DABA MNPs: A new and efficient magnetic bifunctional nanocatalyst for the green synthesis of biologically active pyrano[2,3-: C] pyrazole and benzylpyrazolyl coumarin derivatives

Article abstract of DOI:10.1039/d0nj02666b

In this work, a new core-shell magnetic silica nanocatalyst functionalized with 3,4-diaminobenzoic acid (Fe3O4@SiO2@PTS-DABA) was successfully prepared and characterized using different spectroscopic methods or techniques including FT-IR, FE-SEM, VSM, XRD

Full text of DOI:10.1039/d0nj02666b

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DABA MNPs: a new and efficient magnetic bifunctional
nanocatalyst for green synthesis of biologically active pyrano[2,3-
c]pyrazole and benzylpyrazolyl coumarin derivatives
Received 00th January 20xx,
Accepted 00th January 20xx
DOI: 10.1039/x0xx00000x
Shahriar Karami, Mohammad G. Dekamin,* Ehsan Valiey and Peyman Shakib
www.rsc.org/
In this work, a new core-shell magnetic silica functionalized with 3,4-diaminobenzoic acid nanocatalyst (Fe3O4@SiO2@PTS-
DABA) was successfully prepared and characterized using different spectroscopic methods or techniques including FT-IR, FE-
SEM, VSM, XRD, EDS and TGA. The Fe3O4@SiO2@PTS-DABA catalyst was applied, as a magnetic recoverable catalyst, for the
synthesis of biologically active dihydropyranopyrazole and benzylpyrazolyl coumarin derivatives. These derivatives were
prepared in the presence of Fe3O4@SiO2@PTS-DABA via a four-component reaction with yields of more than 90% under
mild conditions. The Fe3O4@SiO2@PTS-DABA nanocatalyst is easily prepared from commercially available, lower toxicity and
thermally stable precursors through a cost-effective, highly efficient and environmentally friendly procedure. It shows a long
life and can be reused for several catalytic cycles without significant loss of the catalytic activity. Finally, a possible
mechanism is proposed for preparation of dihydropyranopyrazole and benzylpyrazolyl coumarin derivatives in the presence
of Fe3O4@SiO2@PTS-DABA multifunctional magnetic catalyst. The structure of the products were identified by melting point
as well as FT-IR and 1H NMR spectroscopic methods.
specially by silicon reagents bearing organic bridges and appropriate
functional groups for next modifications.13, 14 Indeed, the organic
functional groups can be replaced or altered by more complex
organic molecules bearing two or more functional groups.
Subsequently, the surface polarity of the modified magnetic core-
shell catalysts by organic molecules is tuned for promoting of
different organic transformations, especially multi-component
reactions (MCRs).15-19
1. Introduction
The heterogeneous catalysts play a key role in the development of
inexpensive and environmentally friendly protocols in organic
synthesis.1 The major advantage of these catalysts is the ability to
recycle and reuse catalytic materials compared to other organic or
inorganic homogeneous catalysts.2 The main characteristic and
advantages of heterogeneous catalysts compared to homogeneous
ones is high surface area, simple control, low toxicity, easy separation
and thermal stability as well as producing the desired products and
preventing of by-products formation.3-6 In this regard, magnetic
catalysts are appropriate candidates for the synthesis of organic
compounds according to green and sustainable chemistry principles.
Recently, the stabilization of active catalytic centres or organic
functional groups on the magnetic materials including Fe3O4,
CoFe2O4, CuFe2O4, NiFe2O4, etc has attracted much attention due to
synergistic effects and heat induction through the reaction mixture
as well as easy and good separation in the presence of an external
magnetic field.7-11 Among different magnetic materials, Fe3O4
nanoparticles (NPs) demonstrate better magnetization properties.
However, their reactivity, especially in an acidic environment, is
higher than other magnetic materials. Therefore, they lose their
magnetic properties faster. Usually, silica is used, as a protective
coating shell, for Fe3O4 NPs.12 Furthermore, the silica shell can
prevent Fe3O4 NPs from aggregation as well as high concentration of
Si‒OH groups on the surface of silica allows its further modification
Multi-component reactions (MCRs) are one-pot reactions in
which three or more substrates are combined in order to afford the
target molecules without the need to Intermediates separation.
Major features of the MCRs are high atom economy, environmental
friendliness, simplicity, efficiency and high selectivity as well as the
effective formation of several bonds that have been widely used in
organic chemistry and pharmaceutical chemistry.20, 21 One of the
important intermediates in different MCRs is the formation of
Knoevenagel condensation intermediate as an appropriate Michael
acceptor.22-27 The Knoevenagel condensation is usually less tolerated
under conditions that are compatible with aquatic mediums.28, 29
Indeed, MCRs require acidic, basic or bifunctional catalytic systems
for completion. Therefore, designing of more efficient
heterogeneous catalyst is still in high demand. In continuation of our
interest to develop efficient and environmental friendly
heterogeneous catalysts for different MCRs, herein we wish to report
designing, preparation and characterization of the core-shell
magnetic silica functionalized with 3,4-diaminobenzoic acid
nanocatalyst (Fe3O4@SiO2@PTS-DABA) for the first time. The
Fe3O4@SiO2@PTS-DABA was used as
a green and effective
a. Pharmaceutical and Heterocyclic Compounds Research Laboratory Department of
Chemistry Iran University of Science and Technology. Email: mdekamin@iust.ac.ir
†Electronic Supplementary Information (ESI) available: [details of any
supplementary information available should be included here]. See
DOI: 10.1039/x0xx00000x
bifunctional nanocatalyst for synthesis of the biologically active
dihydropyrano[2,3-c]pyrazole and benzylpyrazolyl coumarin
derivatives through one-pot four-component reactions (Scheme 1).
This journal is © The Royal Society of Chemistry 2020
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Scheme 1. Synthesis of pyrano[2,3-c]pyrazole 5 and benzylpyrazolyl
coumarin 7 derivatives catalyzed by Fe3O4@SiO2@PTS-DABA.
