2-Diazoacethydrazide derivatives and their ring-chain transformations

1-Amino-1,2,3-triazol-5-olates 6, 13 and 14 have been obtained by the introduction of a diazo group into N-benzylidene-protected hydrazides of cyanoacetic and malonic acids. These compounds form open-chain isomers of 1-amino-5-hydroxy-1,2,3-triazoles upon acidification with an aqueous solution of HCl. Compounds 8, 15 and 16 are the first examples of the group of α-diazoacethydrazides