CC(C)C1(NC(=O)C2CC3c4cccc5[nH]cc(c45)CC3N(C)C2)OC2(O)C3CCCN3C(=O)C(Cc3ccccc3)N2C1=O
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?