Synthesis, insecticidal activities and SAR of novel phthalamides targeting calcium channel

Abstract

In order to find novel and environmental friendly insecticides targeting the ryanodine receptor, three series of novel phthalamides containing heptafluoroisopropyl group, low fluorine atoms group and non-fluorine group were designed and synthesized. 35 novel structures of three series were obtained. Insecticidal activities of title compounds against oriental armyworm (Mythimna separata) and diamondback moth (Plutella xylostella) indicated that most of title compounds showed moderate to high activities at the tested concentration. The structure–activity relationship (SAR) was discussed in detail. During synthesizing title compounds B8, C7, D1, D9 and D12, their corresponding positional isomers (B8′, C7′, D1′, D9′ and D12′) were afforded, and their structures were confirmed by 2D NMR. The calcium-imaging technique was also applied to investigate the effects of compounds B2, B10, C4 and C5 on the intracellular calcium ion concentration ([Ca2+]i), which indicated that they released stored calcium ions from endoplasmic reticulum, which denoted that some compounds are potential modulators of the insect ryanodine receptor (RyR).