Using FC(F)(F)CS, CCn1c(C(C)(O)CCl)nc2cc(Cl)c(Cl)cc21 to produce CCn1c(C(C)(O)CSCC(F)(F)F)nc2cc(Cl)c(Cl)cc21, please predict the solvent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.