['CNC', 'C[C@@H](C=O)Sc1nc2ccccc2c(=O)n1C', 'CCC(=O)N(C)C', 'Cn1c(S)nc2ccccc2c1=O', 'C[C@H](S)C(=O)N(C)C', 'Cn1cnc2ccccc2c1=O']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=c1[nH]cnc2ccccc12.