['N#CCCNCCC#N', 'O=CCSc1ncc2ccccn12', 'CCC#N', 'N#CCCNC(=O)CSc1ncc2ccccn12', 'Sc1ncc2ccccn12', 'CC(=O)N(CCC#N)CCC#N', 'c1ccn2cncc2c1', 'N#CCCN(CCC#N)C(=O)CS']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccn2cncc2c1.