Using O=C(CCC(=O)c1cccs1)Nc1cccc2cc(-c3nccs3)[nH]c12 to produce O=C(CCC(O)c1cccs1)Nc1cccc2cc(-c3nccs3)[nH]c12, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.