Using CCOC(=O)c1nc2n(c(=O)c1OCc1ccccc1)CCCC2, BrBr to produce CCOC(=O)c1nc2n(c(=O)c1OCc1ccccc1)CCC=C2Br, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.