Using CC(C)(C)OC(=O)c1ccc(COc2ccc3c(c2)NC(=O)CC3)cc1, BrBr to produce O=C1CCc2cc(Br)c(OCc3ccc(C(=O)O)cc3)cc2N1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.