Methyl iodide → 5-Chloro-2-(methylsulfanyl)[1,3]thiazolo[5,4-b]pyridine

To a round bottom flask was added 5-chloro[1,3]thiazolo[5,4-b]pyridine-2-thiol (1-1) (21.4 g, 106 mmol), anhydrous THF (400 mL), potassium carbonate (20.5 g, 148 mmol), followed by methyl iodide (16.9 g, 119 mmol). The reaction vessel was sealed and stirred at room temperature for 5 minutes. The crude reaction mixture was then suspended in ethyl acetate and washed with a saturated solution of sodium bicarbonate, followed by water, then brine, dried over sodium sulfate, filtered, and concentrated to give 5-chloro-2-(methylthio)[1,3]thiazolo[5,4-b]pyridine (1-2) as a pink solid. HRMS (M+H)+: observed=216.9658, calculated=216.9655.