CN1c2ccccc2N(C)C23N(C)c4ccccc4N(C)C12N(C)c1ccccc1N3C
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?