Using BrCCCBr, CCCNC(=O)Nc1cc(C)c(Oc2ccnc3cc(O)c(OC)cc23)cc1C to produce CCCNC(=O)Nc1cc(C)c(Oc2ccnc3cc(OCCCBr)c(OC)cc23)cc1C, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.