[Synthesis]
General procedure for the synthesis of 2-chloro-7-iodo-5H-pyrrolo[3,2-d]pyrimidine using 2-chloro-5H-pyrrolo[3,2-d]pyrimidine as a raw material: to an aqueous (200 mL) suspension of 2-chloro-5H-pyrrolo[3,2-d]pyrimidine (3.55 g, 23.2 mmol) was added, in order, sodium bicarbonate (19.2 g), potassium iodide (16.41 g, 98.9 mmol). Subsequently, a solution of iodine (5.78 g, 22.8 mmol) in water (25 mL) was added dropwise, and the reaction mixture was stirred at room temperature for 1 hour. Upon completion of the reaction, the reaction mixture was diluted with saturated saline and extracted with ethyl acetate. The organic phases were combined, dried over anhydrous sodium sulfate and filtered, and the filtrate was concentrated under reduced pressure. The resulting crude product was purified by fast column chromatography with chloroform/methanol (25:1 to 20:1, v/v) as eluent to afford the target compound 2-chloro-7-iodo-5H-pyrrolo[3,2-d]pyrimidine (5.33 g, 83% yield). The structure of the product was confirmed by 1H NMR (DMSO-d6, 300 MHz) and 13C NMR (DMSO-d6, 75 MHz): 1H NMR δ 12.50 (s, 1H), 8.82 (s, 1H), 8.20 (s, 1H); 13C NMR δ 143.2, 143.0, 139.7, 139.5, 126.5, 56.2. Mass spectrometry (EMS) was performed on the product. 56.2. Results of mass spectrometry (EI) analysis: m/z calculated values [M]+ 278.91, 280.91, measured values 278.95, 280.95. |