Synthesis and insecticidal activities of novel 1 H -pyrazole-5-carboxylic acid derivatives

Fourteen 1 H -pyrazole-5-carboxylic acid derivatives containing oxazole and thiazole rings were synthesized and characterized by 1 H NMR, mass spectrometry and elemental analysis. Most target compounds were obtained in overall yields in the range of 30–50%. The insecticidal activities of these new compounds against Aphis fabae were evaluated. The bioassays’ results indicate that some of these compounds exhibit good activities, especially compound 7h which shows 85.7% mortality against A. fabae at a concentration of 12.5 mg/L. This activity is comparable to that of the commercial insecticide imidacloprid.