Application of immobilized sulfonic acid on the cobalt ferrite magnetic nanocatalyst (CoFe2O4@SiO2@SO3H) in the synthesis of spirooxindoles

Article abstract of DOI:10.1007/s11164-019-03928-8

Sulfonic acid immobilized on the surface of magnetically cobalt ferrite/silicate is a green, convenient, efficient and recyclable catalyst which can be applied in organic reactions ranges from lab to industry goals as a solid acid to achieve high yield products. After synthesizing (CoFe₂O₄/SiO₂/SO₃H), it was also characterized by using different techniques such as FT-IR, XRD, EDX, VSM, TEM, SEM, TGA and so on which everyone approved presented structure. In this study, we are on to use this catalyst in a certain multicomponent reaction that is a common way to produce heterocycle compounds in order to synthesis spirooxindole derivatives which possess biological capabilities as anticancer and antimicrobial drugs. Hence, the three-component reaction of malononitrile, dimedone and isatin were performed in one pot under optimized situations of 80?°C temperature, reflux condition and water/ethanol (1:1) mixture as the solvent. Also, the present study shows unique advantages, such as simple synthesis of the catalyst, high magnetic properties, easy separation of catalyst with a permanent magnet, and the application of inexpensive and available precursors. At the end of the reaction, we gained the high yields of product at a short time that represents the high catalytic activity of the catalyst.

Full text of DOI:10.1007/s11164-019-03928-8

Research on Chemical Intermediates
https://doi.org/10.1007/s11164-019-03928-8
Application of immobilized sulfonic acid on the cobalt
ferrite magnetic nanocatalyst (CoFe O @SiO @SO H)
2
4
2
3
in the synthesis of spirooxindoles
1
1
1
Bardia Zamani‑Ranjbar‑Garmroodi · Mohammad A. Nasseri · Ali Allahresani ·
Kaveh Hemmat1
Received: 8 April 2019 / Accepted: 1 July 2019
©
Springer Nature B.V. 2019
Abstract
Sulfonic acid immobilized on the surface of magnetically cobalt ferrite/silicate is a
green, convenient, eꢀcient and recyclable catalyst which can be applied in organic
reactions ranges from lab to industry goals as a solid acid to achieve high yield prod-
ucts. After synthesizing (CoFe O /SiO /SO H), it was also characterized by using
2
4
2
3
diꢁerent techniques such as FT-IR, XRD, EDX, VSM, TEM, SEM, TGA and so on
which everyone approved presented structure. In this study, we are on to use this
catalyst in a certain multicomponent reaction that is a common way to produce het-
erocycle compounds in order to synthesis spirooxindole derivatives which possess
biological capabilities as anticancer and antimicrobial drugs. Hence, the three-com-
ponent reaction of malononitrile, dimedone and isatin were performed in one pot
under optimized situations of 80 °C temperature, reꢂux condition and water/etha-
nol (1:1) mixture as the solvent. Also, the present study shows unique advantages,
such as simple synthesis of the catalyst, high magnetic properties, easy separation of
catalyst with a permanent magnet, and the application of inexpensive and available
precursors. At the end of the reaction, we gained the high yields of product at a short
time that represents the high catalytic activity of the catalyst.
Keywords Cobalt ferrite · Solid acid · MCRs · Spirooxindole
Introduction
Green chemistry is a branch of chemistry that tries to make the chemical process
registered with the environment. One of the ꢃelds that green chemistry has always
dealt with is Catalysis. Hence, the researches around the green catalysts have been
*
Mohammad A. Nasseri
manaseri@birjand.ac.ir
1
Department of Chemistry, College of Sciences, University of Birjand, Birjand 97175-615, Iran
Vol.:(012
1
3456789)
3

B. Zamani-Ranjbar-Garmroodi et al.
promoted until heterogenous acids stepped into the arena [1, 2]. Actually despite
high catalytic activity of homogeneous Bronsted acids such as sulfuric acid, they
have some disadvantages which made them ineꢀcient; for instance problems in sep-
aration, hard work up and sulfate wastes that come from neutralization of containing
solutions and speciꢃcally ineꢀciency in complying with requirements for a reus-
able catalyst are just only a few typical issues. So researches around it led to turning
them solid; for this purpose, metal oxide and organic compounds can be applied,
but they are expensive compounds which also possess less active sites. So that sul-
fonic acid is a good vantage point which has no drawbacks associated with them. As
a result, the production of these kinds of eco-friend catalysts resolved those draw-
backs [3–22].
Therefore, heterogenous catalysts have been progressed by transforming them to
magnetic nanoparticles (MNPs) that made them easier to recover in the solution by
using an external magnet. Also, these catalysts are less toxic and possess high cata-
lytic performance in chemical reactions. One common type of these magnetic nano-
catalysts are ferrite materials. Ferrites with general formula MFe O that M refers
2
4
to a divalent cation are very important catalysts which are used in a wide range of
aꢁairs such as industrially important reactions and public health. The features are
like being inexpensive, thermal stability and capability of reducing wastes in chem-
ical industries for environmental demands causes that this kind of catalyst makes
common [23–41].
By considering all these interpretations, we used cobalt ferrite immobilized SiO /
2
SO H in a one-pot multicomponent reaction. A multi-component reaction is an
3
eꢁective method to producing a diversity-oriented synthesis of the large scale of het-
erocycle compounds like spirooxindoles that possess a considerable impact on bio-
logical systems and also pharmaceutical activities, and it was always a big challenge
to produce oxindole derivatives in the ꢃeld of organic chemistry [42–46].
As we noticed before, herein, we synthesized CoFe O @SiO @SO H
2
4
2
3
(
Scheme 1) to examine catalytic activity in the three component reaction of
Scheme 1 Preparation of catalyst (CoFe O @SiO @SO H)
2
4
2
3
1
3

