Using O=C1Cc2ccccc2S1, O=C(Nc1cccc(Cl)c1)Oc1ccccc1 to produce O=C(Nc1cccc(Cl)c1)C1C(=O)Sc2ccccc21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.