['CC', 'CC(CO)Nc1ccc2nnnn2n1', 'CCO', 'CC(C)Nc1ccc2nnnn2n1', 'CCCOCC', 'Nc1ccc2nnnn2n1', 'CCOCC(C)N', 'c1cnn2nnnc2c1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1cnn2nnnc2c1.