759 



nitro-groiips in this tetraiiitrodiplienoi, and therefore also in the 

 ether obtained bj me, must be 3. 3'. 5. 5'. 



No tetranilrotetramethylbenzidine had formed meanwhile. Hence, 

 I made another experiment where I allowed monometlijlamine to 

 act on the tetranltrodiphenokliethjlether. The contents of (he tube 

 also turned orange-red when innnersed in the boiling water-bath 

 and after the operation a red crystalline mass had again deposited 

 in the tube. 



Again I washed with warm alcohol and u^arm water, but !iie 

 latter soon ran through colourless whilst a dark red crystalline mass 

 was left behind on the filter. It could be recrystallised from phenol. 

 The compound so obtained decomposed a( 282°. 



Hence, the synthesis of tetranitrodimethylbenzidine had been success- 

 ful and now it was also proved beyond doubt that it was a 3.3'.5.5' 

 compound, which, of course, also applies to the (eti'anitrotetrametliyl- 

 benzidine and its derivatives. 



The difficult decomposition by boiling acpieous potassium hydroxide 

 must be most likely attributed to the slight solubility of this 

 compound. 



The above cited experiments now also paved the way for the 

 synthesis of all kinds of tetranitroalkylbenzidines. 



For instance, I allowed ethylamine to act on the tetranitrodiphenol- 

 ether and obtained a com|)ound which, when recrystallised from 

 ethyl benzoate, crystallises in yellowish-red small needles, which 

 melt at 248° with decomposition. This same substance, I also could 

 prepare from tetraethylbenzidine. 



I have also allowed propyl-, wopropyl- wobutyl- and all^lamine 

 to react. The compounds so obtained are united in the following 

 table in which are also included the final nitration compounds 

 (nitramines) generated from the different products. All these nitra- 

 mines are of an extremely pale yellow colour. 



Monoalkyl compounds corresponding 



nitramines 



284° (with decomp.) 230° (with decomp.) 



248° „ „ 230° „ 



202° 213° „ 



250° „ „ 209° „ 



194° 205° 



208° „ „ 100° „ 



With tin and hydrochloric acid the telranitrotelfamethyl- and 



49 

 Proceedings Royal Acad. Amsterdam. Vol. XVIll. 



