['Clc1cccnc1', 'O=[N+]([O-])c1cc(F)ccc1N1CCNCC1', 'O=[N+]([O-])c1cccc(F)c1', 'Clc1cccnc1N1CCNCC1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccc(N2CCN(c3ccccn3)CC2)cc1.