Benzenesulfonyl chloride → 5-nitro-1-(phenylsulfonyl)-1H-pyrrolo[2,3-b]pyridine

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Reaction Steps

To a mixture of 5-nitro-1H-pyrrolo[2,3-b]pyridine (2.0 g, 12.3 mmol), triethylamine (2.48 g, 24.6 mmol), 4-dimethylaminopyridine (0.15 g, 1.23 mmol) in dichloromethane/N,N-dimethylformamide (1:1, 60 mL) was added benzenesulfonyl chloride (3.25 g, 18.4 mmol) at 0° C. After stirring for 48 h at room temperature, the reaction was quenched with water (50 mL) and extracted with dichloromethane (2×120 mL). The organic layer was washed with a saturated sodium bicarbonate (2×30 mL), water (2×30 mL), brine (50 mL), dried over anhydrous sodium sulfate and concentrated in vacuo. The residue was purified by flash column chromatography (silica gel from QingDao, 200-300 mesh, 33% dichloromethane/hexanes) to afford 1-benzenesulfonyl-5-nitro-1H-pyrrolo[2,3-b]pyridine (2.8 g, 76%) as a yellow solid: LC/MS m/e calcd for C13H9N3O4S [M+H]+ 304.30, observed 303.9.

Provenance & Evidence