['CC(C)(C)N', 'CN(CC=O)S(=O)(=O)c1c(Cl)cccc1[N+](=O)[O-]', 'CC(=O)NC(C)(C)C', 'CNS(=O)(=O)c1c(Cl)cccc1[N+](=O)[O-]', 'CC(C)C', 'CN(CC(N)=O)S(=O)(=O)c1c(Cl)cccc1[N+](=O)[O-]', 'CNCC(=O)NC(C)(C)C', 'O=[N+]([O-])c1cccc(Cl)c1[SH](=O)=O']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccccc1.