Using COCN1C(=O)CCN(c2ccccc2)c2ccccc21, CC(C)(C)ON=O to produce COCN1C(=O)C(NO)CN(c2ccccc2)c2ccccc21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.