The design, synthesis, and biological activity assay of malononitrile oxime ether compounds as effective fungicides

Plant pathogenic fungi present a significant risk to crop productivity. The most cost-effective and efficient approach to mitigating plant diseases caused by these pathogenic fungi is using antifungal agrochemicals. In this study, we synthesized two sets of compounds incorporating malononitrile structures. Furthermore, we assessed the fungicidal properties of a subset of crucial intermediates and target compounds against specific agricultural fungi. Additionally, we employed predictive methods to estimate the oral LD50 values of selected target compounds in rats. The results demonstrated that the compounds E, particularly those with malononitrile and 1,2,3-triazole structures, exhibited significant inhibition (over 90%) against Rhizoctonia solani, including compound E11 with an EC50 value of 2.621 mg L−1. The toxicity prediction showed that E11 is a low-toxicity compound. Thus, E11 is a potential candidate for the further development of new R. solani selective inhibitory fungicides.