Design, Synthesis, and Insecticidal Activity of Novel meta-Diamide Compounds Bearing a Phthalimide as a Potential GABA Receptor Antagonist

In pursuit of potent and environmentally benign insecticides targeting the γ-aminobutyric acid (GABA) receptor, a series of novel meta-diamide compounds bearing a phthalimide were rationally designed and synthesized. Bioassay studies revealed that most of the target compounds exhibited promising larvicidal activity against Mythimna separata ( M. separata ) and Plutella xylostella ( P. xylostella ). Notably, the most active compound N 15 displayed exceptional potency with LC 50 values of 3.82 and 3.42 mg·L –1 against M. separata and P. xylostella, respectively. Electrophysiological studies using Xenopus oocytes confirmed that compound N 15 exerted its insecticidal activity by targeting the GABA receptors.