Using CCCOc1ccccc1-c1ccc(C(=O)O)c(=O)[nH]1, CO to produce CCCOc1ccccc1-c1ccc(C(=O)OC)c(=O)[nH]1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.