Application of immobilized sulfonic acid on the cobalt ferrite…
malononitrile, dimedone and isatin in 80 °C at the reꢂux and solvent ethanol/
water (1:1) condition which led to the synthesis of spirooxindole derivatives
(
Scheme 2). In the end, the corresponding heterogeneous nanocatalyst was also
characterized by FT-IR, VSM, SEM–EDX, and XRD which will be mentioned
below.
Experimental
Materials
Reagents (Dimedone, Isatin, Malononitrile and their own dependent derivatives)
and solvents (Ethanol, N-hexane, DMSO, CHCl , THF, and CH CN) were pur-
3
3
chased from Merck. Purity determinations of the products were accomplished by
TLC on silica-gel polygram SILG/UV 254 plates. Melting points were measured
on an Electrothermal 9100 apparatus.
Characterization techniques
IR spectra were taken on a Perkin Elmer 781 spectrometer in KBr pellets and
−
1
1
13
reported in cm . HNMR and CNMR spectra were measured on a Bruker
DPX-250 Avance instrument at 250 MHz and 62.9 MHz in CDCl or DMSO-d
3
6
with chemical shift given in ppm relative to TMS as an internal standard. Pow-
der X-ray diꢁraction (XRD) was performed on a Bruker D -advance X-ray dif-
8
fractometer with Cu Kα (λ = 0.154 nm) radiation. The magnetic properties were
determined by using a vibrating sample magnetometer (VSM) leak shore 7200
at 300 K VSM leak shore. TGA was also recorded using a Perkin-Elmer Dia-
mond TG/DTA thermal analyzer in an argon ꢂow rate (100 ml/min) with increas-
−
1
ing the heating rate of 10 °C min . The scanning electron microscope (SEM)
(
Mitra3TEScan-XMU) was used for recording surface morphology. Transmission
electron microscopy (TEM) was performed on a Philips EM208 microscope and
was operated at 100 kV.
Scheme 2 Synthesis of spirooxindole derivatives catalyzed by CoFe O @SiO @SO H
2
4
2
3
1
3

B. Zamani-Ranjbar-Garmroodi et al.
Catalyst preparation
Preparation of CoFe O magnetic nanoparticles
2
4
The 0.001 mol (0.183 g) of Co(NO ) ·6H O and 0.002 mol of Fe(NO ) ·9H O
3
2
2
3 3
2
(
0.808 g) have been dissolved in 100 ml of distilled water and the solution placed
in ultrasonication for 30 min. After that, a 20 ml solution of NaOH (2 M) added
to the mixture drop wisely right as a black precipitate was slowly forming. Then
the mixture was heated in 80°C for 2 h. Finally, the black precipitate (CoFe O )
2
4
washed with ethanol as far as the solution becomes neutralized. Eventually, the
product was placed in the oven at 80 °C for 2 h [47].
Synthesis of CoFe O coated by SiO (CoFe O @SiO )
2
4
2
2
4
2
After synthesizing of CoFe O MNPs, 0.04 g of ferrite was dispersed at ethanol
2
4
in an ultrasonication homogenizer device for 20 min. After that 40 ml of water,
1
ml TEOS (tetraethyl orthosilicate) and 5 ml of ammonia solution were added
into the ꢂask slowly as mixture stirred. After 24 h stirring of the solution, it was
washed with ethanol and separated using the external magnet and ꢃnally placed
in the oven at 80 °C for 4 h [48].
Synthesis of CoFe O @SiO @SO H nanocomposite
2
4
2
3
The 1 g of CoFe O @SiO nanocomposite was entered into a ꢂask and after add-
2
4
2
ing 20 ml of dichloromethane as the solvent, the mixture dispersed for 30 min in
the ultrasonicate instrument. After that, 4 ml of chlorosulfonic acid drop wisely
added to the mixture and then stirred for 5 h. Eventually, the catalyst separated
from containing the solution and after washing the residue, dried in room tem-
perature for 2 h [3].
Catalytic activity
General procedure for the synthesis of spirooxindole derivatives
First, 0.01 g of the CoFe O @SiO @SO H was dispersed for 30 min and after
2
4
2
3
that an amount of 1 mmol from isatin, malononitrile and dimedone with ethanol/
water (ratio 1:1) were mixed, and the ꢃnal mixture was placed in 80 °C at the
reꢂux condition. After completing the reaction by passing a certain time, the con-
taining solution was separated by centrifuging and the crude product extracted
and washed with ethyl acetate, and then Na SO was added to dehydrating the
2
4
product. After that, the solvent was removed by using a rotary evaporator and
ꢃnally the product recrystallized in hot ethanol to gain the pure product. Moreo-
ver, the catalyst was washed and applied for several times to examine reusability.
1
3

