['NC(N)=O', 'CC(C)[C@@H](C=O)Sc1ncc2ccccn12', 'NC=O', 'CC(C)[C@H](Sc1ncc2ccccn12)C(N)=O', 'CC(C)CC(=O)NC(N)=O', 'Sc1ncc2ccccn12', 'c1ccn2cncc2c1', 'CC(C)[C@H](S)C(=O)NC(N)=O']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccn2cncc2c1.