JACKSON AND EARLE. TRIBROMTRINITROBENZOL. 233 



(Br 2 1 . 3,(N0 2 ) 2 4 . 6.), and this was confirmed by treating it with 

 aniline in the cold, when it was converted into the bromanilidodinitro- 

 benzol, * C G H 2 Br(C 6 H 5 NH)(N0 2 ) 2 , recoguized by its melting point 157°. 

 For greater certainty the dibromdiuitrobenzol was dried at 100°, and 

 analyzed with the following results : — 



I. 0.3277 gram of the substance gave 24.6 c.c. of nitrogen at a tempera- 

 ture of 18°. 5 and a pressure of 760.3 mm. 

 II. 0.3195 gram of the substance gave by the method of Carius 0.3707 

 gram of argentic bromide. 



Calculated for Found. 



C 6 H 2 Br 2 (N0 2 ) 3 . I. II. 



Nitrogen 8.59 8.65 



Bromine 49.38 49.08 



The sodic sulphite, therefore, has removed the atom of bromine stand- 

 ing between the two nitro groups in the tribromdinitrobenzol, and 

 replaced it by hydrogen. 



That this was not the only action of the sodic sulphite was shown by 

 the marked yellow color of the products of the reaction. The yellow 

 substance was soluble in water, but, in spite of its strong color, was present 

 in such small quantity that we could not isolate it from the other sub- 

 stances soluble in water, which consisted of sodic bromide and unaltered 

 sodic sulphite. It was undoubtedly the sodium salt of a phenol formed 

 by a secondary reaction. 



Action of Sodic Sulphite in Alcoholic Solution on Tribromtri>iitrobenzol. 



Ten grams of symmetrical tribromtrinitrobenzol (Br, 1.3.5. (N0 2 ) 3 

 2.4.6) were dissolved in 120 c.c. of common alcohol with the assistance 

 of 30 c.c. of benzol, ten grams of normal sodic sulphite added, and the 

 mixture boiled for four hours in a flask fitted with a return condenser. 

 The reaction seemed to run as in the case of the tribromdinitrobenzol, 

 except that it took place more easily, since the red color appeared more 

 quickly. The red solution was filtered, the filtrate evaporated to dryness, 

 and the residue washed with water, after which it was recrystallized from 

 a mixture of alcohol and benzol with the assistance of bone-black, until it 

 showed the constant melting point 135°, when it was dried at 100°, and 

 analyzed with the following results : — 



* Jackson and Cohoe, These Proceedings, XXXVI. 75. 



