1-Methyl-3-(propyl-3-sulfonic acid)imidazolium triflate supported on magnetic nanoparticles: An efficient and reusable catalyst for synthesis of mono- and bis-isobenzofuran-1(3H)-ones under solvent-free conditions

Article abstract of DOI:10.1039/c4ra14112a

1-Methyl-3-(propyl-3-sulfonic acid)imidazolium triflate supported on magnetic nanoparticles ([HSO₃PMIM]OTf-SiO₂@MNPs) was prepared by immobilization of [HSO₃PMIM]OTf onto the surface of silica-coated Fe₃O₄ nanoparticles and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), and FT-IR techniques. Efficient synthesis of mono- and bis-isobenzofuran-1(3H)-ones was performed in the presence of this catalyst under thermal conditions and MW irradiation. The catalyst could be easily separated by an external magnet and reused six times under thermal conditions and MW irradiation without significant loss of its activity.

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DOI: 10.1039/C4RA14112A
1-Methyl-3-(propyl-3-sulfonic acid)imidazolium triflate supported on magnetic
nanoparticles: an efficient and reusable catalyst for synthesis of mono- and bis-
isobenzofuran-1(3H)-ones under solvent-free conditions
Forouz Rastegari, Iraj Mohammadpoor-Baltork,* Ahmad R. Khosropour,* Shahram
Tangestaninejad, Valiollah Mirkhani, and Majid Moghadam
Department of Chemistry, Catalysis Division, University of Isfahan, Isfahan 81746-73441,
Iran. E-mail: imbaltork@sci.ui.ac.ir; arkhosropour@sci.ui.ac.ir
An efficient procedure for the synthesis of isobenzofuran-1(3H)-one derivatives in the presence of
[HSO3PMIM]OTf-SiO2@MNPs as a highly recyclable catalyst under solvent-free thermal conditions
and MW irradiation is reported.

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DOI: 10.1039/C4RA14112A
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ARTICLE TYPE
1-Methyl-3-(propyl-3-sulfonic acid)imidazolium triflate supported on
magnetic nanoparticles: an efficient and reusable catalyst for synthesis
of mono- and bis-isobenzofuran-1(3H)-ones under solvent-free
conditions
5
Forouz Rastegari, Iraj Mohammadpoor-Baltork,* Ahmad R. Khosropour,* Shahram Tangestaninejad,
Valiollah Mirkhani, and Majid Moghadam
Received (in XXX, XXX) Xth XXXXXXXXX 20XX, Accepted Xth XXXXXXXXX 20XX
DOI: 10.1039/b000000x
10
1ꢀMethylꢀ3ꢀ(propylꢀ3ꢀsulfonic acid)imidazolium triflate supported on magnetic nanoparticles
([HSO3PMIM]OTfꢀSiO2@MNPs) was prepared by immobilization of [HSO3PMIM]OTf onto the surface
of silicaꢀcoated Fe3O4 nanoparticles and characterized by Xꢀray diffraction (XRD), transmission electron
microscopy (TEM), vibrating sample magnetometery (VSM), and FTꢀIR techniques. Efficient synthesis
15 of monoꢀ and bisꢀisobenzofuranꢀ1(3H)ꢀones was performed in the presence of this catalyst under thermal
conditions and MW irradiation. The catalyst could be easily separated by an external magnet and reused
six times under thermal conditions and MW irradiation without significant loss of its activity.
Introduction
During the recent years, ionic liquids (ILs) as environmentallyꢀ
with the external magnetic field.23,24,26ꢀ31 This can be considered
20 friendly reaction media or catalysts, have received increasing
interest due to their distinctive physicochemical properties such
as high thermal stability, negligible vapor pressure, nonꢀ
flammability, and the ability to dissolve many organic and
inorganic materials.1ꢀ3 In spite of extensive applications in
25 organic reactions, they suffer from disadvantages such as difficult
product separation, catalyst recovery and the use of large amounts
of ILs. Such disadvantages limit their usefulness in large scale
operation and lead to serious economical and environmental
problems. However, these problems can be solved by
30 immobilization ILs on solid supports such as organic polymers,
silica, ZrO2, TiO2 and Al2O3 and mesoporous MCMꢀ41.4ꢀ10 These
heterogeneous IL catalysts have many advantages over their
unsupported counterpart, such as separation, reusability, and the
ability to provide practical conveniences in a continuous system.
35 In addition, magnetic nanoparticles (MNPs) which have found
many applications in the fields of biotechnology and
biomedicine11ꢀ14 have emerged as viable alternatives to the
conventional heterogeneous supports.15ꢀ25 The magnetic
separation technology offers many advantages over conventional
40 filtration and other purification methods in which the catalysts
can be simply and efficiently recovered from reaction media
50 as a green technology that avoids the consequences brought about
by filtration steps.
Isobenzofuranꢀ1(3H)ꢀones are an important class of compounds
possess a wide range of biological properties such as antiꢀ
bacterial, antiꢀconvulsant, antiꢀHIV, antiꢀasthmatic, antiꢀtumor,
55 antiꢀplatelet activities32ꢀ37 as well as anesthesia prolongation, and
PGF2α inhibitory properties.38ꢀ41 Because of the applications of
these compounds in medicine and in the synthesis of natural
products,42,43 several acidic and basic catalysts such as
trifluoroacetic acid (TFA),44 trifluoromethanesulfonic acid
60 (HOTf),45 Montmorillonite Kꢀ10,46 NaOH,47 KOH,48 KFꢀAl2O3,49
silicaꢀsupported preyssler nanoparticles (H14[NaP5W30O110]/nanoꢀ
SiO2)50 and ZrOCl2·8H2O51 have been reported for their
synthesis.
In continuation of our research on the use of efficient catalytic
65 systems in the synthesis of fine chemicals,52ꢀ57 herein, we wish to
report a convenient method for the synthesis of monoꢀ and bisꢀ
Department of Chemistry, Catalysis Division, University of Isfahan,
Isfahan 81746ꢀ73441, Iran. Fax: +98ꢀ031ꢀ36689732; Tel: +98ꢀ031ꢀ
3793270.
Scheme 1 Synthesis of isobenzofuranꢀ1(3H)ꢀones catalyzed by
[HSO3PMIM]OTfꢀSiO2@MNPs.
