['CN', 'O=CCN1CCCC1c1cccc2ccccc12', 'CNC(C)=O', 'c1ccc2c(C3CCCN3)cccc2c1', 'CNC(=O)CN1CCCC1', 'c1ccc2ccccc2c1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccc2c(C3CCCN3)cccc2c1.