Using BrC(Br)(Br)Br, CN1C(=O)C(c2cn(C)c3ccccc23)=C(c2cc(OCCO)cc3ccoc23)C1=O to produce CN1C(=O)C(c2cn(C)c3ccccc23)=C(c2cc(OCCBr)cc3ccoc23)C1=O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.