112342-70-8

112342-72-0

General procedure for the synthesis of 6-bromothiazolo[4,5-b]pyrazin-2-amine from ethyl (6-bromothiazolo[4,5-b]pyrazin-2-yl)carbamate: 2 N aqueous sodium hydroxide (7.91) was added to a methanolic (8 mL) suspension of ethyl (6-bromothiazolo[4,5-b]pyrazin-2-yl)carbamate (480 mg, 1.58 mmol). mL, 15.83 mmol). The mixture was heated under reflux conditions for 5 hours. Upon completion of the reaction, the mixture was acidified with 2 N HCl to pH < 7. Subsequently, the reaction mixture was neutralized with saturated sodium bicarbonate solution and extracted with ethyl acetate (3 × 10 mL). The organic layers were combined, washed sequentially with saturated sodium bicarbonate solution and saturated aqueous sodium chloride solution, and dried over anhydrous sodium sulfate. The organic phase was concentrated under reduced pressure to give the crude product. The precipitate was collected by filtration to afford 6-bromothiazolo[4,5-b]pyrazin-2-amine (334 mg, 91.0% yield) as a pale yellow solid.1H-NMR (DMSO-d6) δ: 8.37 (s, 1H), 8.59 (brs, 2H).