['COCC=O', 'CCN(CC)CCn1cc(N)cn1', 'CO', 'CCN(CC)CCn1cc(NC(C)=O)cn1', 'CC', 'CCNCCn1cc(NC(=O)COC)cn1', 'CCNCC', 'CCn1cc(NC(=O)COC)cn1', 'COCC(N)=O', 'CCN(CC)CCn1cccn1', 'CCN(CC)CC', 'COCC(=O)Nc1cn[nH]c1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1cn[nH]c1.