Using ClCCl, O=C1NC(=O)C(Cc2cccc3c2ccn3CC(O)c2ccccc2)S1 to produce O=C1NC(=O)C(Cc2cccc3c2ccn3CC(Cl)c2ccccc2)S1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.