Using CC(=O)OC(c1ccc2c(c1)sc1nccn12)C1(Br)C(=O)N2C(C(=O)[O-])=C(Cc3ccc([N+](=O)[O-])cc3)SC21 to produce O=C(O)C1=CSC2CC(=O)N12, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.