Acidic N-dealkylation in nitrotriazolium salts

New selective synthesis of 1-alkyl-5-nitro-1,2,3-triazoles and 1-alkyl-4-nitro-1,2,3-triazoles has been developed, involving acid N-dealkylation of the relative 4-nitro-1,2,3- and 3-nitro- 5-R-1,2,4-triazolium salts. The assortment of novel 1-alkyl- 4(5)-nitro-1,2,3-triazoles has been thus essentially expanded. Treatment of relative 3-nitro-1,2,4-triazolium salts with HCl or HBr proceeds mostly as S_N^ipso-substitution of the nitro group.