s-Triazolopyrimidines. Part IV. Synthesis as potential therapeutic agents

The interaction of cyanogen chloride and 2-hydrazinopyrimidines under mild conditions yields 3-amino-s-triazolo-[4,3-a]pyrimidines, which are isomerised under suitable conditions to the corresponding 2-amino-s-triazolo-[2,3-a]pyrimidines. The mechanisms involved have in part been elucidated starting from 2-hydrazino-pyrimidines with alkoxyl groups in position 4 and/or 6.