['CO', 'CCOCCNc1cnn(C)c(=O)c1Cl', 'CCOC', 'Cn1ncc(NCCO)c(Cl)c1=O', 'COCCO', 'CCNc1cnn(C)c(=O)c1Cl', 'CCOCCOC', 'Cn1ncc(N)c(Cl)c1=O', 'COCCOCCN', 'Cn1nccc(Cl)c1=O']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=c1cccn[nH]1.