Synthesis, Characterization And Biological Activities Of1,2,4-Triazole Derivatives

Nitrogen heterocyclic ring has good biological activities and important application. The derivatives of triazoles attracted more and more attention for there excellent wide range of biological activities. In order to find the higher activity of triazole derivatives, two series of new compounds were synthesized in this paper.(1) The Schiff bases of1,2,4-triazole were synthesized by condensation of the intermediates4-amino-3-mercapto-5-substituted-1,2,4-triazole with a series of aromatic aldehydes or ketones in the presence of glacial acetic acid as catalyst. The intermediates4-amino-3-mercapto-5-substituted-1,2,4-triazole were synthesized by propionic acid, butyric acid and phenylacetic acid with1,3-diaminothiourea.(2) The3,6-disubstituted-1,2,4-triazolo[3,4-b][1,3,4] thiadiazole were synthesized by the intermediates4-amino-3-mercapto-5-substituted-1,2,4-triazole with carboxylic acids in the presence of phosphorus oxychloride as dehydrating agent. The structures of the compounds have been confirmed by elemental analysis, IR,1H NMR.The preliminary biological activities of the compounds to five vegetable pathogens have been tested including Gibberlla nicotiancola, Pythium solani, Gibberlla saubinetii, Alternaria iycopersici and Fusarium oxysporium f.s.p. niveum. The results showed that most of them exhibited good fungicidal activities. The medium inhibition concentration EC50and the95%inhibition concentration EC95of those compounds are less than or relative to those of the comparison. The relationship between the structures and the biological activities has been discussed.