Using COS(=O)(=O)c1ccc([N+](=O)[O-])cc1, O=c1[nH]c(-c2cccc(Cl)c2)cc2ccc(Br)cc12 to produce Cn1c(-c2cccc(Cl)c2)cc2ccc(Br)cc2c1=O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.