Using BrCCCBr, Cc1cc(C(=O)c2cc(=O)c3ccccc3o2)cc(C)c1O to produce Cc1cc(C(=O)c2cc(=O)c3ccccc3o2)cc(C)c1OCCCBr, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.