Chemistry. — "Monochloro-trimtrobenzeiien." By Piof. A. F. 



HOLLEMAN. 



(Communicated at the meeting of June 24, 1922.) 



So far only two of the six possible isomers were known, viz. 

 picrylchloride and a product obtained by Nietzki (see below). For 

 an inquiry into tlie replaceability of snbstituents it was required to 

 prepare also the other four isomers. 1 have only been able so far 

 to lay hands on three, and without doubt I should have waited 

 with the publication of my results till the whole investigation had 

 been completed, if ] had not happened to hear that also others are 

 engaged in a study of the same subject. 



Ql l-chlo)-o-3, 4, h-irinitrobenzene. This compound is 



^1^^ easily accessible; it is indeed surprising that it has 



I. I I not been known long since. The starting-point for 



N^jX/^^ü its preparation is chlorodinitranilinel, 4, 2,6, in which 

 ^^ NO, was substituted for the NH, group according 



to the method of Körner and Contardi. The yield /m 



of raw compound amounts to 707, of the theory, /A 



and there is only little loss in the purification. The | | 



substance may be recrystallized from benzene. It NO,\i/NO, 

 then melts at 168°. Large yellow crystals. ^"» 



CI \-cliloro-2,Z, h-trinitrobenzene. This compound is 



^\"NIO ^^'"'"^^ ^" ^^*T energetic nitration of l-chloro-2,3- 

 II- II' dinitrobenzene with a mixture of fuming nitric acid 



NO,\/NO, and oleum of 50V„. The heating of 160—170° is 

 continued for 5 hours. When the uiixture is poured out into water, an 

 oil is obtained, in which crystals are formed after some time. By centrifu- 

 gation these are separated and then recrystallized from alcohol. Melting- 

 point 106°. The structure of this compound was verified by a treatment 

 with alcoholic ammonia, through which 2-chloro-4,6- qj 



dinitraniline is obtained, melting-point 159°. This com- /2\ 



iNH 

 pound is known. Much more easily, however, than | ^1 ' 



according to the methods used up to now it could be N0j\//N03 



prepared by chlorination of NH, 2-4-dinitraniline with KCIO, 



in hydrochloric acid solution. /\n() "^''^ entrance of a NO,-group 



at the place 5 in 1-mono- I | * chloro-2,3-dinitrobenzene is 



very surprising, as this XX group takes a position at ?« 



with regard to CI and at /> ' with regard to a nitrogroup. 



