['Nc1cc2n(n1)CCCC2', 'Cc1nc([SH](=O)=O)cn1C', 'c1cc2n(n1)CCCC2', 'Cc1nc(S(N)(=O)=O)cn1C']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=S(=O)(Nc1cc2n(n1)CCCC2)c1c[nH]cn1.