Using O=C1CCC(=O)N1Br, CCOC(=O)c1cc(C)nc(C(F)(F)F)n1 to produce CCOC(=O)c1cc(CBr)nc(C(F)(F)F)n1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.