Using CCO, O=c1[nH]c2ccccc2c2cc(Cc3ccccc3)nn12 to produce O=c1[nH]c2ccccc2c2cc(C(O)c3ccccc3)nn12, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.