['CC(C#N)CN(C)C(C)C=O', 'c1cnc(N2CCNCC2)nc1', 'CC(C)C#N', 'CNC(C)C(=O)N1CCN(c2ncccn2)CC1', 'CNCC(C)C#N', 'CCC(=O)N1CCN(c2ncccn2)CC1', 'c1cncnc1', 'CC(C#N)CN(C)C(C)C(=O)N1CCNCC1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1cnc(N2CCNCC2)nc1.