['Cn1ccs/c1=N\\C=O', 'c1ccc(-n2ccnc2)nc1', 'c1c[nH]cn1', 'Cn1ccs/c1=N\\C(=O)c1cccnc1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=C(/N=c1/[nH]ccs1)c1ccc(-n2ccnc2)nc1.