JACKSON AND SOCH. — TRINITROPHENYLMALONIC ESTER. 401 



XVIL 



CONTRIBUTIONS FROM THE CHEMICAL LABORATORY OF 



HARVARD COLLEGE. 



TRINITROPHENYLMALONIC ESTER. 



By C. Loring Jackson and C. A. Soch. 



Presented May 9, 1894. 



At the end of bis paper on the action of sodium acetacetic ester on 

 picrylchloride, Dittrich* states that, in spite of many and varied at- 

 tempts, he had not succeeded in making a picrylmalonic ester from 

 picrylchloride and sodium malonic ester, but that he obtained in every 

 case sodic picrate and viscous products of the decomposition of the 

 malonic ester. This statement impressed us as a strange one, since 

 in work f done in this Laboratory it had been found that tribromdini- 

 trobenzol acted much more easily with sodium malonic ester than with 

 sodium acetacetic ester ; for whereas a good yield of the substituted 

 malonic ester could be obtained even when the reaction took place in 

 the cold, with the acetacetic ester the yield was small even after the 

 reagents had been boiled together. Accordingly, we took up the 

 study of this subject, and found, as we had expected, that the picryl- 

 malonic ester could be obtained without difficulty. It is a white sub- 

 stance melting at 59°, and forms a blood-red sodium salt, which is 

 tolerably stable, dissolving in water without decomposition. The 

 picrylbrommalonic ester CGH2(N0.2)3CBr(COOC2H5)2 was made by 

 treating the substituted malonic ester with an excess of bromine ; 

 it melts at 85°-86°. One object in undertaking this work was to 

 see whether any trinitrobenzol was formed in the action of sodium 

 malonic ester or sodium acetacetic ester on picrylchloride by the re- 

 placement of the atom of chlorine by hydrogen after the analogy of 

 such reductions, which have been noticed frequently in the work done 

 in this Laboratory upon tribromdinitrobenzol and tribromtrinitrobenzol. 

 Unfortunately the research was begun so late in the year that we 



* Ber. d. ch. G., XXIII. 2720. t These Proceedings, XXIV. 2, 274. 



VOL. XXX. (n. S. XXII.) 26 



