Using O=C(NC12CC3CC1CC(c1ccc(N4CCCS4(=O)=O)cc1)(C3)C2)OCc1ccccc1 to produce NC12CC3CC1CC(c1ccc(N4CCCS4(=O)=O)cc1)(C3)C2, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.