Application of immobilized sulfonic acid on the cobalt ferrite…
Structural assignments of the products are based on their HNMR, 13CNMR and
1
IR spectra.
Selected spectral data
2
‑Amino‑2′,5‑dioxo‑5,6,7,8‑tetrahydrospiro‑[chromene‑4,3′‑indoline]‑3‑carbonitr
1
ile: (Table 1, Entry 5) White solid, M.p.>250 °C. H-NMR (250 MHz, DMSO-d ),
6
ppm: 1.91 (2H, t, CH ), 2.14 (2H, m, CH ), 2.66 (2H, t, CH ), 6.66 (1H, d, ArH),
2
2
2
6
.90 (1H, t, ArH), 7.11 (1H, d, ArH), 7.21 (1H, t, ArH), 7.35 (2H, s, NH ), 10.65
2
1
3
(
1H, s, NH). CNMR (62.8 MHz, DMSO-d ), ppm: 19.85, 26.87, 36.40, 46.94,
6
5
1
7.64, 109.19, 111.92, 117.46, 121.85, 123.37, 128.56, 134.64, 142.18, 158.69,
−1
2
66.12, 178.23, 195.12. IR/cm : 3354 (N–H), 3290 (N–H), 3165 (C–H, sp ), 2950
3
(
C–H, sp ), 2203 (CN), 1713 (C=O), 1652 (N–C=O), 1472 (C–H, Ar).
Table 1 The synthesis of spirooxindole derivatives by CoFe O @SiO @SO H
2
4
2
3
Entry
Isatin
R
Carbonyl com-
pound
Product
Time (min)
Yield (%)
R1
1
2
3
4
5
6
7
8
9
H
NO2
Br
Me
H
NO2
Br
Me
H
NO2
Br
H
H
H
H
H
H
H
H
H
H
H
H
3a
3a
3a
3a
3b
3b
3b
3b
3c
3c
3c
3c
4a
4a
4a
4a
4a
4a
4a
4a
4b
4b
4b
4b
60
10
60
60
15
15
10
15
2
20
50
30
20
90
91
78
90
98
98
93
85
1
1
1
0
1
2
2
2
10
Me
Reaction conditions: isatin (1.0 mmol), 1,3-dicarbonyl (1.0 mmol) and malononitrile (1.0 mmol) inE-
tOH/H O (1:1), at 80 °C, 10 mg CoFe O @SiO @SO H
2
2
4
2
3
1
3

B. Zamani-Ranjbar-Garmroodi et al.
2
3
‑Amino‑7,7‑dimethyl‑2′,5‑dioxo‑5,6,7,8‑tetrahydrospiro [chromene‑4,3′‑indoline]‑
‑Carbonitrile: (Table 1, Entry 9) White solid, M.p.>250 °C. H-NMR (250 MHz,
1
DMSO-d ) ppm: 0.96 (6H, s, 2CH ), 2.13 (2H, s, CH ), 2.40 (2H, s, CH ), 6.71–
6
3
2
2
1
3
7
.24 (4H, ArH, 2H, NH , m), 10.35 (1H, s, NH). C-NMR (62.8 MHz, DMSO-
2
d ) ppm: 27.43, 28.05, 32.31, 47.25, 50.43, 57.89, 109.76, 111.23, 117.72, 122.41,
6
−
1
1
23.40, 128.54, 134.79, 142.39, 152.01, 159.34, 164.51, 178.44, 195.36. IR/cm :
2
3
3
372 (N–H), 3316 (NH), 3141 (C–H, sp ), 2923 (C–H, sp ), 2189 (CN), 1719
(
C=O), 1656 (N–C=O), 1602 (C–H, Ar), 1471 (C–H, Ar).
Result and discussion
CoFe O @SiO @SO H was used in a model reaction of isatin, malononitrile, and
2
4
2
3
dimedone which led to a certain product called spirooxindole (Scheme 2). With
regarding the advantages of this solid acid such as easy recovery, non-toxicity, high
catalytic performance, easy synthesizing and reusability, this catalyst can be a suit-
able choice in catalysis. Eventually, this catalyst was characterized by diꢁerent tech-
niques including XRD, EDX, IR, TEM, SEM, TGA and VSM.
FT‑IR spectroscopy
Herein we discuss the IR spectroscopy of the catalyst which performed in the range
−
1
1
−1
of 400 cm to 4000 cm . Based on Fig. 1, we can see a broadening absorption at
−
3
212 cm which belongs to OH-stretching of absorbed water molecules; furthermore,
−1
the peak located at 594 cm is dealing with the bending mode of CO–O and Fe–O
−1
bonds (Fig. 1a). Another sharp and strong absorption at 1091 cm is due to the stretch-
−1
ing band or asymmetric vibrations of Si–O–Si and the peak locating around 794 cm
is because of symmetric vibration of Si–O–Si. Also, the absorption band presenting
at 459 cm− is because of the bending vibration of O–Si–O. Finally, a broad peak in
1
Fig. 1 FT-IR spectra of
CoFe O (a). CoFe O @SiO @
2
4
2
4
2
SO H (b)
3
1
3

