Using CCCc1c(OCc2cccc(Br)n2)ccc(C(C)=O)c1O, O=C(O)c1cccc(S)c1 to produce CCCc1c(OCc2cccc(Sc3cccc(C(=O)O)c3)n2)ccc(C(C)=O)c1O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.