Synthesis And Biological Activity Of Formic Acid Esters Derivatives Of Pyrrolidine Diketone Linked Pyridazinone

Tetramic acids were a class of heterocyclic compounds having various biological activities,they could be derived from natural products.Pyridazinone derivatives were also found exhibiting insecticidal,herbicidal and antifungal activities,which were widely used in green pesticide development.In this paper,pyridazinone moiety were introduced to 3-position of pyrrolidine-2,4-dione,carboxylate group and halogenated phenyl were introduced to 1-and 2-position of pyridazinone,respectively,to design and synthesis thirty six formic acid ester derivatives of pyrrolidine-2,4-dione linked pyridazinone.The fungicidal and herbicidal activities of the target compounds were also preliminarily evaluated.Firstly,six novel pyrrolidine-2,4-dione derivatives linked pyridazinone were prepared from the reactions of esterification,cyclization,acylation,acidification,hydrazination and second cyclization with glycine as the starting material.They were reacted with eight chloroformates,respectively,to give thirty six formic acid ester derivatives of pyrrolidine-2,4-dione linked pyridazinone.The structures of all the target compounds were confirmed by FT-IR,1H NMR,MS and elemental analysis.The herbicidal activities against Brassia campestris and Echinochloa crusgalli were evaluated by small glass method.Some target compounds exhibited certain herbicidal activities at the concentration of 100 ?g/mL.The inhibitory rate of the compound A12 against the root of B.campestris was 58.4%.The inhibitory rate of the compound B20 against the root of E.crusgalli reached 72.4%.And the inhibitory rate of the compound A8 against the stem of E.crusgalli was 62.6%.The fungicidal activities of all the target compounds against Fusarium graminearum,Botrytis cinerea,Rhizoctonia solani and Colletotrichum capsici were evaluated with the mycelial growth rate method.Most of the target compounds showed obvious inhibitory activity at the concentration of 100 ?g/mL.The compounds A1-A16 displayed good antifungal activity.The inhibitory rate of the compound A7 against F.graminearum reached 63.1%.The inhibitory rate of the compound A12 against B.cinerea reached 73.6%.The inhibitory rate of the compound A2 against R.solani reached 85.8%.The inhibitory rate of the compound A5 against C.capsici reached 85.8%.