Regiospecific Isomerization of 2-Benzoxazinon-2-yl Benzoic Acid Toward Some Nitrogen Nucleophiles as Environmental Insecticide

Abstract

Based on the strategies of receptor structure-guided benzoxazinone design, a series of nitrogen nucleophiles such as benzyl amine, sodium azide, 4,4-bis o-toluidine, 4-butanolamine, glucosamine, 2-amino pyridine, 2-picolinyl amine, hydroxyl amine, and hydrazine derivatives, for example, hydrazine hydrate, semicarbazide, thiosemicarbazide, methylhydrazide, phenylhydrazide, could be reacted with 2-benzoxazine-2-yl benzoic acid 1. According the basicity of nucleophiles, regiospecific isomerization of benzoxazinone has been considered through formation of the spiro derivatives. Organic reagents can be controlled on the course of reaction of benzoxazinonyl benzoic acid 1. Preliminary bioassays indicated that the insecticidal spectra of the synthesized compounds were ecofriendly biodegradable materials due to isomerization. Among these analogues, the quinazoline 2–4 showed 100% mortality against Nilaparvata lugens (LC50 = 0.087 mg/L). The insecticidal potency of our designed analogues was dual-controlled by isomerization to quinazolinone and spiro derivatives that observed in vitro and shed light on the novel insecticidal mechanism. The chemical structure of the products can be confirmed by microanalytical, spectral data, optimized and stimulated by quantum chemical parameters.