KIT-6 Mesoporous Silica-coated Magnetite Nanoparticles: A Highly Efficient and Easily Reusable Catalyst for the Synthesis of Benzo[d]imidazole Derivatives

Article abstract of DOI:10.1002/jhet.2686

KIT-6 mesoporous silica-coated magnetite nanoparticles as highly ordered large-pore nanoparticles supply an environmentally friendly procedure for the synthesis of benzo[d]imidazoles through condensation of 1,2-diaminobenzene with aryl aldehydes. These co

Full text of DOI:10.1002/jhet.2686

Month 2016 KIT-6 Mesoporous Silica-coated Magnetite Nanoparticles: A Highly Effi-
cient and Easily Reusable Catalyst for the Synthesis of Benzo[d]imidazole
Derivatives
Leila Zare Fekri* and Roghayeh Maleki
Department of Chemistry, Payame Noor University, P.O. Box 19395-3697, Tehran, Iran
*
E-mail: Chem_zare@yahoo.com
Received February 19, 2016
DOI 10.1002/jhet.2686
Published online 00 Month 2016 in Wiley Online Library (wileyonlinelibrary.com).
KIT-6 mesoporous silica-coated magnetite nanoparticles as highly ordered large-pore nanoparticles sup-
ply an environmentally friendly procedure for the synthesis of benzo[d]imidazoles through condensation of
1
,2-diaminobenzene with aryl aldehydes. These compounds were obtained in high yields and short reaction
times. The catalyst could be easily recovered using an external magnet and reused for six cycles with almost
consistent activity. All of the synthesized compounds were characterized by their physical constant, compar-
ison with authentic samples, ir, 1H nmr, 13C nmr spectroscopy, and elemental analysis.
J. Heterocyclic Chem., 00, 00 (2016).
INTRODUCTION
rearrangement [16], cycloaddition reaction of mesoionic
,3-oxazolium-5-olates with N-(arylmethylene)-benzen-
1
Recent advances in nanotechnology and nano science
have attracted much attention in employing nanometer-sized
particles as an alternative matrix for supporting catalytic re-
actions owing to their easy filtration, easy work-up proce-
dures, waste generation due to recycling of these catalysts,
and minimization of cost. KIT-6 mesoporous silica-coated
magnetite nanoparticles are usually preferred because it dis-
plays many significant properties such as excellent stability
esulfonamides [17], four-component condensation of aryl
glyoxals, primary amines, carboxylic acids and isocyanides
on Wang resin [18], condensation of a 1,2-diketone with an
arylnitrile and primary amine under microwave irradiation
[19], and reaction of N-(2-oxo)-amides with ammonium
trifluoroacetate [20]. Another method for the synthesis of
these compounds is the reaction of o-phenylenediamine
with aldehydes in the presence of acidic catalysts under
various reaction conditions [21–26]. However, many of
these methods suffer from acidic media, unsatisfactory
yields, longer reaction times, difficult work up, excessive
use of reagents and catalyst. It is therefore important to find
more convenient methods for the preparation of these
compounds.
In order to make the reaction simple and green, herein,
KIT-6 mesoporous silica-coated magnetite nanoparticles
(MMNPs) have been successfully applied to perform the
reaction of 1,2-diaminobenzene and arylaldehyde to pro-
vide a series of benzimidazole derivatives in excellent
yields and short reaction times.
(thermal and chemical), high surface area, simple and conve-
nient separation from a reaction media by magnetic separa-
tion, recyclability, and good accessibility.
Compounds with imidazole nucleus are common and im-
portant substructures found in natural products and pharmaco-
logically active compounds. They act as glucagon receptor
antagonists [1], inhibitors of P38 MAP kinase [2], β-raf kinase
[
3], transforming growth factor b1 (TGF-b1) type 1 activin
receptor-like kinase (ALK5), [4] cyclooxygenase-2 (COX-2),
5] CB1 cannabinoid receptor antagonists [6], modulators of
[
P-glycoprotein (P-gp)-mediated multidrug resistance (MDR),
biosynthesis of interleukin-1 (IL-1) [7]. Many functionalized
imidazoles behave as antibacterial [8], antibiotics [9], anti-
ulceretics [10], fungicides [11], antidiabetic, antihypertensive,
and anti-inflammatory agents [12,13].
