Study On "One-Pot" Synthesis And Biological Activities Of 5-Aryl-1H-Pyrazole Derivatives

Pyrazole derivatives are widely used in pesticides due to their well biological activities.So the synthesis of a large number of pyrazole deirviatves with diverse biological activities has a very positive and important significance for the creation of pesticides and pharmaceuticals.In order to explore the biologically activities of pyrazole pesticides,the development of the study of pyrazole deirviatves in pesticides and pharmaceutical fields and the popular synthetic methods were reviewed.In recent years,The “One-Pot" method has become a popular,green,simple and convenient method of organic synthesis,So the “One-Pot” method is used though the synthetic process.First,the ketone containing ?-H was converted to the enolate anion with a strong base.Then adding acid chloride to react with it to form 1,3-dicarbonyl compound intermediates.Finally,the hydrazine and 1,3-dicarbonyl compounds were occurred condensation reaction to form 5-aryl-1H pyrazole derivatives.The reaction conditions in each step were explored and optimized in the experiment.The experimental factors such as solvent types,alkali and its dosage,reaction temperature,reaction time,reaction substrate molar ratio were dicussed.then the type of reaction substrate was also expanded.And finally a series of pyrazole derivatives was sythesized.The 18 new novel pyrazole derivatives were designed and synthesized.The structures were characterized by IR,1H NMR,GC-MS Spectroscopes,and were confirmed by element analysis.Parts of the compounds were characterized by single-crystal X-ray diffraction.In the paper,the insecticidal,herbicidal as well as bactericidal activity of the compounds were tested,and the results showed that compounds 5c~5j and 5n~5o which containing methoxy groups on the 5-ring of pyrazole ring showed some inhibitory activity on Lemna minor,Chinese cabbage and Cynodon dactylon,compounds 5c~5e,5g~5h,5j,5n~5o exhibited partly bactericidal activity.Especially,The ratio of herbicidal activity compound 5h on Lemna minor reached 66.6% and the inhibition activity on Fusarium graminearum reached 51.9%,so it is of great significance in further research and application.