反应详情

温度

0 °C

A solution of the 2-Chloro-7-iodo-5H-pyrrolo[2,3-b]pyrazine from the previous step in 30 mL of tetrahydrofuran stirring at 0° C. under argon atmosphere was treated with lithium hexamethyldisilylazide (6 mL, 1 M in hexanes, 6 mmol), followed by triisopropylsilyl chloride (1.1 mL, 5.2 mmol). After 30 m at 0° C., the solution was warmed to ambient temperature and diluted with 20% ethyl acetate in hexanes, then washed twice with water and once with brine. After drying the organic layer over magnesium sulfate, filtration was followed by solvent removal and flash chromatography of the resultant residue using 2.5% ethyl acetate in hexanes, to furnish 2-Chloro-7-iodo-5-triisopropylsilanyl-5H-pyrrolo[2,3-b]pyrazine (1.68 g, 95% over two steps).

1. washwashed twice with water and once with brine
2. customAfter drying the organic layer
3. filtrationover magnesium sulfate, filtration
4. customwas followed by solvent removal and flash chromatography of the resultant residue