Combination of the Claisen-Schmidt reaction, the Michael addition, and the Hantzsch reaction in the synthesis of 2,6′-bis-aryl-3,4′-bipyridines

Article abstract of DOI:10.1007/s11172-020-2792-9

Pyridine-3-carbaldehyde reacted with 1-(aryl)ethan-1-ones to give 1,5-diaryl-3-(pyridin-3-yl)pentane-1,5-diones, which were further converted to 2′,6′-bis-aryl-3,4′-bipyridines.

Full text of DOI:10.1007/s11172-020-2792-9

Russian Chemical Bulletin, International Edition, Vol. 69, No. 3, pp. 517—524, March, 2020
517
Combination of the Claisen—Schmidt reaction, the Michael addition, and
the Hantzsch reaction in the synthesis of 2´,6´-bis-aryl-3,4´-bipyridines*
V. A. Mamedov, L. V. Mustakimova, O. A. Gerasimov, and A. T. Gubaidullin
A. E. Arbuzov Institute of Organic and Physical Chemistry,
Federal Research Center "Kazan Scientific Center of the Russian Academy of Sciences,"
8 ul. Arbuzova, 420088 Kazan, Russian Federation.
Fax: +7 (843) 273 2253. E-mail: mamedov@iopc.ru
Pyridine-3-carbaldehyde reacted with 1-(aryl)ethan-1-ones to give 1,5-diaryl-3-(pyridin-
3-yl)pentane-1,5-diones, which were further converted to 2´,6´-bis-aryl-3,4´-bipyridines.
Key words: pyridine-3-carbaldehyde, 1-(aryl)ethan-1-ones, ammonium acetate, the
Claisen—Schmidt reaction, the Michael addition, the Hantzsch pyridine synthesis, 2´,6´-bis-
aryl-3,4´-bipyridines.
access 3,4´-bipyridines are mainly given as the separate
Bipyridines are of great interest due to their catalytic
activity, broad applications in industry, medicine, and
as the analytical reagents and ligands for the metal
complex synthesis.1—4 Symmetrical bipyridines can be
synthesized under the modified Ullmann-type reaction
conditions, namely, by metal-catalyzed cross-coupling
of halopyridines.5,6 Only few cases of the synthesis of
examples together with the syntheses of other pyridine
7—10
derivatives. The key step of the Kröhnke-type
Hantzsch-type
and the
11,12
syntheses is the condensation of 1,5-di-
carbonyl compounds with ammonium acetate or other nitro-
gen sources. In general, 1,5-dicarbonyl compounds are
generated in situ by either the reactions of enones with the
pyridinium salts (accessible by the reaction between pyridine
and ketones in the presence of iodine under the Ortoleva—
King conditions) or the reactions of acetoacetic ester (or
its analogs) with aldehydes in the presence of ammonium
acetate.
Our approach to 3,4´-bipyridines is shown in Scheme 1.
3,4´-Bipyridines 5 can be synthesized from 1,5-dicarb-
onyl compounds 4 by cyclization with NH4OAc as the
nitrogen source. In turn, 1,5-dicarbonyl compounds 4 can
be prepared from enones 3 and 1-(aryl)ethan-1-ones 2
under the Michael reaction conditions. We assumed that
depending on the reaction conditions 1-(aryl)ethan-1-ones
2 bearing active methyl group can be used as the starting
material not only in the Claisen—Schmidt synthesis of
enone 3 from pyridine-3-carbaldehyde (1), but also in the
Michael addition reaction with enones 3 to give 1,5-dicarb-
onyl compounds 4.
unsymmetrical bipyridines by the Kröhnke reaction,7—10
11,12
the Hantzsch pyridine synthesis,
the Suzuki—Miyaura
13—15
16,17
coupling,
other cross-couplings,
and the cou-
18,19
pling reactions
of halopyridines have been described.
Comparing with other bipyridines, 3,4´-bipyridines
are still poorly studied biheterocyclic systems although
15,20—25
they attract a considerable interest
of the research-
26,27
ers as cardiotonics.
