OF ARTS AND SCIENCES. 



97 



Attempt to make Dinitrophenylenedlmalonic Ester. 

 The results just described having shown that the behavior of brom- 

 (liuitrophenylmalonic ester toward nitric acid was not so different from 

 that of the trinitro compound as we had at first supposed, it became 

 of interest to determine whether other apparent differences between 

 these two bodies were no better marked, and accordingly we tried 

 to make the dinitrophenylenedlmalonic ester by the method which 

 had given good results with the trinitro compound as follows : — 

 3 gr. of bromdinitrophenylmalonic ester were dissolved in ether, and, 

 after the addition of 1.5 gr. of malonic ester previously treated with 

 0.15 gr. of sodium in a large quantity of alcohol, the mixture was 

 boiled under a return-condenser for three hours ; at the end of this 

 time the solution had turned deep red, and a little solid had separated. 

 The product was treated with water and dilute sulphuric acid, the 

 ether separated, and the aqueous liquid tested for sodic bromide, which 

 it was found to contain in small quantity, but the crystals deposited 

 by the ether melted after one crystallization at 75° -7 6°, the melting 

 point of bromdinitrophenylmalonic ester. We infer from this experi- 

 ment, therefore, that, although a little dinitrophenylenedlmalonic ester 

 may have been formed, its quantity was exceedingly small, and that 

 the reaction, if it goes on at all, certainly takes place with much 

 more difficulty in the case of the dinitro than in that of the trinitro 

 compound. 



VOL. XXVI. (n. s. xviii.) 



