Electrochemical Synthesis of 5-Amino-1,2,4-thiadiazoles from Elemental Sulfur, Isocyanides, and Amidines

1,2,4-Thiadiazoles, an important five-membered heterocyclic ring containing nitrogen and sulfur, are widely present in various functional molecules. Hence, a facile electrochemical three-component reaction of isocyanides, elemental sulfur, and amidines is reported for the construction of 1,2,4-thiadiazoles. A series of 5-amino-1,2,4-thiadiazoles are prepared in a simple undivided cell at room temperature with good functional group tolerance and high atom economy. Cheap, nontoxic, abundant, and stable elemental sulfur is used as a powerful sulfur source.