Using O=C([O-])[O-], CCOC(=O)c1ccc2[nH]cc(C(C)=O)c(=O)c2c1 to produce CCOC(=O)c1ccc2c(c1)c(=O)c(C(C)=O)cn2C, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.