5-Phenylpyrrole-2-carboxylate (20 mg, 0.09 mmol) was dissolved in a solvent mixture of 1 mL of tetrahydrofuran, 0.5 mL of methanol and 0.5 mL of water. After stirring at room temperature, LiOH (4 mg, 0.18 mmol) was added. Stirring was continued at room temperature for 2 h. The progress of the reaction was monitored by thin layer chromatography (TLC) and after confirming that the reaction was complete, the solvent was removed using a rotary evaporator. Ice water was added to the reaction residue, which was then acidified with 1 M HCl solution to the appropriate pH and the precipitate was collected by filtration to afford 5-phenyl-1H-pyrrole-2-carboxylic acid (10 mg, 59% yield).
