A Novel Synthesis of 2-Ferrocenoyl-Substituted Iodobenzofurans

Article abstract of DOI:10.1002/jhet.2625

In the present investigation, the first construction of a series of structurally new 2-ferrocenoyl-substituted iodobenzofurans hybrids has been achieved through a simple and mild two-step procedure, involving the iodination of salicylaldehydes using N-iodosuccinimide reagent in eco-friendly PEG-400 medium at room temperature followed by one-pot Rap–Stoermer reaction with 1-chloroacetylferrocene in refluxing MeCN with the presence of K₂CO₃as base and PEG-400 as the activated additive. These newly synthesized compounds belong to a new class of ferrocene-benzofuran hybrids and could be good candidates for the development of compounds for use in medicinal chemistry.

Full text of DOI:10.1002/jhet.2625

Month 2016
A Novel Synthesis of 2-Ferrocenoyl-Substituted Iodobenzofurans
*
Yang Li, Bairenqing Zhuoma, and Wentao Gao
Institute of Superfine Chemicals, Bohai University, Jinzhou,121000, China
*
E-mail: bhuzh@163.com
Additional Supporting Information may be found in the online version of this article.
Received September 7, 2015
DOI 10.1002/jhet.2625
Published online 00 Month 2016 in Wiley Online Library (wileyonlinelibrary.com).
In the present investigation, the first construction of a series of structurally new 2-ferrocenoyl-substituted
iodobenzofurans hybrids has been achieved through a simple and mild two-step procedure, involving the io-
dination of salicylaldehydes using N-iodosuccinimide reagent in eco-friendly PEG-400 medium at room
temperature followed by one-pot Rap–Stoermer reaction with 1-chloroacetylferrocene in refluxing MeCN
with the presence of K2CO3 as base and PEG-400 as the activated additive. These newly synthesized com-
pounds belong to a new class of ferrocene-benzofuran hybrids and could be good candidates for the devel-
opment of compounds for use in medicinal chemistry.
J. Heterocyclic Chem., 00, 00 (2016).
INTRODUCTION
be rationalized as being due to the unique properties of
the ferrocene nucleus such as membrane permeation, aque-
ous stability, anomalous metabolism, and redox behavior.
As a result, the ferrocene-heterocycle hybrid has been an
attractive synthetic target, and much synthetic effort has
been devoted to design and synthesize more novel and in-
teresting such molecules to expand the structure diversity
for current medicinal chemistry needs [10–12].
Considering the aforementioned valid points as well as
the combination principles for drug design [13], we felt
that it would be of synthetic importance to the construction
of 2-ferrocenoyl-containing iodobenzofurans. Such com-
pounds would likely possess significant biological activi-
ties or could be potentially applied as useful synthetic
building blocks for the development of new medicinal
products with interesting properties. To the best of our
knowledge, the construction of this type of hybrid mole-
cules still remained unknown. Accordingly, with this con-
text and in continuation of our studies on the synthesis of
highly interesting types of hybrid heterocycles [14–19],
we would like to report, herein, the first synthesis of a se-
ries of meaningful 2-ferrocenoyl-based iodobenzofurans.
2-Aroybenzofurans have received considerable interest
from the medicinal community because of their well-
documented biological properties such as antimicrobial
[1], anticonvulsant, anti-inflammatory [2], and antifungal
activities [3] and selective cytotoxicity against a tumori-
genic cell line [4]. Especially, some iodinated derivatives
of such molecules have been recently reported, and their
biological and pharmacological properties look promising.
For example, Amiodarone is widely used in the treatment
of ventricular tachyarrhythmia and atrial fibrillation [5]. In
this regard, an impressive report from Cui et al. described
that iodinated 2-aroybenzofuran displayed high affinity for
Aβ aggregates and could be used as potential probes for de-
tecting β-amyloid plaques in the AD brain [6]. In addition,
the presence of the derivatizable iodo group, representing
potentially useful synthetic building blocks in synthetic
organic chemistry, is another reason for the interest in the
synthesis of such compounds. As a consequence, interest
in the synthesis of new families of iodo-substituted
2-aroybenzofuran derivatives continues unabated.
