['C#CCN', 'Cc1cc(C=O)c2c(C)nn(C)c2n1', 'C#CC', 'Cc1cc(C(N)=O)c2c(C)nn(C)c2n1', 'C#CCNC=O', 'Cc1ccc2c(C)nn(C)c2n1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1cnc2[nH]ncc2c1.