Synthesis of 1H-Substituted 1- pyrazole, and their Biological Activities

In order to search for the new pyrazolyl-heterocycles lead compounds, eight pyrazolyl-heterocycles were synthesized from 3-ethyl-1-methyl- 4-substituted-5-pyrazolecarboxylic acid chloride and nitrogen heterocyclic rings such as 3-methyl-5-pyrazolone, 1H-3-ethyl-5-pyrazole carboxylic ethyl ester, etc. The structures of the new compounds were confirmed by 1H NMR, IR, MS and elementary analysis. The results of pretiminary biological tests indicated that compound 5d showed inhibitory activities (45.6%) against Pyricularia oryzae at 25 μg/mL. 5c showed inhibitory activities (53.9%) against Nephotettix cincticeps at 500 μg/mL.