RESULT AND DISCUSSION
In 1822, Japp and Radziszewki reported the first three-
component cyclocondensation synthesis of the imidazole
nucleus from 1,2-dicarbonyl compounds, aldehydes, and
ammonia to obtain 2,4,5-triphenyl-1H-imidazole [14,15].
In addition, they can also be accessed by the hetero-cope
As a part of our program, seeking at development new
procedures for the preparation of pharmaceutical and het-
erocyclic compounds [27–32] herein triggered us to de-
scribe a new, green, solvent free, cheap, and convenient
method for the synthesis of benzo[d]imidazole via two-
©
2016 Wiley Periodicals, Inc.

L. Z. Fekri and R. Maleki
Vol 9999
Scheme 1. A procedure for synthesis of benzo[d]imidazoles.
Scheme 2. A proposed mechanism for the synthesis of benzo[d]
imidazole.
100
8
0
0
0
0
6
4
2
Figure 1. Scanning electron microscopy image of synthesized
Fe O @SiO @KIT-6.
3 4 2
0
1
2
3
4
5
6
component reaction of aldehydes and 1,2-diaminobenzene
in the presence of synthesized MMNPs (Scheme 1, Fig. 1).
Various derivatives of benzimidazoles were synthesized
from 1,2-diaminobenzene and some derivatives of benzal-
dehyde in the presence of MMNPs (i) under refluxing in
water as a green solvent, (ii) under ultrasound irradiation
at 60°C in water, and (iii) under grinding as a green solvent
free reaction (Table 1, entries 1–12). As can be seen in
Table 1, satisfactory results were obtained only with
MMNPs under grinding. It is worth mentioning that the
recycle run
3 4 2
Figure 2. Reusability of Fe O @SiO @KIT-6 in the synthesis of 3a.
[Color figure can be viewed in the online issue, which is available at
wileyonlinelibrary.com.]
corresponding benzo[d]imidazoles were isolated after sep-
aration of catalyst with washing the crude material with
CHCl in the presence of an efficient magnetic bar. The
3
Table 1
Synthesis of unexpected benzo[d]imidazole derivatives catalyzed by Fe
3
O
4
2
@SiO @KIT-6.
a
Entry
R
Product
Reflux
Time (h)
Ultrasound
Grind
b
b
b
Yield (%)
Time (min)
Yield (%)
Time (min)
Yield (%)
1
2
3
4
5
6
7
8
9
C
6
H
NC
5
3a
3b
3c
3d
3e
3f
3g
3h
3i
4
6
3.5
3.5
8
5
5.5
3
5
6
78
73
83
85
68
63
68
84
81
78
76
80
45
60
30
30
75
60
60
30
60
75
75
30
81
75
85
89
74
75
71
86
78
70
68
86
10
15
5
7
13
7
9
5
7
7
90
88
97
95
82
82
85
96
88
88
89
99
(CH
3
)
2
6
H
4
4-Cl C
4-BrC
6
H
H
4
6
4
4-CH
3
OC
6
H
4
2-ClC
6
H
4
2-OHC
4-NO
4-OHC
2-furyl
4-pyridyl
4-F C
6
H
4
2
C
6
H
4
6
H
4
10
11
12
3j
3k
3l
6.5
3
10
5
6
H
4
a
3 4 2
Reaction and conditions 1,2-diaminobenzene (1 mmol), aldehyde (1 mmol) and Fe O @SiO @KIT-6 (0.05 g).
All yields refer to isolated products.
b
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

Month 2016
KIT-6 @Silica @Magnetite for Synthesis of Benzo[d]imidazoles
Table 2
Comparison of synthesis of compound 3a in this method with some of previous reported methods.
Entry
Reagent
Condition
Time
Yield (%)
Ref.
1
2
3
4
5
6
Silica sulfuric acid
rt
100°C
MW, 50°C
Reflux, 80°C
Solvent free, ball mil
Grinding
1.5 h
20 h
4 min
25 min
120 min
10 min
75
90
97
92
96
90
26
33
34
34
35
RuCl
2
(PPh
3
)
3
AcOH, O
AcOH, O
2
2
FeCl
3
-6H
2
O
KIT-6 mesoporous silica-coated magnetite nanoparticles
This work
reactions worked well with almost all benzaldehydes with
electron-donating or electron-withdrawing substituent. It
was interesting that during the synthesis of the benzo[d]im-
idazole derivatives 3, the product benzoimidazole 4 was
not observed.
