CN1C(=O)C2(C(C#N)=C(N)N(c3ccc(Cl)cc3)C3=C2C(=O)CC(C)(C)C3)c2ccccc21
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?