JACKSON AND SOCH. — TRINITROPHENYLMALONIC ESTER. 407 



more soluble iu methyl than in ethyl alcohol ; insoluble in cold ligroiue, 

 soluble in it when hot although with some difficulty ; essentially insol- 

 uble in water, whether hot or cold. The best solvent for it is alcohol. 

 Its alcoholic solution shows a faint pink color, similar to that given by 

 picrylmalonic ester, but less marked. Strong sulphuric acid dissolves 

 it in the cold with a yellow color; upon warming this solution it 

 becomes brownish black, and bubbles of gas are given off. Sirong 

 hydrochloric acid seems to have no action on it even when hot. In 

 cold strong nitric acid it is insoluble, but dissolves easily if the acid is 

 hot, and boiling this solution for a short time produces no signs of 

 decomposition. A strong solution of sodic hvdrate did not act upon 

 it in the cold, but, when heated with it, gave a red solution. The 

 solution here was undoubtedly preceded by removal of the bromine. 

 As has been stated already, sodic carbonate does not act on this 

 substance. 



Bromdinitrophenylbromnialonic Ester^ 

 CyH2Br(NOo)oCBr(COOC2H5)2. 



This substance was made by dissolving the bromdinitrophenylma- 

 louic ester in glacial acetic acid and adding to the strong solution an 

 excess of liquid bromine. The bromdiuitrophenylmalonic ester was 

 made from tribromdinitrobenzol melting at 192° and sodium malonic 

 ester.* After an excess of bromine had been added, as shown by the 

 color, the liquid was warmed gently on the water bath for a short 

 time, and, if the color had disappeared, more bromine added. It was 

 then, after it was cool, precipitated with water, and the substance 

 obtained solidified by coolinsr, if necessary ; after which it was purified 

 by crystallization from alcohol, until it showed the constant melting 

 point 72°-73°. It is not wise, however, to rely on the melting point 

 as the only proof of purity, since the bromdiuitrophenylmalonic ester 

 from which it is formed melts at 75°-76° ; we have therefore always 

 tested our product also with a solution of sodic hydrate, which gives a 

 red salt with the mother substance, but has no effect in the cold on the 

 desired compound. After purification it was dried in a desiccator, 

 and analyzed with the following results: — 



I. 0.3196 gram of the substance gave by the method of Carius 

 0.2451 orram of argentic bromide. 

 II. 0.1997 gram of the substance gave 0.1550 gram of argentic 

 bromide. 



* These Proceedings, XXIV. 2. 



