Contributions to the Knowledge of the Tetrazoline Group. 209 



Contributions to the Knowledge of the Tetrazoline Group. By 

 S. Ruhemann, M.A., Gonville and Caius College, and R. W. 

 Merriman, B.A. 



[Read 27 November 1905.] 



Ruhemann and Stapleton (Trans. Chem. Soc, 1899, 75, 1131 ; 

 1902, 81, 261) showed that the properties of tetrazoline, 



CHf J,CH, 



differ most markedly from those of its N-aryl derivatives (see 

 Ruhemann, Trans. Chem. Soc, 1899, 55, 242 ; 1890, 57, 50). 

 Of especial interest is the behaviour of methyl iodide towards 

 tetrazoline, which, as previously (loc. cit.) stated, furnishes two 

 compounds, one of them being dark blue, the other colourless. 

 From the analytical results the composition C 3 H 9 N 4 I 3 had been 

 deduced for the former, and C 3 H 7 N 4 I for the colourless substance. 

 We now find that the blue iodide contains two atoms of hydrogen 

 less and therefore corresponds to C 3 H 7 N 4 I 3 , because it is formed 

 directly from the colourless compound by its union with iodine. 

 On further examination of the substance C 3 H 7 N 4 I 3 we have been 

 struck by its resemblance to the periodide of diazobenzene chloride. 

 This fact points to analogous formulae, and leads to the view that 

 the iodide C 3 H 7 N 4 I should be represented thus 



NH<f >N, CH 3 I, 



and that the analogous formula has to be assigned to the additive 

 product C 3 H 7 N 4 T 3 . According to this view, which agrees with the 

 behaviour of the iodides, these compounds would appear as 

 derivatives of a dihydrotetrazine, 



y N = N x 

 OH/ >CH, 



isomeric with bisdiazomethane and tetrazoline. 



Hantzsch and Silberrad (Ber. 1900, 33, 58) have shown that 

 bisdiazomethane under the influence of hydrochloric acid, changes 

 to tetrazoline. This transformation may be assumed to take place 

 thus : 



/N : N x /N = N\ 7/ N-NH v 



CH 2 < >CH 2 -CH,< V)H^CH< y/ CH, 



X N : W " X NH.N^ X NH-N* 



Bisdiazomethane Tetrazoline 



and to be preceded by the formation of the dihydrotetrazine, 



