Using O=C1CCC(=O)N1Br, COC(=O)c1cc(C)c(OC(C)=O)c(C)c1 to produce COC(=O)c1cc(C)c(OC(C)=O)c(CBr)c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.