['CC(C)(C)O', 'O=CNc1ccc2nc(C(=O)O)ccc2c1', 'CC(C)(C)OC=O', 'Nc1ccc2nc(C(=O)O)ccc2c1', 'CC(C)C', 'O=C(O)Nc1ccc2nc(C(=O)O)ccc2c1', 'CC(C)(C)OC(N)=O', 'O=C(O)c1ccc2ccccc2n1', 'O=CO', 'CC(C)(C)OC(=O)Nc1ccc2ncccc2c1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccc2ncccc2c1.