Bromine → 4-Bromo-5-methylthiophene-2-carboxylic acid

Participants

Reaction Steps

A solution of bromine (725 uL, 14.1 mmol) in AcOH (2.8 mL) was added dropwise to 5-methyl-2-thiophenecarboxylic acid (2 g, 14.1 mmol) and FeCl3 (456 mg, 2.81 mmol) in AcOH (28 mL) at 25° C. After 5 h, the solution was poured onto ice and the precipitate was filtered and washed with water affording the title compound (3 g, quant.) as a yellow powder: LCMS (ES) m/z 222 (M+H)+.

Provenance & Evidence