A possible mechanism proposed for these reactions is
depicted in Scheme 2. This mechanism probably involves
an initial MMNPs-promoted condensation of 1,2-
diaminobenzene 2 with aldehydes 1 to yield a diimine in-
termediate 5 followed by a two-step cyclization to the
benzo[d]imidazole 3.
standard procedures. Melting points were measured on an
Electrothermal 9100 apparatus. IR spectra were determined
1
on a Shimadzu FT-IR 8600 spectrophotometer (Japan). H
13
and C NMR spectra were determined on a Bruker 400
DRX Avance instrument (Germany) at 500 and 125MHz.
Elemental analyses were performed on a Carlo-Erba
EA1110CNNO-S analyzer (China) and agreed with the
calculated values.
General procedure for the synthesis of KIT-6 mesoporous
silica coated magnetite nanoparticles.
The synthesis of
MMNPs was carried out as described by [36].
In order to investigate the reusability of synthesized
General procedure for the KIT-6 mesoporous silica coated
magnetite nanoparticles-catalyzed synthesis of 3a-l under
reflux condition. A mixture of aldehydes (1 mmol), 1,2-
Fe O @SiO @KIT-6, a recycling experiment was con-
3
4
2
ducted. The catalyst could be recycled up to six times with-
out significant loss of activity (Fig. 2). To reuse
diaminobenzene (1 mmol), (MMNPs, 0.05 g), and H O
2
Fe O @SiO @KIT-6, the resulting mixture 3a in grind
3
4
2
(10 mL) were refluxed in an oil bath for the required
reaction times (3.5–8 h). The progress of the reaction was
monitored by thin-layer chromatography (TLC) (EtOAc:
petroleum ether 1:4). Then, the reaction mixture was
filtered in the presence an efficient magnetic bar to
separate the catalyst, and the organic compound was
recrystallized from EtOH. The pure products were
collected in 63–85% yields.
method was solved in the CHCl and filtered in the pres-
3
ence of an efficient magnetic bar, washed with CHCl3
(
3 × 10 mL), and dried at 80°C for 12 h under reduced
pressure.
In order to assess the efficiency of this method, the syn-
thesis of benzimidazoles from benzaldehydes and 1,2-
diaminobenzene was compared with some various reported
method (Table 2).
General procedure for the ultrasound-assisted KIT-6
mesoporous silica coated magnetite nanoparticles-catalyzed
synthesis of 3a–l. A mixture of aldehydes (1 mmol), 1,2-
CONCLUSION
diaminobenzene (1 mmol), (MMNPs, 0.05 g), and H O
2
In conclusion, we have investigated the synthesized
MMNPs as a mild and efficient catalyst for the synthesis
of benzo[d]imidazoles. The remarkable advantages offered
by this method are as follows: the catalyst is inexpensive,
non-toxic, easy handling and reusable, simple work-up
procedure, short reaction time, high yields of product with
better purity and green aspect by avoiding toxic catalyst
and hazardous solvent. To the best of our knowledge this
is the first report on synthesis of benzo[d]imidazoles deriv-
atives using Fe O @SiO @KIT-6.
(10 mL) were placed into Pyrex-glass open vessel and
irradiated in a water bath under silent condition by
ultrasound (45 KHz) at 60°C for the required reaction
times (30–75min). The progress of the reaction was
monitored by TLC (EtOAc: petroleum ether 1:4). Then,
the reaction mixture was filtered in the presence of an
efficient magnetic bar to separate the catalyst, and the
organic compound was recrystallized from EtOH. The
pure products were collected in 68–89% yields.
General procedure for the KIT-6 mesoporous silica coated
magnetite nanoparticles-assisted grind synthesis of 3a–l.
