CONTRIBUTIONS FROM THE CHEMICAL LABORATORY OF 

 HARVARD COLLEGE. 



TRINITROPHENYLMALONIC ESTER. 



SECOND PAPER. 

 By C. Loring Jackson and J. I. Phinney. 



Presented October 12, 1898. Received October 20, 1898. 



The work described in this paper was undertaken with the intention of 

 preparing some derivatives of the trinitrophenylmalonic ester (picrylraa- 

 louic ester), C6Ho(N02);5CH(COOaH5)2, discovered by C. A. Soch and 

 one of us.* It has led to the discovery of a second and more stable 

 form of the trinitrophenylmalonic ester, which melts at 64° instead of 08°, 

 the melting point of the form at first obtained ; and we have also pre- 

 pared the nitrite of this ester, 



CeH2(NO,)sCN02(COOC2H5)2, 



melting at 109°, the corresponding trinitrophenyltartronic ester, 



C6H2(N02)3COH(COOC2H5)2, 



melting at 117°, its acetyl derivative, 



CcH2(NOo)3COCOCH3(COOC2H5)2, 



which melts at 125°, and the trinitropheuylacetic acid, 



C6H2(N02)3CHoCOOH, 

 melting at 161°. 



The Two Modifications of Trinitrophenylmalonic Ester. 



The trinitrophenylmalonic ester, as prepared by Soch and one of U8,t 

 crystallized from alcohol in white long rather slender rectangular plates, 

 or when better developed in thick prisms with blunt ends, often as much 

 as two centimeters long. It melted at 58°. J When we first took up the 



* These Proceedings, XXX. 40L 



t Ibid. 



X In the previous paper, this melting point is given as 59°, but it must be changed 

 to 58°, as it was found after that paper was published that the zero point of the 

 thermometer used had changed. 



