5‐Azapurines and the structures of sym‐triazole intermediates

Several isomers are possible when an isocyanate or an isothiocyanate is allowed to react with 3‐amino‐1,2,4‐triazole. It was found that variations in reagents or reaction conditions could be used to produce isomeric derivatives. The effect of substituents on the chemical shifts of adjacent ring protons is described for a number of new triazole derivatives. These data can be used to assign structures to new sym‐triazole reaction products. Appropriate triazoles were used as intermediates in the synthesis of s‐triazolo[1,5‐a]‐s‐triazine (5‐azapurine) derivatives. Spectral properties, methods of synthesis, and modes of degradation are described for several new members of this ring system.