Using COC(=O)C(=C(CBr)OC(=O)OCC1CC1)N1C(=O)C(N2C(=O)c3ccccc3C2=O)C1SC(=O)OCC1CC1 to produce COC(=O)C(=C(O)CBr)N1C(=O)C(N2C(=O)c3ccccc3C2=O)C1S, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.