Using O=C(F)c1c(F)c(F)c(F)c(F)c1C(=O)F, O=C1OC(F)(F)c2c(F)c(F)c(F)c(F)c21 to produce O=C1OC(=O)c2c(F)c(F)c(F)c(F)c21, please predict the solvent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.