['CC(=O)O', 'Cc1ccc(-c2nc(S)n[nH]2)cc1C', 'O=C(O)CS', 'Cc1ccc(-c2ncn[nH]2)cc1C', 'Cc1ccccc1C', 'O=C(O)CSc1nc[nH]n1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccc(-c2ncn[nH]2)cc1.