On the other hand, it has been well established that inter-
change of an aromatic or heterocyclic ring with ferrocene
core in some organic compounds possessing a certain
property (e.g., biological activity) might lead to new hy-
brids with enhanced or unexpected chemical and pharma-
cological properties compared with that of the parent
compound [7,8]. As an example, when a ferrocenyl group
was used to modify chloroquine, the obtained ferroquine
exhibits higher antimalarial activity [9]. This fact could
RESULT AND DISCUSSION
Our strategy to reach this goal is outlined in Scheme 1.
The application of the Rap–Stoermer reaction appeared
to suit us, because it might provide the opportunity for
direct construction of the targeted compounds from
1-chloroacetyl ferrocene and iodinated salicylaldehydes.
© 2016 Wiley Periodicals, Inc.

Y. Li, B. Zhuoma, and W. Gao
Vol 000
Scheme 1. Route for 2-ferrocenoyl-substituted iodobenzofurans (4a–g).
Because the number of commercially available iodo-
substituted salicylaldehydes is exceedingly small, our syn-
thesis commenced with the iodination of some
salicylaldehydes. Prior to the current investigation, there
are some reported methods involving the iodination of
salicylaldehyde such as the use of ICl in AcOH at 120°C
[20], KI/KIO3 in HAC and H3PO4 at 50–70°C [21], and
I2 in pyridine and dioxane [22]. Although they provided
useful access to iodo-substituted salicylaldehydes, these
iodination methodologies suffered from one or more
drawbacks arising out of its toxic, corrosive, and environ-
mentally hazardous nature. Thus, in our search for a
green and mild protocol for the iodination of
salicylaldehydes, we are delightful to find that treatment
of some commercially available salicylaldehydes 1a–g
with N-iodosuccinimide (NIS) in eco-friendly PEG-400
medium at room temperature delivered good isolated
yields of the iodinated salicylaldehyde 2a–g. The results
obtained thus far are summarized in Table 1.
reaction rate. The amount of 15mol% PEG-400 was suffi-
cient to push this reaction forward, and more than that
amount resulted in a lower yield, which might be because
the transition state could be solvated in the larger amount
of PEG-400. Subsequently, we further extended the
reaction to other iodo-salicylaldehydes in a similar fashion.
As expected, this reaction invariably led to the formation of
the corresponding 2-ferrocenoyl-substituted iodoben-
zofurans in satisfactory yields, and the results of this series
of experiments are compiled in the Table 1.
To the best of our knowledge, none of the newly synthe-
sized compounds have yet been reported, and their struc-
tures were easily established based on spectral data
elemental analyses, which were in good agreement with
the compounds expected. For instance, the IR spectrum
of reaction product 4a clearly showed a typical stretching
vibration band at 1632 cmÀ1 due to the carbonyl group,
supporting the signal of its 13C NMR spectrum at
1
184.72ppm. Its H NMR spectrum showed the usual pat-
Having a series of the iodo-substituted salicylaldehydes
2a–g in hand, our attention was transferred to their Rap–
Stoermer reaction with 1-chloroacetylferrocene for build-
ing the 2-ferrocenoylbenzofuran system. At this stage,
we first investigated the reaction of 3-iodo-5-
methylsalicylaldehyde (2b) with 1-chloroacetylferrocene
(3) under solvent-free conditions [23,24] or using 4-
dimethylaminopyridine [25] as catalyst in water in accor-
dance with literature methods. Although these procedures
are very easy, eco-friendly, and impressive, the purported
approaches were ineffective in our hands, and the reaction
did not proceed satisfactorily, giving poor yields of highly
impure products. Our attempts to follow the route as de-
scribed by Cui et al. [6] by using K2CO3 as base in acetone
at room temperature were also frustrated by low yield. Af-
ter many trials, we found that when the reaction was run in
the presence of PEG-400 (15 mol%) as the activated addi-
tive and K2CO3 as the base in refluxing MeCN for 5h
[monitored by thin-layer chromatography (TLC)], the de-
sired 2-ferrocenoyl-7-iodo-5-methylbenzo[b]furan (4b)
was obtained in a good yield of 85%. Presumably, the reac-
tion may be the fact that PEG-400 could stabilize the tran-
sition state [26], thereby resulting in an increase in the
tern of monosubstituted ferrocene (Fc) system―two mag-
netically inequivalent ortho protons (H-2′ and H-5′) at
5.25 downfield from the signals of the two meta protons
(H-3′ and H-4′) at 4.68, and a strong signal at 4.20 due
to the five equivalent hydrogens of the unsubstituted
cyclopentadienylidene ring. A particular characteristic
was the presence of three benzofuran protons in the aro-
matic range between 7.45 and 7.71 ppm, which is consis-
tent with the molecular structure suggested. Further, the
structure assigned to the reaction product 4a was fully sup-
ported by its high-resolution mass spectrometry (HRMS),
which established its molecular formula to be
C19H12FeI2O2 in accordance with the suggested molecular
structure. The other synthesized compounds exhibited sim-
ilar spectral characteristics.
