['CO', 'O=Cc1cc(-c2ccc(F)cc2F)on1', 'COC=O', 'Fc1ccc(-c2ccno2)c(F)c1', 'Fc1cccc(F)c1', 'COC(=O)c1ccon1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccc(-c2ccno2)cc1.