['Cc1cc(Br)ccc1N', 'O=[N+]([O-])c1cccc(Cl)c1[SH](=O)=O', 'Cc1cccc(Br)c1', 'NS(=O)(=O)c1c(Cl)cccc1[N+](=O)[O-]']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=S(=O)(Nc1ccccc1)c1ccccc1.