Using CC(=O)Cc1ccc(C(=O)O)cc1, CC(C)(C)C(=O)OCCl to produce CC(=O)Cc1ccc(C(=O)OCOC(=O)C(C)(C)C)cc1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.