PANKINA et al.
780
the ring of γ-pyrone ІІІ under the action of the hetero-
cyclic amine I or II into the corresponding γ-pyridone
VIа–VIc, VIIа–VIIc that undergoes the condensation
with the second amine molecule.
heated at 120–125°С for 6 h. The solution was evaporated
in a vacuum at heating on a water bath. The dry residue
was triturated in water. The precipitate was filtered off
and recrystallized from an appropriate solvent.
The composition and structure of compounds IVа–
IVc, Vа–Vc are confirmed by the data of elemental analy-
ses and 1Н NMR spectra. The 1Н NMR spectra of com-
pounds IVа–IVc in DMSO-d6 contain the doubled signals
of the N1- and N3-alkyl groups of the imidazole fragment,
doubled singlets of the proton Н4 (7.43– 7.51 ppm), and
doublet signals of the vicinal protons Н6, Н6', Н7, Н7'
(7.08–7.16 and 7.03–7.07 ppm) of the benzene ring, and
also singlets of the protons Н10, Н12 (9.86–9.90 ppm)
and methyl groups at the atoms С9,13 of the pyridone ring
(1.98–2.02 ppm). In the 1Н NMR spectra of compounds
Vа–Vc in DMSO-d6 also doubled signals are present
of N1- and N3-alkyl groups of the imidazole fragment,
doubled doublets of the vicinal protons Н6, Н6', Н7, Н7'
(7.79–7.86 and 7.48–7.54 ppm) of the pyridine ring, and
also singlets of protons Н10, Н12 (10.31–10.42 ppm) and
of methyl groups in the positions 9 and 13 of the pyridone
ring (2.06–2.12 ppm).
The downfield position of the signals of protons Н10
and Н12 (9.88–10.42 ppm) in the spectra of compounds
IVа–IVc, Vа–Vc is apparently caused by the formation
of hydrogen bonds between DMSO-d6 and quinoid pro-
tons СН. In CDCl3 these signals shift to the region 7.86–
7.81 ppm (for compounds Vb, Vc ∆δ is 2.43– 2.50 ppm).
This assumption is confirmed also by the similar shift
of the signals of related protons in the spectrum of the
intermediate VIa (∆δ 2.93 ppm).
5-{2,6-Dimethyl-4-[(1,3-dimethyl-2-oxo-2,3-
dihydro-1Н-benzimidazol-5-yl)imino]pyridin-1-
(4Н)-yl}-1,3-dimethyl-1,3-dihydro-2Н-benzimidazol-
2-one (IVа). Yield 50%, mp 197–200°С (ethanol).
1Н NMR spectrum (DMSO-d6), δ, ppm: 2.02 s (6Н,
С9СН3, С13CH3), 3.27 s (12Н, N1CH3, N3CH3, N1'CH3,
N3'CH3), 7.03 d (2Н, Н7, Н7', J 8.0 Hz), 7.11 d (2Н, Н6,
Н6', J 8.0 Hz), 7.51 s (2Н, Н4, Н4'), 9.88 s (2Н, Н10,
H12). Found,%: С 67.67; H 5.90; N 18.85. C25H26N6O2.
Calculated,%: С 67.86; H 5.92; N 18.96.
5-{2,6-Dimethyl-4-[(1,3-diethyl-2-oxo-2,3-dihydro-
1Н-benzimidazol-5-yl)imino]pyridin-1(4Н)-yl}-
1,3-diethyl-1,3-dihydro-2Н-benzimidazol-2-one
1
(IVb). Yield 55%, mp 84–86°С (ethanol). Н NMR
spectrum (DMSO-d6), δ, ppm: 1.14 t (12Н, N1СН2CH3,
N3СН2CH3, N1'СН2CH3, N3'СН2CH3, J 4.0 Hz),
1.98 s (6Н, С9СН3, С13CH3), 3.76 q (8Н, N1СН2CH3,
N3СН2CH3, N1'СН2CH3, N3'СН2CH3, J 7.2 Hz), 7.04 d
(2Н, Н7, Н7', J 12.0 Hz), 7.08 d (2Н, Н6, Н6', J 12.0 Hz),
7.51 s (2Н, Н4, Н4'), 9.90 s (2Н, Н10, H12). Found, %:
С 69.50; H 6.85; N 16.78. C29H34N6O2. Calculated, %:
С 69.86; H 6.87; N 16.85.
5-{2,6-Dimethyl-4-[(1,3-dibenzyl-2-oxo-2,3-
dihydro-1Н-benzimidazol-5-yl)imino]pyridin-1-
(4Н)-yl}-1,3-dibenzyl-1,3-dihydro-2Н-benzimidazol-
2-one (IVc). Yield 64%, mp 155–157°С (2-propanol).
1Н NMR spectrum (DMSO-d6), δ, ppm: 2.01 s (6Н,
С9СН3, С13CH3), 5.09 s (8Н, N1СН2C6H5, N3СН2C6H5,
N1'СН2C6H5, N3'СН2C6H5), 7.07 d (2Н, Н7, Н7', J 8.0 Hz),
7.16 d (2Н, Н6, Н6', J 8.0 Hz), 7.31–7.37 m (20Н,
N1СН2C6H5, N3СН2C6H5, N1'СН2C6H5, N3'СН2C6H5),
7.43 s (2Н, Н4, Н4'), 9.86 s (2Н, Н10, H12). Found, %:
С 77.87; H 5.64; N 11.12. C49H42N6O2. Calculated, %:
С 78.80; H 5.67; N 11.25.
The computer estimation of the virtual biological
activity of the synthesized compounds IVа–IVc, Vа–Vc
applying the PASS 4.2 program (Prediction of Activity
Spectra of Substance) indicated that these compounds
may possess the antiphlogistic and hypertensive activity,
and also may be inhibitors of muramyl-tetrahydropeptide
carboxypeptidase [5].
1Н NMR spectra were registered on a spectrometer
Bruker Avance II 400 at operating frequency 400 MHz
in DMSO-d6 and CDCl3, internal reference TMS. The
individuality of compounds obtained was checked
by TLC on Silufol UV-254 plates (eluents ethanol,
chloroform, development in iodine vapor or under
UV irradiation).
5-{2,6-Dimethyl-4-[(1,3-dimethyl-2-oxo-2,3-
dihydro-1Н-imidazo[4,5-b]pyridin-5-yl)imino]-
pyridin-1(4Н)-yl}-1,3-dimethyl-1,3-dihydro-2Н-
imidazo[4,5-b]pyridin-2-one (Vа). Yield 53%, mp
1
>250°С (water). Н NMR spectrum (DMSO-d6), δ,
ppm: 2.12 s (6Н, С9СН3, С13CH3), 3.35 s (6Н, N1CH3,
N1'CH3), 3.36 s (6Н, N3CH3, N3'CH3), 7.51 d (2Н, Н7, Н7',
J 8.0 Hz), 7.86 d (2Н, Н6, Н6', J 8.0 Hz), 10.42 s (2Н, Н10,
H12). Found, %: С 61.97; H 5.41; N 25.19. C23H24N8O2.
Calculated, %: С 62.15; H 5.44; N 25.21.
Compounds IVа–IVc, Vа–Vc. A mixture of
1 mmol of compound Iа–Ic, IIа–IIc and 0.5 mmol of
2,6-dimethyl-γ-pyrone in 6 ml of glacial acetic acid was
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 49 No. 5 2013