45 Eꢀmail: imbaltork@sci.ui.ac.ir; arkhosropour@sci.ui.ac.ir
This journal is © The Royal Society of Chemistry [year]
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Scheme 2 Preparation of [HSO3PMIM]OTfꢀSiO2@MNPs.
isobenzofuranꢀ1(3H)ꢀones in the presence of 1ꢀmethylꢀ3ꢀ(propylꢀ
3ꢀsulfonic acid)imidazolium triflate supported on magnetic
5
nanoparticles ([HSO3PMIM]OTfꢀSiO2@MNPs) as a highly
reusable catalyst under thermal conditions and MW irradiation
(Scheme 1). To the best of our knowledge, this is the first report
on the application of MNPs supported IL catalyst in the synthesis
of these important heterocyclic compounds.
Fig. 1 XꢀRay diffraction pattern of: a) SiO2@MNPs and b) standard
magnetite pattern (JCPDS No. 19ꢀ0629).
10 Results and Discussion
The acidic IL supported on magnetic nanoparticles
([HSO3PMIM]OTfꢀSiO2@MNPs) was prepared according to the
procedure shown in scheme 2. The ionic liquid [HSO3PMIM]OTf
was prepared by quaternization of 1ꢀmethylꢀ3Hꢀimidazole with
15 1,3ꢀpropanesultone, followed by treatment with HOTf. The
magnetite nanoparticles (MNPs) was easily prepared via the coꢀ
precipitation method described by Massart58 and protected with a
layer of silica to prevent aggregation.59 The coating process was
performed by ultrasonic suspending of MNPs in ethanol and
20 added tetraethoxysilane (TEOS) to form a silica shell under basic
conditions through a solꢀgel method. Ultimately, a mixture of
MNPs and [HSO3PMIM]OTf in dichloromethane was dispersed
by sonication for 5 h.
45
The prepared catalyst was characterized by Xꢀray diffraction
25 (XRD), transmission electron microscopy (TEM), vibrating
sample magnetometery (VSM) and FTꢀIR techniques. The XRD
patterns of Fe3O4 magnetic nanoparticles and silicaꢀcoated Fe3O4
magnetic nanoparticles are shown in Fig. 1. These patterns show
the characteristic peaks and relative intensity which are wellꢀ
30 matched with those of standard Fe3O4 nanoparticles (JCPDS file
No. 19ꢀ0629). Moreover, the broad peak from 2θ = 20° to 30° is
consistent with an amorphous silica phase in the shell of the
silicaꢀcoated Fe3O4 nanoparticles (Fig. 1a).60,61 The TEM image
of [HSO3PMIM]OTfꢀSiO2@MNPs showed dark nanoꢀFe3O4
35 cores surrounded by grey silica shells (Fig 2a). The TEM image
of the reused catalyst reveals its stability during the reaction (Fig
2b). The histogram of size distribution shows that the average
diameter of nanoparticles is about 8ꢀ12 nm (Fig. 2c).
The magnetic properties of MNPs, SiO2@MNPs and
40 [HSO3PMIM]OTfꢀSiO2@MNPs were measured at room
temperature from −10000 to +10000 Oe. The magnetization
Fig. 2 TEM images of: a) [HSO3PMIM]OTfꢀSiO2@MNPs; b) recovered
[HSO3PMIM]OTfꢀSiO2@MNPs and c) particle size distribution results
for [HSO3PMIM]OTfꢀSiO2@MNPs.
2
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Table 1 Optimization of the reaction conditions for the synthesis of
isobenzofuranꢀ1(3H)ꢀones
15
Entry
Method
T (°C)
Catalyst
Time
Yield (%)a
amount (mg)
1
Thermal
Thermal
Thermal
Thermal
Thermal
Thermal
Thermal
Thermal
Thermal
Thermal
100
100
100
100
100
100
100
80
0
25
ꢀ
2.5 h
2.5 h
2.5 h
2.5 h
2.5 h
2.5 h
2.5 h
2.5 h
2.5 h
2.5 h
0
8
2b
3C
4
69
65
82
95
95
72
83
95
15
20
25
30
25
25
25
25
25
25
5
6
7
8
9
90
110
10
11
12
13
Fig. 3 The VSM result for: a) MNPs; b) SiO2@MNPs and c)
[HSO3PMIM]OTfꢀSiO2@MNPs.
MW (550 W) 100
MW (600 W) 100
MW (650 W) 100
10 min 80
10 min 95
10 min 95
a Isolated yield. b Reaction was performed in the presence of
SiO2@MNPs. c Reaction was performed in the presence of 0.01 mmol
[HSO3PMIM]OTf.
nanoparticles display no hysteresis before and after
20 functionalization. These results clearly demonstrate their
superparamagnetic characteristics,58 which further reinforce by
easy separation of these magnetic nanoparticles with an external
magnetic field.
Further characterization of the catalyst was performed by FTꢀIR
25 spectroscopy. The FTꢀIR spectra of blank SiO2@MNPs,
[HSO3PMIM]OTf and [HSO3PMIM]OTfꢀSiO2@MNPs are
presented in Fig. 4. All these samples show broad bands at
around 3424 and 1630 cmꢀ1, that are assigned to the Si–OH
group and adsorbed water, respectively, in which band at 1630
30 cmꢀ1 is overlapped with band at 1655 cmꢀ1 (Fig. 4b and 4c). The
spectra of the SiO2@MNPs and [HSO3PMIM]OTfꢀSiO2@MNPs
exhibit the characteristic bands at about 1099, 948 and 484 cmꢀ1,
which are attributed to the stretching vibrations of Si–O–Si and
Fe–O, respectively (Fig. 4a and 4c). Furthermore, in the FTꢀIR
35 spectra
of
[HSO3PMIM]OTf
and
[HSO3PMIM]OTfꢀ
SiO2@MNPs, the typical bands at around 1655 cmꢀ1 (C=N), 1572
cmꢀ1 (C=C), 1428 cmꢀ1 (CꢀH), 1179 and 1030 cmꢀ1 (S=O) were
observed (Fig. 4b and 4c). In addition, the characteristic band at
1247 cmꢀ1 is attributed to the CF3 group. These results confirm
40 that IL has been successfully supported on the surface of
SiO2@MNPs (Fig. 4c).
Synthesis of isobenzofuran-1(3H)-ones catalyzed by
[HSO3PMIM]OTf-SiO2@MNPs
The condensation of phthalaldehydic acid (1 mmol) with
45 acetophenone (1 mmol) was chosen as a model reaction for the
optimization of parameters such as the amount of catalyst,
temperature, and MW power. The results are summarized in
Table 1. Initially, the reaction was examined in the absence of the
5
Fig. 4 FTꢀIR spectra of: a) SiO2@MNPs; b) [HSO3PMIM]OTf, c)
[HSO3PMIM]OTfꢀSiO2@MNPs and d) the 6ꢀtimes reused catalyst.
