Using O=C(CCl)NCc1cc(Cc2cc3c(c(Cl)c2Cl)OC(CO)C3)ccc1O to produce NCc1cc(Cc2cc3c(c(Cl)c2Cl)OC(CO)C3)ccc1O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.