( 71 ) 



m-xylene. As in tlie sjinmetric nitro-m-xylene the NOa-group is 

 placed in the nieta-positioii with regard to tiie CH^-groups it did 

 not seem impossible tliat this NO^-group (like the NOj-groups in 

 symmetric dinitrophenol and symmetric dinitromethylaniline) would 

 not prevent the further introduction of the NO^-gi'Oups in the positions 

 2, 4 and 6, so that we ought to arriNC at tetranitro-m-xylene. 

 On the other hand the nitration of m-nitrotoluene ^) and symuietric 

 dinitrotoluene gave reason for believing that not four but at most 

 three nitro-groups would be introduced. 



The symmetric nitrometaxylene was prepared according to Who- 

 BLEWSKi's directions ^). 



Two grams of this substance were treated for twenty minutes on 

 the waterbath with mixed nitric and sulphuric acids; on cooling, 

 long colorless needles were deposited. These were collected at the 

 pump on glasswool and recrystallised from alcohol when long, color- 

 less needles or rods were obtaijied, m. p. J 25°. 



The motherliquor of the acid solution was poured into water 

 which caused a white flocculent precipitate. By recrystallising the 

 product from alcohol fine four-sided crystals mixed with a few 

 needles were obtained ; the crystals melted at 90^ and the needles 

 at 125°. These crystals could be separated by recrystallisation from 

 alcohol. From 2 grams of 5-nitro-m-xylene were obtained about 2 

 grams of the product melting at 125° and 0.5 gram of the product 

 melting at ÖO''. The analysis showed that both substances had the 

 composition of trinitroxylene. 



In the trinitro-m-xylene (m. p. 182^) prepared by nitration of 

 m-xylene the nitro-groups occupy the positions 2, 4 and 6. We had, 

 therefore obtained the two as yet unknown trinitro-m-xylenes. 



oil, CH, CHj 



NO; / \ NOo / XNOo 



NO, \ yen, ' ' NO. \ /dig NO, \ /C1I3 



NO, 



The constitution was determined according to the subjoined scheme. 

 CH3 CH3 C1I3 CII3 



NOj/X with N0o/\ with NO.,/^\Br with NOo/Xbi- 



|125° I NH.,^ ^j 1 850 I Br -^ „ 14G° I liN03-»NOo^|l03° | 



NOaX /CH3 ' CH3^\ /CII3 CHj^X /CII3 CHj'^X /CII3 



NÜ2 NUo NO, NO2 



1) Hepp. Ann. 215. 366. 



-) Recently, Willgerodt (Ber. 38. 1473) has described more fully the preparation 

 of symmetric nilrom-xylene. I had then already made this preparation according 

 to Wroblewski's directions. (Ann. der Chem. 207. 94). 



