96 REPORTS ON THE STATE OF SCIENCE.— 1915, 



[With J. Eeiliy, M.A., M.Sc, and W. Caldwell, M.A.] 



The diazotisation of 5-amino-l : 2 : 4-triazole and its homologues 

 has been further investigated. This base is diazotisable to stable dia- 

 zonium salts in aqueous solutions of the oxy- acids, although in pre- 

 sence of hydrochloric acid 5-chloro-l : 2 : d-triazole is the product 

 actually isolated. In aqueous solutions the diazonium oxy- salt slowly 

 deposits an ill-defined substance which, although containing its diazo- 

 nitrogen, no longer couples with alcoholic or alkaline /i-naphthol. This 

 product is, however, re-converted into a coupling diazonium salt by 

 dissolving in moderately concentrated nitric or sulphuric acid. On 

 adding auric chloride hydrochloride to the solution of these diazonium 

 oxy- salts, a sparingly soluble crystalline a'uric chloride derivative is 

 precipitated. 



[ 



HC-N. -■ 



Similar results have. been obtained with 5-amino-3-methyl-l :2 :4- 

 triazole. This base gives a stable diazo- solution in the presence of 

 nitric or sulphuric acid. The auric chloride derivative and the non- 

 coupling iso-diazo- derivative have been isolated, and are being further 

 investigated. 



A comparative study is being made of 5-amino-3-phenyl-l : 2 : 4- 

 triazole. The diazonium oxy- salts of the bases of the triazole series 

 couple with phenols and the more reactive aromatic bases such as 

 yS-naphthyl-amine yielding azo- derivatives soluble in aqueous alkali 

 hydroxides, this property indicating the acidic character of the triazole 

 ring, the imino-hydrogeu 



/ \ 



EC — Nv ^ 



II ^CN,- 



nnr/ 



NHj 



being replaceable by metallic radicals. 



