Design,Synthesis and Bioactivity of New N-Methoxycarbamate Containing Pyrazole

Strobilurins are one of the most important classes of agricultural fungicides. To discover new strobilurin analogues with high pesticidal activity,a series of new N-methoxycarbamate derivatives containing substituted pyrazoles 3a—3r were synthesized from substituted aryl alkyl ketones as starting material by esterification,cyclization and condensation. The structures of substituted pyrazole derivatives were confirmed by 1H NMR,IR and elemental analysis. Preliminary biological evaluation show that compounds 3 have good fungicidal activity against P. oryzae,P. cubensis and E. graminis at 400 mg/L. The compounds with R1=methyl or methoxy substituted phenyl have best activities against P. oryzae. The compounds with R1=phenyl or methyl substituted phenyl have higher activities against P. cubensis and E. graminis than the others and the compounds with R2=methyl have higher activities against fungi than that with hydrogen.