93587-23-6

1032650-41-1

Under argon protection, 7-bromo-1,5-dihydro-4H-pyrrolo[3,2-d]pyrimidin-4-one (100 mg, 0.5 mmol) was mixed with 6 mL of phosphorus oxytrichloride (POCl3) and the reaction was heated for 3 hours at 115 °C. After the reaction was completed, the mixture was cooled to room temperature and slowly poured into 300 mL of ice water with thorough stirring. The pH was adjusted to alkaline with potassium carbonate solution and subsequently extracted with ethyl acetate (EtOAc). The organic phases were combined, dried over anhydrous sodium sulfate and filtered, and the filtrate was concentrated under reduced pressure to afford 101 mg (93% yield) of the target product, 7-bromo-4-chloro-5H-pyrrolo[3,2-d]pyrimidine, as a beige solid, which could be used in the subsequent reaction without further purification.