369 



Chemistry. — "2.SA.Q-Tetramtro-pheni/hnethi/I- and ethylnitr amine.'' 

 By Prof. VAN Romburgh and l)i-. J. H. Schepers. 



(Communicated in the meeting of September 27, 1913). 



Many years ago appeared a communication^) from one of us 

 (v. R.) on tetranitroplienylmethylnitramine. Tiiis substance was the 

 first aromatic nitramine with four nitro-groups in the nucleus, three 

 of which were placed vicinally, causing- a peculiar mobility of one 

 of those groups. Thus it was shown that water, alcoliol and amines 

 readily react with it at the ordinai-y or at a slightly elevated tempera- 

 ture. As, since the publication of the above paper on this nitramine, 

 nothing more has been published about it, save an occasional 

 reference, it did not seem out of place to continue the research in 

 different directions. 



In the first place attempts have been made to improve the method 

 of preparing the nitramine and w^e have been entirely successful by 

 taking advantage of the fact that the ^f/f^v/nitrophenylmetbylnitramine 

 is insoluble in concentrated sulphuric acid, whereas the ^rmitro-compound 

 is soluble therein. After a number of experiments, undertaken with 

 the object of finding the most favourable conditions for obtaining the 

 largest possible yield, we can recommend the following method. 



10 grams of dimethylaniline are dissolved in 200 gi-ams of strong 

 sulphuric acid. When cold, a cooled mixture of 60 grams of sulphuric 

 and 12 grams of nitric acid (D 1.51) is added drop by drop with 

 vigorous stirring, the whole being cooled in ice and salt so as to 

 keep the temperature at — 2°. Particularly at first the temperature 

 rises strongly after each drop added. The liquid soon turns an orange- 

 like colour. After the first half of the acid has been added, the 

 remainder may be added more freely as there will be no further rise 

 in temperature. After standing for half an hour in the ice and salt 

 mixture, 100 c.c of nitric acid (D. 1.51) are added. The liquid is 

 then cooled for one day in ice or water and then left at rest for 

 some days at the ordinary temperature. 



After one or two days the liquid is congealed to a thick mass of 

 crystals. A continuous evolution of carbon dioxide '■') takes place, not 

 accompanied, however, by brown vapours, because the nitrous acid 

 formed combines with the sulphuric acid. After the lapse of a week 

 the crystals are collected, by filtering, on glass wool and washed 



1) Rec. 8, 282 (1889). 



-) It contains traces of carbon monoxide. 



24 

 Proceedings Royal Acad. Amsterdam. Vol. XVI. 