°
catalyst at 100 C; no desired product was obtained under this conditions
curves for these samples are shown in Fig. 3. The saturation
magnetization (Ms) values of samples are 70, 35 and 20 emu.gꢀ1,
respectively. The decreasing of Ms values from MNPs to
10 [HSO3PMIM]OTfꢀSiO2@MNPs could be attributed to the
coating of iron oxide magnetic nanoparticles with silica and IL.
Furthermore, the magnetization curves of the magnetic
50 even after 2.5 h. Then, the reaction was performed in the presence
of SiO2@MNPs and [HSO3PMIM]OTf and the corresponding
product was obtained in 8% and 69% yields, respectively. In order
to find the optimum amount of [HSO3PMIM]OTfꢀSiO2@MNPs catalyst,
the reaction was performed with different amounts of the catalyst (15, 20,
55 25, and 30 mg) under solventꢀfree conditions at 100 °C. The best yield
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Table 2 Synthesis of isobenzofuranꢀ1(3H)ꢀones catalyzed by
[HSO3PMIM]OTfꢀSiO2@MNPsa
O
13
0.75 90
7
93
92
S
3m
3n
14
3
88
10
Thermal
MW
a Reaction conditions: phthalaldehydic acid (1 mmol), acetophenone (1
mmol), catalyst (25 mg), Thermal (100 °C) or MW (600 W, 100 °C). b
Isolated yield.
Entry Ketone
Product
Time Yield Time Yield
(h) (%)b (min) (%)b
5
1
2.5 95
10
12
95
95
3a
2
3
92
3b
Scheme 3 Selective synthesis of monoꢀ and bisꢀsiobenzofuranꢀ1(3H)ꢀ
ones catalyzed by [HSO3PMIM]OTfꢀSiO2@MNPs
.
3
4
5
6
1.5 60
1.45 87
8
65
91
90
97
3c
10 of the desired product was achieved with 25 mg of
[HSO3PMIM]OTfꢀSiO2@MNPs. Using lower amount of catalyst
resulted in lower yield, while higher amount did not affect the
reaction time and yield. To evaluate the influence of temperature,
4
3d
°
the model reaction was performed in the range of 80ꢀ110 C. It
15 was found that 100 °C was the optimal temperature and the
reaction was incomplete at lower temperature. To find the
optimized MW power, the model reaction was carried out in the
presence of 25 mg catalyst at 550, 600 and 650 W, and the
desired product was obtained in 80%, 95% and 95% yields,
3
85
12
8
3e
°
20 respectively. Therefore, 600 W and 100 C was selected as the
1.5 85
optimum power and temperature.
3f
The scope of this protocol was then extended by using a variety
of acetophenones to synthesize isobenzofuranꢀ1(3H)ꢀones. The
results are summarized in Table 2. Unsubstituted acetophenone
25 and acetophenones with electronꢀwithdrawing or electronꢀ
donating substituents reacted very well with phthalaldehydic acid
in the presence of [HSO3PMIM]OTfꢀSiO2@MNPs catalyst under
thermal conditions, affording good to excellent yields of the
corresponding isobenzofuranꢀ1(3H)ꢀone derivatives (Table 2,
30 entries 1ꢀ12). Acidꢀsensitive ketones such as 2ꢀacetylthiophene
and 4ꢀacetylpyridine were also reacted efficiently to give the
desired products in high yields (Table 2, entries 13 and 14.). In
order to investigate the effect of MW, the reaction of
acetophenones with phthalaldehydic acid was performed under
35 the optimized microwave irradiation. Under these conditions, the
desired isobenzofuranꢀ1(3H)ꢀones were obtained in 65ꢀ98%
yields in very short reaction times (4ꢀ12 min) (Table 2). These
results clearly demonstrated that the yields were slightly
improved, but the reaction times were significantly reduced under
40 microwave irradiation.
7
1
90
8
98
3g
O
8
1.75 95
8
7
8
95
93
96
3h
Cl
9
2
2
92
92
3i
3j
10
11
12
2.5 65
0.75 90
12
7
75
93
3k
3l
Another noteworthy advantage of this catalytic system lies in
the selective reaction of 1,4ꢀdiacetylbenzene with phthalaldehydic
O
acid. Using
a 1:1 molar ratio of 1,4ꢀdiacetylbenzene to
phthalaldehydic acid, only one acetyl group reacted selectively
45 and the corresponding monoꢀisobenzofuranꢀ1(3H)ꢀone 5a was
obtained in 80% and 95% yields under thermal conditions and
MW irradiation, respectively. Whereas, with a 1:3 molar ratio of
I
4
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1,4ꢀdiacetylbenzene to phthalaldehydic acid, both acetyl groups
Conclusions
reacted and the corresponding bisꢀisobenzofuranꢀ1(3H)ꢀ one 5b
was obtained in 85% and 90% yields, under the above mentioned
conditions (Scheme 3). To the best of our knowledge, this is the
first report on the selective synthesis of monoꢀ and bisꢀ
isobenzofuranꢀ1(3H)ꢀone, which shows the efficiency and
applicability of this catalytic system.
In conclusion, we have developed a convenient, efficient, and
40 environmentally benign procedure for the preparation of
isobenzofuranꢀ1(3H)ꢀone derivatives in the presence of
[HSO3PMIM]OTfꢀSiO2@MNPs as a highly recyclable catalyst
under solventꢀfree thermal conditions and MW irradiation. Easy
workꢀup, high yields, short reaction times, high atomꢀeconomy,
45 environmental acceptability, and use of easy recoverable and
reusable catalyst are the significant advantages of the present
protocol in the synthesis of these important compounds.
5
A plausible mechanism for the formation of isobenzofuranꢀ
1(3H)ꢀone is proposed in Scheme 4. Initially, [HSO3PMIM]OTfꢀ
10 SiO2@MNPs activates the formyl group of phthalaldehydic acid
and also catalyzes the ketoꢀenol tautomerization of acetophenone
to give A and B, respectively. Nucleophilic attack of B to A
furnishes the intermediate C. The intermediate C undergoes
intramolecular nucleophilic cyclization in the presence of the
15 catalyst giving the adduct D. Finally, dehydration of D in the
presence of the catalyst produces the desired isobenzofuranꢀ
1(3H)ꢀone 3 and releases the catalyst for the next run.
Fig. 5 Recycling experiment of [HSO3PMIM]OTfꢀSiO2@MNPs
50 under thermal conditions (red) and MW irradiation (green).