A mixture of aldehyde (1mmol), 1, 2-diaminobenzene
3
4
2
EXPERIMENTAL
(1mmol), and Fe O @SiO @KIT-6 (0.05 g) were added to
3 4 2
a mortar, and the mixture was pulverized with a pestle. A
spontaneous reaction took place (Table 1, monitored by
TLC EtOAc: petroleum ether 1:4 drops. After completion of
Chemicals were purchased from Merck and Fluka. All
solvents used were dried and distilled according to
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

L. Z. Fekri and R. Maleki
Vol 9999
the reaction, the product was solved in CHCl (3× 10mL),
142.6, 135.2, 134.5, 133.0, 132.8, 131.2, 129.0, 128.6,
127.3, 126.1, 123.8, 122.2, 120.8, 110.2, 45.9. Anal. Calcd.
for C H Br N : C, 54.33; H, 3.19; N, 6.34. Found: C,
3
and an insoluble catalyst was removed by filtration in the
presence of an efficient magnetic bar. The organic phase
including the product and CHCl3 was evaporated under
vacuum. The resulting crude material was purified by
recrystallization from EtOH to afford pure products. All of
the synthesized compounds were characterized by their
physical constant, comparison with authentic samples, IR,
20
14
2 2
54.27; H, 3.31, N, 6.37.
1-(4-Methoxybenzyl)-2-(4-methoxyphenyl)-1H-benzo[d]
imidazole (3e).
This compound was obtained as pale
brown solid, mp 130–132°C; FT-IR (KBr): 1410, 1246
(
(
C-O stretch), 1511, 1452 (aromatic C = C stretch), 1625
1
13
–1 1
H NMR, C NMR spectroscopy, and elemental analysis.
All of synthesized compounds are known as described by
C = N stretch) cm . H NMR (DMSO-d , 400 MHz): δ:
6
3
1
1
1
.72 (s, 3H), 3.81 (s, 3H), 5.41 (s, 2H), 6.85–7.69 (m,
[34].
13
2H). C NMR (DMSO-d , 100MHz): δ: 159.3, 159.6,
6
Analytical data for selected compounds. 1-Benzyl-2-phenyl-
H-benzo[d]imidazole (3a). This compound was obtained
as white solid, mp 134–136°C; FT-IR (KBr): 2924
54.4, 143.7, 135.4, 130.0, 128.7, 127.4, 123.0, 122.7,
19.2, 114.5, 114.0, 110.8, 55.9, 55.5, 46.7. Anal. Calcd.
1
for C H N O : C, 73.38; H, 6.43; N, 7.44. Found: C,
23 24 2 3
(
(
aliphatic C-H stretch), 1625 (C =N stretch), 3041
aromatic C-H stretch), 1555, 1458 (aromatic C = C
7
3.41; H, 6.37, N, 7.43.
1
-(2-Chlorobenzyl)-2-(2-chlorophenyl)-1H-benzo[d]imidazole
3f). This compound was obtained as pale brown solid, mp
57–158°C; FT-IR (KBr): 2956 (aliphatic C-H stretch), 1623
–
1
1
stretch), 1317 (C = N stretch), 1163 cm ; H NMR
DMSO-d , 400MHz): δ 5.79 (s, 2H), 7.19 (d, 1H,
(
1
(
6
J =7.6 Hz), 7.30–7.39 (m, 2H), 7.50–7.66 (m, 3H), 7.69–
(
(
(
5
1
1
1
C=N stretch), 3017 (aromatic C-H stretch), 1562, 1462
aromatic C=C stretch), 1382 (C-N stretch), 1221, 1048
7
.84 (m, 4H), 7.87–7.96 (m, 3H), 8.50 (d, 1H, J = 7.6 Hz);
1
3
C NMR (DMSO-d , 100MHz): δ : 152.9, 149.1, 143.0,
–1 1
6
C-Cl stretch) cm . H NMR (DMSO-d , 400MHz): δ:
6
1
1
8
35.8, 135.1, 129.6, 129.1, 128.9, 128.4, 127.8, 126.2,
13
.41 (s, 2H), 6.52–7.87 (m, 12H). C NMR (DMSO-d6,
00MHz): δ: 151.8, 142.0, 134.9, 134.5, 133.5, 132.9,
32.5, 131.3, 130.5, 129.7, 129.6, 128.1, 127.8, 127.2,
26.0, 123.4, 122.9, 120.4, 110.6, 45.9. Anal. Calcd. for
22.0, 118.6, 110.6, 47.2. Anal. Calcd. for C H N : C,
2
0 16 2
4.48; H, 5.67; N, 9.85. Found: C, 84.50; H, 9.83, N, 9.85.
