220 



Scientific Proceedings, Royal Dublin Society. 



aniline, or even of a commercial grade containing a proportion of dimethyl- 

 aniline, the possible utilisation of this material for the production of tetryl 

 becomes of technological interest. 



It has been stated by Knowles (J. Ind. and Eng. Chem., 12, 1920, p. 246) 

 that in the nitration of dimethylaniline the amount of metanitro tetryl produced 

 is proportional to the methylaniline present in the raw material. While we are 

 unable to agree with this statement, it is sufficient to point out that the mere 

 production of metanitro tetryl gives rise to the possible subsequent development 

 of m-oxy tetryl by hydrolysis, 



/CHs 

 \ 



N 



NO2 

 O2N / ~\ NO2 



\ / 

 \/ 



I 

 NO2 



NO2 



N 



/CHa 



\ 



NO2 

 /\ 



02N / \ jsro2 



+ H20 



\ / 

 \/ 



I 



NO2 



OH 



+ HNO2 



and it has been established by Farmer (J.C.S., 117, 1920, p. 1605) and by 

 Hinselwood (J.C.S., 119, 1921, p. 722) that this oxy-tetryl has a considerable 

 influence in reducing the stability of tetryl. 



The experiments recorded in this paper bear out the observation of Knowles 

 (Zoc. cit.), as it is found that monomethylaniliae on nitration with nitric acid in 

 the presence of sulphuric acid gives rise to the production of considerable 

 amoxmts of m-nitro tetryl, as shown by the recovery of oxy-tetryl from the 

 waters used in washing the crude product of nitration of monomethylaniline. 

 In our observations the nitration of monomethylaniline is most unattractive for 

 large-scale 'operations. Unless agitation during nitration is very vigorous, there 

 results the formation of sticky, toffee-like masses; if, however, very vigorous 

 agitation is employed, the oily product which separates about half way through 

 the nitration is broken up, and the nitration can be completed to give a readily 

 handled granular product. 



In view of the difference in orienting influence thus shown by the aminie 

 groups in monomethyl and dimethylaniline, it seemed probable that derivatives 

 of monomethylaniline in which the hydrogen of the aminie group was replaced 

 by various radicles might be suitable for the production of tetryl practically 

 free from m-nitro tetryl. In this connection it is apposite to refer to the 

 observation of Ryan ancl Sweeney (Scientific Proc, R.D.S., vol. xvii, p. 157) that 

 tetryl of a high degree of purity is produced by the action of oxides of nitrogen 

 on a a methyl phenyl urea. 



From the technological standpoint, the most suitable derivative of mono- 

 methylaniline for investigation is the nitrosamine, as this product is readily 

 and simply obtained from pure monomethylaniline or a commercial product 

 containing dimethylaniline ; and in the event of a successful nitration, the spent 

 acid from the process would present no unknown features in the subsequent 

 denitration process ; while the nitrous acid used in making the nitrosamine would 

 presumably be thus to some extent recoverable in the form of nitric acid. 



Our experiments show that methj'l phenyl nitrosamine may be nitrated to 

 give tetrjd without the simultaneous production of any appreciable quantity of 



