748
SARAEVA et al.
2-{Cyano(5-nitro-1Н-benzo[d]imidazol-2(3Н)-
(E,Z)-2-({1-[2-(4-Chlorophenyl)-2-oxoethyl]-1Н-
benzo[d]imidazol-2(3Н)-ylidene}(cyano)methyl)-1-
methylpyridinium bromide (VIIIа). Yield 0.295 g
ylidene)methyl}-1-methylpyridinium acetate (VIa).
Acetonitrile Vc (0.5 mmol) was heated in 10 ml of
acetic acid to full dissolution and filtered. After 24 h
the formed precipitate was filtered off and washed
sequentially with acetic acid and acetone. Yield 0.159
g (90%), red powder, mp 199–202°С (СН3СООН). 1Н
NMR spectrum, δ, ppm: 1.88 s (3Н, CH3COO), 4.06 s
(3Н, CH3), 7.32 t (1Н, С5Н, J 6.82 Hz), 7.44 d.d (1Н,
С3Н, J 9.40, 6.82 Hz), 7.21–7.55 m (3Н, НAr), 7.92–
8.20 m [3Н, С4Н, С4Н(С7Н)benzimidazole, С7Н(С4Н)benzimidazole],
8.33 d [1Н, С5Н(С6Н)benzimidazole, J 8.50 Hz], 8.46 d
(1H, С6Н, J 6.82 Hz), NH-proton exchanges with
water. Mass spectrum, m/z (Irel, %): 293 (100) [M – 1]+,
118 (7), 157 (8), 176 (8), 246 (11), 294 (17), 295 (2).
Found, %: C 57.72; H 4.23; N 19.88. C17H15N5O4.
Calculated, %: C 57.79; H 4.28; N 19.82.
1
(61%), yellow powder, mp 228°С (СН3СОСН3). Н
NMR spectrum, δ, ppm: 4.02 s (3Н, CH3, Z), 4.14 s
(3Н, CH3, E), 6.11 br. s (2Н, CH2), 6.98 t (1Н, С5Н, J
6.55 Hz, Z), 7.14 d (1Н, С3Н, J 8.58 Hz, Z), 7.23 d.d
(1Н, СНbenzimidazole, J 5.88, 3.17 Hz), 7.42–7.46 m [1Н,
С5Н (E), 1Н, СНbenzimidazole], 7.53 d.d (1Н,
СНbenzimidazole, J 6.13, 3.09 Hz), 7.58 d (2Н, СНAr, J
8.51 Hz), 7.66 t (1Н, С4Н, J 8.58 Hz, Z), 7.81 d.d (1Н,
СНbenzimidazole, J 6.13, 3.09 Hz), 7.98 d (1Н, С3Н, J
8.58 Hz, E), 8.07–8.14 m [1Н, С4Н (E), 2Н, СНAr],
8.32 d (1H, С6Н, J 6.55 Hz, Z), 8.67 d (1H, С6Н, J
6.51 Hz, E); NH-proton was not detected in DMSO-d6
due to the deuterium exchange; in F3CCOOH 13.01 br.
s (1Н, NH). Mass spectrum, m/z (Irel, %): 248 (100)
[M – aroylmethyl]+, 78 (10), 111 (10), 131 (39), 149
(23), 170 (14), 208 (19), 247 (47), 249 (16). Found, %:
C 57.40; H 3.72; N 11.69. C23H18N4BrOCl. Calculated,
%: C 57.34; H 3.77; N 11.63.
2-({1Н-Benzo[d]imidazol-2(3Н)-ylidene}(cyano)-
methyl)-1-methylpyridinium bromide (VIb). а. To a
suspension of 1.0 mmol of acetonitrile Vа in 10 ml of
acetone was added 1.0 mmol of bromoacetophenone
VIIа. The reaction mixture was refluxed for 4–6 h.
After 24 h acetone was evaporated, the residue was
triturated with 10 ml of acetonitrile. The formed
precipitate was filtered off and washed with
acetonitrile. Yield 0.226 g (69%, bromoacetophenone),
yellow crystals, mp 252°С (СН3СN).
(E,Z)-2-(Cyano-{1-[2-(4-methoxyphenyl)-2-oxo-
ethyl]-1Н-benzo[d]imidazol-2(3Н)-ylidene}methyl)-
1-methylpyridinium bromide (VIIIb). Yield 0.300 g
(63%), yellow powder, mp 188–191°С (СН3СОСН3).
