Using BrBr, CCOC(=O)c1c(OCc2ccccc2)c2n(c1C(C)=O)CCN(C)C2=O to produce CCOC(=O)c1c(OCc2ccccc2)c2n(c1C(=O)CBr)CCN(C)C2=O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.