Synthesis Of The Novel Heterocyclic-Fused Thiadiazoles

This paper discusses the synthesis of thiadiazole fused heterocyclic compounds by using 2-amino-1,3,4-thiadiazole and its derivatives as substrates,the whole in four Parts.In the first part,the synthesis methods of nitrogen-containing sulfur-containing fused heterocyclic compounds with thiadiazole as structural unit and the application prospects of related compounds are reviewed.In the second part,the 2-amino-1,3,4-thiadiazole derivative and ethyl4-chloroacetoacetatewereusedasthestartingmaterials,and[1,3,4]thiadiazolo[3,2-?]thiazolo[5',4':5,6]pyrido[4,3-d]pyrimidinonewas prepared by Thorpe-Ziegle reaction and Pictet-Spengler reaction.Inthethirdpart,thethree-componentreactionof[1,3,4]thiadiazolo[3,2-a]pyrimidine-5,7(6H)-dione,1-methylindoleand aromatic aldehyde was investigated.A two-step one-pot synthesis route using piperidine and a solid acid catalyst Amberlyst-15 as a catalyst was determined.In the fourth part,the synthesis of imidazo[2,1-b][1,3,4]thiadiazole with2-amino-1,3,4-thiadiazole derivatives and 3-bromoacetylcoumarin was investigated.The structure of the synthesized product was characterized by elemental analysis,IR and ~1H NMR.