Synthesis and Antifungal Activity of 5-Trifluoromethyl-1,2,4-oxadiazole derivatives Containing Hydrazide Group as Potential Fungicides

To further investigate the potential fungicide with heterocyclic moiety, three new 5-trifluoromethyl-1,2,4- oxadiazole derivatives derivatives containing hydrazide group were designed, synthesized, and assayed for inhibitory activity against plant pathogenic fungi. Especially, compound 3a presented excellent in vitro antifungal activity against Valsa mali and Botryosphaeria dothidea, which was substantially stronger than chlorothalonil. In vivo antifungal assay revealed that compounds 3a and 3b exhibited prominent protective activity against soybean rust, which were at the same level with benzovindiflupyr. These results indicated that 5-trifluoromethyl-1,2,4-oxadiazole derivatives could be a potential fungicide lead.. KEYWORDS :5-trifluoromethyl-1,2,4-oxadiazole derivatives, Antifungal activity, Hydrazide.