['CCCCC=O', 'Nc1ccc2nc(C3CCCO3)[nH]c2c1', 'CCCCC(N)=O', 'c1ccc2[nH]c(C3CCCO3)nc2c1', 'C1CCOC1', 'CCCCC(=O)Nc1ccc2nc[nH]c2c1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccc2[nH]c(C3CCCO3)nc2c1.