Isoxazole derivatives as a potential insecticide for managing Callosobruchus chinensis

Abstract

A series of twenty 3,5-disubstituted isoxazoles were synthesized (using conventional and microwave methods) by the reaction of substituted chalcones with hydroxylamine hydrochloride and characterized by TLC, IR, ¹H NMR, ¹³C NMR spectroscopic data and elemental analysis. The compounds were screened for insecticidal activity against the pulse beetle, Callosobruchus chinensis. Compounds 1a (LC₅₀ 36 mg L⁻¹), 1d (LC₅₀ 110 mg L⁻¹), 2c (LC₅₀ 93 mg L⁻¹) and 5b (LC₅₀134 mg L⁻¹) were more effective than the recommended organophosphorous insecticide dichlorvos (2,2-dichlorovinyl dimethyl phosphate) (LC₅₀ 155 mg L⁻¹). These compounds provide a lead for designing new substances endowed with insecticidal activity.