Bromine → 2-Bromo-7-chlorothieno[3,2-b]pyridine

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Reaction Steps

To a stirred solution of the chloride 2 (10.12 g, 5.59 mmol) in dry THF (200 ml) at −78° C. was added n-BuLi (24 ml, 76.7 mmol, 2.5 M solution in hexanes) and the resultant suspension was stirred for 15 minutes. Bromine (18.9 g, 120 mmol) was added slowly and the reaction mixture was stirred for additional 30 min, quenched with water and diluted with EtOAc. The organic phase was collected, dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. Purification by column chromatography (9:1 EtOAc/hexane) afforded title compound 41 (10.5 g, 71% yield) as a yellow solid. 1H NMR (400 MHz, CDCl3) δ (ppm): 8.62 (d, J=5.09 Hz, 1H), 7.92 (s, 1H), 7.59 (d, J=5.09 Hz, 1H).

Provenance & Evidence