Tolyltriazole is a mixture of isomers or congeners that differ from benzotriazole by the addition of one methyl group attached somewhere on the benzene ring. "The term tolyltriazole (CAS 29385-43-1) generally [refers to] the commercial mixture composed of approximately equal amounts of 4- and 5-methylbenzotriazole, with small quantities of [their respective 7- and 6-methyl tautomers]".^[1]

Synthesis is much like that of benzotriazole, but starting with methyl-o-phenylenediamine instead of o-phenylenediamine. Isomers of methyl-o-phenylenediamine include 3-methyl-o-phenylenediamine, 4-methyl-o-phenylenediamine, and N-methyl-o-phenylenediamine (not involved here).

Tolyltriazole has uses similar to benzotriazole, but has better solubility in some organic solvents.^{[citation needed]}

Hydroxybenzotriazole