Using C=Cc1ccccc1, Cc1ccc2c(Nc3cccc(Br)c3)ncnc2n1 to produce Cc1ccc2c(Nc3cccc(C=Cc4ccccc4)c3)ncnc2n1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.