Surprisingly, heterocyclic compounds containing pyrazolone or
coumarin scaffolds demonstrate analgesic, antidepressant (Fig. 1,
Part A) as well as long-acting oral anticoagulant activities (Fig. 1, Part
B), respectively. Commercial examples include phenazone,
propyphenazone, ampyrome, metamizole, edaravone, warfarin,
phenprocoumon, coumatetralyl and bromadialone. In order to
prepare these compounds, homogeneous or heterogeneous
catalytic systems have been reported.30, 31 Recent examples include
L-proline,32 piperidine,33 basic ionic liquids,34 melamine-modified
chitosan,35 β-Cyclodextrin nanosponge polymer,36 glacial AcOH,31
[pmIm]Br,37 nano-SiO2 from wheat straw.38 Although each of these
protocols for the synthesis of these biologically active compounds
has its advantages but some of them suffer from disadvantages
including toxic, expensive or odorous catalysts and solvents,
significant difficulties for the large-scale application of the
introduced catalysts, troublesome waste discarding, and long
reaction times affording moderate yields. To address the above
concerns, we wish herein to report a green and effective method for
the synthesis of biologically active dihydropyrano[2,3-c]pyrazole and
benzylpyrazolyl coumarin derivatives through a one-pot four-
component reaction catalyzed by a recyclable and environmentally
friendly magnetic core-shell nanocatalyst of Fe3O4@SiO2@Pr-DABA
(Scheme 1). The magnetic core-shell nanocatalyst is able to provide
Fig. 1 Some of the commercial biologically active pyrazolone (A) and
coumarin (B) derivatives.
2.1.1. FT-IR spectra of the Fe3O4@SiO2@Pr-DABA catalyst
The FT-IR spectra of the Fe3O4, Fe3O4@SiO2, Fe3O4@SiO2@CPTS and
Fe3O4@SiO2@PTS-DABA are shown in Fig. 2. The absorption bands at
about 440 cm-1 are related to Fe‒O bending vibrations. On the other
hand, the 572 cm-1 absorption band is related to Fe—O bond
stretching vibrations and absorbance bands with the centres of 1558
and 3394 cm-1 are related to bending vibrations of the adsorbed
water molecules on the Fe3O4 NPs. The absorption bands at about
800 and 1085 cm-1 are attributed to the symmetric and asymmetric
stretching vibrations of Si—O—Si, respectively (Fig. 2b). The strong
absorption bands observed at about 588 and 1070 cm-1 are related
to C—Cl and C—O bond vibrations, respectively that overlaps with
the asymmetric stretching vibrations of the Si—O—Si bonds (Fig. 2c).
The FT-IR spectroscopy of Fe3O4@SiO2@PTS-DABA shows absorption
bands at about 3300-3600 cm-1 related to the stretching vibrations
of both O—H and N—H bonds. It is also worth noting that scissoring
vibrations appears at about 1500 cm-1 which is related to aromatic
secondary amines and interferes with stretching vibrations of
aromatic C=C bonds. Furthermore, the absorption bands observed at
about 1386 cm-1 related to C—N bond. On the other hand, the
absorption band at about 1658 cm-1 is related to the carbonyl group
of DABA component. Indeed, disappearance of the C—Cl bond at 588
cm-1 confirms functionalization of the surface of Fe3O4@SiO2@PTS-
DABA with DABA moiety (Fig. 2d).
o
the desired products with high efficiency and selectivity at 70 C in
EtOH, as a green solvent, over a short period of time reaction. In
addition, the aforementioned catalyst can be recycled at least six
times without significant loss of catalytic activity and used in the
subsequent cycles of the reaction. At the end, a reaction mechanism
has been proposed to prepare these biologically active derivatives.
2. Results and discussion
2.1. Analysis and characterization of core-shell magnetic silica
functionalized with 3,4-diaminobenzoic acid catalyst
After preparation of the Fe3O4@SiO2@PTS-DABA nanocatalyst, it
was properly characterized using Fourier transform infrared (FT-IR)
spectroscopy, field emission scanning electron microscopy (FESEM),
vibrating sample magnetometer (VSM), X-ray diffraction
spectroscopy (XRD), energy-dispersive X-ray spectroscopy (EDS) and
thermogravimetric analysis (TGA) at first. The structure of the core-
shell magnetic silica functionalized with 3,4-diaminobenzoic acid
(Fe3O4@SiO2@Pr-DABA) has been illustrated in the experimental
section (Scheme 3).
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2.1.3. Vibrating sample magnetometer (VSM) analysis of the
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Fe3O4@SiO2@PTS-DABA catalyst
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The magnetic properties of Fe3O4, Fe3O4@SiO2 and
Fe3O4@SiO2@PTS-DABA nanoparticles were determined by VSM
technique at room temperature (Fig. 4). The values of magnetization
saturation for Fe3O4, Fe3O4@SiO2 and Fe3O4@SiO2@PTS-DABA were
82, 76 and 64 emu.g-1, respectively. Reduction the values of
magnetization saturation for Fe3O4@SiO2 and Fe3O4@SiO2@PTS-
DABA compared with the bare Fe3O4 indicates formation of the thick
layer silica and modification of its surface with propylene
trialkoxysilane and 3,4-diaminobenzoic acid groups in the next steps.
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Fig.
2 The FT-IR spectra of (a) Fe3O4, (b) Fe3O4@SiO2, (c)
Fe3O4@SiO2@CPTS, (d) Fe3O4@SiO2@PTS-DABA.
100
50
0
2.1.2. Field emission scanning electron microscopy (FESEM)
analysis of the Fe3O4@SiO2@Pr-DABA catalyst
The surface morphology and size of the Fe3O4@SiO2@Pr-DABA
nanocatalyst were evaluated using FESEM analysis (Fig. 3). According
to the obtained FESEM images, the shape of the nanocatalyst
particles is mostly spherical with non-smooth surfaces which
increases its surface areas and activity. The FESEM images of the
Fe3O4@SiO2@PTS-DABA catalyst displayed that particles are
uniformly distributed and the sizes of the NPs are at range of 29 - 76
nm. It should be noted that porous structure as well as nano-wires
are formed. This phenomenon may be due to the relatively unusual
reaction conditions created by ultrasonic waves. These waves cause
very high temperatures and pressures in a short time that cannot be
realized in other traditional energy sources.39
-5000
-3000
-1000
1000
3000
5000
-50
-100
Applied Field (Oe)
Fig. 4 Magnetization curves of the (black) Fe3O4, (red) Fe3O4@SiO2,
(green) Fe3O4@SiO2@PTS-DABA.
2.1.4. Energy-dispersive X-ray spectroscopy (EDS) of the
Fe3O4@SiO2@PTS-DABA catalyst
The composition of the Fe3O4@SiO2@PTS-DABA nanocatalyst was
analysed using EDS (Fig. 5). According to the obtained results, the
component of this catalyst included Fe, Si, O, C and N atoms.
Furthermore, the absence of Cl atom shows that it has been
completely replaced by 3,4-diaminobenzoic acid to afford the
Fe3O4@SiO2@PTS-DABA hybrid catalyst.
Fig. 5 EDS of the Fe3O4@SiO2@PTS-DABA catalyst.
