[1] The hydrogen bonding pattern in the hydrate supports the assignment of NH being adjacent to carbon in the ring.

[2] A synthesis of 5-aminotetrazole through the action of nitrous acid on aminoguanidine was reported by Johannes Thiele in 1892.

The correct structural formula was published in 1901 by Arthur Hantzsch, who obtained it from the reaction between cyanamide and hydrazoic acid.

Addition of ammonia or sodium hydroxide followed by heat-induced cyclization gives the anhydrous product in 74% yield.

[9] The structures are very similar, consisting of a planar molecule, including the amino group.