Using O=C1CCC(=O)N1Br, Fc1ccc(-c2nn3ccccc3c2-c2ccnc(F)c2)cc1 to produce Fc1ccc(-c2nn3cc(Br)ccc3c2-c2ccnc(F)c2)cc1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.