2.1.5. X-Ray diffraction (XRD) pattern of the Fe3O4@SiO2@PTS-
DABA catalyst
The XRD pattern of the hybrid organosilica nanocatalyst is presented
in Fig. 6. As shown in this Fig., the standard patterns of Fe3O4 (card
no. JCPDS, 01-088-0315), Fe3O4@SiO2 (card no. JCPDS, 01-082-1572)
Fig. 3. FESEM images of the Fe3O4@SiO2@PTS-DABA catalyst.
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and 3,4-diaminobenzoic acid (card no. JCPDS, 00-037-1947) with the
Fe3O4@SiO2@PTS-DABA nanocatalyst are perfectly matched.
Diffraction signals (2θ) at 8° and 30° are related to 3,4-
diaminobenzoic acid that proved its fixation onto the silica coated
magnetic NPs.
desired pyrano[2,3-c]pyrazole derivative 6a was obtained after 35
minutes (entry 3, Table 1). On the other hand, the yield of desired
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DOI: 10.1039/D0NJ02666B
product 6a decreased to 37% under solvent-free conditions at the
same catalyst loading and reaction time (entry 4, Table 1).
Furthermore, when the model reaction was carried out at room
temperature, only 32% yield for the pyrano[2,3-c]pyrazole derivative
6a was obtained after 40 minutes (entry 5, Table 1). All of these
results indicate that the presence of the magnetic Fe3O4@SiO2@PTS-
DABA catalyst, solvent and heating are necessary for the model
reaction to proceed efficiently.
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(a)
Fig. 6 XRD pattern of the Fe3O4@SiO2@PTS-DABA catalyst.
2.1.6. Thermogravimetric analysis (TGA) and differential thermal
analysis (DTA) of the Fe3O4@SiO2@PTS-DABA catalyst
To investigate the thermal stability of the Fe3O4@SiO2@PTS-DABA,
its thermogravimetric analysis (TGA) was carried out under N2
atmosphere varying from 50 to 1000 oC. The total weight loss of the
nanocatalyst was around 14% (Fig. 7a). The first weight loss at about
100 oC is related to the physically adsorbed water or residual organic
solvents in the prepared nanocatalyst. At higher temperatures above
150 oC as well as 470 to 600 oC organic components and silica coating
are decomposed or dehydrated, respectively. The slight weight loss
at temperatures higher than 600 oC is related to dehydratation of the
magnetic component. These findings were also confirmed by
differential thermal analysis (DTA) results (Fig. 7b). Indeed, thermal
decomposition and chemical reactions appear as broad peaks while
crystalline deformation and melting show themselves as sharp
peaks.
(b)
Fig. 7. (a) TGA and (b) DTA curves of the Fe3O4@SiO2@PTS-DABA
catalyst.
2.2. Optimization of the reaction conditions using the
Fe3O4@SiO2@PTS-DABA catalyst
The efficiency of the Fe3O4@SiO2@PTS-DABA nanocatalyst for
the model reaction was also investigated in water and it was found
that 40% of the desired product 6a was obtained after 35 minutes
(entry 6, Table 1). Subsequently, the progress of the model reaction
was studied in other solvents such as dimethylformamide (DMF) or
tetrahydrofuran (THF). It was found that polar-protic solvents such
as EtOH and water are suitable for this reaction (entries 8 and 7,
Table 1). In addition, the effect of a mixture of EtOH-water solvent
on the rate of model reaction was examined (entries 9-11, Table 1).
The obtained results showed that the best solvent for this reaction is
EtOH. On the other hand, the model reaction in the presence of
Fe3O4 or Fe3O4@SiO2 MNPs afforded moderate yield of the desired
(entries 12 and 13, Table 1). Finally, the model reaction with different
catalyst loading was investigated in EtOH (entries 14-16, Table 1),
which among them 10 mg of catalyst had the best performance
(entry 14, Table 1). In general, synthesis of 6a is achieved at 10 mg of
nanocatalyst loading with excellent yield in EtOH media within 23
In order to optimize the reaction conditions and performance
evaluation of the Fe3O4@SiO2@PTS-DABA nanocatalyst for the
synthesis of pyranopyrazole derivatives, a four-component reaction
of ethyl acetoacetate (1), hydrazine hydrate (2), 4-
chlorobenzaldehyde (3a) and malononitrile (4) was considered as the
model reaction. As shown in Table 1, when the reaction is carried out
in the absence of a catalyst in H2O, as a solvent, the desired product
was not observed after 8 h under reflux conditions (entry 1, Table 1).
However, when the solvent was changed to EtOH, a trace amount of
the
desired
6-amino-4-(4-chlorophenyl)-3-methyl-1,4-
dihydropyrano[2,3-c]pyrazole-5-carbonitrile (6a) was produced at 70
oC and the same time (entry 2, Table 1). Interestingly, in the presence
of 5 mg loading of the magnetic catalyst in EtOH, a 82% yield of the
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min, which is considered as the optimized conditions for the model Table 2. Synthesis of different pyrano[2,3-c]pyrazole derivatives
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a
reaction (entry 14, Table 1).
DOI: 10.1039/D0NJ02666B
using Fe3O4@SiO2@PTS-DABA NPs as a catalyst
Table 1. Optimization of the reaction conditions for the synthesis
of 6aa
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Ent
ry
1
2
3
Aldehyde
3
4-Chlorobenzaldehyde
2-Chlorobenzaldehyde
Product
Time
(min)
23
26
23
Yield
(%)
92
91
91
Obs. m.p.
5
5a
5b
( ͦC) [Lit.]
233-23530
243-24540
Entry
catalyst
Solventb
Time(min)
Yieldc
(%)
-
2,4-
5c
229-23140
Dichlorobenzaldehyde
3-Nitrobenzaldehyde
4
5
5d
5e
28
21
89
90
213-21541
210-21242
1
2
3
-
-
H2O
EtOH
EtOH
480
240
35
4-
Trace
82
Methoxybenzaldehyde
Benzaldehyde
242-24443
209-21140
Fe3O4@SiO2@PTS-
DABA
6
7
5f
5g
23
21
88
91
4-
Methylbenzaldehyde
2-Nitrobenzaldehyde
4-Nitrobenzaldeyde
2-
8
9
10
5h
5i
5g
30
27
35
85
88
80
221-22344
230-23243
209-21145
4
5
Fe3O4@SiO2@PTS-
DABA
-
35
40
40
35
35
25
35
40
37
32d
35
25
28
77
73
71
Hydroxybenzaldehyde
Fe3O4@SiO2@PTS-
DABA
EtOH
H2O
THF
DMF
11
4-
5k
33
81
225-22744
Hydroxybenzaldehyde
3-Bromobenzaldehyde
4-Bromobenzaldehyde
12
13
14
5l
5m
5n
27
25
19
88
91
91
222-22446
180-18247
243-24548
6
Fe3O4@SiO2@PTS-
DABA
4-Flurobenzaldehyde
a
Reaction conditions: ethyl acetoacetate (1, 1 mmol), hydrazine hydrate (2,
1 mmol), 4-chlorobenzaldehyde (3a, 1 mmol), malononitrile (4, 1 mmol), and
catalyst (10 mg) in 3 mL EtOH with continuous stirring at 70 oC.
