Synthesis and bioactivity of novel pyridazin-3(2H)- one derivatives containing 5-phenyl-2-furan (Ⅱ)

A series of novel pyridazin-3(2H)-one derivative with 5-phenyl-2-funran were designed and synthesized. All the title compounds were characterized by IR, 1H NMR and elemental analysis. Bioassay indicated that most compounds exhibited good fungicidal activities against Botrytis cinerea,Fusarium oxysporum,Rhizoctonia solani and Corynespora cassiicola. Among them, compound 3i showed considerable fungicidal activity against B. cinerea(inhibition rate 89.16%±1.73%) and R.solani(81.27%±1.38%) at 50 mg/L, which was equal to that of the fungicide procymidone (88.58%±1.64% and 79.62%±1.15%).The preliminary structure-activity relationship indicated that the difference of R group affected the fungicidal activity.