A novel sulfur‐promoted cyclization of hydrazides and isonitriles to produce 1,3,4‐oxadiazole has been developed. The method is operationally simple and compatible with a wide scope of substrates and various 2‐amino‐ 1,3,4‐oxadiazoles are efficiently obtained in good yields.
A novel, efficient and mild KHSO4 mediatedsynthesis for 2-amino-1,3,4-oxadiazoles has been established via the cyclodesulfurization of benzoylhydrazine and isothiocyanate derivatives in one pot. The reactions proceeded smoothly at room temperature and produced corresponding products in moderate to good yields. This protocol also showed good functional group tolerance.