232 PROCEEDINGS OF THE AMERICAN ACADEMY. 



In the hope of finding an easier method for making this dibromtrinitro- 

 benzol the action of dibroradinitrobenzol (Br a 1 . 8 . (NO a ) a 4 . 6) with 

 nitric and sulphuric acids was studied. This gave the desired dibromtrini- 

 trobenzol, hut the product was mixed with bo large a proportion of tribrom- 

 dinitrobenzo] that the method was not adapted to the preparation of the 

 substance. This tribromdinitrobenzol is a new substance, nu Iting at 150°. 

 There can be no doubt that its constitution is Br 3 1 . 2.3. (NO a ) a 4.6, 

 Bince it is made bv introducing a third atom of bromine into the dibrom- 

 dinitrobenzol Br a 1 . 3 . (NO a ) a 4 . 6, and, if this occupied the only other 

 vacant place (5), the product would be the common tribromdinitro- 

 benzol, which melts at 192°. The formation of this tribromdinitrobenzol 

 during this reaction is strictly according to the analogy of the behavior 

 of the tribromdinitrobenzol, which, when boiled with a mixture of fum- 

 ing nitric and sulphuric acids, gives rise to tribromtrinitrobenzol and 

 tetrabromdinitrobenzol. * 



As neither of the new substances just described can he prepared easily 

 on a large scale, we have confined our work on them to the study of the 

 principal action of sodic ethylate on each. This reaction runs in a nor- 

 mal way. giving styphnic <lieth\ lether, 



C 6 H(NO a ) 8 (OC a H fi ) a , ((OC a H 6 ) a 1.3. (NO s ) 8 2.4.6), 



with dibromtrinitrobenzol, recognized by its melting point 121° ; and 

 with tribromdinitrobenzol a new bromdinitroresorcine monoethylether 

 melting at 78°. The subject did not promise to be of sufficient interest 

 to make it worth while to study the secondary products of these reactions. 



Experimental Part. 



Action of Sodic Sulphite in Alcoholic Solution on Tribromdinitrobenzol. 



Five grams of symmetrica] tribromdinitrobenzol ( Br a 1 .3.5. (N0 2 ) 2 

 •_' . 1 ) were dissolved in 70 c.c. of alcohol mixed with 20 c.c. of benzol, 

 li\ e gram- of normal sodic Bulphite added, and the mixture boiled for five 

 hours iii a flask with a return condenser. The red liquid thus obtained 

 was filtered from the insoluble portion, evaporated to dryness, and the 

 residue washed with water, until the yellow color Mas removed. The 

 part insoluble in water was then recrystallized from alcohol with the aid 

 of bone-black, until it showed the constant melting point 117°. This 

 melting point indicated that it was Koerner's dibromdinitrobenzol t 



* Jackson and Wing \.\I1 189 



izz. Cliira , 1874, 805. 



