Using CC(=O)Nc1cc(NC(C)=O)c2ccc(C)nc2c1OC(C)=O, O=[Cr](=O)([O-])O[Cr](=O)(=O)[O-] to produce CC(=O)NC1=CC(=O)c2ccc(C)nc2C1=O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.