Synthesis and Fungicidal Activity of 2,5-Disubstituted- 1,3,4-oxadiazole Derivatives

Abstract

A series of new 2,5-disubstituted-1,3,4-oxadiazole derivatives have been designed and synthesized by adding pyridine ring and thiazole ring to the structure of 1,3,4-oxadiazole. The structures of target compounds have been confirmed by 1 H NMR, EI-MS, IR spectroscopy and elemental analyses. The structure of 2-[(6-pyridin-3-yl)methylthio]-5-(pyridin-4-yl)-1,3,4-oxadazole has been determined by single crystal X-ray diffraction. The results of preliminary bioassay indicated that some compounds possess potential fungicidal activities against Fusarium oxyporium, Gibberella zeae, Rhizoctonia solani, Dothiorella gregaria and Colletotrichum gossypii at a dosage of 5.0×10-5 g/mL. The fungicidal activities of 1,3,4-oxadiazole derivatives adding thiazole ring were better than those of those adding pyridine ring.

Recent achievements on the agricultural applications of thioether derivatives: A 2010–2020 decade in review

“…As well, compound 21 displayed excellent fungicidal activity against S. lycopersici (85.12%), which was even better than that of Zhongshengmycin. Meanwhile, the synthesis and evaluation of antifungal activity against S. lycopersici, F. oxysporum, and B. cinerea of new 2,5-disubstituted-1,3,4-oxadiazole thioether derivatives were reported by Liu et al [33], and the results indicated that compound 22 (Figure 4) possessed potential fungicidal activities against F. oxysporum (97.83%), G. zeae (92.05%), R. solani (94.74%), D. gregaria (77.72%), and C. gossypii (82.61%) at 50 μg/mL, which were even better than those of the other target compounds.…”

4-Chloro-5-(morpholin-4-yl)-2-[(5-phenyl-1,3,4-oxadiazol-2-yl)methyl]pyridazin-3(2H)-one

“…1,3,4-Oxadiazole derivatives are a promising field of study because they possess good bioactivity (Liu et al, 2014). This substructural unit has been used as a scaffold to design and synthesize chemical compounds with biological, medicinal and agricultural activities (Gan et al, 2016;Shaikh & Meshram, 2016;Luqman et al, 2015;Fershtat et al 2016;Pattison et al, 2009).…”