322 PROCEEDINGS OF THE AMERICAN ACADEMY 



Action of Tribromdinitrobenzol with Water and Sodic 



Carbonate. 



Tribromdinitrobenzol (melting point 192°, made from symmet- 

 rical tribrombenzol) was boiled with an aqueous solution of sodic 

 carbonate in the way just described for the trinitro compound. 

 The action in this case was so slow that it was found better to con- 

 tinue the boiling for. at least twenty-four hours before filtering. 

 As in the preceding case, the color of the solution gradually be- 

 came j'ellow, and later changed to red. After filtering out the 

 unaltered tribromdinitrobenzol, the red filtrate, which contained 

 sodic bromide and sodic nitrite, was acidified with dilute sulphuric 

 acid, which turned it light yellow, and produced a cloudy precipi- 

 tate, which after a long time collected on the bottom in the form 

 of oil-drops. These were removed, the clear liquid extracted with 

 ether, and the extract, which was small in amount and oily, added 

 to the oil which had separated. This was then dissolved in am- 

 nionic hydrate and treated with baric chloride, when a precipitate 

 was formed in a dark red solution. 



The insoluble barium salt was decomposed with hydrochloric 

 acid, and the phenol thus set free crj'stallized from dilute alcohol 

 until it showed the constant melting point 147-148°, when it was 

 dried at 100°, and analyzed with the following results: — 



I. 0.1626 gr. of the substance gave by the method of Carius 

 0.1804 gr. of argentic bromide. 

 II. 0.2053 gr. of the substance gave 15.7 c.c. of nitrogen at a 

 temperature of 26° and a pressure of 759.9 mm. 



These results prove that the substance is a dibromdinitrophenol 

 formed by the replacement of one atom of bromine by one of hy- 

 droxyl, and as it is made from a s}rmmetrical tribrom compound it 

 must be isomeric with the one melting at 146°-146°.5 made by 

 Garzino from metadibromphenol. 



Properties of Dibromdinitrophenol. — This substance c^stallizes 

 from a hot alcoholic solution diluted with water until the substance 

 begins to precipitate in thick yellow needles with square ends,' ar 



