O=C(Nc1nnc(-c2c(Cl)c(Cl)c(Cl)c(Cl)c2-c2nc3cc(C(=O)c4ccccc4)ccc3[nH]2)o1)c1ccc(Cl)cc1
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?