Using COC(=O)C1(CCC(C)(C)C)C(OC)=CC(=O)c2ccccc21 to produce COC(=O)C1(CCC(C)(C)C)C(=O)CC(=O)c2ccccc21, please predict the solvent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.