['CC(C)(C)NCC=O', 'Cc1cccc(N)n1', 'CC(C)(C)N', 'CC(=O)Nc1cccc(C)n1', 'CC(C)C', 'Cc1cccc(NC(=O)CN)n1', 'Cc1ccccn1', 'CC(C)(C)NCC(N)=O']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccncc1.