Using CCOC(=O)C(=O)Nc1c([N+](=O)[O-])cc(Br)c2ccccc12 to produce O=c1[nH]c2c3ccccc3c(Br)cc2n(O)c1=O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.