JACKSON AND KOCH. — TRIBROMDINITROBENZOL. 133 



and is the monoethylether corresponding to the diethylether formed by 

 the action of hot sodic ethylate on tribromdinitrobenzol (see later in this 

 paper). Whether our substance is identical with that discovered by 

 Aronheim, or whether the difference of two degrees in the melting point 

 is caused by a difference in constitution, we are unable to determine with 

 our present knowledge. 



The filtrate, from which the dinitroresorcine monoethylether had been 

 precipitated by acetic acid, still contained a phenol to judge by its color, 

 and to obtain this hydrochloric acid was added, which produced a white 

 precipitate. Without filtering the liquid was extracted with ether, and, 

 as this removed almost all of the color, the aqueous liquid was thrown 

 away. The ether on evaporation usually left a red oily mass, which 

 obstinately refused to crystallize ; on one occasion, however, we succeeded 

 in obtaining about half a gram of a solid, which after recrystallization 

 from alcohol showed the constant melting point 90°, and agreed in its 

 properties with those described for the tribromnitrophenol which melts 

 at 89° according to Daccomo.* To characterize the substance more 

 thoroughly some of the oily mass was treated with a solution of baric 

 hydrate, and the barium salt formed, which liad a gelatinous consistency, 

 was washed with cold water, dissolved in cold alcohol, from which it was 

 allowed to crystallize, and after being dried at 100° analyzed with the 

 following result : — 



0.1816 gram of the salt gave 0.0485 gram of baric sulphate. 



Calculated for 

 (CoHBr3NO.O)2Ba. Found. 



Barium 15.45 15.70 



There can be no doubt, therefore, that the phenol is tribromnitrophenol 

 formed from tribromdinitrobenzol by the replacement of one of the nitre 

 groups by one hydroxyl radical. Our substance also shows two charac- 

 teristic properties, which have been observed in the case of the tribrom- 

 nitrophenol; these are the solubility of its barium salt in alcohol, and the 

 fact that the sodium salt is not decomposed by organic acids. The con- 

 stitution of the phenol follows from its mode of formation from tribrom- 

 dinitrobenzol melting at 192°. It is Br3l,3,5,OH2.N024. 



The following statement of the yields of these various products of the 

 action of cold sodic ethylate on tribromdinitrobenzol will give a general 

 idea of the extent to which each of the reactions takes place, but it 

 should be remembered that these numbers are approximate estimates 



* Ber. d. chem. Ges., XVIII. 1167. 



