Methyl 3-(1-pyrrolidinylmethyl)benzoate (800 mg, 3.6 mmol) was used as a raw material and dissolved in 25% aqueous hydrochloric acid (15 mL). The reaction mixture was stirred at 90 °C for 4 hours. Upon completion of the reaction, the solvent was removed by evaporation to afford 3-(1-pyrrolidinylmethyl)benzoic acid hydrochloride as a brown oil in quantitative yield. The resulting product was used directly in the subsequent reaction without further purification.
