Using Fc1ccc2c(c1)CCN2, O=C(O)c1cc(Cl)c(Br)cn1 to produce O=C(c1cc(Cl)c(Br)cn1)N1CCc2cc(F)ccc21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.