Ryan and O'Riordan — On a-, /3-, and y- Trinitrotoluenes. 179 



compound. He also stated that ^-trinitrotoluene reacted with alcoholic 

 ammonia, on standing, forming a dinitro-metatoluidine melting at 192' C, and 

 that the (3-isomer when heated to 100° C. in a sealed tube with alcoholic 

 ammonia yielded an isomeric substance melting at 94° C. The first action 

 of the ammonia with the y-isomer was to produce a deep blue-green colour, 

 which gradually changed to brown, while with the /3-isomer a yellow colour 

 first developed slowly, and this changed finally to brown. Hepp did not 

 publish any analyses of either of the two dinitrotolylphenylamines obtained 

 by him. 



The observations of Hepp on the formation of additive compounds of 

 aromatic amines with .s-trinitrobenzene and a-trinitrotoluene were further 

 extended by van Eomburgh (Eec. trav. chim. des Pays-Bas xiv (1895), p 67), 

 Noelting and Sommerhoff (Ber. d. Dtsch. Chem. Ges. xxxix (1906), p. 76), 

 Sudborough and co-workers (Journ. Chem. Soc. 1901, p. 522; 1903, p. 1334; 

 1906, p. 583; 1910, p. 773; 1911, p. 209; 1916, p. 1339). These workers con- 

 fined their attention mainly to .s-trinitrobenzene, a-trinitrotoluene, and some 

 similar symmetrically constituted bodies, such as picric acid. 



The main result of all these investigations has been to demonstrate that 

 these additive compounds are all of the type 1 molecule of trinitrobenzene or 

 trinitrotoluene + 1 molecule of amine, provided the amine contains only one 

 independent aromatic nucleus. 



Korczynski (Anz. Akad. Wiss. Krakau, 1908, pp. 033-644) prepared 

 additive compounds of s-trinitrobenzene and of a-trinitrotoluene with 

 ammonia by interaction of these bodies at -10 to - 15° C. The composition 

 of these derivatives was represented by 1 molecule of the nitro-eompound 

 + 2 molecules of ammonia. 



Will (loc. cit.) stated that in acetone solution ammonia gives a greenish 

 yellow colour with j3-trinitrotoluene and a blue colour with the y-isomer. 

 Giua (Atti B. Accad. dei Lincei (5) xxiii (1914), ii, pp. 484-489) stated that 

 these colorations gradually change to a more or less intense red colour, and 

 that in the reaction one of the nitro groups is replaced by an amino group, this 

 replacement being assumed to be preceded by the addition of a molecule of 

 ammonia to the nitro compound, as in the case of a-trinitrotoluene 

 (cf. Korczynski, loc. cit.). 



III. Action of Aldehydes. 



Thiele and Escales (Ber. d. Dtsch. Chem. Ges. xxxiv (1901), pp. 2842-2848) 

 have shown that 2.4-dinitrotoluene reacts with aldehydes, such as benzal- 

 dehyde, in the presence of piperidine diethylamine, triethylamine, or ammonia 

 to form nitrated stilbene derivatives, 



