The chlorination reaction of aromatic compounds is highly important for the synthesis of pharmaceutical products. As the most common chlorination reagent, chlorine is restricted from undergraduate laboratory experiment training due to its toxicity. In this work, we reported the chlorination of aromatic compounds with chlorine generated from the paired electrolysis of N-chlorosuccinimide. The chlorine in this reaction is produced and consumed in an on-demand manner, ensuring the safety of the reaction, workup, and purification. The reaction is evaluated with 5 undergraduate students with reproducible results and conveys the basic concepts of electrochemical organic synthesis and green synthesis to these students.