Using CCCc1nn(C)c2c(=O)[nH]c(C(OC(C)=O)c3ccccc3)nc12 to produce CCCc1nn(C)c2c(=O)[nH]c(C(O)c3ccccc3)nc12, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.