Using COC(=O)c1cc2[nH]c(-c3c(Cl)cccc3Cl)nc2c(F)c1F to produce O=C(O)c1cc2[nH]c(-c3c(Cl)cccc3Cl)nc2c(F)c1F, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.