Synthesis of 1,4-diphenyl-3-phenylimino-1,2-dihydro-1,2,4-triazolium hydroxide (Nitron)

1,4-Diphenyl-3-phenylimino-1,2-dihydro-1,2,4-triazolium hydroxide (Nitron) is prepared by the reaction of Pb3O4 with diphenylthiourea, followed by the reaction of the obtained diphenylcarbodiimide with phenylhydrazine to form triphenylaminoguanidine, whose heterocyclization yields 1,4-diphenyl-3-phenylimino-1,2-dihydro-1,2,4-triazole, which is subsequently oxidized.