Using COC(=O)c1cc(Cl)c2[nH]c3c(c2c1C(=O)OC)CCCC3 to produce COC(=O)c1cc(Cl)c2[nH]c3ccccc3c2c1C(=O)OC, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.