7
Fe3O4@SiO2@PTS-
DABA
8
Fe3O4@SiO2@PTS-
DABA
containing electron-donating or electron-withdrawing groups in the
presence of Fe3O4@SiO2@PTS-DABA nanocatalyst. The results are
summarized in Table 2. In all cases, the desired products were
obtained in excellent yields and short time.
9
Fe3O4@SiO2@PTS-
DABA
EtOH-H2O
(3:1)
10
11
Fe3O4@SiO2@PTS-
DABA
EtOH-H2O
(2:1)
The excellent performance of the prepared magnetic
heterogeneous nanocatalyst in the synthesis of pyrano[2,3-
c]pyrazole derivatives encouraged us to study its effect on the
synthesis of highly-functionalized biologically active benzylpyrazolyl
coumarin derivatives. It was found that the core-shell magnetic
nanocatalyst functionalized with 3,4-diaminobenzoic acid affords the
excellent yield of desired product 7a through one-pot four-
component reaction of ethyl acetoacetate (1), hydrazine hydrate (2),
benzaldehyde (3a) and 4-hydroxycomarin (6) under mild reaction
conditions. The obtained results for the synthesis of 4-((4-hydroxy-2-
oxo-2H-chromen-3-yl)(phenyl)methyl)-5-methyl-1,2-dihydro-3H-
pyrazol-3-one (7a) in the presence of Fe3O4@SiO2@PTS-DABA
nanocatalyst are shown in Table 3. The optimized conditions were
found to be 10 mg of Fe3O4@SiO2@PTS-DABA nanocatalyst loading
in EtOH-H2O (1:1) medium at 70 oC (entry 14, Table 3). Several
derivatives of the benzylpyrazolyl coumarin scaffold have been
prepared using the optimized reaction conditions and the results are
presented in Table 4.
Fe3O4@SiO2@PTS-
DABA
EtOH-H2O
(1:1)
e
Fe3O4
EtOH
EtOH
EtOH
12
13
14
90
35
23
58
65
92
e
Fe3O4@SiO2
Fe3O4@SiO2@PTS-
DABAf
15
16
Fe3O4@SiO2@PTS-
EtOH
EtOH
20
20
90
92
DABAg
Fe3O4@SiO2@PTS-
DABAh
a Reaction conditions: ethyl acetoacetate (1, 1 mmol), hydrazine hydrate
(2, 1 mmol), 4-chlorobenzaldehyde (3a, 1 mmol), malononitrile (4, 1
mmol), catalyst (5 mg) with continuous stirring at 70 oC . b 3 mL solvent. c
d
e
f
Isolated yield. Room temperature. 5 mg catalyst loading. 10 mg
catalyst loading. g 15 mg catalyst loading. h 20 mg catalyst loading.
After success in optimizing of the reaction conditions, we decided
to expand the catalyst performance scope under these conditions
(entry 14, Table 1). Accordingly, a number of pyrano[2,3-c]pyrazole
derivatives were prepared using various aromatic aldehydes
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Table 3. Optimization of the reaction condition for the synthesis of
benzylpyrazolyl coumarin 7aa
View Article Online
DOI: 10.1039/D0NJ02666B
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6
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Entry
catalyst
Solventb
Time(min)
Yieldc
(%)
-
10
56
d
1
2
3
-
-
EtOH
EtOH
480
310
35
Entry
Aldehyde
3
Product
7
Time
(min)
Yield
(%)
Obs.
m.p.
( ͦC)
Fe3O4@SiO2@PTS- EtOH
DABA
[Lit.]
4
Fe3O4@SiO2@PTS-
DABA
-
40
37
1
2
3
4
Benzaldehyde
7a
7b
7c
7d
30
38
35
31
91
89
89
86
231-
23349
4-Methylbenzaldehyde
4-Methoxybenzaldehyde
3-Nitrobenzaldehyde
227-
22950
5
Fe3O4@SiO2@PTS- H2O
DABA
40
60
60
60
40
45
45
35
30
25
25
82
85
78
229-
23135
6
Fe3O4@SiO2@PTS- DMF
DABA
204-
20650
7
Fe3O4@SiO2@PTS- THF
DABA
a Reaction conditions: ethyl acetoacetate (1, 1 mmol), hydrazine hydrate (2, 1
mmol), aldehyde derivatives (3, 1 mmol), 4-hydroxycoumarin (6, 1 mmol) and
catalyst (10 mg) in 3 mL EtOH-H2O (1:1) with continuous stirring at 70 oC.
8
Fe3O4@SiO2@PTS- DCM
DABA
9
Fe3O4@SiO2@PTS- EtOH-H2O
DABA
2.3. Mechanism of reaction
(1:1)
In according to the characteristics of the Fe3O4@SiO2@PTS-DABA
nanocatalyst and literature survey, a possible mechanism for the
synthesis of biologically active pyrano[2,3-c]pyrazol and benzyl
pyranopyrazole coumarin derivatives is shown in Scheme 2. At first,
a reaction occurs between activated ethyl acetoacetate (1) by the
multifunctional Fe3O4@SiO2@PTS-DABA nanocatalyst and hydrazine
hydrate (2) which the pyrazolone ring (a) is formed by the loss of H2O
and EtOH and subsequent tautomerization of intermediates (I) and
(II), respectively. In the following step, the aldehyde derivatives (3)
and malononitrile (4) are combined through the Knoevenagel
condensation catalyzed by the magnetic catalyst to afford the
intermediate (b) with loss of H2O through intermediate (III). Finally,
10
11
Fe3O4@SiO2@PTS- EtOH-H2O
(1:2)
DABA
Fe3O4@SiO2@PTS- EtOH-H2O
DABA
(1:3)
e
12
13
14
15
16
Fe3O4
EtOH-H2O
(1:1)
EtOH-H2O
(1:1)
90
40
31
25
30
51
60
90
85
90
e
Fe3O4@SiO2
Fe3O4@SiO2@PTS- EtOH-H2O
DABAf
(1:1)
Fe3O4@SiO2@PTS- EtOH-H2O
DABAg
(1:1)
Fe3O4@SiO2@PTS- EtOH-H2O
DABAh
(1:1)
the desired products
6 are formed from reaction between
intermediates (a) and (b) through Fe3O4@SiO2@PTS-DABA-catalyzed
Michael addition, 6-exo-dig cyclization, and tautomerization
between intermediates (a) and (b) to form corresponding
intermediates (V) and (VI), respectively. We predict that acidic and
basic sites on the catalyst surface facilitate the intramolecular
electrophilic cyclization by tautomerization (Part A). Moreover,
synthesis of biologically active benzylpyrazolyl coumarin derivatives
is promoted through multifunctional Fe3O4@SiO2@PTS-DABA-
catalyzed Knoevenagel condensation between 4-hydroxycoumarin
(6) and aldehyde derivatives (3) with the loss of H2O to form
intermediate(II), as a Michael acceptor, which reacts further with the
a Reaction conditions: ethyl acetoacetate (1, 1 mmol), hydrazine hydrate
(2, 1 mmol), 4-chlorobenzaldehyde (3a, 1 mmol), malononitrile (4, 1
mmol), catalyst (5 mg) with continuous stirring at 70 oC . b 3 mL solvent. c
d
e
f
Isolated yield. Room temperature. 5 mg catalyst loading. 10 mg
catalyst loading. g 15 mg catalyst loading. h 20 mg catalyst loading.
