Tetrazoles. 24. Preparation of 1,4-dimethyl- and 2,4-dimethyl-5-aryl-tetrazolium salts

Alkylation of 1-methyl-5-aryltetrazoles with dimethyl sulfate leads to the formation of 1,4-dimethyl-5-aryltetrazolium ion salts. Alkylation of isomeric 2-methyl-5-aryltetrazoles also apparently takes place at the N(4) atom. 1-Methyl-5-aryltetrazoles display greater reactivity with respect to methylation than the isomeric 2-methyl-5-aryltetrazoles. 1,4-Dimethyl-5-aryltetrazolium methylsulfate salts isomerize upon heating to give the more stable 2,4-dimethyl-5-aryltetrazolium ion salts.For Communication No. 22, see Ref. 1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 502–506, April, 1988.