Experimental
General information
The chemicals used in this work were purchased from Fluka and
Merck chemical companies. Melting points were determined with
55 a Stuart Scientific SMP2 apparatus. FTꢀIR spectra were recorded
1
on a NicoletꢀImpact 400D spectrophotometer. H NMR (400 and
500 MHz) and 13C NMR (100 and 125 MHz) spectra were
recorded on a Bruker Avance spectrometer using CDCl3 and
DMSOꢀd6 as solvent. XꢀRay diffraction (XRD) images were
60 obtained from a Bruker XRD D8 Advance instrument with Co Kα
radiation at 40 kV. The transmission electron microscopy (TEM)
was carried out on a Philips CM10 transmission electron
microscope operating at 200 kV. The magnetic measurements
were performed with a vibrating sample magnetometer (VSM) at
65 Meghnatis Daghigh Kavir Co. The microwave system used in
these experiments includes the following items: MicroꢀSYNTH
labstation, equipped with a glass door, a dual magnetron system
with pyramid shaped diffuser, 1000 W delivered power, exhaust
system, magnetic stirrer, ‘quality pressure’ sensor for flammable
70 organic solvents, and a ATCFO fiber optic system for automatic
temperature control.
20
Scheme
4
Proposed mechanism for the synthesis of
isobenzofuranꢀ1(3H)ꢀones catalyzed by [HSO3PMIM]OTfꢀ
SiO2@MNP
Recyclability of the catalyst
25 Finally, we turned our attention to the possibility of recycling
the catalyst, since the recovery and reuse of the catalyst are
highly preferable for a green process. In this respect, the
reusability of the catalyst was investigated in the reaction of
phthalaldehydic acid with acetophenone under thermal conditions
30 and MW irradiation. At the end of the reaction, the mixture was
cooled to room temperature and chloroform (15 mL) was added.
The catalyst was easily separated by a permanent magnet, dried
and reused for subsequent reactions. The experimental results
suggest that there is no appreciable loss in catalytic activity even
Synthesis of 1-methyl-3-(propyl-3-sulfonic acid)imidazolium
triflate
supported
on
magnetic
nanoparticles
35 after sixth recycle (Fig. 5). The comparison of FTꢀIR spectra of 75 ([HSO3PMIM]OTf-SiO2@MNPs)
fresh and reused catalyst suggests the stability of the present
catalyst during the reaction (Fig. 4d).
Synthesis of 1-methyl-3-(propyl-3-sulfonic acid)imidazolium
triflate ([HSO3PMIM]OTf) ionic liquid. A mixture of 1ꢀ
methylꢀ3Hꢀimidazole (0.82 g, 10 mmol) and 1,3ꢀpropanesultone
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(1.22 g, 10 mmol) was stirred magnetically for 72 h at room
65 3.78 (dd, 1H, J = 17.6, 5.6 Hz), 3.37 (dd, 1H, J = 17.6, 7.6 Hz),
2.58 (s, 1H), 1.86ꢀ1.95 (m, 4H), 1.78 (d, 1H, J = 12.4 Hz),1.41ꢀ
1.58 (m, 4H), 1.28ꢀ1.36 (m, 1H). 13C NMR (100 MHz, CDCl3): δ
195.7, 170.2, 154.7, 149.9, 134.2, 134.1, 129.4, 128.4, 127.3,
126.0, 125.7, 122.9, 77.4, 44.8, 43.6, 34.1, 26.7, 26.0.
temperature. The resulting white solid was washed with diethyl
ether (3×10 mL) and dried in vacuum to afford the desired
zwitterion in 90% yield. Then, trifluoromethanesulfonic acid (1.5
g, 10 mmol) was added to this white solid zwitterion and the
5
°
mixture was stirred for 2 h at 40 C. The resulting crude material
70 3-[2-(4-Methoxyphenyl)-2-oxoethyl]isobenzofuran-1(3H)-one
was washed repeatedly with toluene and diethyl ether and dried in
°
°
vacuum to give 1ꢀmethylꢀ3ꢀ(propylꢀ3ꢀsulfonic acid)imidazolium
(3c): Mp: 118ꢀ120 C (Ref.48 120 C). FTꢀIR (KBr, cmꢀ1): νmax
3116, 2966, 1786, 1763, 1607, 1355, 1282, 1048, 940, 838, 751.
1H NMR (500 MHz, CDCl3): δ 7.92ꢀ7.96 (m, 3H), 7.65ꢀ7.68 (m,
1H), 7.53ꢀ7.59 (m, 2H), 6.96 (d, 2H, J = 8.8 Hz), 6.18 (t, 1H, J =
75 6.6 Hz), 3.89 (s, 3H), 3.74 (dd, 1H, J = 17.4, 5.7 Hz), 3.34 (dd,
1H, J = 17.3, 7.5 Hz).
1
triflate ([HSO3PMIM]OTf) ionic liquid in quantitative yield. H
10 NMR (400 MHz, D2O): δ 8.54 (s, 1H), 7.36 (dd, 1H, J = 15.2, 8.0
Hz), 7.26 (dd, 1H, J = 18.0, 6.8 Hz), 4.19 (t, 2H, J = 7.2 Hz), 3.73
(s, 3H), 2.77 (t, 2H, J = 7.2 Hz), 2.16 (q, 2H, J = 7.6 Hz). 13C
NMR (100 MHz, D2O): δ 137.0, 135.8, 123.5, 121.9, 47.5, 47.0,
35.5, 24.8.
3-[2-(4-Methylphenyl)-2-oxo-ethyl]isobenzofuran-1(3H)-one
15 Synthesis
of
silica-coated
Fe3O4
nanoparticles
°
°
(3d): Mp: 147ꢀ149 C (Ref.50 149 C). FTꢀIR (KBr, cmꢀ1): νmax
2903, 1762, 1673, 1604, 1296, 1082, 942, 800, 763. 1H NMR
80 (400 MHz, CDCl3): δ 7.90 (d, 1H, J = 7.6),7.85ꢀ7.87 (m, 2H),
7.64ꢀ7.68 (m, 1H), 7.53ꢀ7.58 (m, 2H),7.27ꢀ7.29 (m, 2H), 6.18 (t,
1H, J = 6.5 Hz), 3.76 (dd, 1H, J = 17.5, 5.7 Hz), 3.37 (dd, 1H, J =
16.2, 7.5 Hz), 2.42 (s, 3H).
(SiO2@MNPs). Magnetite nanoparticles (MNPs) were prepared
according to the reported procedure.58 In this manner,
FeCl3·6H2O (11.0 g) and FeCl2·4H2O (4.0 g) were dissolved in
250 mL deionized water under N2 with vigorous stirring at 85 °C,
20 during which the pH of the solution adjusted to 9 using conc.
