['CC(C)CN', 'O=CCn1cc(Br)c(=O)[nH]c1=O', 'CC(C)C', 'NC(=O)Cn1cc(Br)c(=O)[nH]c1=O', 'CC(=O)NCC(C)C', 'O=c1[nH]cc(Br)c(=O)[nH]1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=c1cc[nH]c(=O)[nH]1.