Amrinone (5-amino-1H-3,4´-
bipyridin-6-one) and milrinone (2-methyl-6-oxo-1,6-
dihydro-3,4´-bipyridine-5-carbonitrile) have pronounced
positive inotropic effect in myocardium and also func-
tion as vasodilators.28—33
Indeed, pyridine-3-carbaldehyde reacts with 4-chloro-,
4-bromo-, and 3-bromoacetophenones in a 10% solution
of KOH in MeOH for 18 h followed by dilution with water
and acidification with 10% HCl to give 1,5-diaryl-3-
(pyridin-3-yl)pentane-1,5-diones 4a—c (Scheme 2). Form-
As for the synthesis of 3,4´-bipyridines, it is very dif-
ficult to find the publications devoted to the synthesis of
compounds of this precise type. The known methods to
1
ation of these compounds was confirmed by H NMR
spectroscopy showing the characteristic signals of the A2B2X
spin system for the —CH(CH2)2 moiety, the signals of the
aryl ring, and 3-substituted pyridine ring. In the IR spectra
of these compounds, the carbonyl group absorptions are
* Based on the materials of the International Markovnikov
Congress on Organic Chemistry (June 21—28, 2019, Moscow—
Kazan, Russia).
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 0517—0524, March, 2020.
1066-5285/20/6903-0517 © 2020 Springer Science+Business Media LLC

Mamedov et al.
518
Russ. Chem. Bull., Int. Ed., Vol. 69, No. 3, March, 2020
Scheme 1
i. Cyclization with the N atom source. ii. The Michael addition. iii. The Claisen—Schmidt condensation + the Michael addition.
iv. The Claisen—Schmidt condensation.
observed at the 1678—1692 cm–1 range that is shifted to
Scheme 3
the shorter wavelengths by 20—30 cm–1 compared to the
standard values. This deviation from the standard values is
apparently due to the –I and –M effects as well as the
steric effect of the substituted benzene rings.
Scheme 2
Ar = Ph (a), 4-ClC6H4 (b), 4-BrC6H4 (c)
Reagents and conditions: 10% KOH/MeOH, MeOH, 0—5 C,
~30—40 min.
Scheme 4
4
a
b
c
Ar
Yield (%)
4-ClC6H4
4-BrC6H4
3-BrC6H4
77
79
75
Ar = 4-ClC6H4 (3b, 4a), 4-BrC6H4 (3c, 4b)
Reagents and conditions: 10% KOH/MeOH, MeOH, ~20 C,
~18 h.
Reagents and conditions: 10% KOH/MeOH, MeOH, 0—5 C,
~18 h.
When the reaction time was shorten to 30—40 min,
the intermediate 1-aryl-3-(pyridin-3-yl)prop-2-en-1-ones
3a—c were isolated in good yields (Scheme 3). Com-
pounds 3b,c were also converted into 1,5-diaryl-3-(pyr-
idin-3-yl)pentane-1,5-diones 4a,b (Scheme 4).
Structure of the substituted 1,5-diaryl-3-(pyridin-3-yl)
pentane-1,5-dione (4a) was established by X-ray diffrac-
tion analysis. The obtained X-ray diffraction data show
that compound 4a crystallizes in the orthorhombic crystal
system in the chiral space group P212121 with one molecule
in the asymmetric unit of the unit cell. The molecular
geometry of compound 4a is shown in Fig. 1, the bond
lengths and bond angles agree with the standard values
within the experimental errors. Selected bonds lengths for
compound 4a are given in Table 1. The dihedral angles
between the pyridine ring plane and the planes of the aryl
substituents are 86.3(2) and 74.2(2). The aryl substituents
are almost coplanar; the dihedral angle between their
planes is 12.7(2).