In summary, the synthesis of a series of hitherto unre-
ported 2-ferrocenoyl-substituted iodobenzofurans deriva-
tives has been achieved with good yields under mild
reaction conditions. These molecules we have synthesized
should allow us, in the future, to investigate structure–
activity relationships over various biotests. Moreover, all
these molecules could be potentially applied as useful
synthetic building blocks for the development of more
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

Month 2016
Synthesis of 2-Ferrocenoyl-Substituted Iodobenzofurans
Table 1
Yields of the newly synthesized compounds 2a–g and 4a–g.
Yield
(%)a
Entry
1
Iodosalicylaldehyde
Yield (%)a
83
Product
81
85
79
88
2
3
4
87
84
81
5
6
7
83
80
87
85
82
84
aIsolated yields.
complex ferrocene-based compounds because iodine group
on the benzofuran ring can be further elaborated to a
variety of other functional groups, for example, via
metal-catalyzed coupling reactions. Currently, the studies
concerning their application are underway.
The IR spectra were obtained as KBr pellets in the
range of 400–4000 cmÀ1 on a Shimadzu FTIR-8400S
1
spectrophotometer (Shimadzu, Japan). H NMR and 13C
NMR spectra were recorded on a Bruker Avance NMR
spectrometer (Bruker Company, Switzerland) using CDCl3
as the solvent. The reported chemical shifts (δ values) are
given in parts per million downfield from tetramethylsilane
as the internal standard. The mass spectra were determined
using an MSD VL ESI1 spectrometer. HRMS (ESI) data
were acquired on a Bruker Customer micrOTOF-Q 125
high-resolution mass spectrometer with ESI. The progress
of reactions was monitored by TLC on silica gel GF254
using hexane/ethyl acetate mixture as eluent (4:1, v/v).
EXPERIMENTAL
General. All chemicals (analytical reagent (AR) graded)
were commercially available and used without further
purification. The melting points were determined by using
WRS-1B melting points apparatus and were uncorrected.
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

Y. Li, B. Zhuoma, and W. Gao
Vol 000
General
procedure
for
the
synthesis
of
precipitated on standing, was collected. Recrystallization
iodo-salicylaldehydes 2a–g.
Respective substituted
from EtOH gave the corresponding pure product 4a–g.
salicylaldehyde (1a–g) (1.0 mmol) and NIS (0.27g,
1.2mmol) (unsubstituted salicylaldehyde required
2.2mmol of NIS) was dissolved in PEG-400 (4mL) and
then stirred at room temperature for 4h. After completion
of the reaction as monitored by TLC, the reaction
mixture was poured into water. The crude product
obtained after filtration and washing with water was
recrystallized from ethanol to give pure 2a–g.
2-Ferrocenoyl-5,7-diiodobenzo[b]furan (4a).
