['CCN', 'FC(F)(F)c1ccccc1N1CCNCC1', 'NCCN1CCNCC1', 'FC(F)(F)c1ccccc1', 'FC(F)F', 'NCCN1CCN(c2ccccc2)CC1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccc(N2CCNCC2)cc1.