Investigation of Novel Pesticides with Insecticidal and Antifungal Activities: Design, Synthesis and SAR Studies of Benzoylpyrimidinylurea Derivatives

In order to find pesticides with insecticidal and antifungal activities, a series of novel benzoyl pyrimidinylurea derivatives were designed and synthesized. All target compounds were identified by1H-NMR spectroscopy and HRMS. Insecticidal and antifungal activity of these compounds were evaluated and the structure-activity relationships (SAR) were clearly and comprehensively illustrated. Compound7, with low toxicity to zebrafish (LC50= 378.387 µg mL−1) showed 100% inhibition against mosquito (Culex pipiens pallens) at 0.25 µg mL−1. Both compounds19and25exhibited broad-spectrum fungicidal activity (>50% inhibitory activities against 13 phytopathogenic fungi), which were better than those of the commercial pesticide pyrimethanil (>50% inhibitory activities against eight phytopathogenic fungi). Furthermore, compounds19and25exhibited protective activity againstSclerotinia sclerotiorumon leaves ofBrassica oleraceaL. during in vivo experiments.Keywords:benzoylpyrimidinylurea derivatives;antifungal activity;insecticidal activity;embryo toxicity;zebrafish