Synthesis and alkylation reaction of 1-arylmethyleneamino- and 1-arylsulfonyl-5-hydroxy-1H-1,2,3-triazoles

Abstract

New derivatives of 1H-1,2,3-triazole 4, 6, 7 were prepared from malonic acid derivatives by a diazo group transfer reaction with p-tosyl azide. It was found that alkylation of sodium 1-aryl- and 1-arylmethyleneamino-1,2,3-triazol-5-olates 7, 4 with methyl iodide, benzyl chloride or substituted phenacyl bromides results in 3-alkyltriazol-3-ium-5-olates 8, 9 that are compounds of mesoionic structure. In contrast, alkylation of 1-arylsulfonyl-substituted triazoles 6 with methyl iodide leads to the 2-methyl-1,2-dihydro-1,2,3-triazol-5-ones 12. Hydrolysis of azomethines 9 affords 1-aminotriazoles 10, which in turn can be deaminated by nitrous acid or butyl nitrite to give 1-alkyl-4-hydroxytriazoles 11.