26493-11-8

1035219-96-5

The general procedure for the synthesis of 2-bromo-6,7-dihydrothiazolo[5,4-b]pyridin-4(5H)-ones using 2-amino-6,7-dihydrothiazolo[5,4-c]pyridin-4(5H)-ones as starting material was as follows: intermediate 3 (8 g, 39.8 mmol), copper(II) bromide (10.43 g, 46.68 mmol) and 3-methyl-1- Nitrosoxybutane (6.8 g, 58.35 mmol) were dissolved in acetonitrile (100 mL) and the reaction was stirred at room temperature for 1.5 hours. Upon completion of the reaction, the solvent was removed by vacuum evaporation. The resulting residue was dissolved in ethyl acetate and washed with water. The organic layer was separated, dried with anhydrous sodium sulfate, filtered and the solvent was evaporated in vacuum to give Intermediate 4 (5 g, 55% yield), which could be used in subsequent steps without further purification.