NH3·H2O. The mixture was further stirred for 4 h and the
resulting MNPs precipitates were washed with deionized water
and ethanol until the pH reached 7. The black precipitate (MNPs)
was collected with a permanent magnet. For coating of a layer of
25 silica on the surface of MNPs, the MNPs (2.0 g) in ethanol (400
ml) were sonicated for 30 min at room temperature under N2.
Then, conc. NH3·H2O (12.0 mL) and TEOS (4.0 mL) was added
sequentially, and the mixture was dispersed for 24 h under the
above mentioned conditions. Finally, the black precipitate
30 (SiO2@MNPs) was collected using a permanent magnet, washed
with ethanol three times and dried in a vacuum.
3-[2-(3,4-Dimethoxyphenyl)-2-oxo-ethyl]isobenzofuran-1(3H)-
°
85 one (3e): Mp: 116ꢀ119 C. FTꢀIR (KBr, cmꢀ1): νmax 2965, 1765,
1
1650, 1469, 1256, 1171, 1034, 941, 750. H NMR (400 MHz,
CDCl3): δ 7.92 (d, 1 H, J = 7.6 Hz), 7.65ꢀ7.69 (m, 2H), 7.57ꢀ7ꢀ60
(m, 2H), 7.54 (d, 2H, J = 2.0 Hz), 6.18 (t, 1H, J = 6.6 Hz), 3.96
(s. 3H), 3.95 (s, 3H), 3.75 (dd, 1H, J = 17.2, 6.0 Hz), 3.37 (dd,
90 1H, J = 17.2, 7.2 Hz) . 13C NMR (100 MHz, CDCl3): δ 194.5,
170.2, 153.9, 149.8, 149.2, 134.3, 129.4, 129.3, 125.9, 125.7,
123.2, 122.9, 110.1, 110.0, 77.5, 56.2, 56.0, 43.2.
Synthesis of [HSO3PMIM]OTfꢀSiO2@MNPs. 5.0 g of
SiO2@MNPs was dispersed in 50 mL CH2Cl2 by sonication for 1
h. Then, a solution of [HSO3PMIM]OTf (1.0 g) in CH2Cl2 (15
35 mL) was added, and the mixture was sonicated for 5 h. Finally,
3-[2-(2-Hydroxyphenyl)-2-oxo-ethyl]isobenzofuran-1(3H)one
°
°
(3f): Mp: 134ꢀ136 C (Ref.47 134ꢀ136 C). FTꢀIR (KBr, cmꢀ1):
95 νmax 3038, 2920, 1773, 1634, 1443, 1297, 1078, 965, 759. 1H
NMR (500 MHz, CDCl3): δ 12.03 (s, 1H), 7.94 (d, 1H, J = 7.6
Hz), 7.65ꢀ7.72 (m, 2H), 7.56ꢀ7.59 (m, 2H), 7.51ꢀ7.54 (m, 1H),
7.04 (dd, 1H, J = 8.4, 1.0 Hz), 6.90ꢀ6.93 (m, 1H), 6.17 (t, 1H, J =
6.5 Hz), 3.8 (dd, 1H, J = 17.6, 6.2 Hz), 3.45 (dd, 1H, J = 17.6, 6.8
100 Hz).
the [HSO3PMIM]OTf-SiO2@MNPs catalyst was separated by a
permanent magnet, washed with nꢀhexane (3×15 mL) and dried
under vacuum. The loading of the catalyst was determined by
elemental analysis to be 14% W.
40 General procedure for the synthesis of isobenzofuran-1(3H)-
ones under thermal conditions and MW irradiation.
A mixture of phthaladehyic acid (1 mmol), acetophenone (1
3-[2-(4-Nitrophenyl)-2-oxo-ethyl]isobenzofuran-1(3H)-one
mmol) and [HSO3PMIM]OTfꢀSiO2@MNPs (25.0 mg) was stirred
at 100 °C or subjected to MW irradiation (600 W, 100 °C) for the
45 appropriate time according to Table 2. The progress of the
reaction was monitored by TLC (eluent: petroleum ether/ethyl
acetate, 5:2). After completion of the reaction, the mixture was
cooled to room temperature, chloroform (15 mL) was added and
the catalyst was easily separated by a permanent magnet. The
50 filtrate was evaporated and the crude product was purified by
chromatography on silica gel (eluent: petroleum ether/ethyl
acetate, 5:2) or by recrystallization from acetone and ethanol
(1:2) to afford the pure product.
3-(2-Oxo-2-phenyl)isobenzofuran-1(3H)-one (3a): Mp: 143ꢀ
55 145 °C (Ref.44 145 °C). FTꢀIR (KBr, cmꢀ1): νmax 3053, 2930, 1629,
1466, 1365, 1335, 1098, 1045, 793. 1H NMR (400 MHz, CDCl3):
δ 7.93ꢀ7.98 (m, 3H), 7.56ꢀ7.70 (m, 4H), 7.49ꢀ7.54 (m, 2H), 6.20
(t, 1H, J = 6.6 Hz), 3.80 (dd, 1H, J = 17.6, 5.6 Hz), 3.41 (dd, 1H,
J = 17.6, 7.6 Hz).
°
°
(3g): Mp: 208ꢀ210 C (Ref.51 210 C). FTꢀIR (KBr, cmꢀ1): νmax
3104, 2909, 1748, 1689, 1603, 1456, 1320, 1270, 1085, 982, 854,
1
752. H NMR (400 MHz, CDCl3): δ 7.93 (d, 1H, J = 7.6), 7.86ꢀ
105 7.90 (m, 2H), 7.66ꢀ7.74 (m, 3H), 7.55ꢀ7.58 (m, 2H), 6.16 (t, 1H, J
= 6.2 Hz), 3.72 (dd, 1H, J = 17.0, 5.8 Hz), 3.36 (dd, 1H, J = 17.6,
6.8 Hz).
3-[2-(3-Chlorophenyl)-2-oxo-ethyl]isobenzofuran-1(3H)-one
(3h): Mp: 142ꢀ144 °C. FTꢀIR (KBr, cmꢀ1): νmax 2927, 1754, 1634,
1
110 1423, 1227, 1163, 1097, 946, 799. H NMR (400 MHz, CDCl3):
δ 7.76ꢀ7.84 (m, 4H), 7.61ꢀ7.65 (m, 1H), 7.47ꢀ7.55 (m, 2H), 7.37
(t, 1H, J = 6.4 Hz), 6.08 (t, 1H, J = 6.4 Hz), 3.64 (dd, 1H, J =
17.8, 6.6 Hz), 3.42 (dd, 1H, J = 17.8, 6.2 Hz). 13C NMR (100
MHz, CDCl3): δ 194.7, 170.0, 149.4, 137.6, 135.0, 134.4, 133.6,
115 130.2, 129.5, 128.1, 126.4, 125.8, 125.6, 122.7, 76.9, 42.9.
