Using O=C1CCC(=O)N1Br, Cc1ccc(-c2cccc(C(=O)OC(C)(C)C)c2)cc1 to produce CC(C)(C)OC(=O)c1cccc(-c2ccc(CBr)cc2)c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.