| Due to a variety of physiological activities, recently, indole derivatives have been widely used in pharmaceutical and pesticide fields, and become a focus on the organic and medicinal chemistry research. In this dissertation, a series of 2-((N-substituted phenylsulfonyl indol-3-yl) methylene) malonate derivatives were synthesized and tested their antifungal activities.1. 3-Formyl indole derivatives (2a-g) wer synthesized by Vilsmeier-Haack reaction. Then the 3-formyl indoles reacted with dethyl malonate to give diethyl 2-((1H-indol-3-yl)methylene)malonate derivatives (3a-f) by Knoevenagel reation. Finally, ten 2-((N-substituted phenylsulfonyl indol-3-yl)methylene) malonate derivatives (4a-j) were obtained by the reaction of 3a-c with substituted benzenesulfonyl chlorides. All compounds (14 compounds are new ones) were characterized by melting points, 1HNMR and MS spectra.2. 23 compouds have been assayed their antifungal activitie at 0.1mg/mL against seven phytopathogenic fungi, such as Fusarium graminearum, Helminthosporium sorokinianum, Fusarium oxysporium f.sp.vasinfectum, Pyricularia oryzae, Alternaria brassicae, Fusarium oxysporium f.sp.cucumarinum, and Alternaria alternata. Hymexazole as the positive control. Compounds 2d, 2b, 2f, 2g, 3a have the broad-spectrum antifungal activities, and generally the 3-formyl indoles displayed the better antifungal activities as compared with their corresponding 2-((1H-indol-3-yl) methylene)malonates and 2-((N-substituted phenylsulfonyl indol-3-yl)methylene)malonates. Meanwhile, the antifungal activities of 2-((1H-indol-3-yl) methylene)malonates were more potent than those of 2-((N-substituted phenylsulfonyl indol-3-yl)methylene)malonates. Therefore, it demonstrated that the free-nitrogen of indole ring was a important site for the antifungal activity. The above results will pave the way for the further study of indole derivatives as antifungal agents. |
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