3-[2-(4-Fluorophenyl)-2-oxo-ethyl]isobenzofuran-1(3H)-one
(3i): Mp: 132ꢀ134 °C (Ref.48130ꢀ133 °C). FTꢀIR (KBr, cmꢀ1): νmax
1
3080, 2965, 2911, 1756, 1681, 1596, 1213, 973, 837. H NMR
60 3-[2-(4-Cyclohexylphenyl)-2-oxo-ethyl]isobenzofuran-1(3H)-
(500 MHz, CDCl3): δ 7.98ꢀ8.00 (m, 2H), 7.92 (d, 1H, J = 7.6 Hz),
120 7.67 (t, 1H, J = 7.5 Hz), 7.53ꢀ7.57 (m, 2H), 7.15 (t, 2H, J = 8.5),
6.16 (t, 1H, J = 6.5 Hz), 3.74 (dd, 1H, J = 17.5, 6.0 Hz), 3.38 (dd,
1H, J = 17.5, 7.0 Hz).
°
one (3b): Mp: 188ꢀ191 C. FTꢀIR (KBr, cmꢀ1): νmax 3043, 2927,
1
2790, 1760, 1674, 1605, 1445, 1294, 1088, 972, 826, 760. H
NMR(400 MHz, CDCl3): δ 7.89ꢀ7.94 (m, 3H), 7.65ꢀ7.68 (m, 1H),
7.49ꢀ7.59 (m, 2H), 7.27ꢀ7.40 (m, 2H), 6.20 (t, 1H, J = 6.4 Hz),
6
| Journal Name, [year], [vol], 00–00
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RSC Advances
Page 8 of 9
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DOI: 10.1039/C4RA14112A
The authors are grateful to the Research Council of the University
of Isfahan for financial support of this work.
3-[2-(4-Chlorophenyl)-2-oxo-ethyl]isobenzofuran-1(3H)-one
°
°
(3j): Mp: 144ꢀ146 C (Ref.44 146 C). FTꢀIR (KBr, cmꢀ1): νmax
1
3070, 2924, 1753, 1680, 1590, 1217, 1085, 988, 821. H NMR
60 Notes and references
(500 MHz, CDCl3): δ 7.89ꢀ7.92 (m, 3H), 7.67 (t, 1H, J = 7.5 Hz),
7.54ꢀ7.57 (m, 2H), 7.46 (d, 2H, J = 8.6 Hz), 6.16 (t, 1H, J = 6.5
Hz), 3.73 (dd, 1H, J = 17.5, 6.0 Hz), 3.38 (dd, 1H, J = 17.5, 7.0
Hz).
5
1. S. Chowdhury, R. S. Mohan and J. L. Scott, Tetrahedron, 2007, 63,
2363ꢀ2389.
2. T. L. Greaves and C. J. Drummond, Chem. Rev., 2008, 108, 206ꢀ237.
3. W. Miao and T.H. Chan, Acc. Chem. Res., 2006, 39, 897ꢀ908.
65 4. H. Li, P. S. Bhadury, B. Song and S. Yang, RSC Adv., 2012, 2,
12525ꢀ12551.
3-[2-(4-Bromophenyl)-2-oxo-ethyl]isobenzofuran-1(3H)-one
(3k): Mp: 146ꢀ148 °C. FTꢀIR (KBr, cmꢀ1): νmax 3040, 2965, 1760,
1
10 1681, 1583, 1405, 1290, 1215, 965, 756. H NMR (500 MHz,
CDCl3): δ 7.92 (d, 1H, J = 7.8 Hz), 7.81ꢀ7.83 (m, 2H), 7.66ꢀ7.69
(m, 1H), 7.62ꢀ7.64 (m, 2H), 7.54ꢀ7.57 (m, 2H), 6.16 (t, 1H, J =
6.5 Hz), 3.72 (dd, 1H, J = 17.5, 6.0 Hz), 3.37 (dd, 1H, J = 17.5,
7.0 Hz).
5. C. DeCastro, E. Sauvage, M. Valkenberg and W. Hölderich, J.
Catal., 2000, 196, 86ꢀ94.
6. B. Gadenne, P. Hesemann and J. J. Moreau, Chem. Commun., 2004,
70
1768ꢀ1769.
7. N. E. Leadbeater and M. Marco, Chem. Rev., 2002, 102, 3217ꢀ3274.
8. K. B. Sidhpuria, A. L. DanielꢀdaꢀSilva, T. Trindade and J. A.
Coutinho, Green Chem., 2011, 13, 340ꢀ349.
9. Y.Yang, C.Deng and Y. Yuan, J. Catal., 2005, 232, 108–116.
75 10. Y. Yang, H. Lin, C. Deng, J. She and Y. Yuan, Chem. Lett., 2005,
15 3-[2-(4-Iodophenyl)-2-oxo-ethyl]isobenzofuran-1(3H)-one
°
(3l): Mp: 174ꢀ175 C. FTꢀIR (KBr, cmꢀ1): νmax 3085, 2903, 1758,
1
1678, 1457, 1295, 1076, 987, 765. H NMR (500 MHz, CDCl3):
34, 220ꢀ221.
δ 7.93(d, 1H J = 7.7 Hz), 7.86ꢀ7.88 (m, 2H), 7.66ꢀ7.70 (m, 3H),
7.57 (t, 2H, J = 7.0 Hz), 6.16 (t, 1H, J = 6.3 Hz), 3.72 (dd, 1H, J
20 = 17.6, 5.8 Hz), 3.37 (dd, 1H, J = 17.6, 6.8 Hz). 13C NMR (125
MHz, CDCl3): δ 195.3, 170.0, 149.6, 138.2, 135.5, 134.3, 129.5,
129.4, 125.9, 122.7, 102.1, 76.9, 74.0, 43.6.
11. L. Babes, B. t. Denizot, G. Tanguy, J. J. Le Jeune and P. Jallet, J.
Colloid Interface Sci., 1999, 212, 474ꢀ482.
12. S. GomezꢀLopera, R. Plaza and A. Delgado, J. Colloid Interface Sci.,
80
2001, 240, 40ꢀ47.
13. A. Jordan, R. Scholz, P. Wust, H. Fähling and R. Felix, J. Magn.
Magn. Mater., 1999, 201, 413ꢀ419.
