Using COC(=O)c1ccc(Br)c(NC(=O)C(C)(C)C)c1[N+](=O)[O-] to produce COC(=O)c1ccc(Br)c(NCC(C)(C)C)c1[N+](=O)[O-], please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.