Reactions of 3-nitro-1,2,4-triazoles with alkylating agents. 6*. Alkylation of a neutral heterocycle by alcohols in acid media*

Reaction of 3-nitro-1,2,4-triazole and 5-methyl-3-nitro-1,2,4-triazole with secondary and tertiary alcohols in conc. H₂SO₄ takes place at the N(2) atom. Alkylation by 2-propanol occurs regioselectively to form the 1-isopropyl-3-nitro-and 1-isopropyl-3-methyl-5-nitro-1,2,4-triazoles. As a consequence of isomerization the alkylation using cyclohexyl or tert-butyl alcohols gives respectively a mixture of regioisomers substituted at atom N(1) (1-cyclohexyl-3-nitro-and 1-cyclohexyl-5-methyl-3-nitro-1,2,4-triazoles) and at atom N(2) (5-nitro-1-cyclohexyl-and 1-cyclohexyl-3-methyl-5-nitro-1,2,4-triazoles) and, in the second case, to 1-tert-butyl-3-nitro-1,2,4-triazole. * For Communication 5 see [1]. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1680–1687, November, 2008.