Boron tribromide → 2-Amino-4-(4-hydroxyphenyl)thiophene-3-carbonitrile

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Reaction Steps

To compound 47B (1.1 g, 3.59 mmol) in DCM (80 mL) was added 1.0 M BBr3 (36 mL, 36 mmol) in DCM at rt. A precipitate formed upon addition and gradually disappeared after stirring at rt for 2 hours. The solvent was removed, and the residue was partitioned between water and EtOAc. The organic layer was isolated. The aqueous layer was extracted with EtOAc. The combined organic layers were washed with brine, dried over MgSO4, filtered, and concentrated under reduced pressure. The crude material was purified by column chromatography on silica gel eluting with 3:2/hexanes:EtOAc to provide 0.65 g of the desired product 47C: 1H NMR (DMSO-d6): δ 9.58 (s, 1H), 7.35 (d, J=8.73 Hz, 2H), 7.15 (s, 2H), 6.80 (d, J=8.73 Hz, 2H), 6.34 (s, 1H); MS (ESI(+)): m/z 217 (M+H).

Provenance & Evidence