889447-19-2

875781-43-4

889447-19-2

General procedure for the synthesis of 2-chloro-5H-pyrrolo[2,3-b]pyrazine from 5-bromo-4,7-diazaindole: 2-bromo-5H-pyrrolo[2,3-b]pyrazine (3.1 g, 16 mmol) was dissolved in 1,4-dioxane (20 mL), and phosphorochloridic acid (2.27 mL, 24.1 mmol) was added. Subsequently, triethylamine (220 μL, 1.58 mmol) was added and the reaction was carried out at 110 °C for 6 hours. After completion of the reaction, the reaction mixture was dried with anhydrous sodium sulfate and concentrated. Purification by column chromatography (petroleum ether/ethyl acetate, v/v=2/1) gave 1.3 g of gray solid product in 54% yield.