Using C=CCc1cc2c(=O)c3c(Cl)cccc3oc2c(Cl)c1O, O=C([O-])[O-] to produce O=C(O)C1Cc2cc3c(=O)c4c(Cl)cccc4oc3c(Cl)c2O1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.