LAUSR

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 1 H NMR, 13 C 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 IC 50 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 IC 50 values of 11.91, 14.92 and 16.98 μg/mL, respectively.