Using CCc1ccc2c(-c3cccc(C(N)=O)c3)cc(CC(C)(C)C)nn12, O to produce CCc1ccc2c(-c3cccc(C(=O)O)c3)cc(CC(C)(C)C)nn12, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.