CONTRIBUTIONS FROM THE CHEMICAL LABORATORY OF 

 HARVARD COLLEGE. 



ON THE ACTION OF SODIC ETHYLATE ON 

 TRIBROMDINITROBENZOL. 



By C. Loring Jackson and Waldemar Koch. 



Presented October 12, 1898. Received October 20, 1898. 



The principal object of the work described in this paper was to 

 determine the constitution of the dinitroresorcine diethylether melt- 

 ing at 133°, formed by the action of a hot solution of sodic ethylate 

 on tribromdinitrobenzol (Br3l,3,5(N02)22,4), or on the bromdiuitrore- 

 sorcine diethylether melting at 184°. This determination was of interest 

 to us, as it formed part of an investigation of the replacement of bromine 

 by hydrogen under the influence of sodium malonic ester, sodic ethylate, 

 and similar reagents, which has now been in progress for several years in 

 this Laboratory. In all the cases studied here, with a single exception, 

 the atom of bromine (or iodine) has stood between two other radicals, 

 each in the ortho position to it, and it was necessary to determine whether 

 this arrangement also existed in this case, since a consideration of the 

 possibilities shows that this dinitroresorcine diethylether might have either 

 the symmetrical structure, if the bromine between the two nitro groups 

 was replaced by hydrogen, or the adjacent structure, if this replacement 

 occurred with one of the other atoms of bromine. 



The constitution of the diethylether was determined by saponifying it 

 to the corresponding dinitroresorcine, which proved to be the symmetrical 

 compound (OH)ol,5(N0.2)22,4, melting at 212°.5, according to Typke.* 

 The proof that this body has the structure assigned to it has been given 

 by Nietzki and Schmidt,t who converted it into diimidoresorcine, which 

 in turn yielded dioxyquinone by treatment with sodic hydrate, and this 

 dioxyquinone gave with nitric acid nitranilic acid, which is paradinitro- 

 dioxyquiuone, a result that is in harmony only with the symmetrical 

 structure for the dinitroresorcine. It follows therefore that the bromine 

 replaced by hydrogen in tribromdinitrobenzol is the one between the 



* Ber. d. chem. Ges., XVL 552. t Ibid., XXL 2374. 



