Cc1cc2c3c(c1)C1(C(=O)N3C(C)(C)CC2C)C(C#N)=C(N)Oc2[nH]nc(C)c21
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?