Bromine → N-{5-[(2-amino[1,3]thiazolo[5,4-b]pyridin-5-yl)oxy]-2-chlorophenyl}-2,2,2-trifluoroacetamide

N-{5-[(5-Aminopyridin-2-yl)oxy]-2-chlorophenyl}-2,2,2-trifluoroacetamide (12 g, 36.2 mmol) and potassium thiocyanate (14.1 g, 145 mmol) were suspended in acetic acid (145 mL), bromine (8.67 g, 54.3 mmol) was added dropwise under ice-cooling, and the reaction mixture was stirred at room temperature for 16 hr. The reaction mixture was filtered through celite, and the filtrate was concentrated under reduced pressure. The residual oily substance was dissolved in ethyl acetate (100 mL), and aqueous sodium hydrogen carbonate solution (150 mL) was gradually added to partition the solution. The organic layer was dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residual solid was collected by filtration with diisopropyl ether (100 mL), and dried to give the title compound (10.1 g, 72%) as a pale-yellow solid.