Using O=C(Nc1ccccc1C(=O)O)C(=Cc1ccccc1)C(=O)Nc1ccccc1C(=O)O to produce O=c1oc(C(=Cc2ccccc2)c2nc3ccccc3c(=O)o2)nc2ccccc12, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.