Using BrC(Br)(Br)Br, COC(=O)c1cc2c(OCCO)cccc2n1Cc1ccc(Cl)c(Cl)c1 to produce COC(=O)c1cc2c(OCCBr)cccc2n1Cc1ccc(Cl)c(Cl)c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.