Using CCOC(=O)C(=O)CC(=O)C(C)(C)C, NNc1cccc(Br)c1 to produce CCOC(=O)c1cc(C(C)(C)C)n(-c2cccc(Br)c2)n1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.