['CO', 'NCCCS(=O)(=O)N1CCN(c2ccccc2)CC1', 'NCCC[SH](=O)=O', 'COc1ccc(N2CCNCC2)cc1', 'COc1ccccc1', 'NCCCS(=O)(=O)N1CCNCC1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccc(N2CCNCC2)cc1.