['O=Cc1ccncc1', 'NC(=O)C1CCNCC1', 'NC=O', 'O=C(c1ccncc1)N1CCCCC1', 'c1ccncc1', 'NC(=O)C1CCN(C=O)CC1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=C(c1ccncc1)N1CCCCC1.