Using O=C1CC(=O)CC(c2ccccc2Cl)C1, CCOC(=O)C(=O)CBr to produce CCOC(=O)c1coc2c1C(=O)CC(c1ccccc1Cl)C2, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.