Using ClCl, CC1Cc2cc(OCC(=O)O)c(Cl)c(Cl)c2C1=O to produce CC1(Cl)Cc2cc(OCC(=O)O)c(Cl)c(Cl)c2C1=O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.