Using O=C[O-], CCCC(CC(=O)O)n1c(=O)n(Cc2cc(Br)cc3c2ccn3C)c2ccccc21 to produce CCCC(CC(=O)O)n1c(=O)n(Cc2cccc3c2CC(=O)N3C)c2ccccc21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.