Using CCOC(=O)C(C(=O)OCC)C(=O)c1ccc2oc3ncccc3c(=O)c2c1 to produce CC(=O)c1ccc2oc3ncccc3c(=O)c2c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.