['Nc1cccnc1Cl', 'CC(C)CN(CC=O)CC(C)C', 'CC(C)C', 'CC(C)CNCC(=O)Nc1cccnc1Cl', 'CC(C)CNCC(C)C', 'CC(=O)Nc1cccnc1Cl', 'Clc1ccccn1', 'CC(C)CN(CC(N)=O)CC(C)C']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccncc1.