OF ARTS AND SCIENCES. 237 



substances. This recalls the observation of Victor Meyer,* that hom- 

 ologues can be obtained from benzylcyauide by using the alkylhaloid 

 with powdered solid sodic hydrate instead of sodic ethylate, or from 

 desoxy benzoin by the use of an alcoholic solution of an alkaline 

 hydrate. 



Study of the Reactions hj which the Bromdinitrophenylmalonic Ester 



is formed. 



One of the most important points, which want of time prevented us 

 from considering in our first paper, was the mechanism of the reac- 

 tions by which the bromdinitrophenylmalonic ester was formed from 

 the tribromdinitrobenzol, and accordingly this was one of the first 

 points to which we turned our attention in taking up the subject 

 again. The reaction consists essentially, as our aiwyses of the pro- 

 duct showed, in the replacement of one of the bromine atoms in the 

 tribromdinitrobenzol by the malouic ester radical C1I(C00C 2 II 5 ) 2 , 

 and of a second by hydrogen forming C c H 2 Br(N0 2 ) 2 CH(COOC,H.) a , 

 and the obscure part of it is the manner in which this second atom of 

 bromine is replaced by hydrogen. The first step toward clearing up 

 this obscurity was obviously to make out whether this atom of bro- 

 mine was eliminated in the form of some organic compound, or as 

 sodic bromide, which was done by the following quantitative deter- 

 minations of the amount of sodic bromide formed in the reaction. 



I. 20 grs. of tribromdinitrobenzol were treated with the sodium 

 malonic ester from 16 grs. of malonic ester in the way already de- 

 scribed, and, after precipitating the bromdinitrophenylmalonic ester 

 from the aqueous solution with dilute nitric acid, and filtering it out, 

 the amount of sodic bromide was determined by precipitation of argen- 

 tic bromide from an aliquot part of the filtrate, and calculating the 

 amount in the entire solution. In this way the whole solution was 

 found to yield 13.81 grs. of argentic bromide, corresponding to 5.88 grs. 

 of bromine. The benzol solution on evaporation yielded 5.1 gr>. of 

 tribromdinitrobenzol, which had not taken part in the reaction, leaving 

 14.9 grs. which had acted, and which would yield 5.89 grs. of bromine, 

 if two of the atoms of bromine had been removed from each molecule 

 as sodic bromide. 



II. 20 grs. of tribromdinitrobenzol gave under the same conditions 

 13.8 grs. of argentic bromide corresponding to 5.87 grs. of bromine, 

 but only 4.9 grs. of tribromdinitrobenzol were recovered unaltered. 



* Ber. d. cli. G. 1888, p. 1201. 