4
-(1-(4-(Dimethylamino)benzyl)-1H-benzo[d]imidazol-2-yl)-
N,N-dimethylbenzenamine (3b). This compound was
obtained as off-white solid, mp 250–251°C; FT-IR (KBr):
C H Cl N : C, 68.00; H, 3.99; N, 7.93. Found: C, 68.05;
20
14
2 2
H, 4.01, N, 7.98.
1
1
4
7
1
1
612 (C =N stretch), 1521, 1911 (aromatic C= C stretch),
2-((2-(2-Hydroxyphenyl)-1H-benzo[d]imidazol-1-yl)methyl)
–1 1
376 (C-N stretch), 1219, 1043cm . H NMR (DMSO-d ,
6
phenol (3g). This compound was obtained as pale brown
solid, mp 206–207°C; FT-IR (KBr): 1503, 1462 (Aromatic
C = C stretching), 1621 (C = N stretching), 1408, 1241 (C-
00MHz): δ: 2.73 (s, 6H), 2.85 (s, 6H), 5.41 (s, 2H), 6.58–
13
.12 (m, 12H); C NMR (DMSO-d , 100 MHz): δ : 155.7,
6
51.4, 149.4, 142.6, 135.6, 130.5, 40.2, 126.2, 124.6, 122.5,
19.1, 117.2, 112.7, 111.1, 110.6, 48.1, 40.5. Anal. Calcd.
–1
1
O stretching), 1159cm ; H NMR (DMSO-d , 400
6
MHz): δ : 5.53 (s, 2H), 6.21–7.28 (m, 12H), 9.52 (s, br.,
for C H N : C, 77.80; H, 7.07; N, 15.12. Found: C, 77.75;
13
24 26 4
1
H), 10.08 (s, br., 1H). C NMR (DMSO-d , 100 MHz):
6
H, 7.10, N, 15.14.
δ: 151.2, 142.3, 135.0, 134.7, 133.8, 133.2, 132.8, 131.5,
1
-(4-Chlorobenzyl)-2-(4-chlorophenyl)-1H-benzo[d]imidazole
3c). This compound was obtained as off-white solid, mp
38–140°C; FT-IR (KBr): 1628 (C=N stretch), 1279, 1095
1
30.5, 129.0, 128.2, 129.6, 127.4, 126.3, 125.7, 123.5,
(
1
1
21.7, 120.7, 110.2, 45.8. Anal. Calcd. for C H N O :
2
0 16 2 2
C, 75.93; H, 5.10; N, 8.86. Found: C, 75.89; H, 5.12, N,
.89.
–1
1
(C-Cl stretch), 1406 (aromatic C=C stretch) cm ;
H
8
NMR (DMSO-d , 400MHz): δ : 5.61 (s, 2H), 7.20–7.25
6
1
-(4-Nitrobenzyl)-2-(4-nitrophenyl)-1H-benzo[d]imidazole
3h). This compound was obtained as pale brown solid,
mp 116–118°C; FT-IR (KBr): 2961 (aliphatic C-H stretch),
609 (C =N stretch), 1344, 1521 (NO stretch), 1418, 1452
(
m, 3H), 7.30–7.40 (m, 1H), 7.52–7.61 (m, 4H), 7.69–7.76
(
13
(m, 2H), 8.20–8.23 (m, 2H); C NMR (DMSO-d6,
1
1
1
3
00MHz): δ : 152.1, 142.1, 135.7, 135.0, 133.2, 133.9,
30.1, 129.5, 128.6, 127.7, 126.5, 123.5, 122.4, 120.4,
10.6, 46.7. Anal. Calcd. for C H Cl N : C, 68.00; H,
1
2
-1
1
(aromatic C=C stretch) 1232, 1108cm ; H NMR
20
14
2 2
(
DMSO-d , 400MHz): δ : 5.81 (s, 2H), 7.24–7.26 (m, 3H),
6
.99; N, 7.93. Found: C, 68.08; H, 3.95, N, 7.89.
