Synthesis and Fungicidal Activities of New 1,2,4-Triazolo[1,5-a]pyrimidines

摘要

A series of new acetohydrazone-containing 1,2,4-triazolo[1,5-a]pyrimidine derivatives were designed and synthesized for the purpose of searching for novel agrochemicals with higher fungicidal activity. Their in vitro fungicidal activities against Rhizoctonia solani were evaluated, and the most promising compound, 2-[(5,7-dimethyl[1,2,4]triazolo[1,5-a]pyrimidin-2-yl)sulfanyl]-2'-[(2-hy droxyphenyl)methylidene]acetohydrazide (2-17), showed a lower EC50 value (5.34 mu g ml(-1)) than that of commercial carbendazim (EC50 = 7.62 mu g ml(-1)). Additionally, compound 2-17 was also found to display broadspectrum fungicidal activities, and its EC50 value (4.56 mu g ml(-1)) against Botrytis cinereapers was very similar to that of carbendazim. Qualitative structure-activity relationships (QSARs) of the synthesized compounds were also discussed.