288 PROCEEDINGS OF THE AMERICAN ACADEMY 



XXIII. 



CONTRIBUTIONS FROM THE CHEMICAL LABORATORY OF 



HARVARD COLLEGE. 



ON TETRABROMDINITROBENZOL. 



By C. Lorixg Jackson and W. D. Bancroft. 



Presented May 28, 1889. 



After it had been determined that the tribromdinitrobenzol, melting 

 at 192°, reacted easily with a variety of substances, it seemed of in- 

 terest to try similar experiments with a tetrabrom compound, and we 

 selected for this purpose the tetrabromdinitrobenzol, melting at 228°, 

 and describe in this paper the results of our work, which may be briefly 

 summarized as follows. Tetrabromdinitrobenzol is not acted on by 

 alcoholic ammonia in open vessels, but, if heated with it in a sealed 

 tube, is converted into a yellow substance insoluble in all the common 

 solvents, which seems to be the bromtriamidodinitrobenzol. With ani- 

 line the bromtrianilidodinitrobenzol, melting at 175°-] 76°, is formed. 

 With sodium malonic ester it gives in the cold dibromdinitrophenyl- 

 malonic ester, melting point 89°, which possesses acid properties form- 

 ing a red sodium salt, and is converted by aniline into the bromanili- 

 dodinitrophenylmalonic ester, melting at 127°. The action of these 

 reagents on the tetrabromdinitrobenzol is therefore similar to their 

 behavior with tribromdinitrobenzol, the fourth atom of bromine re- 

 maining unaffected in all these reactions. We were prevented by 

 want of time from trying to remove this fourth atom of bromine by 

 reactions carried on at higher temperatures. We have studied also 

 the reduction of the dibromdinitrophenylmalonic ester with tin and 

 hydrocliloric acid, and have obtained in this way the bromamidooxindol, 

 QsH.BrNHolCHaCONH), melting at about 212°, and its chloride, 

 C6H2BrNH.,(CH.,CONH)HClH20. We may add, that in preparing 

 the tetrabromdinitrobenzol from somewhat impure tetrabrombenzol we 

 obtained the as yet undescribed pentabromnitrobenzol, which melts at 

 248°, and on another occasion the hexabrombenzol. 