7
.49–7.52 (s, br, 1H), 7.64-7.66 (s, br, 2H), 8.38 (d, 2H,
1
-(4-Bromobenzyl)-2-(4-bromophenyl)-1H-benzo[d]
13
J= 8.0 Hz), 8.47 (d, 2H, J=7.6Hz); C NMR (DMSO-d6,
imidazole (3d). This compound was obtained as off-white
solid, mp 196–198°C; FT-IR (KBr): 1629 (C = N stretch),
1
1
1
00MHz): δ : 152.0, 149.1, 147.0, 142.7, 141.8, 136.0,
35.2, 129.5, 125.7, 124.8, 124.1, 123.6, 122.9, 121.0,
10.7, 45.6. Anal. Calcd. for C H N O : C, 64.17; H,
1
526, 1403 (aromatic C= C stretch) 1068 (C-Br stretch)
20 14 4 4
–
1 1
cm . H NMR (DMSO-d , 400MHz): δ : 5.57 (s, 2H),
6
3.77; N, 14.97. Found: C, 64.18; H, 3.80, N, 14.93.
1-(4-Hydroxybenzyl)-2-(4-hydroxyphenyl)-1H-benzo[d]
imidazole (3i). This compound was obtained as pale brown
solid, mp 253–254°C. FT-IR (KBr): 1622 (C =N stretch),
7
2
.28 (s, br, 2H), 7.41 (s, br, 1H), 7.47 (s, br, 1H), 7.62 (s, br,
H), 7.75 (s, br, 2H), 7.84 (d, 2H, J = 8.0Hz), 8.18 (d, 2H,
13
J =8.0 Hz); C NMR (DMSO-d , 100 MHz): δ : 151.6,
6
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

Month 2016
KIT-6 @Silica @Magnetite for Synthesis of Benzo[d]imidazoles
1
1
7
7
510, 1462 (aromatic C=C stretch) 1401, 1281 (C-O stretch),
S. W. R.; Strickler, J. E.; McLaughlin, M. M.; Siemens, I. R.; Fisher, S. M.;
Livi, G. P.; White, J. R.; Adams, J. L.; Young, P. R. Nature 1994, 372, 739.
3] Takle, A. K.; Brown, M. J. B.; Davies, S.; Dean, D. K.;
Francis, G.; Gaiba, A.; Hird, A. W.; King, F. D.; Lovell, P. J.; Naylor,
A.; Reith, A. D.; Steadman, J. G.; Wilson, D. M. Bioorg Med Chem Lett
–1 1
1.63cm ; H NMR (DMSO-d , 400MHz): δ : 5.34 (s, 2H),
6
[
.18 (s, 2H), 6.65 (d, 2H, J= 7.2Hz), 6.92 (t, 4H, J=8.8Hz),
13
.54 (d, 4H, J=6.0Hz), 8.04 (d, 2H, J=7.6Hz); C NMR
2006, 16, 378.
(DMSO-d , 100MHz): δ : 152.8, 142.3, 135.8, 135.2, 133.9,
6
[4] Khanna, I. K.; Weier, R. M.; Yu, Y.; Xu, X. D.; Koszyk, F. J.;
133.5, 130.3, 129.1, 128.2, 127.0, 125.3, 122.8, 122.2, 120.7,
Collins, P. W.; Koboldt, C. M.; Veenhuizen, A. W.; Perkins, W. E.;
Casler, J. J.; Masferrer, J. L.; Zhang, Y. Y.; Gregory, S. A.; Seibert, K.;
Isakson, P. C. J Med Chem 1997, 40, 1634.
110.2, 45.2. Anal. Calcd. for C H N O : C, 75.93; H, 5.10;
20 16 2 2
N, 8.86. Found: C, 75.98; H, 5.05, N, 8.89.
-(2-Furyl)-1-(2-furylmethyl)-1H-benzimidazole (3j). This
compound was obtained as pale brown solid, mp 94–95°C.
FT-IR (KBr): 3017 (C–H), 2943 (C–H stretch), 1593
[5] Lange, J. H. M.; Van Stuivenberg, H. H.; Coolen, H. K. A. C.;
2
Adolfs, T. J. P.; McCreary, A. C.; Keizer, H. G.; Wals, H. C.; Veerman,
W.; Borst, A. J. M.; de Loof, W.; Verveer, P. C.; Kruse, C. G. J Med
Chem 2005, 48, 1823.
[6] Eyers, P. A.; Craxton, M.; Morrice, N.; Cohen, P.; Goedert, M.
(C = N stretch), 1518, 1477 (C = C stretch), 1335 (C–N
Chem Biol 1998, 5, 321.
