Using O=C(c1cccs1)c1cc2c(c(Cl)c1Cl)OC(C(=O)O)C2 to produce O=C(O)C1Cc2cc(C(O)c3cccs3)c(Cl)c(Cl)c2O1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.