Ethyl 4-methyl-1,2,3-thiadiazole-5-carboxylate is a bioactive nitrogen-containing heterocycle.Ethyl 4-methyl-1,2,3-thiadiazole-5-carboxylate may be used in the preparation of following compounds with potent fungicidal activity: · 1,2,3-thiadiazole bearing hydrazone derivatives. · 2-(4′-methyl-1′,2′,3′-thiadiazol)-5-substituted-1,3,4-oxadiazole derivatives. · 1,2,3-thiadiazole bearing 1,2,4-triazole derivatives. Ethyl 4-methyl-1,2,3-thiadiazole-5-carboxylate is a bioactive nitrogen-containing heterocycle.