–1 1
stretch), 1231 (C–O stretch) cm ; H NMR (DMSO-d ,
6
[7] Gallagher, T. F.; Fier-Thompson, S. M.; Garigipati, R. S.;
Sorenson, M. E.; Smietana, J. M.; Lee, D.; Bender, P. E.; Lee, J. C.;
Laydon, J. T.; Griswold, D. E.; Chabot-Fletcher, M. C.; Breton, J. J.;
Adams, J. L. Bioorg Med Chem Lett 1995, 5, 1171.
13
4
00MHz): δ : 5.62 (s, 2H), 6.16–7.57 (m, 10H);
C
NMR (DMSO-d , 100MHz): δ : 150.2, 145.7, 143.5,
1
1
6
42.2, 142.9, 135.5, 123.3, 122.0, 119.3, 113.2, 112.2,
10.8, 110.4, 109.9, 109.7, 43.1. Anal. Calcd. for
[
8] Antolini, M.; Bozzoli, A.; Ghiron, C.; Kennedy, G.; Rossi, T.;
Ursini, A. Bioorg Med Chem Lett 1999, 9, 1023.
9] Brogden, R. N.; Heel, R. C.; Speight, T. M.; Avery, G. S.
Drugs 1978, 16, 387.
10] (a) Niwano, Y.; Seo, A.; Kanai, K.; Hamaguchi, H.; Uchida, K.;
[
C H N O : C, 72.72; H, 4.58; N, 10.60. Found: C,
16 12 2 2
7
2.80; H, 4.49; N, 10.55.
[
2
-(Pyridin-2-yl)-1-(pyridin-2-ylmethyl)-1H-benzo[d]imidazole
3k). This compound was obtained as pale brown solid, mp
33–135°C. FT-IR (KBr): 3032 (C–H), 2918 (C–H stretch),
578 (C=N stretch), 1519, 1459 (C= C stretch), 1326 (C–N
Yamaguchi, H. Antimicrob Agents Chemother 1994, 38, 2204; (b) Di
Santo, R.; Tafi, A.; Costi, R.; Botta, M.; Artico, M.; Corelli, F.; Forte, M.;
Caporuscio, F.; Angiolella, L.; Palamara, A. T. J Med Chem 2005, 48, 5140.
(
1
1
[
11] Brimblecombe, R. W.; Duncan, W. A. M.; Durant, G. J.;
Emmett, J. C.; Ganellin, C. R.; Parsons, M. E. J Int Med Res 1975, 3, 86.
12] Pathan, M. Y.; Paike, V. V.; Pachmase, P. R.; More, S. P.;
Ardhapure, S. S.; Pawar, R. P. Arkivoc 2006, xv, 205.
13] Bellina, F.; Cauteruccio, S.; Rossi, R. Tetrahedron 2007, 63, 4571.
–1
1
[
stretch), 1243 (C–O stretch) cm ; H NMR (DMSO-d ,
00MHz): δ : 5.53 (s, 2H), 6.42–7.52 (m, 12H); C NMR
DMSO-d , 100MHz): δ : 149.9, 148.0, 146.0, 143.3, 134.6,
6
13
4
[
(
6
[14] Radziszewski, B. Chem Ber 1882, 15, 1493.
1
34.2, 133.5, 132.2, 131.9, 128.6, 128.0, 125.9, 125.4, 124.8,
[15] Japp, F. R.; Robinson, H. H. Chem Ber 1882, 15, 1268.
[
16] Lantos, I.; Zhang, W. Y.; Shiu, X.; Eggleston, D. S. J Org
Chem 1993, 58, 7092.
17] Zhang, C.; Moran, E. J.; Wiowade, T. F.; Short, K. M.; Mjalli,
A. M. M. Tetrahedron Lett 1996, 37, 751.
18] Claiborne, C. F.; Liverton, N. J.; Nguyen, K. T. Tetrahedron
Lett 1998, 39, 8939.
123.9, 123.6, 120.7, 110.5, 45.4. Anal. Calcd. for C H N : C,
18 14 4
75.50; H, 4.93; N, 19.57. Found: C, 75.48; H, 5.02; N, 19.63.
[
1
-(4-Fluorobenzyl)-2-(4-fluorophenyl)-1H-benzo[d]imidazole
3l). This compound was obtained as pale brown solid, mp
83–184°C. FT-IR (KBr): 1628 (C=N stretch), 1505, 1454
[
(
1
[19] Consonni, R.; Croce, P. D.; Ferraccioli, R.; Rosa, C. L. J Chem
–1 1
(aromatic C =C stretch), 1234, 1164 (C-F stretch) cm . H
Res 1991, S, 188.
