Using O=C1CCC(=O)N1Br, COC(=O)c1ccc(-c2nccnc2N)cc1F to produce COC(=O)c1ccc(-c2nc(Br)cnc2N)cc1F, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.