273-05-2

3H-1,2,3-Triazolo[4,5-c]pyridine is an N-acylating and N-alkoxycarbonylation reagent that can be used as a P2X7 modulator for therapy. It can also be used as an inhibitor of hormone-sensitive lipase (HSL) and endothelial lipase (EL).

The general procedure for the synthesis of 3H-1,2,3-triazolo[4,5-c]pyridine from 3,4-diaminopyridine was as follows: 3,4-diaminopyridine (2.0 g, 0.048 mol) was dissolved in a 2 N aqueous hydrochloric acid solution (25 mL) and the solution was cooled to 0 °C. Subsequently, sodium nitrite (1.9 g, 0.027 mol) was dissolved in distilled water (3 mL) and slowly added to the above cooled solution with continuous stirring for 1 hour. Upon completion of the reaction, the resulting solid product was collected by filtration and washed with distilled water to finally obtain 3H-1,2,3-triazolo[4,5-c]pyridine (1.96 g, 89% yield) as a yellow solid.

[1] Patent: KR101798840, 2017, B1. Location in patent: Paragraph 0372-0375
[2] Tetrahedron Letters, 1997, vol. 38, # 50, p. 8607 - 8610