Using O=Cc1cccnc1, CC(C)(C)C(=O)COc1ccc(Cl)cc1Cl to produce CC(C)(C)C(=O)C(=Cc1cccnc1)Oc1ccc(Cl)cc1Cl, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.