Design, Synthesis, and Bioactivity of Eighteen Novel 2H‐1,4‐Benzoxazin‐3(4H)‐one Containing a Propanolamine Moiety

Abstract

To develop a novel skeleton for broad-spectrum pesticides with high-efficiency against tea tree diseases, a series of aniline 2H-1,4-benzoxazin-3(4H)-one derivatives containing a propanolamine structure was synthesized and confirmed by 1 H-NMR, 13 C-NMR, 19 F-NMR, HRMS, and single-crystal diffraction analysis. Bioactivities were evaluated against tobacco mosaic virus (TMV, the model virus), three kinds of bacteria, and five typical plant fungi. Bioassay results showed that compound 2i (EC 50 = 395.05 μg/mL) had the best curative activity against TMV, 3d (EC 50 = 45.70 μg/mL) had the best inhibitory activity against Pseudomonas syringae pv. Actinidiae, and 3a (EC 50 = 13.53 μg/mL) had the best inhibitory activity against Pestalotiopsis trachicarpicola. Scanning electron microscope morphological observation of P. trachicarpicola treated with 0, 100, and 200 μg/mL 3a revealed dried, flattened and folded outer walls of the hyphae at higher concentrations, leading to inhibition of fungal growth. The broad-spectrum bioactivities (against viruses, bacteria and fungi) of this series of target compounds indicate that these 2H-1,4-benzoxazin-3(4H)-one derivatives containing a propanolamine moiety are potential skeletons for developing pesticides with wide-ranging activities against various tea tree diseases.

Cинтез Нових Похідних Бензоксазину За Реакцією Віттіга

“…Низка похідних 2H-1,4-бензоксазин-3(4H)-ону, що містять структурний фрагмент у пропаноламіну, можуть використовуватись як пестициди широкого спектру дії завдяки їх антибактеріальним, противірусним та фунгіцидним властивостям (Rao et al, 2022).…”