126 PROCEEDINGS OF THE AMERICAN ACADEMY. 



case in which one of three radicals in the symmetrical position has 

 been removed, as Lobiy de Bruyn * has converted symmetrical trini- 

 trobenzol into dinitranisol or dinitrophenetol by the action of the sodic 

 alcoholates in open vessels. The work of Blau and Lobry de Bruyn, 

 therefore, establishes this as a general behavior of symmetrical com- 

 pounds, and such replacements are the more remarkable, because a 

 single negative radical has no effect upon one other in the meta 

 position. 



In the work with unsymmetrical tetrabrombenzol, mentioned above, 

 it was only the fourth atom of bromine (in the diortho para position to 

 the others) that was replaced by hydrogen, but in some work upon the 

 corresponding dinitro compound C6Br^(N02)2, done some years ago by 

 W. D. Bancroft and one of us, this atom of bromine remained obsti- 

 nately unat tacked when other atoms of bromine were removed ; t in the 

 same way the reduction of tetrabromdinitrobenzol with tin and hydro- 

 chloric acid gave monobromphenylene diamine. | so that in these cases 

 the symmetrical atoms of bromine alone were removed, and the action 

 was exactly the reverse of that obtained with tetrabrombenzol and sodic 

 ethylate. This difference is explained by the facts that in the tetra- 

 brombenzol the three atoms of bromine in the trimeta position are the 

 loosening radicals, whereas in the tetrabromdinitrobenzol they are those 

 which are loosened. In this connection we decided to try the action of 

 sodic ethylate on tetrabromdinitrobenzol, as this experiment had not 

 been included in the previous work of AV. D. Bancroft and one of us, 

 and we found that tetrabromdinitrobenzol (Br.NO2.Br.NO2.Br.Br) 

 was converted by the action of a cold solution of sodic ethylate 

 into the tribromnitroresorcine diethylether melting at 101°, and first 

 obtained by W. II. Warren and one of us § by the action of sodic 

 ethylate on tribromtrinitrobenzol. This substance has the formula 

 C6Br3N02(OC2H5)2, and must have been formed in this case by the 

 replacement of one nitro group and the fourth atom of bromine by 

 etboxy groups, just as it was formed from the tribromtrinitrobenzol by 

 the replacement of two nitro radicals by ethoxyls. If the action with 

 the tetrabrom body is analogous to that with the trinitro compound, 

 there should be formed at the same time by a parallel reaction a substi- 

 tuted phloroglucine, in this case dinitrobromphloroglucine or its ethers ; 



* Rec. d. Tr. Chim., IX. 208, XIII. 149. 



t These Proceedings, XXIV. 288. Sodium malonic ester gave the compound 

 C6HBr._,(NO.j)2 CH(COOC2H5)2 ; reduction of this gave bromamidoxindol; ani- 

 line gave C6Br(NOo)2 (C6H5NH)3. 



t See tlie following paper. § These Proceedings, XXV. 183. 



