Using O=C1CC2(C(=O)Nc3ccc(Cl)cc32)C(=O)N1Cc1ccccc1, C=CC(=O)OC(C)(C)C to produce CC(C)(C)OC(=O)CCN1C(=O)C2(CC(=O)N(Cc3ccccc3)C2=O)c2cc(Cl)ccc21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.