Microwave-Assisted Synthesis and Biological Activity of 2,5-disubstituted-1,3,4-thiadiazole

Abstract

The reaction of substitute aryl and alkyl acid with thiosemicarbazide in the presence of dehydrating agent POCl₃, affords a series of 2-amino-5-aryl-1,3,4-thiadiazoles under microwave irradiation. 2,5-Disubstituted-1,3,4-thiadiazoles have attracted much attention due to their diverse biological activities, such as antimicrobial, antibacterial, anesthetic, anticonvulsant and antiinflammatory activities. Compared with classical methods, this method has the advantages of high yields, short reaction time, easy preparation and mild reaction conditions. The preliminary biological test showed that the synthesized compound has weak activity to G. zeae Petch, B. cinerea Pers, Phytophthora infestans (Mont.) de Bary, Botryosphaeria berengeriana f. sp. piricola (Nose) koganezawa et Sakuma, Fusarium oxysporum f.sp. cucumerinum and Cercospora arachidicola. The structures of compounds were characterized by melting points, ¹H NMR and IR.