Application of immobilized sulfonic acid on the cobalt ferrite…
the range of 1091 cm−1 represents S–O absorption which is directly alluded to SO H
3
groups and coated on the surface of CoFe O @SiO nanocomposites (Fig. 1b).
2
4
2
In comparison to other spectra mentioned in other articles, about (a) that represents
uncoated cobalt ferrite, we can exemplify Demirelli et al. which has a metal–oxygen
−1
−1
band revealed in 560 cm comparing to this spectrum in 594 cm it is partial dif-
ferences in shift; also in order to compare Si–O–Si bands in (b) we can reference it
to Kurtan et al. and Runowski et al. which there are MnFe O and Fe O in the for-
2
4
3 4
mer and later coated by silicate. In these articles, asymmetric and symmetric vibra-
−1
−1
tions of Si–O–Si respectively are revealed at 1080 cm and around 800 cm which in
comparing both data to this one, concludes that there are no signiꢃcant diꢁerences in
presented peak for CoFe O @SiO @SO H. The same conclusion happens for O–Si–O
2
4
2
3
−1
vibration that is based on noted articles and concedes 460 cm while herein it shows at
1
4
59 cm− [49–51].
X‑ray difraction (XRD) analysis oꢀ CoFe O @SiO @SO H
2
4
2
3
Figure 2 shows the XRD patterns of synthesized (a) CoFe O and (b) CoFe O @
2
4
2 4
SiO @SO H. Corresponding the peaks of phase analysis shows that all the peaks
2
3
belong to CoFe O and cobalt ferrite-silicon oxide phase which both proves the struc-
2
4
ture. Based on the results, the existence of a broad peak at 2θ=23.6° approves the
silicate immobilization and also sulfonic acid functionalization over the cobalt ferrite
MNPs. The average grain size of the CoFe O @SiO @SO H is calculated by using the
2
4
2
3
Debye–Scherrer formula. From the well-known Scherrer formula the average crystal-
lite size, L is:
Kꢀ
L =
,
ꢁ
cos ꢂ
Fig. 2 XRD pattern of CoFe O
2
4
(
a). CoFe O @SiO @SO H (b)
2 4 2 3
1
3

B. Zamani-Ranjbar-Garmroodi et al.
where λ is the X-ray wavelength (nm), θ is the Bragg’s angle, K is a constant related
to crystallite shape, normally taken as 0.9, and β is the full width of the diꢁraction
line at the half maximum intensity. The average crystallite size of synthesized prod-
ucts was thus calculated at about 42.41 nm [52–54].
Energy‑dispersive X‑ray (EDX) pattern oꢀ CoFe O @SiO @SO H
2
4
2
3
Figure 3 demonstrates energy-dispersive X-ray spectroscopy (EDX) of CoFe O @
2
4
SiO @SO H nanocomposite. This analyze is recorded because of the determination
2
3
of elemental composition in the catalyst. The results show that Co, Fe, S, Si, and O
are existing in the sample. We should note that there is no impurity in the product.
Vibrating sample magnetometer (VSM) analysis oꢀ CoFe O @SiO @SO H
2
4
2
3
The magnetic properties of (a) CoFe O (b) CoFe O @SiO and (c) CoFe O @
2
4
2
4
2
2
4
SiO @SO H were studied by a vibrating sample magnetometer (VSM) at 300 K
2
3
(
Fig. 4). Figure 4 shows the absence of the hysteresis phenomenon and indicates
that the product has superparamagnetism at room temperature. The saturation mag-
netization values for CoFe O , CoFe O @SiO and CoFe O @SiO @SO H were
2
4
2
4
2
2
4
2
3
3
9.124, 30.387 and 13.614 emu/g, respectively [52, 54].
Thermal gravimetric analysis (TGA)
Figure 5 presents the thermogravimetric analysis (TGA) of CoFe O @SiO @SO H
2
4
2
3
nanoparticles. The TGA curve was separated into three areas according to three
mass loss ranges. The ꢃrst area, which occurred below 150 °C, showed a mass loss
Fig. 3 The EDX pattern of CoFe O @SiO @SO H
2
4
2
3
1
3

