Using COC(=O)C(C)(Br)CCc1cccc(C(=O)c2ccccc2)c1 to produce COC(=O)C(C)=CCc1cccc(C(=O)c2ccccc2)c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.