Synthesis and antimicrobical evaluation of a novel class of 1,3,4-thiadiazole: Derivatives bearing 1,2,4-triazolo[1,5-a]pyrimidine moiety

Abstract A series of novel 1,3,4-thiadiazole derivatives bearing 1,2,4-triazolo[1,5- a ]pyrimidine moiety were synthesized by the method of splicing active substructures. Among these derivatives, compounds 12 , 13 , 15 – 22 and 24 – 31 were firstly reported. All the compounds were assayed for antimicrobial activities against five fungi strains and four bacteria strains. The preliminary results indicated that compounds 25 and 28 – 31 showed good antifungal activities against Physaclospora piricola and Rhizoctonia solani . Compound 26 exhibited good antifungal activities against Cercospora beticola and R . solani . Most of the compounds showed better antibacterial activities against Gram-negative bacteria strains than Gram-positive bacteria strains. Compounds 25 and 28 showed the best activities against Pseudomonas fluorescence while compounds 30 – 31 showed good activities against Escherichia coli .