In the crystal of pentane-1,5-dione 4a, no classical
H-bonding is observed and the main structure-forming
interactions are the C—H...O and C—H...N hydrogen
bonds that have connected the molecules of 4a into a 3D
hydrogen-bonding network. The parameters of inter-
molecular contacts are given in Table 2. It is of interest
that in this case the directions of the intermolecular inter-
actions are dictated by all the three O and N hydrogen
bond acceptors. Thus, along the 0a axis, the shortest axial
direction in the unit cell, the bifurcated H-bonds that in-
volved the O(1) atom of the carbonyl group are realized

Synthesis of 2´,6´-bis-aryl-3,4´-bipyridines
Russ. Chem. Bull., Int. Ed., Vol. 69, No. 3, March, 2020
519
N(31)
O(5)
С(5)
С(33)
O(1)
C(1)
С(3)
С(51)
С(4)
Сl(2)
С(2)
С(11)
Cl(1)
Fig. 1. Crystal geometry of compound 4a with partial atomic numbering scheme. Nonhydrogen atoms are drawn as displacement
ellipsoids at the 50% probability level, hydrogen atoms are drawn as spheres with arbitrary radii.
Table 1. Bond lengths (d) in com-
pound 4a
why pentane-1,5-dione 4a is chiral and crystallizes in the
Sohncke space group.
It should be noted that in such molecular packing the
crystal lacks the solvent-accessible void space and a suffi-
ciently dense packing is achieved. The calculated packing
efficiency is equal to 71.6%, which is within the highest
values characteristic of the organic compounds (0.65—0.75).
1,5-Diketones 4a—c react with 5-fold excess of am-
monium acetate on refluxing in acetic acid in the presence
of pyridine for 12 h to give high yields of 2´,6´-bis-aryl-
3,4´-bipyridines 5a—c that are not contaminated with any
1,4-dihydropyridine derivatives A, the precursors of com-
pounds 5 (Scheme 5).
Bond
d/Å
C(3)—С(33)
C(3)—С(4)
C(3)—С(2)
C(5)—O(5)
C(1)—O(1)
N(31)—C(32)
N(31)—C(36)
C(14)—Cl(1)
C(54)—Cl(2)
1.505(7)
1.537(7)
1.535(7)
1.216(6)
1.227(6)
1.328(6)
1.328(7)
1.744(5)
1.732(6)
Structures of 2´,6´-bis-aryl-3,4´-bipyridines 5a—c
were unambiguously confirmed by their 1H NMR spectra
showing the characteristic signals of differently substituted
pyridine rings and para- (compounds 5a,b) and meta-
(see Table 2 and Fig. 2, a). Along the 0c axis, the similar
H-bonded chains of the molecules are formed due to the
bifurcated H-bonds that involve the N(31) pyridine ring
atom (see Fig. 2). The thus formed 2D H-bonded layers of
the molecules are linked along the 0b crystallographic axis
via the hydrogen bonds involving the O(5) atom of the
second carbonyl group of the molecule (see Fig. 2, b).
Nonequivalence of two carbonyl oxygen atoms O(1) and
O(5) in the intermolecular H-bonding is the exact reason
1
substituted (compound 5c) benzene rings. In H NMR
spectra of compounds 5a and 5b, the proton signals of the
meta-substituted pyridine ring have the same chemical
shifts and multiplicities and appear at  7.60 (dd, H(5),
J = 8.1, 4.8 Hz), 8.47 (ddd, H(4), J = 8.1, 2.1, 1.4 Hz),
8.71 (dd, H(6), J = 4.8, 1.4 Hz), and 9.27 (d, H(2),
Table 2. Intermolecular interactions in the crystal of compound 4a
Fragment
D—H…A
Distance/Å
Angle/deg
D—H—A
Symmetry codes
H…A
D…A
C(15)—H(15)...O(5´)
C(2)—H(21)...N(31)
C(4)—H(42)…N(31)
C(34)—H(34)...O(1*)
C(2)—H(22)…O(1*)
2.49
2.60
2.67
2.50
2.64
3.368(7)
3.474(7)
3.517(7)
3.441(7)
3.585(7)
154
147
144
172
159
1/2 – x, 2 – y, 1/2 + z
1 – x, –1/2 + y, 1/2 – z
1 – x, –1/2 + y, 1/2 – z
1 + x, y, z
1 + x, y, z

Mamedov et al.
520
Russ. Chem. Bull., Int. Ed., Vol. 69, No. 3, March, 2020
a
H(42)
N(31)
H(21)
H(22)
H(34)
O(1)
b
H(15)
O(5)
O(5)
Fig. 2. Two projections of the supramolecular crystal structure of compound 4a drawn along the 0a axis (a) and approximately along
the 0c axis. Only the hydrogen atoms involved in the hydrogen bonding are shown, H-bonds are shown by dotted lines.
