['CC(C)CCCN', 'O=CNNC(=O)c1c[nH]c2ccccc12', 'CCCC(C)C', 'NC(=O)NNC(=O)c1c[nH]c2ccccc12', 'c1ccc2[nH]ccc2c1', 'CC(C)CCCNC(=O)NNC=O']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccc2[nH]ccc2c1.