Using COC(=O)c1c(O)c(O)c(C(=O)OC)n1Cc1ccccc1, BrCCBr to produce COC(=O)c1c2c(c(C(=O)OC)n1Cc1ccccc1)OCCO2, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.