['CC', 'O=C(NO)c1ccc(NC2CC2)nc1', 'NC1CC1', 'CCONC(=O)c1cccnc1', 'C1CC1', 'CCONC(=O)c1ccc(N)nc1', 'CCONC=O', 'c1ccc(NC2CC2)nc1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccc(NC2CC2)nc1.