Table 4. Synthesis of some benzylpyrazolyl coumarins in the
poresence of Fe3O4@SiO2@PTS-DABA NPs as a catalysta
6 | New J. Chem., 2020, 44, 1-11
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pyrazolone ring (a) to afford the intermediate (IV). This intermediate
in turn gives the desired product (7) on tautomerization in the
presence of Fe3O4@SiO2@PTS-DABA nanocatalyst (Part B ).
View Article Online
DOI: 10.1039/D0NJ02666B
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Scheme 2. A proposed mechanism for the synthesis of pyrano[2,3-c]pyrazole 5 and benzylpyrazolyl coumarin 7 derivatives catalyzed by
Fe3O4@SiO2@PTS-DABA nanocatalyst.
The ability to recycle and reuse heterogeneous catalysts is very
important from green chemistry points of view. It is also an
important criterion for evaluating of the catalyst performance. In
order to investigate recovery of the prepared Fe3O4@SiO2@PTS-
2.4. Comparison of the catalytic activity of Fe3O4@SiO2@PTS-
DABA catalyst with other catalytic systems
In order to evaluate the catalytic activity and performance of the
DABA nanocatalyst in the model reactions, it was separated from the
Fe3O4@SiO2@PTS-DABA hybrid catalyst with previously reported
crude reaction products during their crystallization by an external
magnet for reusing in next runs. The recycled catalyst was washed
with EtOH two times and dried at 80 oC for 4 h and used for the next
run. It was found that the magnetic catalyst can be used at least six
times without significant loss of the catalytic activity (Fig. 8).
catalysts for the one-pot multi component, we compared the results
obtained for synthesis of 5a and 7a in Table 5. As seen in Table 5, all
catalysts are capable of producing the desired products in
satisfactory yields but they afforded lower yields than
Fe3O4@SiO2@PTS-DABA or required more reaction times. Therefore,
the present magnetic nanocatalyst is significantly effective in the
synthesis of these biologically active derivatives and could be the
best alternative to other reported catalysts.
Table 5. Comparative results of different catalytic systems for the
synthesis of 5a and 7a
2.5. Catalytic recovery capability
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coated with flourescent indicator F254 and visualizedVuieswinAgrtiUcleVOlniglihnet
at 254 nm and iodine vapour. The purity oDf OthI:e10p.1r0o3d9u/cDt0sNwJ0a2s6a6l6sBo
checked by TLC. Melting points were measured in open capillary
tubes using a BUCHI 510 apparatus. The crystalline structures of the
samples were evaluated by X-ray diffraction (XRD) analysis on a
bruker D8 Advance diffractometer with Cu Kα radiation at 40 kv and
20 mA. Fourier transform infrared (FT-IR) spectra were recorded as
KBr pellets on a Shimadzu FT IR-8400S spectrometer in the range of
400-4000 cm-1. Magnetization measurements were carried out on a
BHV-55 vibrating sample magnetometer (VSM). 1H NMR spectra
were recorded on a Bruker DRX-500 instrument at 500 MHz for
samples in DMSO-d6, as solvent, at ambient temperature. Energy-
Dispersive X-ray (EDS) analysis was carried out using a TESCAN Vega
model instrument. The morphology of the particles was observed by
field emission scanning electron microscopy (FESEM) under
acceleration voltage of 26 kV. The curves obtained from thermo-
gravimetric analysis (TGA) and differential thermal analysis (DTA)
analysis were recorded in air using a Bahr company STA 504
instrument.
4
5
6
7
8
9
Entry
Product
Catalyst
Reaction
conditions
Time
(min)
Yiel
d
(%)
Ref.
54
HDBAC (30
mol%)
EtOH, Reflux
H2O, Reflux
45
35
50
30
81
γ-Alumina (30
90
82
85
46
10
11
12
13
14
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16
17
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22
23
24
25
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59
60
mol%)
Trityl chloride
(10 mol%)
Solvent-Free,
60 oC
55
47
[(CH2)4SO3HMI
M][HSO4] (0.25
mmol)
RT
1
56
Sodium
benzoate (15
mol%)
Solvent-Free,
RT
60
92
(5a)
Fe3O4@SiO2@
Pr-DABA (10
mg)
Cs-Pr-Me (20
mg)
EtOH, 70 o
C
23
35
92
90
This
wor
k
35
EtOH-H2O,
Reflux
3.2. Preparation of the magnetic Fe3O4 nanoparticles (MNPs)
A mixture of FeCl3. 6H2O (5.84 g) and FeCl2. 4H2O (2.15 g) was heated
in 50 mL of deionized water at 80 oC for 20 min under nitrogen
atmosphere until an orange brown solution was formed. Then, 15
mL of aqueous NH3 (25%) was quickly added to the obtained mixture
glacial acetic
acid (10 mol%)
H2O, Reflux
35
30
91
91
31
2
Fe3O4@SiO2@
Pr-DABA (10
mg)
(7a)
o
EtOH-H2O, 70
oC
and it was vigorously stirred at 80 C for 2 h. The colour of the bulk
This
wor
k
solution turned from orange brown to black immediately. The
precipitated Fe3O4 NPs were separated with an external magnet and
washed with distilled water and EtOH three times until the pH value
reached the neutral position. Then, the obtained Fe3O4 NPs were
dried in a vacuum oven at 60 oC for 24 h.
