['CC(C)(C)N', 'O=Cc1cnc(-c2ccccc2)nc1', 'CC(C)C', 'NC(=O)c1cnc(-c2ccccc2)nc1', 'CC(C)(C)NC=O', 'c1ccc(-c2ncccn2)cc1', 'c1ccccc1', 'CC(C)(C)NC(=O)c1cncnc1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccc(-c2ncccn2)cc1.