IR spectrum, ν, cm–1: 3421 (N–Н), 2179 (C≡N), 1679
(С=О). 1Н NMR spectrum, δ, ppm: 3.89 s (3Н, ОCH3),
3.98 s (3Н, CH3, Z), 4.10 s (3Н, CH3, E), 6.03 br.s
(2Н, CH2), 6.92 t (1Н, С5Н, J 6.24 Hz, Z), 7.03 d (2Н,
СНAr, J 8.61 Hz), 7.12 d (1Н, С3Н, J 8.53 Hz, Z), 7.19
d.d (1Н, СНbenzimidazole, J 5.66, 3.09 Hz), 7.33 t (1Н,
С5Н, J 6.26 Hz, E), 7.40 d.d (1Н, СНbenzimidazole, J 5.66,
3.09 Hz), 7.50 d.d (1Н, СНbenzimidazole, J 5.95, 3.03 Hz),
7.62 t (1Н, С4Н, J 8.53 Hz, Z), 7.79 d.d (1Н,
СНbenzimidazole, J 5.95, 3.03 Hz), 7.98–8.03 m [1Н, С4Н
(E), 1Н, С3Н (E), 2Н, НAr], 8.28 d (1H, С6Н, J 6.24 Hz,
Z), 8.60 d (1H, С6Н, J 6.26 Hz, E); NH-proton was not
detected in DMSO-d6 due to the deuterium exchange;
in F3CCOOH 13.01 br. s (1Н, NH). Found, %: C
60.45; H 4.38; N 11.79. C24H21N4BrO2. Calculated, %:
C 60.39; H 4.43; N 11.74.
b. The salts VІІа and VIIb (1.0 mmol) were heated
in 20 ml of acetonitrile to full dissolution and filtered.
After 24 h the formed precipitate was filtered off and
washed with acetonitrile. Yield 0.243 g (70%, p-
chlorobromoacetophenone), yellow crystals, mp 170°С
(СН3СN) (monohydrate VIb); 0.249 g (76%, p-
methoxybromoacetophenone), mp 252°С (СН3СN). IR
spectrum, ν, cm–1: 3128, 3187, 3295 (N–Н), 2180
1
(C≡N). Н NMR spectrum, δ, ppm: 4.08 s (3Н, CH3),
7.26 d.d (2Н, СНbenzimidazole, J 3.50, 5.06 Hz), 7.41 d.d
(2Н, СНbenzimidazole, J 3.50, 5.06 Hz), 7.49 t (1Н, С5Н, J
6.80 Hz), 8.05 d (1Н, С3Н, J 8.44 Hz), 8.13 t (1Н,
С4Н, J 8.44 Hz), 8.63 d (1H, С6Н, J 6.80 Hz), 13.03 s
(2Н, NH). Mass spectrum, m/z (Irel, %): 249 (100) [M]+.
Found, %: C 54.78; H 3.91; N 17.09. C15H13N4Br.
Calculated, %: C 54.73; H 3.98; N 17.02. Found, %: C
51.80; H 4.41; N 16.09. C15H15N4BrО (monohydrate).
Calculated, %: C 51.89; H 4.35; N 16.14.
REFERENCES
1. Khoroshilov, G., Demchak, I., and Saraeva, T.,
Synthesis, 2008, no. 10, p. 1541.
2. Mukaiyama, T., Angew. Chem. Int. Ed., 1979, vol. 18,
no. 10, p. 707.
3. Mukaiyama, T., Challenges in synthetic organic
chemistry, Oxford: Oxford Univ. Press, 2002, 226 p.
4. Zefirov, Yu.V. and Zorkii, P.M., Usp. Khim., 1989,
vol. 58, no. 5, p. 713.
5. Burgi, H.-B. and Dunitz, J.D., Structure correlation,
Weinheim: VCH, 1994, vol. 2, p. 741.
General procedure of preparation of compounds
VIIIа and VIIIb. To a suspension of 1.0 mmol of
acetonitrile Vа in 10 ml of acetone was added 1.0 mmol
of the corresponding ω-bromoacetophenones VIIb and
VIIc. The reaction mixture was refluxed for 4–6 h.
After 24 h the precipitate was filtered off and washed
with acetone.
6. Sheldrick, G., Acta Cryst. (A), 2008, vol. 64, no. 1, p. 112.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 82 No. 4 2012