O=S(=O)(c1ccccc1)[C@@]1(c2ccc(Br)cc2)C[C@@H]2ON=C(c3cccc(Br)c3)[C@@H]2C1
A rotatable bond is defined as any single non-ring bond, attached to a non-terminal, non-hydrogen atom. Amide C-N bonds are not counted because of their high barrier to rotation.  How many rotatable bonds does the molecule have?