Hydrogen Bromide → 5-Bromothiophene-3-carboxylic acid

Participants

Reaction Steps

To a solution of thiophene-3-carboxylic acid (12.6 g, 0.1 mol) in AcOH (96 ml), being stirred at room temperature, HBr solution (8 ml) was added, and the stirring continued until the color of mixture turned to yellow. Pyridinium bromide perbromide (27 g) was then sequentially added. The mixture was poured into ice-water, stirred for about 30 minutes. A white precipitate was formed, which was filtered and dried to obtain 5-bromo-thiophene-3-carboxylic acid (10.8 g) as a white solid after crystallization in hot water. HPLC: 92%.

Provenance & Evidence