solution of sodium malonic ester is added to tribrom- 

 diuitrobenzol (melting point 192°) dissolved in ether, the first drop 

 imparts to the ethereal solution a blood-red color, which increases in 

 intensity as more of the solution of sodium malonic ester is added, and 

 the liquid contains the sodium salt of a new substance, which we pre- 

 pared in the following way. To an ethereal solution of a weighed 

 quantity of tribromdinitrobenzol we added an alcoholic solution of 

 sodium malonic ester in the proportion of three molecules of the ester 

 to one of the tribromdiuitrobenzol. The following were found to be 



