Using COC(=O)c1ccc(Cc2sc3cc(OC)ccc3c(=O)c2-c2ccc(C(=O)OC)cc2)cc1 to produce O=C(O)c1ccc(Cc2sc3cc(O)ccc3c(=O)c2-c2ccc(C(=O)O)cc2)cc1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.