Dark red
solid, mp 170–171°C. IR (KBr) ν/cmÀ1: 3106, 1632
(C=O), 1548, 1442, 1374, 1309, 1284, 1234, 1168, 824,
808; 1H NMR (500MHz, CDCl3) δ (ppm): 7.71 (d,
J = 1.4 Hz, 1H, furan-H), 7.55 (d, J = 6.8 Hz, 1H, Ben-H),
7.45 (dd, J = 6.8, 1.4 Hz, 1H, Ben-H), 5.25 (s, 2H, Fc-H),
4.68 (s, 2H, Fc-H), 4.20 (s, 5H, Fc-H); 13C NMR
(125 MHz, CDCl3) δ (ppm): 184.72, 155.33, 143.08,
134.16, 131.68, 130.91, 129.26, 111.15, 87.70, 79.87,
73.63, 71.25, 70.43; HRMS (ESI, m/z). Calcd. for
C19H13FeI2O2 [M+ H]+ 582.8354. Found 582.8370.
3,5-Diiodosalicylaldehyde (2a).
Yield 83%, mp 104–
105°C (Lit. [21]: 101–103°C); 1H NMR (CDCl3,
400MHz): 11.47 (s, 1H, OH), 9.90 (s, 1H, CHO), 8.31
(s, 1H, Ben-H), 8.08 (s, 1H, Ben-H); MS (ESI, m/z):
375.1 [M + H]+.
2-Ferrocenoyl-7-iodo-5-methylbenzo[b]furan (4b).
red solid, mp 140–141°C. IR (KBr) ν/cmÀ1: 3084, 2916,
Dark
5-Methyl-3-iodosalicylaldehyde (2b). Yield 87%, mp 90–
91°C; H NMR (CDCl3, 400 MHz): 11.88 (s, 1H, OH),
1628 (C=O), 1552, 1440, 1377, 1311, 1291, 1233, 1140,
825, 807; H NMR (400MHz, CDCl3) δ (ppm): 8.65 (d,
1
1
9.65 (s, 1H, CHO), 7.95 (s, 1H, ArH), 2. 83 (s, 3H,
CH3); 13C NMR (CDCl3, 100MHz): 189.33, 155.69,
148.06, 138.35, 115.20, 87.44, 81.53, 31.35; MS (ESI,
m/z): 263.0 [M+ H]+.
J = 2.0 Hz, 1H, Ben-H), 8.59 (d, J = 2.4 Hz, 1H, Ben-H),
7.79 (s, 1H, Furan-H), 5.34 (t, J= 2.0 Hz, 2H, Fc-H), 4.78
(t, J = 2.0 Hz, 2H, Fc-H), 4.15 (s, 5H, Fc-H), 2.05 (s, 3H,
Me); 13C NMR (100MHz, CDCl3) δ (ppm): 185.27,
154.06, 136.55, 132.62, 129.17, 129.01, 124.61, 111.04,
87.39, 80.07, 73.48, 71.05, 70.43, 15.08; HRMS (ESI, m/
z). Calcd. for C20H16FeIO2 [M+ H]+ 470.9544. Found
470.9523.
3-Methyl-5-iodosalicylaldehyde (2c). Yield 84%, mp 87–
1
88°C (Lit. [27]: 85–86°C); H NMR (CDCl3, 400MHz):
10.90 (s, 1H, OH), 10.00 (s, 1H, CHO), 7.91 (d, 1H,
Ben-H), 7.79 (s, 1H, Ben-H), 2.17 (s, 3H, CH3); MS
(ESI, m/z): 263.1 [M +H]+.
2-Ferrocenoyl-5-iodo-7-methylbenzo[b]furan (4c).
Dark
3-tert-Butyl-5-iodosalicylaldehyde (2d). Yield 81%, mp
red solid, mp 105–106°C. IR (KBr) ν/cmÀ1: 3078, 2964,
1
53–54°C (Lit. [20]: 55°C); H NMR (DMSO, 600MHz):
1629 (C=O), 1541, 1445, 1375, 1328, 1286, 1232, 1134,
1
11.75 (s, 1H, OH), 9.93 (s, 1H, CHO), 8.01 (s, 1H, ArH),
7.70 (s, 1H, ArH), 1.36 (s, 9H, t-Bu); MS (ESI, m/z):
305.1 [M + H]+.