J = 2.1 Hz). The H(3´) and H(5´) protons of the trisub-
stituted pyridine rings of both compounds resonate as the
singlets at almost the same range at  8.35 and 8.36, re-
spectively. The signals of para-substituted benzene ring of
para-chloro-substituted derivatives 5a are shifted to the
lower filed by 0.1 ppm. The H(3´) and H(5´) protons of
compound 5c bearing meta-bromo-substituted benzene
rings resonate as the singlets at  8.42. The protons of meta-
substituted benzene rings of these compounds are observed
at  7.57 (dd, H(5), J1 = J2 = 7.9 Hz), 7.71 (dd, H(6),
J = 7.9, 1.0 Hz), 8.38 (d, H(4), J = 7.9 Hz), and 8.55 (dd,
H(2), J = 1.8, 1.0 Hz).
These data indicate that the chemical shifts of the H(3´)
and H(5´) pyridine rings depend on the nature and the
position of the substituents in the benzene rings, which is
an agreement with the published data. For instance, the

Synthesis of 2´,6´-bis-aryl-3,4´-bipyridines
Russ. Chem. Bull., Int. Ed., Vol. 69, No. 3, March, 2020
521
Scheme 5
the Federal Research Center "Kazan Scientific Center of the
Russian Academy of Sciences" using the equipment of the
Collective spectral and analytical center for physicochemical
studies of the structure, properties, and composition of com-
pounds and materials.
X-ray diffraction data were collected with a Bruker Kappa
Apex II CCD diffractometer ((Mo-K) = 0.71073 Å, graphite
monochromator, φ and  scan modes). The main crystallo-
graphic data and refinement details are given in Table 3.
The data were collected, processed, and the unit cell para-
meters were refined using APEX2 software.35 Semiempirical
absorption corrections (Mo = 0.373 mm–1) were applied using
SADABS program.36 The structure was solved by the direct
method and refined by the full-matrix least-squares method first
in isotropic and then in anisotropic approximations (for all non-
hydrogen atoms) with SHELXL program.37 The positions of
hydrogen atoms were calculated based on stereochemical con-
siderations and refined using the corresponding riding models.
The Flack parameter is equal to 0.07(11). All calculations
were performed with WinGX program.38 Intermolecular interac-
tions were analyzed and the crystal structures were visualized
using PLATON39 and Mercury software.40 The atomic coordi-
nates and structural parameters of compound 4a were deposited
with the Cambridge Crystallographic Data Centre (CCDC
1957532) and are available free of charge at www.ccdc.cam.ac.uk/
data_request/cif.
5
a
b
c
Ar
Yield (%)
4-ClC6H4
4-BrC6H4
3-BrC6H4
83
84
72
Reagents and conditions: AcONH4, Py, AcOH, , 12 h.
Synthesis of 1,5-diaryl-3-(pyridin-3-yl)pentane-1,5-diones
4a—c (general procedure). A. To a stirred mixture of 3-pyridine-
carboxaldehyde (10 mmol) and the appropriately substituted
acetophenone (20 mmol) in MeOH cooled to 0—5 C, a 10%
solution of KOH in MeOH (5 mL) was slowly added dropwise.
The mixture was kept at room temperature for 18 h, poured into
water, and acidified with 10% HCl to рH ~7. The crystals formed
were collected by filtration, washed with water, dried in air, and
crystallized from EtOH.
B. To a stirred mixture of the appropriate 1-aryl-3-(pyridin-
3-yl)prop-2-en-1-one 3b,c (10 mmol) and the appropriately
substituted acetophenone (20 mmol) in MeOH, a 10% solution
of KOH in MeOH (5 mL) was slowly added dropwise at room
temperature. The mixture was kept at room temperature for 18 h,
poured into water, and acidified with 10% HCl to pH ~7. The
crystals formed were collected by filtration, washed with water,
dried in air, and crystallized from EtOH.
