Using O=C(Cl)c1ccc(Cl)cc1Cl, O=C1NC(=O)c2c(Cl)c(Cl)c(Cl)c(Cl)c21 to produce O=C(c1ccc(Cl)cc1Cl)N1C(=O)c2c(Cl)c(Cl)c(Cl)c(Cl)c2C1=O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.