Using O=C([O-])[O-], CCOC(=O)C(C(=O)OCC)(C(=O)OCC)c1ccc(C(=O)c2ccccc2)[nH]1 to produce CCOC(=O)C1(C(=O)OCC)CCn2c(C(=O)c3ccccc3)ccc21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.