['CC(C)CC(C)O', 'NC(=O)C1CC(C=O)=NN1c1ccccc1', 'CCCC(C)C', 'NC(=O)C1CC(C(=O)O)=NN1c1ccccc1', 'NC=O', 'CC(C)CC(C)OC(=O)C1=NN(c2ccccc2)CC1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is C1=NN(c2ccccc2)CC1.