H(3´) and H(5´) protons of trisubstituted pyridine ring
of dihydroxy analog of compounds 5a and 5b resonate at
 8.03.34
In summary, we developed simple and efficient
method for synthesizing three dihalo-substituted 2´,6´-di-
aryl-3-pyridin-4´-ylpyridine derivatives that initiated by
the Claisen—Schmidt reaction and the Michael addition
and finalized by the Hantzsch pyridine synthesis. The
transformations started by the reaction of pyridine-3-
carbaldehyde with 1-(aryl)ethan-1-ones to give α,β-un-
saturated ketones. In the next step, α,β-unsaturated ketones
react with the second molecule of 1-(aryl)ethan-1-ones to
afford 1,5-diaryl-3-(pyridin-3-yl)pentane-1,5-dione de-
rivatives. The last compounds undergo cyclization in the
presence of ammonium acetate followed by aromatization
of the plausible dihydropyridine intermediate to give
2´,6´-bis-aryl-3,4´-bipyridines.
1,5-Bis(4-chlorophenyl)-3-(pyridin-3-yl)pentane-1,5-dione
(4a). White powder. Yield 3.1 g (77%), m.p. 163—165 C.
Found (%): C, 66.34; H, 4.30; Cl, 17.80; N, 3.52; O, 8.04.
C22H17Cl2NO2. Calculated (%): C, 66.44; H, 4.19; Cl, 17.61;
N, 3.39; O, 8.37. IR, /cm–1: 3349, 3063, 3031, 3001, 2901,
1920, 1793, 1691, 1680, 1589, 1573, 1486, 1475, 1430, 1419,
1400, 1364, 1330, 1273, 1231, 1211, 1169, 1090, 1056, 1026,
1011, 990, 922, 903, 826, 808, 790, 773, 718, 634, 611, 583, 533,
519. 1H NMR (CDCl3), : 3.35 (dd, 2 H, CH(CH2)2, JAB = 17.0 Hz,
JBX = 7.1 Hz); 3.52 (dd, 2 H, CH(CH2)2, JAB = 17.0 Hz,
Experimental
IR spectra were recorded with a Bruker Tensor 27 FT-IR
spectrometer (Germany) in KBr pellets in the frequency range
from 4000 to 400 cm–1. Data collection and primary analysis
were accomplished using OPUS 7/2012 software. 1H NMR
spectra were run on Avance-400 (working frequency of 399.93 MHz),
Avance-600 (working frequency of 600.1 MHz), and Avance-500
(working frequency of 500.1 MHz) spectrometers. The chemical
shifts are given in the  scale relative to the residual solvent signals.
Melting points were measured with an IA 9200 apparatus.
Single crystal X-ray diffraction analysis of compound 4a was
carried out in the Laboratory of diffraction research methods of
the A. E. Arbuzov Institute of Organic and Physical Chemistry,
JAX = 6.8 Hz); 4.02—4.12 (m, 1 H, CH(CH2)2, JAX + JBX
=
= 13.9 Hz); 7.22 (dd, 1 H, H(5), Py, J = 7.8 Hz, J = 4.8 Hz);
7.44, 7.88 (both d, 4 H each, ArCO, J = 8.7 Hz); 7.65 (ddd,
1 H, H(6), pyridyl, J = 7.8 Hz, J = 2.0 Hz, J = 1.6 Hz); 8.46 (dd,
1 H, H(4), pyridyl, J = 4.8 Hz, J = 1.6 Hz); 8.57 (d, 1 H, H(2),
pyridyl, J = 2.0 Hz).
1,5-Bis(4-bromophenyl)-3-(pyridin-3-yl)pentane-1,5-dione
(4b). White powder. Yield 3.8 g (79%), m.p. 178—180 C.
Found (%): C, 54.63; H, 3.82; Br, 32.39; N, 2.46; O, 6.70.

Mamedov et al.
