Using COc1ccccc1Sc1ccc(C=O)c(Cl)c1Cl, O=C(O)CC(=O)O to produce COc1ccccc1Sc1ccc(C=CC(=O)O)c(Cl)c1Cl, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.