2?2 PROCEEDINGS OP THE AMERICAN ACADEMY 



Preliminary Experiments. 



After the tetrabromdinitrobenzol had been prepared, the following 

 experiments were tried to determine the ease with which it reacted 

 with various substances. 



As has been stated in an earlier paper, alcoholic ammonia has no 

 action on tetrabromdinitrobenzol in the cold, or even if the substances 

 are heated together in open vessels. If however the mixture is heated 

 to 100° in a sealed tube for four or more hours, a reaction takes place 

 giving an orange precipitate and a red alcoholic solution in addition to 

 some unaltered tetrabromdinitrobenzol. The orange insoluble sub- 

 stance was undoubtedly the bromtriamidodinitrobenzol, but, as it was 

 insoluble in all the common solvents, we could only try to purify it by 

 washing, and even after repeated treatment with water, alcohol, chloro- 

 form, and benzol were unable to obtain a substance giving constant 

 results on analysis ; the bromine varied in different samples from 

 25.34 to 29.07 per cent, the amount required by the formula, 



C 6 Br(N0 2 ) 2 (NH 2 ) 8 , 



being 27.39. Although it is probable that further work on this sub- 

 stance would have enabled us to find a method of purifying it, we did 

 not think it worth while to sacrifice the time, as these analyses show 

 that the reaction has run in the same way as that between tribrom- 

 dinitrobenzol and alcoholic ammonia, and nothing of interest was likely 

 to be found in its investigation. The substance is an orange-yellow 

 powder, insoluble in all the common solvents, and not melting even at 

 285°. The alcoholic filtrate contained a yellow substance melting at 

 185° in the crude state, but we did not obtain enough of it for investi- 

 gation. With aniline a more favorable result was obtained, which is 

 described fully in the next section of this paper. 



When boiled with potassic sulphocyanate in alcoholic solution in a 

 flask with a return condenser, there was very little action, but, if amyl 

 alcohol was substituted for ethyl alcohol, so that the action would take 

 place at a higher temperature, a dark red substance was formed insolu- 

 ble in all the common solvents. In this respect the tetrabromdinitro- 

 benzol behaved exactly like the tribromdinitrobenzol, and, as it had 

 been found impossible to purify the corresponding product from the 

 tribrom compound, we did not think it worth while to continue work 

 in this direction. 



With sodium malonic ester or sodium acetacetic ester it behaves 

 like the tribromdinitrobenzol. The action with sodium malonic ester 

 is described in detail later in this paper. 



