Abstract From the reaction mixture of 2-pyridyl isothiocyanate with azoimide in dioxane 5-(2- pyridyl-amino) tetrzole, 2-pyridylthiourea and elemental sulfur were isolated instead of the expected 5-(2-pyridylamino)-1, 2, 3, 4-thiatriazole. The mechanism of the reaction mentioned was studied on the basis of the synthesis of the assumed intermediates and the isolation of the intermediates by means of compounds with an activated acetylenic or ...