Synthesis and Properties of Pyridine-4-carboxamide-1,3,4-oxadiazoles

Four new 2,5-disubstituted 1,3,4-oxadiazole derivative N-(5-aromatic-1,3,4-oxadiazol-2-yl)picolinamides 2a similar to 2d were obtained by condensation, oxidization and acylation reactions, with isonicotinic acid and single substituted aromatic aldehydes as raw materials. These compounds were characterized by IR, 1H NMR and elemental analysis. Fluorescence test results indicated that Cu2+ could make this series compounds fluorescence quenching, and Zn2+ could only enhance the fluorescence intensity of N-[5-(4-methoxyphenyl)-1,3,4-oxadiazol-2-yl]isonicotinamide (2b). Furthermore, those compounds all showed good fungicidal activity against the tested bacteria, and among them, N-(5-p-tolyl-1,3,4-oxadiazol-2-yl)isonicotinamide (2d) against Gibberella zeae was reached 100%.