Using CN1C(=O)NCC1C(=O)OC(C)(C)C, O=S(=O)(OCC(F)F)C(F)(F)F to produce CN1C(=O)N(CC(F)F)CC1C(=O)OC(C)(C)C, please predict the solvent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.