The Reaction of N-Cyanocarbonimidate and Related Compounds with Hydroxylamine

O-ethyl S-methyl N-cyanocarbonimidothioate reacted with hydroxylamine to give 5-amino-3-ethoxy-1,2,4-oxadiazole, whereas diethyl N-cyanocarbonimidate reacted to give 3-amino-5-ethoxy-1,2,4-oxadiazole. The reaction of ethyl N-cyanocarbamate or S-methyl N-cyanothiocarbamate with hydroxylamine afforded 3-amino-1,2,4-oxadiazol-5(4H)-one.