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

Abstract

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 by ¹H-NMR spectroscopy and HRMS. Insecticidal and antifungal activity of these compounds were evaluated and the structure-activity relationships (SAR) were clearly and comprehensively illustrated. Compound 7, 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 compounds 19 and 25 exhibited 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, compounds 19 and 25 exhibited protective activity against Sclerotinia sclerotiorum on leaves of Brassica oleracea L. during in vivo experiments.