['N#CCO', 'O=CCCc1nc(-c2ccccc2)no1', 'CC#N', 'O=C(O)CCc1nc(-c2ccccc2)no1', 'CCC(=O)OCC#N', 'c1ccc(-c2ncon2)cc1', 'c1ccccc1', 'N#CCOC(=O)CCc1ncno1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccc(-c2ncon2)cc1.