Related Experiment Video
Updated: May 26, 2026

Facile Preparation of 4-Substituted Quinazoline Derivatives
Published on: February 15, 2016
N,N'-Bis(pyridin-2-yl)benzene-1,4-diamine-quinoxaline (2/1)
Barbara Wicher1, Maria Gdaniec
1Faculty of Chemistry, Adam Mickiewicz University, 60-780 Poznań, Poland.
Abstract:
The asymmetric unit of the title compound, 2C(16)H(14)N(4)·C(8)H(6)N(2), consits of one mol-ecule of N,N'-bis-(pyridin-2-yl)benzene-1,4-diamine (PDAB) and one half-mol-ecule of quinoxaline (QX) that is located around an inversion centre and disordered over two overlapping positions. The PDAB mol-ecule adopts a non-planar conformation with an E configuration at the two partially double exo C N bonds of the 2-pyridyl-amine units. In the crystal, these self-complementary units are N-H⋯N hydrogen bonded via a cyclic R(2) (2)(8) motif, creating tapes of PDAB mol-ecules extending along [010]. Inversion-related tapes are arranged into pairs through π-π stacking inter-actions between the benzene rings [centroid-centroid distance = 3.818 (1) Å] and the two symmetry-independent pyridine groups [centroid-centroid distance = 3.760 (1) Å]. The QX mol-ecules are enclosed in a cavity formed between six PDAB tapes.
Related Concept Videos
Aryldiazonium Salts to Azo Dyes: Diazo Coupling
Nomenclature of Aromatic Compounds with Multiple Substituents
For disubstituted benzene derivatives, with two groups attached to the benzene ring, three constitutional isomers are possible. For example, consider dimethyl benzene, often called xylene, where the second methyl group can be substituted at the second, third, or fourth carbon. The relative position of the substituents is represented by prefixes ortho, meta, or...
Nucleophilic Aromatic Substitution of Aryldiazonium Salts: Aromatic SN1
In the Sandmeyer reaction, for example, the diazonio group is replaced by a chloro, bromo, or cyano...
1° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Mechanism
Diazonium Group Substitution: –OH and –H
Diazonium Group Substitution with Halogens and Cyanide: Sandmeyer and Schiemann Reactions