842, 809; H NMR (400MHz, CDCl3) δ (ppm): 8.34 (d,
J = 2.0 Hz, 1H, Ben-H), 8.06 (d, J = 2.0 Hz, 1H, Ben-H),
7.67 (s, 1H, furan-H), 5.47 (t, J =2.0 Hz, 2H, Fc-H), 4.80
(t, J = 2.0 Hz, 2H, Fc-H), 4.24 (s, 5H, Fc-H), 2.05 (s, 3H,
Me); 13C NMR (100MHz, CDCl3) δ (ppm): 184.88,
156.73, 141.57, 132.68, 130.71, 129.83, 126.41, 111.03,
93.13, 80.93, 73.88, 71.34, 70.52, 34.18; HRMS (ESI, m/
z). Calcd. for C20H16FeIO2 [M+ H]+ 470.9544. Found
470.9532.
5-tert-Butyl-3-iodosalicylaldehyde (2e).
Yield 73%, mp
78–79°C (Lit. [28]: 75–77°C); 1H NMR (DMSO,
600MHz) 11.34 (s, 1H, OH), 9.95 (s, 1H, CHO), 8. 05
(s, 1H, ArH), 7.83 (s, 1H, ArH), 1.28 (s, 9H, t-Bu); MS
(ESI, m/z): 304.9 [M +H]+.
5-Chloro-3-iodosalicylaldehyde (2f). Yield 80%, mp 78–
78°C (Lit. [29]: 77°C); 1H NMR (CDCl3, 400MHz): 11.65
(s, 1H, OH), 9.66 (s, 1H, CHO), 7.91 (s, 1H, ArH), 7.50 (s,
1H, ArH); MS (ESI, m/z): 283.0, 284.8 [M +H]+.
5-Bromo-3-iodosalicylaldehyde (2g). Yield 87%, mp 81–
81°C (Lit. [29]: 80°C); 1H NMR (CDCl3, 400MHz): 11.71
(s, 1H, OH), 9.70 (s, 1H, CHO), 8.07 (s, 1H, ArH), 7.67 (s,
1H, ArH); MS (ESI, m/z): 326.9, 329.1 [M +H]+.
2-Ferrocenoyl-5-iodo-7-t-butylbenzo[b]furan (4d).
Dark
red solid, mp 106–107°C. IR (KBr) ν/cmÀ1: 3072, 2968,
2866, 1630, 1552, 1439, 1372, 1335, 1284, 1233, 1125,
1
824, 802; H NMR (400MHz, CDCl3) δ (ppm): 7.60 (d,
J = 2.0 Hz, 2H, Ben-H), 7.55 (d, J =1.7 Hz, 1H, furan-H),
5.33 (t, J = 1.9 Hz, 2H, Fc-H), 4.69 (t, J = 1.9 Hz, 2H, Fc-
t
H), 4.22 (s, 5H, Fc-H), 1.39 (s, 9H, Bu-H); 13C NMR
General
procedure
for
the
synthesis
of
To a
(100 MHz, CDCl3) δ (ppm): 184.78, 153.11, 137.86,
133.80, 131.65, 130.17, 129.66, 111.09, 88.00, 79.96,
73.31, 70.91, 70.30, 34.46, 29.75; HRMS (ESI, m/z).
Calcd. for C23H22FeIO2 [M + H]+ 513.0014. Found
512.9992.
2-ferrocenoyl-substituted iodobenzofurans (4a–g).
stirred solution of 1-chloroacetyl ferrocene (3) (0.262 g,
1.0mmol) and respective iodo-salicylaldehydes (2a–g)
(1.1 mmol) in acetonitrile (12 mL) was added K2CO3
(0.276 g, 2.0mmol) and PEG-400 (15 mmol%). The
resulting reaction mixture was heated at refluxing
temperature for 5 h. After the reaction was complete
(TLC), the mixture was cooled at room temperature and
poured into water, and the resulting solid, which
2-Ferrocenoyl-5-t-butyl-7-iodobenzo[b]furan (4e).
