Synthesis, characterization and fungicidal activities of novel fluorinated 3,5-disubstituted-4H-1,2,4-triazol-4-amines

Thiocarbohydrazide and substituted benzoyl hydrazine were used as starting materials to synthesize fifteen fluorinated 3,5-disubstituted-4H-1,2,4-triazol-4-amines. All the title compounds were characterized using IR, 1H and 19F NMR spectroscopy, mass spectrometry (MS) and elemental analysis. The structures of compounds 6g and 7 were confirmed by X-ray diffraction crystallography. The preliminary bioassay results showed that these compounds exhibited certain fungicidal activities against Rhizoctonia solani, Fusarium graminearum, Botrytis cinerea and Colletotrichum capsici at the concentration of 100 μg/mL.

Graphical abstractFifteen 3,5-disubstituted-4H-1,2,4-triazol-4-amines were designed, synthesized and characterized, two of them were confirmed by X-ray diffraction crystallography. These title compounds showed certain fungicidal activities against the plant pathogens.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Fifteen fluorinated 3,5-disubstituted-4H-1,2,4-triazol-4-amines were synthesized. ► Two title compounds were confirmed by X-ray diffraction crystallography. ► The title compounds showed certain fungicidal activities. ► The compounds with trifluoromethyl showed better activity than those with single fluorine.