Modular Assembly of Chalcones, N-Tosylhydrazones, and KSCN/KSeCN for the Synthesis of Trisubstituted Imidazo[2,1-b][1,3,4]thiadiazoles/selenadiazoles

A modular protocol that achieved the efficient synthesis of imidazo[2,1-b][1,3,4]thiadiazoles/selenadiazoles via using easily available N-tosylhydrazones, chalcone derivatives, and KSCN/KSeCN is proposed. The method overcomes the elongated synthesis steps and prefunctionalized synthons of previous methods. It solves the problem of traditional preparation methods, which makes it difficult to synthesize thickened selenium-containing heterocyclic molecules, further expanding the number of members in its family. The fluorescence of these compounds also reveals the potential values of the scaffolds we synthesized.