['c1ccc2[nH]cnc2c1', 'O=C/C=C/c1cc(Br)ccc1O', 'Cc1cc(Br)ccc1O', 'CC(=O)c1nc2ccccc2[nH]1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=C(/C=C/c1ccccc1)c1nc2ccccc2[nH]1.