Acetyl chloride → N-(6-bromo-[1,2,4]triazolo[1,5-a]pyridin-2-yl)acetamide

To a solution of 6-Bromo-[1,2,4]triazolo[1,5-a]pyridin-2-ylamine (3) (7.10 g, 33.3 mmol) in dry acetonitrile (150 mL) at 5° C. was added triethylamine (11.6 mL, 83.3 mmol) followed by acetyl chloride (2.35 mL 83.3 mmol). The reaction mixture was then allowed to warm to room temperature (20° C.) and stirred until all starting material was consumed (if required, further triethylamine (4.64 mL, 33.3 mmol) and acetyl chloride (33.3 mmol) were added to ensure complete reaction). After this time the solvent was removed in vacuo and to the resultant residue was added 7 N (Methanolic ammonia solution (50 mL)). The reaction mixture was stirred at room temperature (20° C.) to hydrolyze any bis-acylated material. After 16 h evaporation in vacuo and trituration from diethyl ether (50 mL) afforded the title compound which was collected by filtration, washed with water (2×50 mL), acetone (50 mL) and diethyl ether (50 mL) and then dried in vacuo.