O=C1[C@@H]2[C@@H]3CCCN3[C@@]3(C(=O)Nc4ccccc43)[C@@H]2C(=O)N1c1cc(Cl)cc(Cl)c1
Hydrogen bond acceptor: The atom, ion, or molecule component of a hydrogen bond which does not supply the bridging (shared) hydrogen atom. How many hydrogen bond acceptors does the molecule have?