C#CCCOC(=O)N1C2=NC(C(=O)OC)=C(C(=O)OC)[C@@H]3Nc4ccccc4[C@]23C[C@H]1C(=O)OC
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?