Application of immobilized sulfonic acid on the cobalt ferrite…
Fig. 4 Magnetization curves of CoFe O (a). CoFe O @SiO (b). CoFe O @SiO @SO H(c)
2
4
2
4
2
2
4
2
3
Fig. 5 TGA curve of CoFe O @SiO –SO H MNPs
2
4
2
3
that was attributed to the loss of physically adsorbed solvent and surface hydroxyl
groups. The second region (150–600 °C) shows that the silica-coated MNPs are
thermally stable. Finally, the third area that occurred between 600 and 800 °C
belongs to the mass loss of SO H groups.
3
Transmission electron microscopy (TEM)
The grain size of the CoFe O @SiO @SO H was investigated by TEM. They
2
4
2
3
have a narrow distribution of sizes, from 55 to 68 nm (Figs. 6, 7). The average size
1
3

B. Zamani-Ranjbar-Garmroodi et al.
Fig. 6 TEM images of CoFe O @SiO @SO H
2
4
2
3
Fig. 7 Particle size distribution of CoFe O @SiO @SO H nanoparticle
2
4
2
3
of CoFe O @SiO @SO H NPs is determined, and average size distribution of
2
4
2
3
6
2.90 nm is observed for CoFe O @SiO @SO H NPs (Fig. 7).
2 4 2 3
Scanning electron microscopy (SEM)
SEM analysis of the product (Fig. 8) provided information on the size and morphol-
ogy of CoFe O @SiO @SO H nanoparticles.
2
4
2
3
Evaluating the acidity oꢀ CoFe O @SiO @SO H
2
4
2
3
In order to determine acidity of the catalyst, we have decided to choose the ion
+
exchange to analyze a method for evaluating amounts of H on the surface of
CoFe O @SiO @SO H for this purpose, about 50 mg of the catalyst was dissolved
2
4
2
3
in the 25 ml aqueous solution of NaCl, 0.1 M, and primary pH was recorded; then,
1
3

Application of immobilized sulfonic acid on the cobalt ferrite…
Fig. 8 SEM images of CoFe O @SiO @SO H
2
4
2
3
the mixture stirred for about 2 h; after that, the secondary pH was recorded. Finally,
the result of subtraction of pHs which is assigned directly to the catalyst acidic capa-
+
bility contributed to proportional 0.02 mol of H instead of each gram of catalyst.
The catalytic activity oꢀ CoFe O @SiO @SO H ꢀor the synthesis oꢀ spirooxindoles
2
4
2
3
To optimize the reaction conditions, a wide series of reactions was performed
with 1 mmol of substrates malononitrile, isatin, and dimedone in the presence, and
absence of the catalyst CoFe O @SiO @SO H nanocomposite and so changing the
2
4
2
3
situations by using diꢁerent solvents at 80 ° . For the ꢃrst step, in the model reaction
C
of 1 mmol from substrates with ethanol/water (ratio 1:1), the amount of catalyst was
optimized based on (Fig. 9). So the best amount of CoFe O @SiO @SO H which
2
4
2
3
lead to the product at a short time was 0.01 g of it that showed; whereas this reaction
in the absence of catalyst after 30 min ꢃnished by only 20% yield.
Fig. 9 The eꢁect of diꢁerent
amounts of CoFe O @SiO @
2
4
2
SO H. Reaction conditions:
3
isatin (1.0 mmol), malon-
onitrile (1.0 mmol), dimedone
(
(
1.0 mmol) in EtOH:H O
2
1:1), at 80 °C. Final optimized
amount of catalyst=0.01 g
1
3

B. Zamani-Ranjbar-Garmroodi et al.
Fig. 10 The eꢁects of solvent on the yield of model reaction spirooxindoles. Reaction conditions: isatin
(
1.0 mmol), malononitrile (1.0 mmol), dimedone (1.0 mmol) in 10 mg CoFe O @SiO @SO H, at 80 °C
2 4 2 3
After an amount optimization, we have carried out the same reaction by chang-
ing solvent in a wide range of polarity (Fig. 10). Based on the experiments by con-
sidering of obvious rise in yield, we can conclude that the model reaction can be
performed in polar solvents. So the best situation in the solvent was selected in a
mixture of ethanol and water (1:1).
In the end, temperature optimization was performed and based on the results,
after increasing temperature from room temp to 80 °C, an obvious increase in yield
was observed (Fig. 11).
To expand the scope of catalyst CoFe O @SiO @SO H we have tested it in the
2
4
2
3
reaction by changing substrates 1,3-diketone, malononitrile and isatin derivatives
which in any reaction there was only a single substrate variable and other conditions
(
including temperature, solvent, etc.) have been considered constantly (Table 1). So,
for comparing the yield, a range of time 2–60 min was recorded, and as a result,
we ꢃnd out that dimedone as a 1,3 dicarbonyl compound can accelerate the veloc-
ity of the reaction more eꢀciency than 1,3-cyclohexadione (Table 1, entries 9–12).
The same result has been recorded for isatin when we investigated the eꢁect of the
substituent on the isatin because it has the electron-withdrawing groups such as nitro
or halogens attached in the phenyl ring (Table 1, entries 2, 3, 6, 7, 10, 11). But by
changing 4-Hydroxycoumarin instead of 1,3-diketones we observed that the rate of
the reaction would not progress in comparison to other diketones (Table 1, entries
1
–4).
In Scheme 3, we have presented the reasonable mechanism for preparation
of spirooxindole derivatives. The CoFe O @SiO @SO H as an acidic catalyst
2
4
2
3
that activates the carbonyl group of isatin, and then malononitrile because of the
Fig. 11 The eꢁect of tem-
perature on the yield of the
model reaction spirooxin-
doles. Reaction conditions:
isatin (1.0 mmol), malon-
onitrile (1.0 mmol), dimedone
(
1.0 mmol) in EtOH:H O (1:1),
2
2
1
0 mg CoFe O @SiO @SO H
2
4
3
1
3