92
92
91
91
90
88
90
87
100
80
60
40
20
0
85
87
86
84
3.3. Preparation of silica coated magnetic nanoparticles
(Fe3O4@SiO2, SCMNPs)
The silica-modification of the prepared Fe3O4 NPs were performed
using the well-known Stöber's method with a little modification.57 An
amount of 1 g of the prepared Fe3O4 was suspended in a mixture of
40 mL EtOH and 15 mL deionized water and sonication for 15 min
was carried out to maintain Proper dispersion. Then, tetraethyl
orthosilicate (TEOS, 1.3 mL) was added slowly to the mixture and
sonicated for another 10 min. After that, aqueous ammonia (1.2 mL)
was added slowly over 10 min under mechanical stirring. The
reaction was allowed to proceed at 45 oC for 12 h. After completion
of the reaction, the silica coated magnetic nanoparticles (SCMNPs)
were separated from the reaction mixture using an external magnet
and washed several times with distilled water and EtOH, and left to
dry, in a vacuum oven at 60 oC for 24 h.
1
2
3
4
5
6
Number of runs
Fig. 8 Recyclability of the Fe3O4@SiO2@PTS-DABA nanocatalyst in the
synthesis of 6a (blue diagram) and 7a (red diagram) under optimized
conditions.
3. Experimental
3.4.
Preparation
of
modified
silica
coated
MNPs
3.1. Materials and Instrumentation
(Fe3O4@SiO2@CPTS)
The obtained SCMNPs (1 g) were suspended in Toluene (50 mL) with
sonication and then 3-chloropropyl triethoxysilane (1 mL) was added
under nitrogen atmosphere. The mixture was heated under reflux
conditons at 110 oC for 24 h and the obtained solid was magnetically
separated, washed with EtOH to remove the unreacted residue of
silylating reagent and then vacuum dried at 80 oC.
Ferrous chloride tetrahydrate (FeCl2. 4H2O), ferric chloride
(FeCl3.6H2O), 3-chloropropyl triethoxysilane (CPTES, 99%), tetraethyl
orthosilicate (TEOS, 99%), ammonia (25 wt%) and 3,4-
diaminobenzoic acid (MW= 152.15) were purchased from Merck and
used without further purification. The progress of reactions was
monitored by thin-layer chromatography (TLC) using Merck silica gel
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3.5. Immobilization of 3,4-Diaminobenzoic acid on the surface of An equimolar mixture of the ethyl acetoacetate (1, 1 mmol),
modified silica coated magnetite NPs (Fe3O4@SiO2@PTS-DABA)
hydrazine hydrate (2, 1 mmol) and nanocataDlyOstI:(1100.10m3Vg9i)e/Dww0AeNrrtiJec0lea2Od6nd6l6einBde
to EtOH-H2O (1:1, 3 mL) in a 5 mL round-bottomed flask equipped
with a condenser and heated in an oil bath at 70 oC under stirring for
5 min. Then aromatic aldehyde derivatives (3, 1 mmol) and 4-
hydroxycoumarin (6, 1 mmol) were added. The obtained mixture was
stirred under reflux conditions for times indicated in Table 4. The
progress of the reaction was monitored by TLC. After completion of
the reaction, hot EtOH was added and the catalyst was recovered by
an external magnet. The crude products were purified by
recrystallization from EtOH. All the products were identified by
melting point measurement as well as FT-IR and 1H NMR
spectroscopic methods.
The 3,4-diaminobenzoic acid (1 g) was added into a suspension of
Fe3O4@SiO2@CPTS Powder (1 g) in EtOH (30 mL). The reaction
mixture was heated under reflux conditons in an oil bath for 24 h.
The obtained solid was separated magnetically and then washed
with EtOH several times to remove the unreacted residue of the 3,4-
diamine benzoic acid and then dried in an oven under vacuum at 80
oC.
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3.9. Spectral characterization of compounds 5a, 5g and 7a
6-amino-4-(4-chlorophenyl)-3-methyl-1,4-dihydropyrano[2,3-
c]pyrazole-5-carbonitrile (5a)
o
Light yellow solid, m.p. 233-235 C; FT-IR (KBr, cm-1) υ = 3407 (NH),
1
3303 and 3367 (NH2), 2187 (CN), 1608 (C=N), 1602 (C=C); H NMR
(500 MHz, DMSO-d6) δ ppm 1.79 (s, 3H, CH3), 4.61 (s, 1H, CH), 6.90
(s, 2H, NH2), 7.19-7.20 (d, 2H, J = 5.0 Hz, Ar-H), 7.37-7.38 (d, 2H, J =
5.0 Hz, Ar-H), 12.12 (s, 1H, NH).
6-amino-4-(4-methylphenyl)-3-methyl-1,4-dihydropyrano[2,3-
c]pyrazole-5-carbonitrile (5g)
White solid, m.p. 209-211 oC; FT-IR (KBr, cm-1): υ = 3402 (NH), 3245
and 3186 (NH2), 2189 (CN), 1639 (C=N), 1600 (C=C); H NMR (500
Scheme 3. Schematic preparation of the Fe3O4@SiO2@PTS-DABA
nanocatlyst.
1
MHz, DMSO-d6): δ = 1.79 (s, 3H, CH3), 2.26 (s, 3H, Ar-CH3), 4.53 (s, 1H,
C-4), 6.82 (s, 2H, NH2), 7.03-7.05 (d, 2H, J = 10.0 Hz, Ar-H), 7.10-7.12
(d, 2H, J = 10.0 Hz, Ar-H), 12.06 (s, 1H, NH).
3.6. Determination of the acidity of the prepared nanocatalyst
The back-titration method was used to determine the acidity of the
nanocatalyst. In this way, 0.1 g nanocatalyst, 0.1 g of NaCl, and 2 mL
of NaOH 0.1 M were added to 7 mL of distilled water and stirred with
a magnet for 24 h. After that, a few drops of phenolphthalein were
added into the mixture and the colour changed to purple. Finally, the
mixture was titrated by the solution of HCl (0.1 M, 0.5 mL) to reach
the neutral pH. Accordingly, the pH of the nanocatalyst was
calculated 1.669. This means that the Bronsted acid loading of the
prepared Fe3O4@SiO2@PTS-DABA is about 1.9 mmol.g-1.