Dark
red solid, mp 102–103°C. IR (KBr) ν/cmÀ1: 3080, 2950,
2903, 1635, 1557, 1443, 1374, 1327, 1287, 1219, 1140,
1
845, 819; H NMR (400 MHz,CDCl3) δ (ppm): 8.54 (d,
J = 2.2 Hz, 1H, Ben-H), 8.30 (d, J = 2.3 Hz, 1H, Ben-H),
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

Month 2016
Synthesis of 2-Ferrocenoyl-Substituted Iodobenzofurans
[2] Dawood, K. M.; Abdel-Gawad, H.; Rageb, E. A.; Ellithey, M.;
Mohamed, H. A. Bioorg Med Chem 2006, 14, 3672.
[3] Romagnoli, R.; Baraldi, P. G.; Carrion, M. D.; Cara, C. L.;
Cruz-Lopez, O.; Tolomeo, M.; Grimaudo, S.; Cristina, A. D.; Pipitone,
M. R.; Balzarini, J.; Zonta, N.; Brancale, A.; Hamel, E. Bioorg Med Chem
2009, 17, 6862.
[4] Hayakawa, I.; Shioya, R.; Agatsuma, T.; Furukawa, H.;
Naruto, S.; Sugano, Y. Bioorg Med Chem Lett 2004, 14, 4383.
[5] Roy, D.; Talajic, M.; Dorian, P.; Conolly, S.; Eisenberg, M. J.;
Green, M.; Kus, T.; Lambert, J.; Dubuc, M.; Gagne, P.; Nattel, S.;
Thibault, B. New Engl J Med 2000, 342, 913.
7.74 (s, 1H, furan-H), 5.32 (t, J =1.9 Hz, 2H, Fc-H), 4.75
(t, J = 1.9Hz, 2H, Fc-H), 4.22 (s, 5H, Fc-H), 1.68 (s, 9H,
tBu-H); 13C NMR (100 MHz, CDCl3) δ (ppm): 185.32,
153.49, 137.43, 132.80, 131.35, 131.01, 129.83, 110.97,
91.06, 80.18, 75.17, 73.86, 71.35, 34.89, 31.69; HRMS
(ESI, m/z). Calcd. for C23H22FeIO2 [M+ H]+ 513.0014.
Found 513.0021.
5-Chloro-2-ferrocenoyl-7-iodobenzo[b]furan (4f).
Dark
red solid, mp 125–126°C. IR (KBr) ν/cmÀ1: 3091, 1628,
[6] Cui, M.; Ono, M.; Kimura, H.; Liu, B.; Saji, H. Bioorg Med
Chem 2011, 19, 4148.
1
1545, 1454, 1376, 1351, 1287, 1216, 1147, 820, 805; H
[7] Schatzschneider, U.; Metzler-Nolte, N. Angew Chem Int Ed
2006, 45, 1504.
NMR (400 MHz, CDCl3) δ (ppm): 7.61 (d, J= 2.8 Hz,
1H, Furan-H), 7.47 (d, J = 1.7 Hz, 1H, Ben-H), 7.27–7.30
(m, 1H, Ben-H), 5.30 (t, J= 1.9 Hz, 2H, Fc-H), 4.68 (t,
J =1.9 Hz, 2H, Fc-H), 4.21 (s, 5H, Fc-H); 13C NMR
(100 MHz, CDCl3) δ (ppm): 185.75, 154.35, 137.96,
133.36, 131.38, 129.57, 125.14, 111.50, 89.13, 81.26,
[8] Zhao, C.; Liu, Z. Q. Biochimie 2012, 94, 1805.
[9] Blackie, M. A. L.; Beagley, P.; Croft, S. L.; Kendrick, H.;
Moss, J. R.; Chibale, K. Bioorg Med Chem 2007, 15, 6510.
[10] Monserrat, J. P.; Chabot, G. G.; Hamon, L.; Quentin, L.;
Scherman, D.; Jaouen, G.; Hillard, E. A. Chem Commun 2010, 46, 5145.
[11] Prasath, R.; Bhavana, P.; Ng, S. W.; Tiekink, E. R. T.
