Using O=C1OC(=O)c2c(F)c(F)c(F)c(F)c21, OCC(F)(F)F to produce O=C(O)c1cc(F)c(F)c(OCC(F)(F)F)c1F, please predict the solvent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.