['Cc1csc(C)n1', 'CC(=O)C(C#N)c1nc2ccccc2o1', 'c1ccc2ocnc2c1', 'Cc1nc(/C=C/C(=O)CC#N)cs1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=C(/C=C/c1cscn1)Cc1nc2ccccc2o1.