Using CCOC(=O)C(=O)Nc1c([N+](=O)[O-])cc(Cl)cc1C(F)(F)F to produce O=c1[nH]c2c(C(F)(F)F)cc(Cl)cc2n(O)c1=O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.