Bromine → Methyl 4-bromo-5-chlorothiophene-2-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a 1 L round bottom flask was added aluminum chloride (11.32 g, 85 mmol) and methyl 5-chloro-2-thiophenecarboxylate (10 g, 56.6 mmol) dissolved in CHCl3 (250 mL). Br2 (4.08 ml, 79 mmol) was added dropwise over 10 minutes. After stirring for 6 h at 25° C., the light orange reaction solution was washed with sat NaHCO3. The organic layer was dried Na2SO4, filtered and concentrated. The residue was purified on silica gel [hexanes/EtOAc, 9:1] to give the product [12 g, 80%] as a white solid. LCMS (ES) m/z 256 (M+H)+.

Provenance & Evidence