Synthesis and antiviral activity of 2-substituted methylthio-5-(4-amino-2-methylpyrimidin-5-yl)-1,3,4-oxadiazole derivatives.

A series of novel 2-substituted methylthio-5-(4-amino-2-methylpyrimidin-5-yl-)-1,3,4-oxadiazole derivatives were synthesized and evaluated for antiviral activities against tobacco mosaic virus (TMV) via half-leaf method. The preliminary biological results showed that these compounds exhibited good antiviral activity against TMV in vivo. Among these compounds, compounds 8f, 8h, 8k, 8n, 8q and 8w exhibited the similar curative effect against TMV (EC50=290.98-438.29μg/mL) as the commercial product Ningnanmycin (301.83μg/mL). Notably, compound 8i exhibited the excellent curative effect against TMV, with EC50 value of 246.48μg/mL, which was better than that of Ningnanmycin. To the best of our knowledge, this was the first Letter of 2-substituted methylthio-5-(4-amino-2-methylpyrimidin-5-yl-)-1,3,4-oxadiazole derivatives with potent antiviral against TMV.