4-((4-hydroxy-2-oxo-2H-chromen-3-yl)(phenyl)methyl)-5-methyl-
1,2-dihydro-3H-pyrazol-3-one (7a)
Cream crystalline solid, m.p. 231-233 oC; FT-IR (KBr, cm-1): υ = 3035,
2727, 1616, 1539, 1357, 1184, 1041, 752; 1H NMR (500 MHz, CDCl3):
δ 2.27 (3H, s), 5.59 (1H, s), 7.10-7.14 (4H, m), 7.19-7.26 (4H, m), 7.29-
7.31 (1H, d, J = 10.0), 7.51-7.54 (1H, t, J = 7.8 Hz), 7.78-7.80 (1H, d, J
= 10.0), 12.89 (1H, s).
3.7. General procedure for the synthesis of pyranopyrazole
derivatives 5 catalyzed by Fe3O4@SiO2@PTS-DABA nanocatalyst
Conclusions
An equimolar mixture of the ethyl acetoacetate (1, 1 mmol),
hydrazine hydrate (2, 1 mmol) and nanocatalyst (10 mg) were added
to EtOH (3 mL) in a 5 mL round-bottomed flask equipped with a
condenser and heated in an oil bath at 70 oC under stirring for 5 min.
In summary, we have developed a new and efficient bifunctional
organocatalyst immobilized on the surface of modified silica coated
magnetite NPs for the preparation of bioactive pyrano[2,3-c]pyrazole
as well as benzylpyrazolyl coumarin derivatives under green
conditions. The presence of acidic and basic sites on the catalyst
surface, facilitated the Knoevenagel condensation and Michael
addition as well as subsequent cyclization of intermediates to afford
Then aromatic aldehyde derivatives (3a-n,
1 mmol) and
malononitrile (4, 1 mmol) were added. The obtained mixture was
stirred under reflux conditions for times indicated in Table 2. The
progress of the reaction was observed by TLC. After completion of
the reaction, hot EtOH was added and the catalyst was recovered by
an external magnet. The crude products were purified by these bioactive derivatives. On other hand, avoiding the use of
recrystallization from EtOH. All the products were identified by
melting point measurement as well as FT-IR and 1H NMR
spectroscopic methods.
transition metals or corrosive reagents for modification of the
catalytic activity, simplicity of procedure, short reaction time, high
efficiency, environmentally friendly solvents, mild reaction
conditions and easily recyclable catalyst as well as its reusability for
five cycles without significant losing of the catalytic activity make this
method more attractive.
3.8. General procedure for the synthesis of benzylpyrazoly
coumarin derivatives
7 catalyzed by Fe3O4@SiO2@PTS-DABA
nanocatalyst
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20.
21.
22.
M. G. Dekamin, M. Azimoshan and L. Ramezani, Green
View Article Online
Conflicts of interest
There are no conflicts to declare.
Chemistry, 2013, 15, 811-820.
DOI: 10.1039/D0NJ02666B
Z. Alirezvani, M. G. Dekamin and E. Valiey, ACS omega,
2019, 4, 20618-20633.
M. Puripat, R. Ramozzi, M. Hatanaka, W. Parasuk, V.
Parasuk and K. Morokuma, The Journal of organic
chemistry, 2015, 80, 6959-6967.
X.-H. Chen, X.-Y. Xu, H. Liu, L.-F. Cun and L.-Z. Gong, Journal
of the American Chemical Society, 2006, 128, 14802-14803.
C. G. Evans and J. E. Gestwicki, Organic letters, 2009, 11,
2957-2959.
P. A. Hopes, A. J. Parker and I. Patel, Organic process
research & development, 2006, 10, 808-813.
N. Etivand, J. Khalafy and M. G. Dekamin, Synthesis, 2020,
52, 1707-1718.
S. Ilkhanizadeh, J. Khalafy and M. G. Dekamin, International
Journal of Biological Macromolecules, 2019, 140, 605-613.
M. G. Dekamin, M. Eslami and A. Maleki, Tetrahedron,
2013, 69, 1074-1085.
M. G. Dekamin and M. Eslami, Green Chemistry, 2014, 16,
4914-4921.
A. Saha, S. Payra and S. Banerjee, Green Chemistry, 2015,
17, 2859-2866.
P. P. Ghosh, G. Pal, S. Paul and A. R. Das, Green Chemistry,
2012, 14, 2691-2698.
H. Mecadon, M. R. Rohman, I. Kharbangar, B. M. Laloo, I.
Kharkongor, M. Rajbangshi and B. Myrboh, Tetrahedron
Letters, 2011, 52, 3228-3231.
Acknowledgements
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
We are grateful for the financial support from The Research Council
of Iran University of Science and Technology (IUST), Tehran, Iran
(Grant No: 160/18517), is highly appreciated. The partial financial
support of The Iran Nanotechnology Initiative Council (INIC) is also
gratefully acknowledged.
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Notes and references
1.
2.
R.-Y. Guo, Z.-M. An, L.-P. Mo, S.-T. Yang, H.-X. Liu, S.-X.
Wang and Z.-H. Zhang, Tetrahedron, 2013, 69, 9931-9938.
S. N. Maddila, S. Maddila, K. K. Gangu, W. E. van Zyl and S.
B. Jonnalagadda, Journal of Fluorine Chemistry, 2017, 195,
79-84.
3.
4.
5.
6.
7.
8.
S. V. Bhaskaruni, S. Maddila, K. K. Gangu and S. B.
Jonnalagadda, Arabian Journal of Chemistry, 2017.
S. Shabalala, S. Maddila, W. E. van Zyl and S. B.
Jonnalagadda, Catalysis Communications, 2016, 79, 21-25.
A. Alinasab Amiri, S. Javanshir, Z. Dolatkhah and M. G.
Dekamin, New Journal of Chemistry, 2015, 39, 9665-9671.
S. Hasanzadeh Banakar, M. G. Dekamin and A. Yaghoubi,
New Journal of Chemistry, 2018, 42, 14246-14262.
S.-C. Lee, C.-M. Fu and F.-H. Chang, Applied Physics Letters,
2013, 103, 163104.
R. Ghosh, L. Pradhan, Y. P. Devi, S. Meena, R. Tewari, A.
Kumar, S. Sharma, N. Gajbhiye, R. Vatsa and B. N. Pandey,
Journal of Materials Chemistry, 2011, 21, 13388-13398.
Z. Donglin, Z. Xianwei, X. Qisheng and T. Jintian, Rare
Metals, 2006, 25, 621-625.
33.
34.
35.
36.
37.
38.
39.
40.
41.
G. Vasuki and K. Kumaravel, Tetrahedron Letters, 2008, 49,
5636-5638.
J. M. Khurana and A. Chaudhary, Green Chemistry Letters
and Reviews, 2012, 5, 633-638.
