['CC(=O)NCCN', 'COCCN(CC=O)Cc1ccco1', 'CC=O', 'COCCN(CC(=O)NCCN)Cc1ccco1', 'CO', 'CCN(CC(=O)NCCNC(C)=O)Cc1ccco1', 'CCOC', 'CC(=O)NCCNC(=O)CNCc1ccco1', 'CC(=O)NCCNC(C)=O', 'COCCNCc1ccco1', 'CCNC(C)=O', 'COCCN(CC(N)=O)Cc1ccco1', 'CC(N)=O', 'CCNC(=O)CN(CCOC)Cc1ccco1', 'Cc1ccco1', 'COCCNCC(=O)NCCNC(C)=O', 'c1ccoc1', 'COCCN(C)CC(=O)NCCNC(C)=O']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccoc1.