['CO', 'CC(C#N)CN(C)Cc1cc2ccccc2nc1Cl', 'CNCC(C)C#N', 'COc1ccc2cc(C)c(Cl)nc2c1', 'CC(C)C#N', 'CNCc1cc2ccc(OC)cc2nc1Cl', 'CC(C#N)CN(C)C', 'COc1ccc2ccc(Cl)nc2c1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccc2ncccc2c1.