['CC=O', 'C[C@@H](c1ccc(-n2cncn2)cc1)N(C)CC(=O)NCCN', 'CC(=O)NCCN', 'C[C@@H](c1ccc(-n2cncn2)cc1)N(C)CC=O', 'CC(N)=O', 'CCNC(=O)CN(C)[C@@H](C)c1ccc(-n2cncn2)cc1', 'CCNC(C)=O', 'C[C@@H](c1ccc(-n2cncn2)cc1)N(C)CC(N)=O', 'CC(=O)NCCNC(C)=O', 'CN[C@@H](C)c1ccc(-n2cncn2)cc1', 'CNCC(=O)NCCNC(C)=O', 'CCc1ccc(-n2cncn2)cc1', 'c1ccc(-n2cncn2)cc1', 'CCN(C)CC(=O)NCCNC(C)=O', 'c1nc[nH]n1', 'CC(=O)NCCNC(=O)CN(C)[C@@H](C)c1ccccc1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccc(-n2cncn2)cc1.