Using O=C1CCC(=O)N1Br, CCOC(=O)C=C1c2ccc(C)cc2C=Cc2ccc(F)cc21 to produce CCOC(=O)C=C1c2ccc(CBr)cc2C=Cc2ccc(F)cc21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.