Using CCCC[Sn](CCCC)(CCCC)c1cnccn1, O=C(Nc1cc2ccc(Br)cc2cn1)C1CC1 to produce O=C(Nc1cc2ccc(-c3cnccn3)cc2cn1)C1CC1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.