Using CCOC(=O)CCn1c(=O)n(Cc2csc3ccc(Cl)cc23)c2ccccc21 to produce O=C(O)CCn1c(=O)n(Cc2csc3ccc(Cl)cc23)c2ccccc21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.