( 72 ) 



CH» Clh CHg 



NO2X \N02 NO2/ \ NO2 NO2X \N02 



|90°| f?;/,^-^ II n|127°| Bi--^ II j^|l7óo| 



NOo\ /CII3 ' CIl3^^\ /CII3 CHs'^X /CIIs ^ 



13r 

 CII3 Cl '3 CII3 CH3 CIIj 



I I mev.-.- i -'f'" i -^ILSü, i 1^:^° | -^ II .J 175° ] ^NO^^ilö'io I 



NOjX /CII3 ■NU,^y^C'Il3 ' NUjX y^ClJ3CIl3^\/ai3 C1J3'^\/CH3 



NII2 Br Br Br Br 



CHj CH3 CHj CHj 



I 450 I -» !-l'°| -» |l9;Jo| -^ll^|-175^1 

 Br\ y^UIIs Br^^ClIa BrX^^UIla CIIs^X^/CII, 

 NII2 Br Br Br 



We therefore sec tliat llic siihslaiice melting at 00' is 2-5-6-triiiitro- 

 iii-xjlene ; the compound melting at 125° must therefore be 4-5-6- 

 trinitro-m-xylene. 



Both trijiitroxylenes contain a moveable NO^-group ; in the compound 

 m.p. 90° the KG,, -group 5 is under the influence of an ortlio- and 

 a para-placed NO^-group, whilst in the compound melting at 125'', 

 the NOj-group 5 stands between two ortho-placed groups. By the 

 action of alcoholic ammonia or methjlamine these groups are readily 

 substituted by NH, or NHCH,. 



Of special interest is also the formation of 4-5-6-trinitro-in-xylene 

 from 4-iodo-5-nitro-m-xylene. 



While 4-bromo-5-nitro-m-xylene (see above scheme) and 4-chloro- 

 5-nitro-m-xylene readily yield trinitrochloro(bromo)metaxylene on 

 treatment with a mixture of nitric acid (sp. gr. 1.52) and sulphuric 

 acid, 4-iodo-5-nitro-m-xylene yields 4-5-6-trinitroxylene with elimina- 

 tion of the iodine atom from the benzene core : 



CH3 CHj 



I 51° I -^ I -165° I 



CH3 ^ NOsX /CHs m}^\^ycih 



01 Cl 



1 105° I -^ 1 125° I 



N0,\ /CH.-, N0,\ /OH3 



I NO 



After this had l)een observed, the 4-iodo-6-nitro-m-xylene was also 

 nitrated. Here the iodine atom was also replaced by NO.^ and 2-4-6- 

 triuitro-m-xylene was formed m.p. 182°. 



