['CC(C)CN', 'O=CCCC(=O)N1CC(=O)Nc2ccccc21', 'CC(C)CNC(=O)CCC=O', 'O=C1CNc2ccccc2N1', 'CC(C)C', 'NC(=O)CCC(=O)N1CC(=O)Nc2ccccc21']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=C1CNc2ccccc2N1.