Using O=C(c1cccs1)c1cc2c(c(Cl)c1Cl)OC(C(=O)O)C2 to produce O=C(c1cccs1)c1cc2c(c(Cl)c1Cl)OC(CO)C2, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.