Hollow Fe3O4@DA-SO3H: an efficient and reusable heterogeneous nano-magnetic acid catalyst for synthesis of dihydropyridine and dioxodecahydroacridine derivatives

Article abstract of DOI:10.1007/s13738-016-1029-1

Abstract: In this work, for the first time, a highly stable and efficient super-paramagnetic catalyst, H-Fe₃O₄@DA-SO₃H, involving hollow morphology of Fe₃O₄ as core and dopamine as shell was prepared

Full text of DOI:10.1007/s13738-016-1029-1

J IRAN CHEM SOC
DOI 10.1007/s13738-016-1029-1
ORIGINAL PAPER
Hollow Fe3O4@DA‑SO3H: an efficient and reusable
heterogeneous nano‑magnetic acid catalyst for synthesis
of dihydropyridine and dioxodecahydroacridine derivatives
Marzie sadat Mirhosseyni1 · Firouzeh Nemati1 · Ali Elhampour1
Received: 4 August 2016 / Accepted: 5 December 2016
© Iranian Chemical Society 2016
Abstract In this work, for the first time, a highly sta-
ble and efficient super-paramagnetic catalyst, H-Fe3O4@
DA-SO3H, involving hollow morphology of Fe3O4 as core
and dopamine as shell was prepared through hydrother-
mal template-free method. It has been used as a new and
recoverable catalyst for various one-pot multi-component
organic reactions such as synthesis of 1,4-dihydropyridine
(1,4-DHP) and 1,8-dioxodecahyroacridine derivatives.
The new magnetic catalyst was characterized with differ-
ent analyses including X-ray powder diffraction (XRD),
Fourier transform infrared spectroscopy (FT-IR), field
emission scanning electron microscopy (FE-SEM), trans-
mission electron microscopy (TEM), energy-dispersive
X-ray spectroscopy (EDX), vibrating sample magnetom-
eter (VSM) and thermogravimetric analysis (TGA). Moreo-
ver, the ρshell of the prepared hollow-Fe3O4 microparticles
was calculated, being found just slightly lighter than that
of solid sphere-like Fe3O4. The catalyst was conventionally
recovered, using an external magnet and reused at least in
six successive runs, without appreciable loss of its activity.
Graphical Abstract
* Firouzeh Nemati
fnemati@semnan.ac.ir
1
Department of Chemistry, Semnan University,
35131-19111 Semnan, Iran
1 3

J IRAN CHEM SOC
Keywords Hollow magnetite · Green chemistry ·
Dopamine · Sulfamic acid · Multi-component organic
reaction · Solvent free
our research work in the synthesis of new nano-magnetic
catalysts [59–62] and their application in organic transfor-
mations [63–67], we are going to describe the first-time
preparation and characterization of H-Fe3O4@DA-SO3H
magnetic nanoparticle as a superior heterogeneous acid
(Scheme 1). This new synthesized catalyst has been suc-
cessfully used for some one-pot multi-component reactions
to synthesize different useful heterocyclic compounds such
as 1,4-dihydropyridine (1,4-DHPs) and 1,8-dioxodecahy-
droacridine derivatives.
Introduction
Hollow sphere particles (HSPs) have attracted much atten-
tion because of their special structure, physical and chemi-
cal properties such as well-defined morphology, uniform
size, low density, light weight and high surface area which
make them applicable in various fields such as drug deliv-
ery [1, 2], medicine [3], chemical sensors [4], fuel cells
[5] and photonic materials [6]. In addition, many hollow-
structure particles are used in various organic reactions as
catalyst [7–17].
Experimental
Material and instrument
For these broad and prospective applications of HSPs,
different methods have been developed to prepare these
useful particles in different organic [18, 19] inorganic
[20–22] and hybrid material types [23–25] including hard-
template [26–28], soft-template [29, 30] and template-free
[31–33] strategies.
On the other hand, the use of common Bronsted acidic
catalysts such as HF, sulfuric or phosphoric acid bears vari-
ous disadvantages such as high toxicity, waste generation
and limited solubility phase contact with the starting mate-
rials. To overcome these drawbacks, homogenous acid cat-
alysts were immobilized on the surface of magnetic solid-
supported materials [34–38] which results in their simple
separation by using an external magnet [39]. Among them,
hollow-Fe3O4 particle has become an important object of
research and attracts a growing interest because of its spe-
cial physical and magnetic properties [40–43]. However,
surface functionalization of hollow magnetic particles is
an interesting way to fill the gap between homogenous and
heterogeneous catalysts realm [44].
Dopamine (DA) is an important organic chemical of
catecholamine families that plays several important roles
in the brain and body and also is applicable in different
branches of science such as pharmacy, biology and chem-
istry [45–47]. Recently, dopamine has been proposed as a
novel organic coating material [48–57]. So another objec-
tive of this study was to investigate the role of dopamine as
a linker of acidic functional group on the surface of hollow-
Fe3O4 substrate.
In the present study, we chose dopamine (DA) as the
linker to connect the –SO3H group to the iron oxide shell
of the magnetic nanoparticles because the spectroscopic
study by Rajh [58] suggested that bidentate enediol ligands
such as DA convert the under-coordinated Fe surface sites
back to a bulk-like lattice structure with an octahedral
geometry for oxygen-coordinated iron, which may result
in tight binding of DA to iron oxide. In continuation of
Chemical reagents in high purity were purchased from
Merck and Aldrich and were used without further puri-
fication. Melting points were determined in open capil-
laries using an Electrothermal 9100 without further cor-
rections. The progress of the reactions was monitored by
TLC on commercial aluminum-backed plates of silica gel
60 F254, visualized, using ultraviolet light. X-ray diffrac-
tion (XRD) was detected by Philips using Cu-Ka radiation
of wavelength 1.54Å. Scanning electron microscopy, FE-
SEM–EDX, analysis was performed using Tescanvega II
XMU digital scanning microscope. Samples were coated
with gold at 10 mA for 2 min prior to analysis. The mag-
netic properties were characterized using a vibrating sample
magnetometer (VSM, Lakeshore7407) at room temperature.
The transmission electron microscopy (TEM) micrographs
were taken with a CM30300Kv field emission transmission
electron microscope. Thermogravimetric analyses (TGA)
were conducted with a LINSEIS model STS PT 16000 ther-
mal analyzer under air atmosphere at a heating rate of 5 °C
min−1. 1H NMR and 13C NMR spectra were recorded using
a Bruker spectrometer at 500 and 125 MHz, respectively.
Preparation of catalyst
Preparation of H‑Fe3O4
Firstly, the hollow-Fe3O4 particles were prepared accord-
ing to literature report [68]. Following the procedure, first,
FeCl3·6H2O (1.35 g, 5 mmol) and NaOAc.3H2O (3.85 g,
12.6 mmol) were dissolved in 25 ml ethylene glycol (EG),
then 1 g PVP (polyvinylpyrrolidine) was dissolved in 15 ml
EG and added to the first solution with a magnetic stir-
ring for 15 min. The resulted solution was transferred to a
100-ml Teflon-lined stainless steel autoclave and heated at
200 °C for 12 h. The resulting black mixture was washed
repeatedly with ethanol and deionized water (1:1). It was
dried at 80 °C in an oven.
1 3

