Synthesis and fungicidal activity of 3-anilinomethylene-5,6-dihydro-6-alkyl(aryl)-2H-pyran-2,4-diones

3-Anilinomethylene-6-alkyl(aryl)-5,6-dihydro-2H-pyran-2,4-diones(3) were pr epared by the condensation reaction of 6-alkyl(aryl)-5, 6-dihydro-2H-pyran- 2,4-diones(1). substituted anilines(2) and ethyl orthoformate. A pair of co nformational isomers 4 and 5 exist in products 3 due to the formation of th e intramolecular hydrogen bond. Compound 3 was tested in vitro against many fungi such as P. Zeae , C. Arachidicala, P, Piricola, A, Solani, B, Cinera e, S, Sclerotiorum, H. Oryzae, etc. The bioassay results show that they hav e some fungicidal activity.