Using CCOC(=O)Cn1cc(-c2ccc(Br)cc2)n(C2CC2)c1=O to produce O=C(O)Cn1cc(-c2ccc(Br)cc2)n(C2CC2)c1=O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.