Bromine → 2-bromo-4H,5H,6H-thieno(2,3-c)pyrrol-6-one

Participants

Reaction Conditions

Reaction Steps

A solution of 4H-thieno[2,3-c]pyrrol-6(5H)-one (1.0 g, 7.2 mmol) in acetic acid (9 mL) and water (7 mL) was cooled to 0° C. Bromine (407 μL, 7.92 mmol) was added and the reaction was maintained at 0° C. for 1.5 h. At completion, water (30 mL) was added and the mixture was and extracted with EtOAc (2×50 mL). The combined organics were washed with 5% aq. Na2SO3 (30 mL), sat. aq. NaHCO3 (30 mL) and brine (30 mL), then dried over Na2SO4, filtered, concentrated. The crude material was purified by flash chromatography over silica gel (5% MeOH/DCM) to yield 2-bromo-4H-thieno[2,3-c]pyrrol-6(5H)-one (1.3 g, 83% yield) as a white solid. 1H NMR (400 MHz, METHANOL-d4) δ ppm 7.28 (s, 1H), 4.39 (s, 3H); MS (EI) m/z=140.2 [M+1]+.

Provenance & Evidence