Using COC1(OC)CC(c2ccc(Br)cc2)(N2C(=O)c3ccccc3C2=O)C1 to produce O=C1CC(c2ccc(Br)cc2)(N2C(=O)c3ccccc3C2=O)C1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.