J Organometal Chem 2013, 726, 62.
[12] Zhang, Y. M.; Liu, P.; Zhang, H. L.; Feng, G. L.; Geng, L. J.
J Chem Res 2012, 36, 536.
[13] Dolle, R. E.; Nelson, K. H. Jr. J Comb Chem 1999, 1, 235.
[14] Li, Y.; Gao, W. Beilstein J Org Chem 2010, 6, 966.
[15] Li, Y.; Lin, G. H.; Gao, W. T. Poly Arom Compd 2012, 32,
469.
[16] Li, Y.; Sun, M.; Gao, W. J Heterocycl Chem 2012, 49, 167.
[17] Zhang, H.; Li, Y.; Gao, W. Helv Chim Acta 2013, 96, 2134.
[18] Gao, W. T.; Xing, X. D.; Li, Y. Tetrahedron 2014, 70, 2180.
[19] Li, Y.; Lv, M.; Gao, W. Turk J Chem 2014, 38, 470.
[20] Sakthivel, S.; Punniyamurthy, T. Tetrahedron: Asymmetry
2010, 21, 2834.
[21] Xu, S. P.; Zhu, G. Z.; Fang, R. Q.; Li, X. L.; Zhu, H. L. Chin J
Struct Chem 2009, 28, 87.
[22] Niamnont, N.; Khumsri, A.; Promchat, A.; Tumcharern, G.;
Sukwattanasinitt, M. J Hazard Mater 2014, 280, 458.
[23] Yoshizawa, K.; Toyota, S.; Toda, F.; Csöregh, I. Green Chem
2003, 5, 353.
73.82, 71.14, 70.47; HRMS (ESI, m/z). Calcd. for
35
C19H ClFeIO2 [M +H]+ 490.8998. Found 490.9012.
13
5-Bromo-2-ferrocenoyl-7-iodobenzo[b]furan (4g). Dark red
solid, mp 137–138°C. IR (KBr) ν/cmÀ1: 3060, 1633, 1555,
1
1452, 1376, 1342, 1288, 1212, 1140, 828, 807; H NMR
(400MHz, CDCl3) δ (ppm): 7.72 (s, 1H, Furan-H), 7.61 (s,
1H, Ben-H), 7.54–7.58 (m, 1H, Ben-H), 5.27 (t, J=1.7Hz,
2H, Fc-H), 4.65 (t, J=1.9Hz, 2H, Fc-H), 4.20 (s, 5H,
Fc-H); 13C NMR (100MHz, CDCl3) δ (ppm): 186.26,
153.47, 138.28, 132.59, 132.13, 129.77, 126.24, 110.76,
88.94, 81.35, 73.60, 71.37, 70.41; HRMS (ESI, m/z). Calcd.
79
for C19H BrFeIO2 [M+H]+ 534.8493. Found 534.8502.
13
Acknowledgments. The authors would like to thank the Scientific
Research Foundation of the National Natural Science Foundation of
China (grant nos. 21476028 and 21402011) for financial support.
[24] Rao, M. L.; Awasthi, N. D. K.; Banerjee, D. Tetrahedron Lett
2007, 48, 431.
[25] Shang, Y. J.; Wang, C.; He, X. W.; Ju, K.; Zhang, M.; Yu, S. Y.;
Wu, J. P. Tetrahedron 2010, 66, 9629.
[26] Wang, M. L.; Chang, K. R. Can J Chem Eng 1991, 69, 340.
[27] Liu, Y.; Qian, J.; Lou, S.; Xu, Z. J Org Chem 2010, 75, 6300.
[28] Stokker, C. E.; Schultz, E. M. Syn Comunn 1982, 12, 847.
[29] Han, W.; Wu, J.; Dai, W. M. Synlett 2014, 25, 2019.
REFERENCES AND NOTES
[1] Alper-Hayta, S.; Arisoy, M.; Temiz-Arpaci, Ö.; Yildiz, I.; Aki,
E.; Özkan, S.; Kaynak, F. Eur J Med Chem 2008, 43, 2568.
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet