['COCCN', 'NC(=O)c1ccc(CNCCC=O)cc1', 'CO', 'CCNC(=O)CCNCc1ccc(C(N)=O)cc1', 'CCOC', 'NC(=O)CCNCc1ccc(C(N)=O)cc1', 'CCC(=O)NCCOC', 'NCc1ccc(C(N)=O)cc1', 'Cc1ccc(C(N)=O)cc1', 'COCCNC(=O)CCN', 'NC=O', 'COCCNC(=O)CCNCc1ccccc1', 'NC(=O)c1ccccc1', 'CNCCC(=O)NCCOC']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccccc1.