['CO', 'Cc1c(NC(=O)CCl)c(C=O)nn1C', 'O=CCCl', 'COC(=O)c1nn(C)c(C)c1N', 'NC(=O)CCl', 'COC(=O)c1cc(C)n(C)n1', 'COC=O', 'Cc1c(NC(=O)CCl)cnn1C']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1cn[nH]c1.