GENERAL METHOD: A mixture of benzaldehyde and ethylenediamine (molar ratio 5:1) in toluene was refluxed in a Dean-Stark apparatus for 5 hours. After completion of the reaction, the solvent was removed under reduced pressure and the residue was dissolved in ethanol. NaBH4 (molar ratio 1:2.5) was slowly added at 0°C, followed by continued stirring for 4 hours at room temperature. At the end of the reaction, ethanol was removed under reduced pressure and the residue was dissolved in dichloromethane and washed with saturated saline. The organic phase was separated, dried over anhydrous sodium sulfate and concentrated under reduced pressure to remove the solvent. The resulting residue was purified by fast column chromatography using a mixture of dichloromethane/methanol/33% ammonia (9:1:0.1, v/v) as eluent, and the target product 3-benzylaminopropylamine was finally obtained.
