316 Mr Ruhemann, The Dihydrotetrazines. 



The Dihydrotetrazines. By S. Ruhemann, M.A., Cams College. 



[Read 26 February 1906.] 



Lately Ruhemann and Merriman {Camb. Ph. Soc., vin. 209 ; 

 Trans. Chem. Soc, 1905, lxxxvii. 1768) showed that, in the pre- 

 sence of piperidine, tetrazoline condensed with aldehydes to form 

 compounds which were represented thus : 



N : N 

 R . CH : C< >CH ; 



it was, therefore, assumed that their formation was accompanied 

 by the change of tetrazoline into its isomeride. This view seemed 

 to be supported by the properties of the iodide C 3 H 7 N 4 I which 

 is formed by the action of methyl iodide on tetrazoline, and by 

 the behaviour of the hydrochloride of the base towards platinic 

 chloride. Recently Stolle (Ber. 1906, xxxix. 826) expressed the 

 view that since diphenyltetrazoline, 



// 



N— NH> 



C 6 H 5 .C\ /.CH . C 6 H 5 



yielded with benzaldehyde a compound which on account of its 

 synthesis had the formula, 



C G H 5 .C^ clc 6 Ii C.C 6 H 5 . 



an analogous constitution had to be assigned to the products 

 which were produced by the interaction of tetrazoline with alde- 

 hydes. In a note which, shortly, will appear in the Berichte I 

 have pointed out that such a conclusion is not justified since the 

 behaviour of tetrazoline is markedly different from dimethyl- 

 tetrazoline. This difference is also manifested by the following 

 facts : 



Dimethyltetrazoline reacts with methyl iodide to yield almost 

 exclusively the iodide C 5 H n N 4 I which may be transformed into 

 the periodide C 5 H n N 4 I 3 . This is brown whereas the correspond- 

 ing compound from tetrazoline is dark blue. Again, the iodide 

 C 3 H 7 N 4 I produced from tetrazoline, in the presence of an alkali, 

 is oxidised by the oxygen of the air to yield a blue solution, 