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Russ. Chem. Bull., Int. Ed., Vol. 69, No. 3, March, 2020
Table 3. Crystallographic parameters and X-ray data collection and structure
refinement statistics for compound 4a
Parameter
4
Molecular formula
C22H17Cl2NO2
100
T/K
M
398.26
Crystal system
Orthorhombic
P212121
Space group
a/Å
5.6710(9)
14.901(2)
21.647(3)
1829.2(5)
0.71073
b/Å
c/Å
V/Å3
/Å
Z
4
dcalc/g cm–3
Crystal size/mm3
Scanning range, θ/deg
Index ranges h, k, l
1.446
0.0750.1230.540
2.89—28.33
–5  h  7,
–17  k  19,
–26  l  28
244
Number of refined parameters
Number of reflections
measured
18311
4458
0.1194
2212
independent
Rint
with I > 2σ(I)
R Factors (based on 2212 reflections with F2  2σ)
R1
wR2
0.0628
0.0953
R Factors (based on all independent reflections)
R1
wR2
GOOF
0.1640
0.1201
0.913
Residual electron density
(max/min)/e Å–3
0.337/–0.336
C22H17Br2NO2. Calculated (%): C, 54.24; H, 3.52; Br, 32.80;
N, 2.88; O, 6.57. IR, /cm–1: 3366, 3085, 3060, 3030, 3001,
2930, 2900, 2570, 1920, 1794, 1692, 1585, 1479, 1429, 1418,
1397, 1362, 1273, 1229, 1210, 1169, 1070, 1027, 1008, 989, 903,
822, 806, 772, 717, 633, 610, 579, 534, 495. 1H NMR (DMSO-d6),
: 3.34 (dd, 2 H, CH(CH2)2, JAB = 17.4 Hz, JBX = 7.6 Hz); 3.48
(dd, 2 H, CH(CH2)2, JAB = 17.4 Hz, JAX = 6.3 Hz); 3.92—3.99
(m, 1 H, CH(CH2)2, JAX + JBX = 13.9 Hz); 7.18 (dd, 1 H, H(5),
pyridyl, J = 7.8 Hz, J = 4.8 Hz); 7.56, 7.78 (both d, 4 H each,
ArCO, J = 8.4 Hz); 7.64 (br.d, 1 H, H(6), pyridyl, J  7.8 Hz);
8.33 (br.d, 1 H, H(4) pyridyl, J  4.8 Hz); 8.50 (br.d, 1 H, H(2),
pyridyl, J  2.0 Hz).
1 H CH(CH2)2, JAX + JBX = 13.9 Hz); 7.27 (dd, 1 H, H(5),
pyridyl, J = 7.8 Hz, J = 4.7 Hz); 7.48 (dd, 2 H, H(5), ArCO,
J = 7.9 Hz, J = 7.9 Hz); 7.79 (ddd, 1 H, H(6), pyridyl, J = 7.8 Hz,
J = 2.0 Hz, J = 1.0 Hz); 7.82 (dd, 2 H, H(4), ArCO, J = 7.9 Hz,
J = 1.0 Hz); 7.92 (br.d, 1 H, H(6), ArCO, J  7.9 Hz); 8.07 (dd,
2 H, H(2), ArCO, J = 1.7 Hz, J = 1.6 Hz); 8.46 (dd, 1 H, H(4),
pyridyl, J = 4.7 Hz, J= 1.0 Hz); 8.54 (d, 1 H, H(2), pyridyl, J = 2.0 Hz).
Synthesis of 1-aryl-3-(pyridin-3-yl)prop-2-en-1-ones 3a—c
(general procedure). To a stirred mixture of 3-pyridinecarbox-
aldehyde (10 mmol) and the appropriately substituted acetophen-
one (10 mmol) in MeOH cooled to 0—5 C, a 10% solution of
KOH in MeOH (5 mL) was slowly added dropwise. The reaction
mixture was kept at room temperature for 30—40 min, poured
into water, acidified with 10% aqueous HCl to pH ~7, and ex-
tracted with dichloromethane (3½50 mL). The combined or-
ganic layers were dried with MgSO4, concentrated in vacuo, and
the obtained residue was triturated with diethyl ether. The crys-
tals formed were collected by filtration, washed with diethyl ether,
and dried in air.
1,5-Bis(3-bromophenyl)-3-(pyridin-3-yl)pentane-1,5-dione
(4c). Yellowish crystals. Yield 3.7 g (75%), m.p. 226—228 C.
