Synthesis, crystal structure, characterization and antifungal activity of 3,4-diaryl-1H-Pyrazoles derivatives

Abstract

A series of 3,4-diaryl-1H-pyrazoles derivatives were designed and synthesized by the reaction of 3-heteroarylchromones and 3-phenylchromones with hydrazine hydrate in good yields. All of those compounds were characterized by 1H NMR, 13C NMR, IR, and HRMS. Moreover, 3-(2,4-dihydroxyphenyl)-4-(4-hydroxyphenyl)-1H-pyrazole and 3-(2,4-dihydroxy phenyl)-4-(4-methoxyphenyl)-1H-pyrazole were further conformed by the single crystal X-ray diffraction. In addition, the antifungal activity against five phytopathogenic fungi (Cytospora sp., Colletotrichum gloeosporioides, Botrytis cinerea, Alternaria solani and Fusarium solani) of 3,4-diaryl-1H-pyrazoles were evaluated. 3-(2-Hydroxy-4-isopropoxyphenyl)-4-phenyl-1H-pyrazole was more better and broader inhibitory effect on Cytospora sp., C. gloeosporioides, A. solani and Fusarium solani with IC50 values of 26.96, 28.84, 16.77 and 22.10 μg/mL, respectively. 4-(4-Fluorophenyl)-3-(2-hydroxy-4-methoxyphenyl)-1H-pyrazole exhibited fairly effective antifungal activity against Cytospora sp., C. gloeosporioides and A. solani with IC50 values of 11.91, 14.92 and 16.98 μg/mL, respectively.