Using O=C(O)CC(=O)O, CCNC(=O)Nc1ccc(S(=O)(=O)O)cc1 to produce CCN1C(=O)CC(=O)N(c2ccc(S(=O)(=O)O)cc2)C1=O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.