E. Valiey, M. G. Dekamin and Z. Alirezvani, International
journal of biological macromolecules, 2019, 129, 407-421.
M. J. Nasab, A. R. Kiasat and R. Zarasvandi, Reaction
Kinetics, Mechanisms and Catalysis, 2018, 124, 767-778.
A. Saha, S. Payra, S. K. Verma, M. Mandal, S. Thareja and S.
Banerjee, RSC Advances, 2015, 5, 100978-100983.
K. G. Patel, N. M. Misra, R. H. Vekariya and R. R. Shettigar,
Research on Chemical Intermediates, 2018, 44, 289-304.
R. K. Sharma, S. Dutta, S. Sharma, R. Zboril, R. S. Varma and
M. B. Gawande, Green Chemistry, 2016, 18, 3184-3209.
T. Zhang, J. Zhou, Y. Chen and Y. Li, Research on Chemical
Intermediates, 2018, 44, 5329-5344.
A. R. Moosavi-Zare, M. A. Zolfigol, R. Salehi-Moratab and E.
Noroozizadeh, Journal of Molecular Catalysis A: Chemical,
2016, 415, 144-150.
S. K. Shinde, M. U. Patil, S. A. Damate and S. S. Patil,
Research on Chemical Intermediates, 2018, 44, 1775-1795.
R. S. Aliabadi and N. O. Mahmoodi, RSC advances, 2016, 6,
85877-85884.
M. Bihani, P. P. Bora, G. Bez and H. Askari, ACS Sustainable
Chemistry & Engineering, 2013, 1, 440-447.
M. A. Chaudhari, J. B. Gujar, D. S. Kawade, N. R. Jogdand
and M. S. Shingare, Cogent Chemistry, 2015, 1, 1063830.
H. Mecadon, M. R. Rohman, M. Rajbangshi and B. Myrboh,
Tetrahedron letters, 2011, 52, 2523-2525.
J. Ebrahimi, A. Mohammadi, V. Pakjoo, E. Bahramzade and
A. Habibi, Journal of Chemical Sciences, 2012, 124, 1013-
1017.
9.
10.
R. Mohammadi, S. Esmati, M. Gholamhosseini-Nazari and
R. Teimuri-Mofrad, New Journal of Chemistry, 2019, 43,
135-145.
11.
12.
13.
Y. Liu, L. Li, S. Liu, C. Xie and S. Yu, RSC Advances, 2016, 6,
81310-81317.
K. V. Ranganath and F. Glorius, Catalysis Science &
Technology, 2011, 1, 13-22.
M. Shao, F. Ning, J. Zhao, M. Wei, D. G. Evans and X. Duan,
Journal of the American Chemical Society, 2012, 134, 1071-
1077.
42.
43.
44.
45.
46.
47.
14.
15.
16.
17.
18.
19.
P. Wang, H. Liu, J. Niu, R. Li and J. Ma, Catalysis Science &
Technology, 2014, 4, 1333-1339.
L. M. Rossi, N. J. Costa, F. P. Silva and R. Wojcieszak, Green
Chemistry, 2014, 16, 2906-2933.
M. Ishani, M. G. Dekamin and Z. Alirezvani, Journal of
Colloid and Interface Science, 2018, 521, 232-241.
F. Davoodi, M. G. Dekamin and Z. Alirezvani, Applied
Organometallic Chemistry, 2019, 33, e4735.
Z. Alirezvani, M. G. Dekamin and E. Valiey, Scientific
Reports, 2019, 9, 17758.
N. Nikooei, M. G. Dekamin and E. Valiey, Research on
Chemical Intermediates, 2020, DOI: 10.1007/s11164-020-
04179-8.
48.
A. B. Atar, J. T. Kim, K. T. Lim and Y. T. Jeong, Synthetic
Communications, 2014, 44, 2679-2691.
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50.
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52.
53.
54.
55.
56.
57.
A. V. Chate, B. A. Shaikh, G. M. Bondle and S. M. Sangle,
View Article Online
DOI: 10.1039/D0NJ02666B
Synthetic Communications, 2019, 49, 2244-2257.
Z. Piruzmand, J. Safaei-Ghomi and M. Ghasemzadeh,
medicinal chemistry, 2016, 9, 10.
M. G. Dekamin, F. Mehdipoor and A. Yaghoubi, New
Journal of Chemistry, 2017, 41, 6893-6901.
M. G. Dekamin, Z. Karimi and M. Farahmand, Catalysis
Science & Technology, 2012, 2, 1375-1381.
M. G. Dekamin, S. Sagheb-Asl and M. R. Naimi-Jamal,
Tetrahedron letters, 2009, 50, 4063-4066.
K. Ablajan, W. Liju, A. Tuoheti and Y. Kelimu, Letters in
Organic Chemistry, 2012, 9, 639-643.
A. R. Moosavi-Zare, M. A. Zolfigol and A. Mousavi-Tashar,
Research on Chemical Intermediates, 2016, 42, 7305-7312.
H. Kiyani, H. Samimi, F. Ghorbani and S. Esmaieli, Current
Chemistry Letters, 2013, 2, 197-206.
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W. Stöber, A. Fink and E. Bohn, Journal of colloid and
interface science, 1968, 26, 62-69.
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DABA MNPs: a new and efficient magnetic bifunctional nanocatalyst for green
synthesis of biologically active pyrano[2,3-c]pyrazole and benzylpyrazolyl coumarin
derivatives
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Shahriar Karami, Mohammad G. Dekamin,* Ehsan Valiey and Peyman Shakib
In this work, a new core-shell magnetic silica functionalized with 3,4-diaminobenzoic acid nanocatalyst (Fe3O4@SiO2@PTS-DABA) was
successfully prepared and characterized using different spectroscopic methods or techniques including FT-IR, FE-SEM, VSM, XRD, EDS and
TGA. The Fe3O4@SiO2@PTS-DABA catalyst was applied, as a magnetic recoverable catalyst, for the synthesis of biologically active
dihydropyranopyrazole and benzylpyrazolyl coumarin derivatives. These derivatives were prepared in the presence of Fe3O4@SiO2@PTS-
DABA via a four-component reaction with yields of more than 90% under mild conditions. It shows a long life and can be reused for several
catalytic cycles without significant loss of catalytic activity. Finally, a possible mechanism is proposed for preparation of
dihydropyranopyrazole and benzylpyrazolyl coumarin derivatives in the presence of Fe3O4@SiO2@PTS-DABA multifunctional magnetic
catalyst. The structure of the products was identified by melting point as well as FT-IR and 1H NMR spectroscopic methods.
12 | New J. Chem., 2020, 44, 1-11
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