The cyclization processes of 2-diazomalondithioamides, generated by five different methods, have been studied. The ambient character of the derivatives of 2- diazomalondithioamide is the cause of previously unknown rearrangements of 5-mereapto- 1, 2, 3-triazole-and 5-amino-1, 2, 3-thiadiazole-4-NR-carbothioamides to 5-NR-amino-1, 2, 3- thiadiazole-4-carbothioamides. NMR 1H and 13C spectra and mass-spectra are ...