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Subject: Chemistry × Author: Chopra, Indu × End date: 2016 × Type: Thesis × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Synthesis, Characterization and Evaluation of some Substituted isoxazoles as nematicides against root-knot nematode (meloidogyne javanica).
    (CCSHAU, 2004) Chopra, Indu; Rajvir Singh
    Isoxazole derivatives exhibit wide spectrum of biological activities. This nucleus has different agrochemical and pharmaceutical properties and has a lot of potential for their use in agrochemical (pesticides). Keeping this in mind, synthesis and bioevaluation of substituted isoxazoles (15-22 and 36-44) have been undertaken. Condensation of substituted aldehydes (1-4) and substituted acetophenones (5-6) refluxing in 20% ethanolic sodium hydroxide solution gave various substituted chalcones (7-14) in good yields. The reaction of chalcones (7-14) with hydroxylamine hydrochloride in presence of anhydrous sodium acetate gave substituted isoxazoles (15-22). Similarly substituted hydroxy isoxazoles (27-29) were prepared using substituted aldehydes (1, 3, 4) and hydroxy acetophenone (23). These compounds (27- 29) were further treated with epichlorohydrin in presence of catalytic amount potassium carbonate which yielded 3-(4-oxiranylmethoxyphenyl)-5-(4-chloro-/methyl- /2-chlorophenyl) isoxazoles (30-32). These compounds (30-32) were then reacted with substituted phenols (33-35) and yielded 3-{4-[3-(4-substitutedphenoxy)-2- hydroxypropoxy]phenyl}-5-(4-substitutedphenyl)isoxaz oles (36–44). The synthesized compounds were characterized by spectroscopic technique (NMR, IR) and elemental analysis data. All the synthesized compounds (15-22 and 36-44) were evaluated for nematicidal activity aginst root-knot nematode (Meloidogyne javanica) at 1000, 500, 250 and 125 ppm concentrations. It was found that compound 16 among 15-22 and compound 40 among compounds 36-44 were found to be most nematoxic. These compounds deserve for investigations for their possible use in agrochemicals for plant disease control.