Thiophene-3-carboxylic acid → 5-Bromothiophene-3-carboxylic acid

Participants

Reaction Steps

To a stirred solution of 3-thiophenecarboxylic acid (1.00 g, 7.80 mmol) in glacial acetic acid (9 mL) at ambient temperature under nitrogen atmosphere was slowly added bromine (0.39 mL, 7.53 mmol) in glacial acetic acid (6 mL). The reaction mixture was stirred for 15 minutes, then quenched with cold water (50 mL). The precipitate was filtered, washed with water and dried in vacuum oven at 50° C. to afford 5-bromo-3-thiophenecarboxylic acid as a colorless solid (0.78 g, 50%): mp 133-135° C.; 1H NMR (300 MHz, CDCl3) δ 8.12 (d, J=1.5 Hz, 1H), 7.51 (d, J=1.5 Hz, 1H).

Provenance & Evidence