SYNTHESIS, CHARACTERIZATION AND BIOLOGICAL EVALUATION OF NEW BAYLIS-HILLMAN DERIVED NITRO METHYLENE IMIDAZOLE DERIVATIVES AS INSECTICIDAL AGENTS

A series of Baylis-Hillman derived N-cinnamyl substituted nitro methylene imidazole derivatives 4a-swere synthesizedfrom Baylis-Hillman acetates and nitro methylene imidazole compoundsand characterised by ¹H NMR, IR, Mass and HRMS spectroscopy. Their insecticidal activities were evaluated against T. Castaneum and compared with a standard insecticide Permethrane. Preliminary biological activity tests showed that most of the compounds exhibited good insecticidal activity against T. Castaneum at 100µg/cm² especially compounds 4b, 4g, 4i, 4l, 4n and 4r showed good insecticidal activity against T. castaneum, interestingly compound 4b with p-fluoro substitution displayed 75% activity. The structure-activity relationship showed that compounds with electron-with drawing substitutions like -F, -Br, -Cl, -NO₂, -CF₃ at the para position havinggood insecticidal activity and compounds with electron-with drawing groups like -F, -Br at the meta position have shown moderate activity.This work provides some hints for further structural modifications on the Baylis-Hillman derivatives and the enhancement of insecticidal activity.