1H-Pyrrolo(2,3-b)pyridine → 3-Bromo-1H-pyrrolo[2,3-b]pyridine

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Reaction Steps

7-Azaindole (2, 3.57 g, 30.2 mmol) was dissolved in tetrahydrofuran (240 mL) under an atmosphere of nitrogen. At −40° C., N-bromosuccinimide (5.38 g, 30.2 mmol) in tetrahydrofuran was added under an atmosphere of nitrogen. The reaction mixture was stirred for a few hours as it was gradually warmed to room temperature and the reaction was followed by TLC. The reaction was quenched with sodium thiosulfate pentahydrate (7.50 g, 30.2 mmol) in water (1M). Two layers were separated, and the aqueous layer was extracted with ethyl acetate. The combined organic layers were washed with water, brine, dried with anhydrous sodium sulfate, and evaporated to dryness. The crude material was purified by column chromatography (25-40% ethyl acetate in hexanes) to yield the desired product as a white solid, 3, (4.20 g, 21.3 mmol). MS(ESI) [M+H+]+=198.5.

Provenance & Evidence