Using O=C1CCC(c2ccc(Cl)c(Cl)c2)c2ccccc21, CCOC(=O)OCC to produce CCOC(=O)C1CC(c2ccc(Cl)c(Cl)c2)c2ccccc2C1=O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.