['CCNCC', 'O=CCn1cc(C(=O)C(=O)Cl)c2ccccc21', 'CC', 'CCNC(=O)Cn1cc(C(=O)C(=O)Cl)c2ccccc21', 'O=CC(=O)Cl', 'CCN(CC)C(=O)Cn1ccc2ccccc21', 'CCN(CC)C(C)=O', 'O=C(Cl)C(=O)c1c[nH]c2ccccc12']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccc2[nH]ccc2c1.