[Objective] This study aimed to analyze the deprotection of acetyl group on amino group. [Method] A simple, convenient one-pot amino protection group of amide removed by thionyl chloride and pyridine via efficient chlorination and hydroly- sis with 1, 2-dichloroethane as solvent at ambient temperature has been developed. [Result] Pyridine is crucial to the reaction; the best solvent is 1, 2-dichloroethane, and the most suitable reaction temperature is the ambient temperature; in addition, the yield is the highest as the molar ratio of pyridine to N-（4-bromophenyl） ac- etamide is 1：1. [Conclusion] The significant features of this protocol include short re- action time, cleaner reaction profiles, under mild reaction conditions and easy purifi- cation, and simple workup that precludes the use of toxic solvents.