Found (%): C, 54.63; H, 3.82; Br, 32.39; N, 2.46; O, 6.70.
C22H17Br2NO2. Calculated (%): C, 54.24; H, 3.52; Br, 32.80;
N, 2.88; O, 6.57. IR, /cm–1: 3338, 3074, 3052, 3028, 2989,
2934, 2902, 1957, 1817, 1678, 1566, 1470, 1421, 1354, 1279,
1261, 1202, 1173, 1104, 1068, 1025, 1013, 994, 971, 912, 833,
1
807, 789, 770, 720, 707, 679, 556. H NMR (CDCl3), : 3.51
3-(Pyridin-3-yl)-1-phenylprop-2-en-1-one (3a). White pow-
der. Yield 1.7 g (83%), m.p. 104—106 C. Found (%): C, 80.14;
H, 5.42; N, 6.73; O, 7.71. C14H11NO. Calculated (%): C, 80.36;
(dd, 2 H, CH(CH2)2, JAB = 17.8 Hz, JBX = 7.7 Hz); 3.58 (dd,
2 H, CH(CH2)2, JAB = 17.8 Hz, JAX = 6.2 Hz); 3.84—3.91 (m,

Synthesis of 2´,6´-bis-aryl-3,4´-bipyridines
Russ. Chem. Bull., Int. Ed., Vol. 69, No. 3, March, 2020
523
H, 5.30; N, 6.69; O, 7.65. IR, /cm–1: 3473, 3086, 3062, 1958,
1902, 1661, 1604, 1579, 1564, 1474, 1447, 1423, 1346, 1338,
1309, 1221, 1182, 1122, 1098, 1044, 1015, 993, 982, 928, 869,
811, 768, 683, 626, 574, 517. 1H NMR (DMSO-d6), : 7.48—7.52
(m, 1 H, H(5), pyridyl); 7.58 (dd, 2 H, H(3), H(5), Ph, J = 7.8 Hz,
J = 7.5 Hz); 7.67 (ddd, 1 H, H(4), Ph, J = 7.4 Hz, J = 7.3 Hz,
J = 1.0 Hz); 7.78 (d, 1 H, CH=, J = 15.7 Hz); 8.07 (d, 1 H,
CH=, J = 15.7 Hz); 8.17 (d, 2 H, H(2), H(6), Ph, J = 8.1 Hz);
8.35 (br.d, 1 H, H(4), pyridyl, J  7.8 Hz); 8.62 (br.d, 1 H, H(6),
pyridyl, J  4.6 Hz); 9.03 (br.s, 1 H, H(2), pyridyl).
1-(4-Chlorophenyl)-3-(pyridin-3-yl)prop-2-en-1-one (3b).
White powder. Yield 2.0 g (82%), m.p. 157—159 C. Found (%):
C, 69.12; H, 4.28; Cl, 14.49; N, 5.59; O, 6.52. C14H10ClNO.
Calculated (%): C, 69.00; H, 4.14; Cl, 14.55; N, 5.75; O, 6.57.
IR, /cm–1: 3064, 3032, 1930, 1798, 1668, 1609, 1589, 1570,
1476, 1401, 1341, 1312, 1223, 1178, 1090, 1028, 1011, 986, 837,
798, 698, 667, 631, 584. 1H NMR (DMSO-d6), : 7.51 (dd, 1 H,
H(5), pyridyl, J = 7.8 Hz, J = 4.7 Hz); 7.67, 8.21 (both d,
4 Heach, ArCO, J = 8.6 Hz); 7.80 (d, 1 H, CH=, J = 15.7 Hz);
8.08 (d, 1 H, CH=, J = 15.7 Hz); 8.37 (ddd, 1 H, H(6), pyridyl,
J = 7.8 Hz, J = 2.0 Hz, J = 1.5 Hz); 8.63 (dd, 1 H, H(4), pyridyl,
J = 4.7 Hz, J = 1.5 Hz); 9.04 (d, 1 H, H(2), pyridyl, J = 2.0 Hz).
1-(4-Bromophenyl)-3-(pyridin-3-yl)prop-2-en-1-one (3c).
