['NC1CCc2ncnn2C1', 'Cc1cnn(C)c1[SH](=O)=O', 'c1nc2n(n1)CCCC2', 'Cc1cnn(C)c1S(N)(=O)=O']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=S(=O)(NC1CCc2ncnn2C1)c1ccn[nH]1.