Application of immobilized sulfonic acid on the cobalt ferrite…
Scheme 3 The reasonable mechanism for the synthesis of spirooxindole derivatives
activated alpha hydrogens will have a nucleophilic attack on activated carbon to gen-
erate intermediate 2, This intermediate generates intermediate 3 by the elimination
of Knoevenagel condensation, ꢃnally with adding of dimedone to this intermediate
the corresponding product was synthesized. In all steps of the reaction, everywhere
that the catalyst takes part in, the anionic intermediates were stabilized by heteroge-
neous solid acid CoFe O @SiO @SO H; therefore, this catalyst has a huge eꢁect
2
4
2
3
on the reaction.
The model reaction of spirooxindole has been performed by using 0.01 g
CoFe O @SiO @SO H in the reaction of dimedone, isatin and malononitrile in
2
4
2
3
8
0 °C via solvent ethanol/water (1:1) to examine reusability of the catalyst. Based
on the experiments, the results which are recorded in (Fig. 12) show that after ꢃve
cycles, there is no speciꢃc reduction in the yield so we can use it for several times
without problems of reusability.
To elucidate this strong durability, the recovered catalyst after the third run was
studied by FT-IR, XRD characteristic methods. By comparing the FT-IR spectrum
of the recovered catalyst by the corresponding fresh spectrum, there cannot be
Fig. 12 Recyclability of CoFe O @SiO @SO H in the synthesis of spirooxindoles. Reaction condi-
2
4
2
3
tions: isatin (1.0 mmol), malononitrile (1.0 mmol), dimedone (1.0 mmol) in EtOH:H O (1:1), 10 mg
2
CoFe O @SiO @SO H, 80 °C
2
4
2
3
1
3

B. Zamani-Ranjbar-Garmroodi et al.
Fig. 13 a FT-IR spectrum, and b XRD pattern of the recovered catalyst after third recycle
found any change wherein, conꢃrming the structure of the catalyst during the reac-
tion. Also, the XRD image of the recovered catalyst corroborates that the results
showed that the recovered catalyst did not show signiꢃcant diꢁerences in the struc-
ture (Fig. 13).
To show the advantage and uniqueness of the present method, the catalyst
CoFe O @SiO @SO H was compared with the previously reported catalyst for the
2
4
2
3
preparation of spirooxindole (Table 2).
Conclusions
In conclusion, a facile methodology was developed for the preparation of biologi-
cally active spirooxindole derivatives using CoFe O @SiO @SO H nanoparticles
2
4
2
3
as an eꢀcient heterogeneous catalyst. The catalyst represents an outstanding activity
in water/EtOH at 80 °C, which have high yields in short reaction times. The cata-
lyst was characterized by FT-IR, VSM, EDX, TEM, TGA, SEM and XRD analy-
ses. Then, the eꢀciency of the prepared CoFe O @SiO @SO H was studied in
2
4
2
3
the reaction of malononitrile, isatins with 1,3-dicarbonyl compounds to synthesize
Table 2 Comparison of results using CoFe O @SiO @SO H with various catalysts
2
4
2
3
Entry
Catalyst
Solvent/T (°C)
Time (min)
Yield (%)
References
1
2
3
4
5
6
Sodium stearate
TEBA
B-CD
GN/SO3H
NET3
H O/60 °C
180
120
480
40
30
2
95
88
88
95
80
98
[55]
[56]
[57]
[3]
[58]
This work
2
H O/90 °C
2
H2O/60 °C
EtOH/H O (1:1)/ref.
2
EtOH/ref.
CoFe O @SiO @SO H
EtOH/H O (1:1)/80 °C
2
4
2
3
2
Malononitrile (1 mmol), isatin (1 mmol), dimedone (1 mmol)
1
3

