136 PROCEEDINGS OF THE AMERICAN ACADEMY. 



VII. 



CONTRIBUTIONS FROM THE CHEMICAL LABORATORY OF 

 HARVARD COLLEGE. 



BROMINE DERIVATIVES OF METAPHENYLENE 

 DIAMINE. 



By C. Loring Jackson and Sidney Calvert. 



Presented May 9, 1894. 



Introduction. 



In the course of an extended investigation of the behavior of the tri- 

 bromdinitrobeuzol melting at 192°, carried on now for some years in this 

 laboratory, we took up the reduction of this substance with tin and 

 hydrochloric acid, since, if the bromine was not removed, new bromine 

 derivatives of metaphenylene diamine must be obtained, or, on the other 

 hand, the replacement of the bromine by hydrogen would be of interest, 

 because cases in which a halogen is removed from the benzol ring under 

 these conditions, are far from common. As, however, two of those 

 already observed had occurred in the work on derivatives of tribromdi- 

 nitrobenzol done in tiiis laboratory, we had reason to hope that the 

 proposed experiments might furnish us with an additional case, and 

 contribute something toward determining the conditions under which 

 this replacement of bromine by hydrogen takes place. After we had 

 begun our work there appeared a paper * by Schlieper on the removal 

 of bromine from aromatic compounds by tin and hydrochloric acid, in 

 which he announced his intention of making an extended research in 

 this field ; we accordingly wrote to Victor Meyer, under whose direc- 

 tion Schlieper was working, asking if we might finish our work, and 

 he has with great courtesy given us permission to do so. 



We have succeeded in finding only the following cases in which 

 bromine is replaced by hydrogen in aromatic compounds by reduction 

 with tin and hydrochloric acid. Unsymmetrical brommetadinitrobenzol 

 gives metaphenylene diamine.f Tribromdinitrobenzol sulphonic acid 



* Ber. d. ch. G. XXV. 552. 



t Zincke and Sintenis. Ber. d. ch. G., V. 792. 



