['CNC(N)=S', 'CC1(c2ccc(F)cc2)CCOCC1', 'CNC(=S)NC', 'Fc1ccc(C2CCOCC2)cc1', 'Fc1ccccc1', 'CNC(=S)NCC1CCOCC1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccc(C2CCOCC2)cc1.