Chemistry. — “On the Nitration-Products of p-Dichlor-Benzene’’. 
By Dr. A. J. Den HorLANDER and Dr. F. E. van HaArFTEN. 
(Communicated by Prof. A. F. HOLLEMAN). 
(Communicated at the meeting of November 29, 1919). 
In 1868 Junrerreiscu *) nitrated p-dichlor-benzene by boiling it 
with a mixture of fuming nitric acid and sulphuric acid for some 
hours. In this way he obtained a mixture of dinitro-p-dichlor-benzenes, 
about whose constitution opinions are still divided. Theoretically 
three isomers are possible, viz. : ; 
Cl Cl Cl 
NO.” \no /\NO, 7 \NO 
= hi | 3 | If NO and NO (RUT peek 
Ww INGA DA 
Cl Cl Cl 
JuNGFLEIScH himself isolated two compounds out of it, which he 
denoted by « and 3, but of which he did not determine the structure. 
For the e-compound he gave 87° as melting-point, for the g-compound 
107°. There is formed much more of the former compound according 
to him than of the latter. KöRNER ®), and much later ULLMANN and 
Sake*), proved that structure I applies to this chief product; the 
melting-point was, however, found at 105° by them. ENGELHARDT and 
Larscuinorr *) had also observed this higher melting-point, and could 
isolate the p-compound also from the reaction-product; hence they 
confirmed JuNGriviscn’s results in the main. 
On the other hand Morcan and Norman *) assert that compound 
III is formed as chief product; Harriey and Conen ®), who repeated the 
former’s experiments, confirm this, and give as melting-point 105—106°. 
Two year ago, Miss Epirn Nason ’) nitrated p-dichlor-benzene anew, and 
succeeded in also isolating IL from the reaction mixture in a yield 
of 45,6°/,, for which she, however, found the melting-point 81°. 
}) A. ch. (4), 15 259. 
%) J. 1875, 324. 
3) B. 44, 3780 (1912). 
4) Z. 1870, 234. 
5) Soc. 81, 1378, 1382 (1902). 
*) Soc. 85, 868 (1904). 
7) Am. Soc. 40, 1602 (1918). 