14. H. P. Khng, D. Cunliffe, S. Davies, N. A. Turner and E. N. Vulfson,
Biotechnol. Bioeng., 1998, 60, 419ꢀ424.
85 15. R. AbuꢀReziq, H. Alper, D. Wang and M. L. Post, J. Am. Chem. Soc.,
2006, 128, 5279ꢀ5282.
16. A. Hu, G. T. Yee and W. Lin, J. Am. Chem. Soc., 2005, 127, 12486ꢀ
12487.
3-(2-Oxo-2-thiophen-2-yl-ethyl)isobenzofuran-1(3H)-one
°
(3m): Mp: 132ꢀ135 C. FTꢀIR (KBr, cmꢀ1): νmax 3084, 2926,
1
25 1767, 1654, 1519, 1291, 1067, 855, 754. H NMR (400 MHz,
CDCl3): δ 7.94 (d, 1H, J = 7.6 Hz), 7.67ꢀ7.72 (m, 3H), 7ꢀ55ꢀ7.60
(m, 2H), 7.17 (s, 1H), 6.17 (t, 1H, J = 6.4 Hz), 3.70 (dd, 1H, J =
16.6, 6.0 Hz), 3.35 (dd, 1H, J = 16.8, 6.8 Hz). 13C NMR (100
MHz, Acetoneꢀd6): δ 189.7, 170.4, 150.8, 144.8, 135.6, 135.0,
30 134.3, 130.2, 129.4, 127.0, 125.9, 123.7, 77.8, 44.3.
17. D. Lee, J. Lee, H. Lee, S. Jin, T. Hyeon and B. M. Kim, Adv. Synth.
90
Catal., 2006, 348, 41ꢀ46.
18. N. T. Phan and C. W. Jones, J. Mol. Catal. A: Chem., 2006, 253,
123ꢀ131.
3-[2-Oxo-2-(pyridine-4-yl)ethyl]isobenzofuran-1(3H)-one
(3n): Mp: 168ꢀ170 °C. FTꢀIR (KBr, cmꢀ1): νmax 3071, 2959, 2928,
2859, 1770, 1730, 1600, 1465, 1352, 1285, 1125, 1070, 916, 747.
1H NMR (500 MHz, CDCl3): δ 8.82ꢀ8.83 (m, 2H), 7.90 (d, 1H, J
35 = 7.6 Hz), 7.66ꢀ7.73 (m, 3H), 7.54ꢀ7.57 (m, 2H), 6.14 (t, 1H, J =
5.0 Hz), 3.74 (dd, 1H, J = 17.9, 6.3 Hz), 3.43 (dd, 1H, J = 17.9,
6.5 Hz). 13C NMR (125MHz, CDCl3): δ 195.7, 169.9, 151.2,
149.2, 141.8, 134.4, 128.7, 125.9, 125.8, 122.7, 120.9, 76.5, 43.9.
3-[2-(4-Acetylphenyl)-2-oxo-ethyl]isobenzofuran-1(3H)-one
40 (5a): Mp: 135ꢀ137 °C. FTꢀIR (KBr, cmꢀ1): νmax 2923, 1758, 1679,
1608, 1403, 1358, 1215, 970, 829, 755. 1H NMR (400 MHz,
CDCl3): δ 7.60ꢀ7.65 (m, 4H), 7.50 (dd, 2H, J = 7.0, 2.2 Hz), 7.45ꢀ
7.48 (m, 2H), 6.11 (t, 1H, J = 6.4 Hz), 3.72 (dd, 1H, J = 17.6, 6.0
Hz), 3.37 (dd, 1H, J = 17.6, 6.8 Hz), 2.59 (s, 3H). 13C NMR (100
45 MHz, DMSOꢀd6): δ 196.7, 196.3, 169.7, 149.7, 139.4, 134.3,
129.3, 128.5, 125.4, 124.9, 123.5, 122.8, 122.3, 76.9, 43.1, 27.0.
3,3'-(1,4-Phenylenebis(2-oxoethane-2,1-
19. P. D. Stevens, J. Fan, H. M. Gardimalla, M. Yen and Y. Gao, Org.
Lett., 2005, 7, 2085ꢀ2088.
95 20. T.ꢀJ. Yoon, W. Lee, Y.ꢀS. Oh and J.ꢀK. Lee, New J. Chem., 2003, 27,
227ꢀ229.
21. Y. Zheng, P. D. Stevens and Y. Gao, J. Org. Chem., 2006, 71, 537ꢀ
542.
22. R. AbuꢀReziq, D. Wang, M. Post and H. Alper, Chem. Mater., 2008,
100
20, 2544ꢀ2550.
23. L. M. Rossi, L. L. Vono, F. P. Silva, P. K. Kiyohara, E. L. Duarte and
J. R. Matos, Appl. Catal. A: Gen., 2007, 330, 139ꢀ144.
24. S. Shylesh, V. Schünemann and W. R. Thiel, Angew. Chem. Int. Ed.,
2010, 49, 3428ꢀ3459.
105 25. S. Shylesh, J. Schweizer, S. Demeshko, V. Schünemann, S. Ernst and
W. R. Thiel, Adv. Synth. Catal., 2009, 351, 1789ꢀ1795.
26. V. Polshettiwar, R. Luque, A. Fihri, H. Zhu, M. Bouhrara and J.ꢀM.
Basset, Chem. Rev., 2011, 111, 3036ꢀ3075.
27. T. Hara, T. Kaneta, K.Mori, T. Mitsudome, T. Mizugaki, K. Ebitani,
110
and K. Kaneda, Green Chem., 2007, 9, 1246ꢀ1251.
28. D. m. Lai, L. Deng, J. Li, B. Liao, Q. x. Guo and Y. Fu,
ChemSusChem, 2011, 4, 55ꢀ58.
29. E. Rafiee and S. Eavani, Green Chem., 2011, 13, 2116ꢀ2122.
30. H. Yang, Y. Wang, Y. Qin, Y. Chong, Q. Yang, G. Li, L. Zhang and
W. Li, Green Chem., 2011, 13, 1352ꢀ1361.
31. X. Zheng, S. Luo, L. Zhang and J.ꢀP. Cheng, Green Chem., 2009, 11,
455ꢀ458.
