In an attempt to search for new compounds with agricultural bioactivity, a series of new polysubstituted pyridine derivatives, ethyl or methyl 5-cyano-4-(furan or thiophen-2-yl)-2-methyl-6-(prop-2-ynylthio)pyridine-3-car~boxylate and 5-acetyl-4-(furan or thiophen-2-yl)-6-methyl-2-(prop-2-ynylthio)pyridine-3-carbonitrile have been designed and synthesized by a three-step synthetic route. The structures of all the compounds prepared were confirmed by elemental analyses and ¹H NMRspectra. The results of preliminary bioassay indicate that compounds 7 possess certain herbicidal and fungicidal activities.

Key words: polysubstituted pyridine, synthesis, biological activity