Using CCCC[Sn](CCCC)(CCCC)c1ccncc1, CON=C1CCc2cc(-c3oc(C=O)cc3Br)ccc21 to produce CON=C1CCc2cc(-c3oc(C=O)cc3-c3ccncc3)ccc21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.