['CCN', 'O=CC1CCN(CN2CCSC2=S)CC1', 'CC', 'NC(=O)C1CCN(CN2CCSC2=S)CC1', 'CCNC=O', 'S=C1SCCN1CN1CCCCC1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is S=C1SCCN1CN1CCCCC1.