Using O=S([O-])c1ccc(Cl)nc1, CCOC(=O)C(C)(C)Br to produce CCOC(=O)C(C)(C)S(=O)(=O)c1ccc(Cl)nc1, please predict the solvent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.