Application of immobilized sulfonic acid on the cobalt ferrite…
biologically spirooxindole derivatives, and the results showed excellent yields. In the
end, advantages of this method are the low-cost catalyst, less toxicity (eco-friendly),
clean reaction proꢃles, and reusability, the reaction was completed in a short period
of time with small amounts of catalyst. In addition, it is easy to separate the catalyst
for catalytic recycling. Finally, the catalyst could be readily reused for at least ꢃve
consecutive runs without any metal leaching, or signiꢃcant loss in catalytic activity.
The analyses of the recovered catalyst demonstrated its stability and durability.
Acknowledgements We gratefully acknowledge the support of this work by the University of Birjand.
References
1
2
3
4
5
6
7
8
9
.
.
.
.
.
.
.
.
.
R.A. Sheldon, I. Arends, Ulf. Hanefeld, Green Chem and Cat (Wiley-VCH, Weinheim, 2007), p. 1
R. Dalpozzo, Green Chem. 17, 3671 (2015)
A. Allahresani, B. Taheri, M.A. Nasseri, Res. Chem. Intermed. 44, 6979 (2018)
J. Cao, S. Shen, P. Yang, J. Qu, Org. Lett. 15, 3856 (2013)
P.T. Anastas, J.B. Zimmermann, Environ. Sci. Technol. 37, 94A (2003)
M. Maruthamuthu, E. Subramanian, J. Chem. Sci. 101, 259 (1989)
H. Liu, T. Jiang, B. Han, S. Liang, W. Wang, T. Wu, G. Yang, Green Chem. 13, 1106 (2011)
S. Inagaki, S. Guan, T. Ohsuna, O. Terasaki, Nature 416, 304 (2002)
K. Wilson, A.F. Lee, D.J. Macquarie, J.H. Clark, Appl. Catal. A Gen. 228, 27 (2002)
1
1
0. E. Cano-Serrano, J.M. Campos-Martin, J.L.G. Fierro, Chem. Commun. 247, 246 (2003)
1. N. Koukabi, E. Kolvari, M.A. Zolꢃgol, A. Khazaei, B.S. Shaghasemi, B. Fasahatib, Adv. Synth.
Catal. 354, 2001 (2012)
1
2. N.G. Salunkhe, A. Chandrashekhar, N.V. Ladole Thakare, A.S. Aswar, Res. Chem. Intermed. 45,
2
56 (2017)
1
1
3. S.B. Kalidindi, B.R. Jagirdar, Chemsuschem 5, 65 (2012)
4. M.B. Gawande, H. Guo, A.K. Rathi, P.S. Branco, Y. Chen, R.S. Varma, D.L. Peng, RSC Adv. 3,
1
050 (2013)
1
1
1
5. M.B. Gawande, A.K. Rathi, P.S. Branco, I.D. Nogueira, A. Velhinho, J.J. Shrikhande, U.U. Indulkar,
R.V. Jayaram, C.A.A. Ghumman, N. Bundaleski, Chem. Eur. J. 18, 12628 (2012)
6. M.B. Gawande, A. Rathi, I.D. Nogueira, C.A.A. Ghumman, N. Bundaleski, O.M.N.D. Teodoro, P.S.
Branco, ChemPlusChem 77, 865 (2012)
7. L.M. Rossi, A.L. Parize, J.C. Rubim, in Green Synthesis and Applications of Magnetic Nanoparti-
cles- Handbook of Green Chemistry, ed. by P.T. Anastas (Wiley, Weinheim, 2012), p. 61
8. G. Bystrzejewska-Piotrowska, J. Golimowski, P.L. Urban, Waste Manag. 29, 2587 (2009)
9. M.B. Gawande, R. Luque, R. Zboril, ChemCatChem 6, 3312 (2014)
1
1
2
2
2
0. M.M. Dutta, K.K. Rajbongshi, P. Phukan, Synth. Commun. 47, 2330 (2017)
1. F. Bonyasi, M. Hekmati, H. Veisi, J. Colloid Interface Sci. 496, 177 (2017)
2. H.D. Nguyen, M.H.T. Nguyen, T.D. Nguyen, P.T. Nguyena, Environ. Prog. Sustain. Energy 35, 603
(
2016)
2
2
2
2
2
2
2
3
3
3
3
3
3. N.G. Salunkhe, C.A. Ladolel, N.V. Thakare, A.S. Aswar, Res. Chem. Intermed. 44, 355 (2017)
4. M.N. Chen, L.P. Mo, Z.S. Cui, Z.H. Zhang, Curr. Opin. Green Sustain. Chem. 15, 27 (2019)
5. M. Zhang, P. Liu, Y. Liu, Z.R. Shang, H.C. Hu, Z.H. Zhang, RSC Adv. 6, 106160 (2016)
6. M. Zhang, Y.H. Liua, Z.R. Shang, H.C. Hu, Z.H. Zhang, Catal. Commun. 88, 39 (2017)
7. V. Polshettiwar, R.S. Varma, Green Chem. 12, 743 (2010)
8. M.B. Gawande, P.S. Branco, R.S. Varma, Chem. Soc. Rev. 42, 3371 (2013)
9. S. Bagheri, N.M.J. Julkapli, Magn. Magn. Mater. 416, 117 (2016)
0. R. Mrówczyński, A. Nan, J. Liebscher, Rsc Adv. 4, 5927 (2014)
1. R.B.N. Baig, R.S. Verma, Chem. Commun. 49, 752 (2013)
2. L.M. Rossi, N.J.S. Costa, F.P. Silva, R. Wojcieszak, Green Chem. 16, 2906 (2014)
3. R. Hudson, Y. Feng, R.S. Verma, A. Moores, Green Chem. 16, 4493 (2014)
4. T. Cheng, D. Zhang, H. Li, G. Liu, Green Chem. 16, 3401 (2014)
1
3

