Using O=C1c2ccccc2C(=O)c2c1ccc(O)c2O, O=S(=O)(O)O to produce O=C1c2ccccc2C(=O)c2c(O)c(O)cc(O)c21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.