Constitution of the Diazoamido- Compounds. 519 



(11) Mixed alkyl-derivatives of group (9) are resolved by 

 acids into their constituents, the diazo-salt and the alkylamine, 

 but not into a mixture of diazo-salts and alkylamines, as is 

 the case with the compounds of group 9*. 



(12) Normal compounds, by the action of weak reducing 

 agents, are reduced to the original amine X . NH 2 , and the 

 hydrazine X . N 2 H 3 . Mixed compounds give, on reduction, 

 the base X . NH 2 and the hydrazine Y . X 2 H 3 , or the base 

 Y . NH 2 and the hydrazine X . N 2 H 3 t. 



(13) Alkyl-derivatives of normal compounds reduce to the 

 hydrazine X . N 2 H 3 and the alkylamine X . NHB4- Alkyl- 

 derivatives of mixed compounds give, on reduction, the 

 hydrazine X- or Y . N 2 H 3 , and the alkylamine Y- or X . NHR§. 

 This production of alkylamines indicates that the N-atom 

 which is in combination with the alkyl-radical is also attached 

 to the aromatic nucleus || . 



From the foregoing summary it will be seen that the mixed 

 diazoamido-compounds and their alkyl-derivatives display the 

 most striking characters, and are of special importance to the 

 present discussion, because it is in the attempt to formulate 

 these compounds on Kekule's plan that the greatest difficulties 

 are encountered. In view of the objections which apply to 

 all the formulae hitherto proposed it has been no easy matter 

 to suggest any alternative formula ; but I believe that the true 

 solution of the problem will be arrived at by regarding phenyl 

 as a triatomic radical, CgHg" 7 , instead of monatomic, as has 

 always been assumed in previous formulae. This suggestion 

 is in accordance with Fittig's theory of the constitution of 



* To this class, in addition to the ethyl-derivatives of m.p. 174°-175° and 

 187° (Nos. 7 and 8 in the Table), belong the two following compounds : — 

 (1) produced by the action of diazotized p-toluidine upon ethylaniline, 

 and (2) prepared by the action of diazotized aniline on ethyl-p-toluidine. 

 These two compounds are isomeric ; the first being decomposed by acids 

 (hot) into p-cresol and ethylaniline, and the second into phenol and 

 ethyl-p-toluidine (Nolting and Binder, Bull. Soc. Chim. vol. xlii. p. 341 ; 

 Gastiger, ibid. p. 342). , This pair of isomerides is completely analogous 

 to our two ethyl-derivatives (Nos. 7 and 8), which they resemble in their 

 mode of decomposition. 



t Thus the compound produced by the action of diazotized aniline 

 upon p-toluidine or the reverse gives, on reduction, phenylhydrazine and 

 p-toluidine (Nolting and Binder, loc. cit. p. 336). 



X Thus the compound obtained by the action of diazotized aniline on 

 methylaniline reduces to phenylhydrazine and methylaniline (loc. cit.). 



j Thus the compound prepared by Gastiger by the action of diazotized 

 aniline on ethyl-p-toluidine reduces to phenylhydrazine and ethyl-p- 

 toluidine (loc. cit. p. 342). 



|| The presence of substituents in one or both aromatic radicals may 

 interfere with the formation of hydrazines ; in such cases the correspond- 

 ing substituted amines are formed, or, if the substituent is N0 2 , the cor- 

 responding diamines. 