B. Zamani-Ranjbar-Garmroodi et al.
3
5. R.K. Sharma, S. Dutta, S. Sharma, R. Zboril, R.S. Varma, M.B. Gawande, Green Chem. 18, 3184
(
2016)
3
3
3
3
4
4
4
4
4
4
6. M. Kooti, M.F. Afshari, Sci. Iran. 19, 1991 (2012)
7. J. Chen, Z.-H. Lu, Y. Wang, X. Chen, L. Zhang, Int. J Hydrog. Energy 40, 4777 (2015)
8. M. Zhang, J. Lu, J.-N. Zhang, Z.-H. Zhang, Catal. Commun. 78, 26 (2016)
9. S. Mandal, S. Hazra, S. Sarkar, C. Bodhak, A. Pramanik, Appl. Organomet. Chem. 33, 1 (2019)
0. A. Rezaei, A. Ramazani, F. Gouranlou, S. Woo Joo, Lett. Org. Chem. 114, 86 (2017)
1. H. Ahankar, A. Ramazani, K. Ślepokura, T. Lis, S. Woo Joo, Green Chem. 18, 3582 (2016)
2. A.M. Malekzadeh, A. Ramazani, S.J.T. Rezaei, H. Niknejad, J. Colloid Interface Sci. 490, 64 (2017)
3. H. Ramadoss, D. Saravanan, S.P.N. Sudhan, S. Sheik Mansoor, Der Pharm. Lett. 8, 25 (2016)
4. Z. Hosseinzadeh, A. Ramazani, H. Ahankar, K. Ślepokura, T. Lis, Silicon 11, 45 (2018)
5. M. Zhang, Q.Y. Fu, G. Gao, H.Y. He, Y. Zhang, Y.S. Wu, Z.H. Zhang, ACS Sustain. Chem. Eng. 5,
6
175 (2017)
4
4
4
4
5
5
5
6. T.L. Pavlovska, R.G. Redkin, V.V. Lipson, D.V. Atamanuk, Mol. Divers. 20, 299 (2016)
7. J. Saꢁari, D. Ghanbari, N. Mir, K. Khandan-Barani, J. Ind. Eng. Chem. 20, 4119 (2014)
8. E. Raꢃee, N. Rahpeyma, Chin. J. Catal. 36, 1342 (2015)
9. U. Kurtan, M. Amir, A. Yıldız, A. Baykal, Appl. Surf. Sci. 376, 16 (2016)
0. M. Runowski, S. Lis, J. Lumin. 170, 484 (2016)
1. M. Demirelli, E. Karaoğlu, A. Baykal, H. Sözeri, E. Uysal, J. Alloy. Compd. 582, 201 (2014)
2. M. Amir, A.D. Korkmaz, A. Baykal, M. Geleri, H. Sözeri, H. Güngüneş, M. Sertkol, S.E. Shirsath,
J. Inorg. Organomet. Polym. 27, 1740 (2017)
5
5
3. C. Cannas, A. Musinu, A. Ardu, F. Orrù, D. Peddis, M. Casu, R. Sanna, F. Angius, G. Diaz, G. Pic-
caluga, Chem. Mater. 22, 3353 (2010)
4. T. Dippong, O. Cadar, E.A. Levei, I. Bibicu, L. Diamandescu, C. Leostean, M. Lazar, G. Borodi,
L.B. Tudorand, Ceram. Int. 43, 2113 (2017)
5
5
5
5. L.M. Wang, N. Jiao, J. Qiu, J.J. Yu, J.Q. Liu, F.L. Guo, Y. Liu, Tetrahedron 66, 339 (2010)
6. S.L. Zhu, S.J. Ji, Y. Zhang, Tetrahedron 63, 9365 (2007)
7. R. Sridhar, B. Srinivas, B. Madhav, V.P. Reddy, Y.V.D. Nageswar, K.R. Rao, Can. J. Chem. 87,
1
704 (2009)
5
8. V.Y. Mortikov, Y.M. Litvinov, A.A. Shestopalov, L.A. Rodinovskaya, A.M. Shestopalov, Russ.
Chem. Bull. 57, 2373 (2008)
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