ISSN 0036-0244, Russian Journal of Physical Chemistry A, 2017, Vol. 91, No. 2, pp. 246–251. © Pleiades Publishing, Ltd., 2017.
Original Russian Text © Ya.I. Koval’, E.M. Okul’, A.V. Yatsenko, E.V. Babaev, I.N. Polyakova, V.B. Rybakov, 2017, published in Zhurnal Fizicheskoi Khimii, 2017, Vol. 91,
No. 2, pp. 247–252.
NANOMATERIALS
AND ENVIRONMENT
Theoretical and Experimental Study of the Transformation
of 2-Pyridone-5-amide into Nitrile
Ya. I. Koval’a, E. M. Okul’a*, A. V. Yatsenkoa, E. V. Babaeva, I. N. Polyakovab, and V. B. Rybakova
a Department of Chemistry, Moscow State University, Moscow, 119991 Russia
b Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Moscow, 117901 Russia
*e-mail: okulem@struct.chem.msu.ru
Received June 16, 2016
Abstract—Molecular and crystal structures of 2,4-dimethyl-6-oxo-1,6-dihydropyridine-3-carboxamide
(1), 2,4-dimethyl-6-oxo-1,6-dihydropyridine-3-carbonitrile (2), and 2-chloro-4,6-dimethylniсotinoni-
trile (3), which are the products of sequential transformations, are studied by means of single crystal dif-
fraction. The procedure for synthesizing each compound is described. All of the compounds are charac-
1
terized using IR and H NMR spectra. Possible reaction pathways are simulated using the density func-
tional theory (DFT).
Keywords: pyridone-2, X-ray diffraction, single crystals, 1H NMR, density functional theory (DFT)
DOI: 10.1134/S0036024417020182
INTRODUCTION
column chromatography, a white crystalline solid
(as needles) was obtained with a yield of 62%.
In this work, the transformation of 2-pyridone-
5-amide into nitrile was investigated via X-ray map-
ping; this required study of the initial materials and
the intermediate and final products of multistage
reactions by means of diffraction to track changes in
the interatomic distances and bond angles. If possi-
ble, the intermediates were also investigated. In
addition to our structural study, all products were
characterized using 1H NMR spectra. Our first
works in this area were published in the late 1990s
[1]. This work describes only a small part of the
multistage process of obtaining and converting
4,6-dimethyl-5-cyano-2-pyridone.
A similar method was used to obtain chloropyri-
dine (1) without transforming the side amide group
into a nitrile group. The reaction was conducted in
freshly distilled POCl3 in the presence of triethyl-
benzylammonium chloride to increase the concen-
tration of Cl– ions. Chloropyridine (3), however,
was obtained instead of expected reaction
product (4). The yield was 70%, higher than in two-
step synthesis.
All of the synthesized compounds were charac-
1
terized by H NMR spectra, X-ray structure analy-
O
CH3
CH3
N
EXPERIMENTAL
POCl3/
DMF
H2N
Our study is briefly described by Scheme 1.
H3C
N
H
O
H3C
N
H
O
As is well known, Vilsmeier reagent (DMF/POCl3)
can be used to dehydrate an amide group, converting
it into a nitrile group [2]. We transformed the amide
group of pyridone (1) into a nitrile group (2) using this
approach. The reaction mixture was refluxed for 5 h
yielding a dark brown preparation. The product was
isolated via extraction in a Soxhlet apparatus with
chloroform. A light yellow product was obtained with
a yield of 52%.
1
2
POCl3/
DMF
POCl3/
DMF
O
CH3
CH3
N
N
POCl3/
DMF
H2N
H3C
N
Cl
H3C
Cl
4
3
The next step was to obtain chloropyridine (3).
Pyridone (2) was added to a mixture of DMF with
POCl3 and refluxed for 5 h. After purification via
Scheme 1.
246