3-Amino- and 3-cyano-1,2,4-oxadiazole

3-Amino-1,2,4-oxadiazole (3a) has been prepared from t-butoxycarbonylamino-1,2,4-oxadiazole (3h), and also from hydroxyguanidine and formyl fluoride. The amine is unexpectedly stable; on acid hydrolysis it gives hydroxyguanidine. 3-Cyano-1,2,4-oxadiazole (3m), prepared by dehydration of 1,2,4-oxadiazole-3-carboxamide (3l), is highly reactive but thermally stable. Some reactions of the amine (3a) and the nitrile (3m) are described.