4922-68-3

274-80-6

4922-68-3

General procedure for the synthesis of 3-bromo-[1,2,4]triazolo[4,3-a]pyridine from [1,2,4]triazolo[4,3-a]pyridine: [1,2,4]triazolo[4,3-a]pyridine (1.26 g) and N-bromosuccinimide (NBS, 1.98 g) were dissolved in chloroform, and the reaction was carried out at reflux for 5 h followed by a 14-h stand at room temperature. Upon completion of the reaction, saturated aqueous potassium carbonate (200 mL) and potassium hydroxide (20 g) were added to the mixture, and the organic layer was separated after sufficient shaking. The aqueous layer was extracted twice with dichloromethane (DCM). All organic layers were combined and dried over anhydrous sodium sulfate (Na2SO4) followed by evaporation of the solvent under vacuum to afford the target product 3-bromo-[1,2,4]triazolo[4,3-a]pyridine in 60% yield.