NMR (DMSO-d , 400MHz): δ : 5.76 (s, 2H), 6.90 (m, 1H),
[20] Balalaie, S.; Hashemi, M. M.; Akhbari, M. Tetrahedron Lett
003, 44, 1709.
6
2
7.14–7.18 (m, 1H), 7.06 (d, 1H, J=9.2Hz), 7.25 (t, J=5.2Hz,
[
[
21] Pertry, R. J.; Wilson, B. D. J Org Chem 1993, 58, 7016.
22] Esser, F.; Ehrengart, P.; Ignanatow, H. P. J Chem Soc Perkin
1
H), 7.56–7.64 (m, 4H), 7.93–8.01 (m, 2H), 8.58–8.62 (m,
13
2
1
1
1
4
1
H) ppm; C NMR (DMSO-d , 100MHz): δ : 151.8, 142.7,
37.7 ( J =1520Hz), 136.6 ( J =160Hz), 133.4, 132.6,
31.5 ( J =48Hz), 129.7 ( J = 42 Hz), 128.2, 127.3,
26.3, 123.2, 121.5 ( J =2Hz), 120.1 ( J =3 Hz), 110.7,
6.5 ppm. Anal. Calcd. for C H F N : C, 74.99; H, 4.41; F,
1.86; N, 8.75. Found: C, 78.01; H, 4.43.
Trans 1999, 1, 1153.
23] Anastasiou, D.; Campi, E. M.; Chaouk, H.; Jackson, W. R.
Tetrahedron 1992, 48, 7467.
24] Brain, C. T.; Brunton, S. A. Tetrahedron Lett 2002, 43, 1893.
6
1
1
[
C–F
C–F
2
2
C–F
C–F
[
3
3
C–F
C–F
[25] Perumal, S.; Mariappan, S.; Selvaraj, S. Arkivoc 2004, viii, 46.
[26] Salehi, P.; Dabiri, M.; Zolfigol, M. A.; Otokesh, S.;
Baghbanzadeh, M. Tetrahedron Lett 2006, 47, 2557.
20 14 2 2
[
27] Zare, L.; Mahmoodi, N. O.; Yahyazadeh, A.; Mamaghani, M.
Synth Commun 2011, 41, 2323.
28] Zare, L.; Mahmoodi, N. O.; Yahyazadeh, A.; Nikpassand, M.
Ultrason Sonochem 2012, 19, 740.
[
Acknowledgments. Financial support from the Research Council
of Payame Noor University of Rudsar branch is sincerely
acknowledged.
[
[
[
[
29] Nikpassand,M.;Zare,L.;Saberi,M.MonatshChem2012, 143, 289.
30] Zare Fekri, L.; Nikpassand, M. Russ J Gen Chem 2013, 83, 2395.
31] Zare Fekri, L.; Nikpassand, M. Russ J Gen Chem 2014, 84, 1629.
32] Zare Fekri, L.; Nikpassand, M.; Hassanpour, K. Curr Org Syn
2
015, 12, 76.
[33] Cho, C. S.; Kim, J. U. Bull Korean Chem Soc 2008, 29, 1097.
34] Azarifar, D.; Pirhayati, M.; Maleki, B.; Sanginabadi, M.;
Nejatabadi, R. J Serb Chem Soc 2010, 75, 1181.
35] Jin, M.; Song, G.; Li, Z.; Zhou, F.; Fan, B.; Ouyang, P. J
Hetero Chem 2014, 51, 1838.
36] Khabazipour, M.; Shariati, S.; Safa, F. Synth React Inorg Me
016, 46, 759.
REFERENCES AND NOTES
[
[
1] Chang, L. L.; Sidler, K. L.; Cascieri, M. A.; Laszlo, S.; Koch,
G.; Li, B.; Maccoss, M.; Mantlo, N.; Okeefe, S.; Pang, M.; Rolando, A.;
Hangmann, W. K. Bioorg Med Chem Lett 2001, 11, 2549.
2] Lee, J. C.; Laydon, J. T.; McDonnell, P. C.; Gallagher, T. F.;
Kumar, S.; Green, D.; McNulty, D.; Blumenthal, M. J.; Keys, J. R.; Vatter,
[
[
[
2
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet