Synthesis And Biological Activities Of-3-substituted-6-pyrazole1,2,4-triazolo[3,4-b]-1,3,4-tiadiazoles

Nowadays, because of the diverse structure, high activity and low pollution ofheterocyclic compound, much attention has been paid to it. Nitrogenous heterocycliccompounds is the key research object, especially pyrazole with its high efficiency, low poisonand wide biological activity as a representativet.1,2,4-triazolo[3,4-b]-1,3,4-tiadiazolescompounds also have a wide variety of biological and Pharmacological activities, such asantitumor, antibacterial, anticancer, anti tuberculosis, diminish inflammation, weeding,insecticidal activity and the regulation to plant growth.In order to more in-depth research contains thick heterocyclic serial change activity andlooking for a new requirements of pesticide and medicine. According to the activesuperposition principle, the pyrazole into all triazole and showed two azole, by changing thefused ring substituent, design synthesis more did not see the new compounds reported in theliterature. And looking forward to have a better biological activity.we connected differentsubstituents pyrazole compound to triazole-oxadiazole, design a series of unreportedcontaining pyrazolyl triazole and thiadiazole compounds.4-substituted acetophenone and diethyl oxalate were used as the starting materials, basedon the methods of Claisen condensation, Knorr cyclization, reaction with hydtazine hydate,replace, hydrolysis and a series of reaction, and the intermediates of pyrazole-3-carboxylicacids were obtained. And the other series of intermediates4-amino-5-sulfhydryl-1,2,4-alltriazole were obtained by reaction with different substituted acid.The39new3-substituted-6-pyrazolyl-1,2,4-triazolo[3,4-b]1,3,4-tiadiazoles compounds which have notyet been reported have been synthesized under the thionyl chloride between their two seriesintermediates.The structures of the title compounds were characterized by IR, NMR and elementalanalyses. The compound Ⅵ8was characterized by HSQC and HMBC for further studying thestructures.The wheat gemma method preliminary bioassay results indicated that the concentrationof10mg/L of some compounds display herbicidal activity to some extent. However,when1-hydrogen is substituded by methyl in pyrazolo. The title compounds VII series of auxinactivity are better than VI series.In addition the punch for determination of the target product in50mg/L concentration ofescherichia coli and staphylococcus aureus bacteriostatic activity, The four compounds thathave better good bacteriostatic activity were determined by the minimum inhibitoryconcentration (MIC). The MIC of escherichia coli and staphylococcus aureus were: Ⅵ7: 3.13mg/L and6.25mg/L, Ⅵ8:6.25mg/L and12.5mg/L, Ⅶ6:6.25mg/L and12.5mg/L, Ⅶ7:12.5mg/L and12.5mg/L. the test results show that most of the compounds have goodbacteriostatic activity. compound Ⅵ7and Ⅵ8exhibit higher than the others, and were similarwith chloramphenicol. There havn’t been substituted by methyl in pyrazolo of VI seriesantibacterial activity are better than methyl substituted VII series...