32. A. Arnone, G. Assante, G. Nasini, S. Strada and A. Vercesi, . Nat.
Prod., 2002, 65, 48ꢀ50.
diyl))bis(isobenzofuran-1(3H)-one (5b): Mp: 273ꢀ275 °C. FTꢀIR
(KBr, cmꢀ1) νmax 3094, 1756, 1676, 1294, 1223, 1087, 969, 759,
1
115
50 690. H NMR (400 MHz, DMSOꢀd6): δ 8.08ꢀ8.18 (m, 4H), 7.86ꢀ
7.94 (m, 3H), 7.75ꢀ7.83 (m, 4H), 7.61ꢀ7.69 (m, 1H), 6.14 (dd,
2H, J = 7.8, 3.8 Hz), 3.95 (dd, 2H, J = 18.4, 3.8 Hz), 3.81 (dd,
2H, J = 18.4, 8.4 Hz). 13C NMR (100 MHz, DMSOꢀd6): δ 206.5,
196.4, 139.8, 138.4, 134.3, 129.3, 124.9, 122.9, 119.1, 117.4,
55 76.9, 30.6.
120 33. P. Kulanthaivel, Y. F. Hallock, C. Boros, S. M. Hamilton, W. P.
Janzen, L. M. Ballas, C. R. Loomis, J. B. Jiang and B. Katz, J. Am.
Chem. Soc., 1993, 115, 6452ꢀ6453.
34. G. Lin, S. S.ꢀK. Chan, H.ꢀS. Chung and S.ꢀL. Li, Stud. Nat. Prod.
Chem., 2005, 32, 611ꢀ669.
Acknowledgements
125 35. J. E. Baldwin and K. W. Bair, Tetrahedron Lett., 1978, 19, 2559ꢀ
2562.
This journal is © The Royal Society of Chemistry [year]
Journal Name, [year], [vol], 00–00 | 7

Page 9 of 9
RSC Advances
View Article Online
DOI: 10.1039/C4RA14112A
36. K. Kim, M. Spatz and F. Johnson, Tetrahedron Lett., 1979, 20, 331ꢀ
334.
37. N. Narasimhan and R. Mali, Synthesis, 1975, 12, 796ꢀ797.
38. S. F. Brady, M. M. Wagenaar, M. P. Singh, J. E. Janso and J. Clardy,
Org. Lett., 2000, 2, 4043ꢀ4046.
5
39. K. Yoganathan, C. Rossant, S. Ng, Y. Huang, M. S. Butler and A. D.
Buss, J. Nat. Prod., 2003, 66, 1116ꢀ1117.
40. Y. Ogawa, K. Hosaka, K. Kubota and M. Chin, Chem. Abstra., 1992,
117, 69721.
10 41. H. Sato, H. Yorozu and S. Yamaoka, Biomed. Res., 1993, 14, 385ꢀ
390.
42. X. Yang, T. Rotter, C. Piazza and P. Knochel, Org. Lett., 2003, 5,
1229ꢀ1231.
43. R. Karmakar, P. Pahari and D. Mal, Chem. Rev. 2014, 114, 6213ꢀ
15
6284.
44. M. V. Paradkar, S. Y. Gadre, T. A. Pujari, P. P. Khandekar and V. B.
Kumbhar, Synth. Commun., 2005, 35, 471ꢀ474.
45. R. Rendy, Y. Zhang, A. McElrea, A. Gomez and D. A. Klumpp, J.
Org. Chem., 2004, 69, 2340ꢀ2347.
20 46. S. M. Landge, M. Berryman and B. Toeroek, Tetrahedron Lett.,
2008, 49, 4505ꢀ4508.
47. D. C. Pinto, A. Silva, J. A. Cavaleiro and J. Elguero, Eur. J. Org.
Chem., 2003, 747ꢀ755.
48. E. W. Bousquet, M. D. Moran, J. Harmon, A. L. Johnson and J. C.
25
Summers, J. Org. Chem., 1975, 40, 2208ꢀ2211.
49. D. Villemin, N. Cheikh, B. MostefaꢀKara, N. Bar, N. Choukchouꢀ
Braham and M. A. Didi, Tetrahedron Lett., 2006, 47, 5519ꢀ5521.
50. M. M. Heravi, V. Rasmi, F. F. Bamoharram, S. Sadjadi, L. Fotouhi,
S. Sadjadi and M. Bakavoli, Synth. Commun., 2009, 39, 4109ꢀ4116.
30 51. J. N. Sangshetti, S. A. M. Ansari and D. B. Shinde, Chin. Chem.
Lett., 2011, 22, 163ꢀ166.
52. S. Anvar, I. MohammadpoorꢀBaltork, S. Tangestaninejad, M.
Moghadam, V. Mirkhani, A. R. Khosropour, A. Landarani Isfahani
and R. Kia, ACS comb. Sci., 2014, 16, 93ꢀ100.
35 53. M. Ghotbinejad, A. R. Khosropour, I. MohammadpoorꢀBaltork, M.
Moghadam, S. Tangestaninejad and V. Mirkhani, J. Mol. Catal. A:
Chem., 2014, 385, 78ꢀ84.
54. A. Landarani Isfahani, I. Mohammadpoor‐Baltork, V. Mirkhani, A.
R. Khosropour, M. Moghadam, S. Tangestaninejad and R. Kia, Adv.
40
Synth. Catal., 2013, 355, 957ꢀ972.
55. I. Mohammadpoor‐Baltork, A. R. Khosropour, M. Moghadam, S.
Tangestaninejad, V. Mirkhani, M. Soltani and A. Mirjafari, J.
Heterocycl. Chem., 2011, 48, 1419ꢀ1427.
56. M. NasrꢀEsfahani, I. MohammadpoorꢀBaltork, A. R. Khosropour, M.
Moghadam, V. Mirkhani, S. Tangestaninejad and H. Amiri Rudbari,
J. Org. Chem., 2014, 79, 1437ꢀ1443.
45
57. S. Safaei, I. MohammadpoorꢀBaltork, A. R. Khosropour, M.
Moghadam, S. Tangestaninejad, V. Mirkhani and R. Kia, RSC Adv.,
2012, 2, 5610ꢀ5616.
50 58. A. Bee, R. Massart and S. Neveu, J. Magn. Magn. Mater., 1995, 149,
6ꢀ9.
59. Y. P. M. Shokouhimehr, J. Kim, Y. Jang and T. Hyeon, Angew.
Chem., Int. Ed., 2007, 46, 7039ꢀ7043.
60. J. Lee, Y. Lee, J. K. Youn, H. B. Na, T. Yu, H. Kim, S. M. Lee, Y.
55
M. Koo, J. H. Kwak and H. G. Park, Small, 2008, 4, 143ꢀ152.
61. X. Wang, P. Dou, P. Zhao, C. Zhao, Y. Ding and P. Xu,
ChemSusChem, 2009, 2, 947ꢀ950.
8
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This journal is © The Royal Society of Chemistry [year]