Synthesis of novel thiadiazoles and bis-thiadiazoles from carbonothioic dihydrazide

Efficient syntheses of 1,3,4-thiadiazoles and bis-thiadiazoles by the reaction of hydrazonoyl halides with carbonothioic dihydrazide are reported. In addition, 1,2,4-triazolo[3,4- b ][1,3,4]thiadiazole is obtained via oxidative cyclization of bis-(substituted methylene)carbonothioic dihydrazone.