['CC', 'Cc1nn(-c2ccccc2)c(O)c1C=O', 'CCO', 'Cc1nn(-c2ccccc2)cc1C=O', 'c1ccccc1', 'CCOc1[nH]nc(C)c1C=O']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccc(-n2cccn2)cc1.