COC(=O)[C@@]1(Cc2ccccc2)[C@H]2c3cc(C(=O)N4CCCC4)n(Cc4ccccn4)c3C[C@H]2CN1C(=O)c1ccccc1
Hydrogen bond acceptor is the chemical compound which contains the lone electron pairs that participate in the hydrogen bond formation. This compound should contain a more electronegative atom (more electronegative than hydrogen) with lone electron pairs. Then it can attract protons from a donor. Moreover, the electronegative atoms usually involved in hydrogen bonding are oxygen, nitrogen and fluorine. How many hydrogen bond acceptors does the molecule contain?