Cyclization of Substituted 2,3-Diaminopyridines into Derivatives of 1H-1,2,3-Triazolo[4,5-b]pyridine 2-Oxide in the Course of Nitration

摘要

It was shown formerly that the treatment with nitrating mixture at 60°C of 3,4-diaminopyridine, its diacetyl derivative, and 3-amino-4-alkylaminopyridines led to the formation of N~1-substituted 4-nitro-1H-1,2,3-triazolo[4,5-c]pyridine 2-oxides. Under similar conditions 3,4-diamino-2-chloropyridine, its diacetyl derivative, and 3-amino-4-methylamino-2-chloropyridine were converted into derivatives of 4-chloro-1H-1,2,3-triazolo[4,5-c]pyridine 2-oxide. Raising temperature to 80-90°C in reaction with the nitrating mixture of 3,4-diamino-2-chloropyridine, its diacetyl derivative, and 3-amino-4-methylamino-2-chloropyridine resulted in obtaining 7-nitro-4-chloro-1H-1,2,3-triazolo[4,5-c]pyridine 2-oxides [1,2]. It seemed purposeful to carry out this reaction with diverse substituted 2,3-diaminopyridines.