['CCCCOCCN', 'O=Cc1cncc(Br)c1', 'CCCC', 'O=C(NCCO)c1cncc(Br)c1', 'CCCCO', 'CCNC(=O)c1cncc(Br)c1', 'CCCCOCC', 'NC(=O)c1cncc(Br)c1', 'Brc1cccnc1', 'CCCCOCCNC=O']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccncc1.