Using CC(C)(C)OC(=O)NC12CC3CC(C1)C(=O)C(C3)C2, C=[N+]=[N-] to produce CC(C)(C)OC(=O)NC12CC3CC(=O)C(CC(C3)C1)C2, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.