Using CCOC(=O)/C=C/n1c(=O)n(Cc2cccc3ccccc23)c2ccccc21 to produce O=C(O)/C=C/n1c(=O)n(Cc2cccc3ccccc23)c2ccccc21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.