Using COc1cccc(C(O)c2ccc(=O)n(Cc3ccc(Cl)cc3)c2)c1 to produce COc1cccc(C(=O)c2ccc(=O)n(Cc3ccc(Cl)cc3)c2)c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.