22090-26-2

124-38-9

22090-27-3

To the reaction flask was added 0.1 mol 1-(4-bromophenyl)pyrrolidine (reactant) and 120 mL of tetrahydrofuran (solvent), the device was sealed and stirred. Nitrogen displacement was performed to remove air and the reaction mixture was subsequently cooled to -70 °C. Under stirring, 2.5 M butyl lithium (reactant) was slowly added dropwise for 20 minutes. Next, dry carbon dioxide gas was passed to saturation. The reaction was maintained at this temperature for 2 hours. Upon completion of the reaction, the reaction solution was poured into a beaker containing 20 mL of concentrated hydrochloric acid (for pH adjustment) and 100 mL of water for hydrolysis. After separation, the aqueous phase was extracted once with 50 mL of ethyl acetate (solvent). The organic phases were combined and washed to neutrality with brine, followed by drying with anhydrous sodium sulfate (desiccant). The solvent was concentrated to give a pale yellow solid. The solid was washed twice with ethyl acetate (solvent), followed by recrystallization to give white crystals 4-(1-pyrrolidinyl)benzoic acid (product) in 90% yield and 98.0% HPLC purity.