Yellowish crystals. Yield 2.4 g (84%), m.p. 127—129 C. Found (%):
C, 58.31; H, 3.46; Br, 27.76; N, 4.91; O, 5.56. C14H10BrNO.
Calculated (%): C, 58.36; H, 3.50; Br, 27.73; N, 4.86; O, 5.55.
IR, /cm–1: 3319, 3258, 3064, 3029, 1931, 1874, 1796, 1730,
1682, 1667, 1609, 1586, 1568, 1475, 1426, 1396, 1340, 1311,
1274, 1223, 1178, 1126, 1109, 1071, 1026, 1007, 986, 889, 835,
799, 729, 698, 666, 630, 609, 581. 1H NMR (DMSO-d6), : 7.50
(dd, 1 H, H(5), pyridyl, J = 7.7 Hz, J = 4.8 Hz); 7.74—7.84 (m,
3 H, H(2), H(6), ArCO, CH=); 8.07 (d, 1 H, CH=, J = 15.8 Hz);
8.12 (d, 2 H, H(3), H(5), ArCO, J = 8.5 Hz); 8.36 (br.d, 1 H,
H(4), pyridyl, J  7.7 Hz); 8.63 (br.d, 1 H, H(6), pyridyl, J  4.8 Hz);
9.04 (br.s, 1 H, H(2), pyridyl).
(DMSO-d6), : 7.61 (ddd, 1 H, H(5), pyridyl, J = 8.1 Hz,
J = 4.8 Hz, J = 0.7 Hz); 7.75, 8.33 (both d, 4 H each, Ar,
J = 8.6 Hz); 8.36 (s, 2 H, H(3´), H(5´), pyridyl); 8.47 (ddd, 1 H,
H(4), pyridyl, J = 8.1 Hz, J = 2.4 Hz, J = 1.5 Hz); 8.71 (dd,
1 H, H(6), pyridyl, J = 4.8 Hz, J = 1.5 Hz); 9.27 (dd, 1 H, H(2),
pyridyl, J = 2.4 Hz, J = 0.7 Hz).
2´,6´-Bis(3-bromophenyl)-3,4´-bipyridine (5c). White powder.
Yield 3.4 g (72%), m.p. 268—270 C. Found (%): C, 56.71;
H, 3.00; Br, 34.23; N, 6.06. C22H14Br2N2. Calculated (%):
C, 56.68; H, 3.03; Br, 34.28; N, 6.01. IR, /cm–1: 3124, 3057, 1939,
1713, 1653, 1608, 1590, 1565, 1544, 1475, 1446, 1427, 1377,
1333, 1274, 1252, 1242, 1191, 1161, 1127, 1092, 1071, 1052,
1022, 996, 958, 917, 874, 838, 801, 777, 750, 721, 712, 696, 683,
1
661, 631, 614, 506. H NMR (DMSO-d6), : 7.57 (dd, 2 H,
H(5´), Ar, J = 7.9 Hz, J = 7.9 Hz); 7.62 (dd, 1 H, H(5), pyridyl,
J = 8.1 Hz, J = 4.8 Hz); 7.71 (dd, 2 H, H(6), Ar, J = 7.9 Hz,
J = 1.0 Hz); 8.38 (br.d, 2 H, H(4), Ar, J  7.9 Hz); 8.42 (s, 2 H,
H(3´), H(5´), pyridyl); 8.52 (ddd, 1 H, H(4), pyridyl, J = 8.1 Hz,
J = 2.2 Hz, J = 1.5 Hz); 8.55 (dd, 2 H, H(2), Ar, J = 1.8 Hz,
J = 1.0 Hz); 8.73 (dd, 1 H, H(6), pyridyl, J = 4.8 Hz, J = 1.5 Hz);
9.32 (d, 1 H, H(2), pyridyl, J = 2.2 Hz).
The authors are grateful for the staff of the Assigned
Spectral and Analytical Center for Study of the Structure,
Properties and Composition of Substances and Materials
of the Federal Research Center "Kazan Scientific Center
of the Russian Academy of Sciences" for the physico-
chemical studies.
This work was financially supported in part by the
Russian Science Foundation (Project No. 18-13-00315).
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Received October 15, 2019;
accepted December 10, 2019