Synthesis of pyridazinone‐substituted 1,3,4‐thiadiazoles, ‐1,3,4‐oxadiazoles and ‐1,2,4‐triazoles

Several 1‐(1‐aryl‐1,4‐dihydro‐3‐carboxy‐6‐methylpyridazin‐4‐one)‐4‐aryl thio‐semicarbazides and their corresponding oxadiazole, thiadiazole and triazole derivatives were prepared and characterized by their spectral data. The preliminary biological tests showed that some new compounds exhibit good anti‐fungal activity.