['CO', 'Cc1ccc(-c2nc(CC=O)cs2)cc1', 'COC(C)=O', 'Cc1ccc(-c2nccs2)cc1', 'Cc1ccccc1', 'COC(=O)Cc1cscn1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccc(-c2nccs2)cc1.