J IRAN CHEM SOC
Scheme 1 Preparation of hol-
low Fe3O4@DA-SO3H
Preparation of H‑Fe3O4@DA and H‑Fe3O4@DA‑SO3H
s, C–H), 3.95 (4H, q, CH2), 2.27 (6H, s, 2Me) and 1.12
(6H, s, 2Me); 13C NMR (125 MHz, DMSO-D6) δ: 167.61,
147.98, 146.47, 131.28, 130.07, 128.63, 102.39, 59.89,
39.44, 19.06 and 14.98.
To a stirred well suspension of H-Fe3O4 (1 g) in deionized
water (50 ml) was dissolved dopamine (2 g) and refluxed
for 12 h at 100 °C. The reaction mixture filtered using a
magnet and filtrate (H-Fe3O4@DA) was washed with ace-
tone and dried at 70 °C [54]. Then, in a flask, equipped
with a constant-pressure dropping funnel and a gas inlet
tube for conducting HCl gas over an adsorbing solution,
H-Fe3O4@DA (1 g) was charged. Then, neat chlorosulfonic
acid (0.3 ml, 4.5 mmol) was added drop-wise over a period
of 15 min at room temperature. A voluminous evolution of
HCl gas was observed. The mixture was stirred until HCl
evolution ended up. Then, the H-Fe3O4@DA-SO3H was
collected as a black powder (0.9 g).
9-(4-chlorophenyl)-3,4,6,7-tetrahydro-3,3,6,6-tetra-
methylacridine 1,8(2H, 5H, 9H, 10H)-dione (5c): light yel-
low solid; mp: 297–299 °C; IR νmax (KBr): 842, 1081.99,
1392.51, 1519.80,1691.46, 1714.60, 2956.67, 3103.25 and
1
3315.41 cm−1; H NMR (500 MHz, DMSO-D6) δ: 9.32
(1H, s, N–H), 7.20 (2H, d, Ar–H), 7.16 (2H, d, Ar–H), 4.78
(1H, s, C–H), 2.49-1.97 (8H, m, 4CH2), 1.00 (6H, s, 2Me)
and 0.85 (6H, s, 2Me); 13C NMR (125 MHz, DMSO-D6)
δ: 195.2, 150.3, 146.9, 130.8, 130.3, 128.3, 111.9, 51.03,
33.54, 32.99, 29.90, 27.34.
Loading of H+
Results and discussion
The loading of H+ for the acidic magnetic nanoparticles
was determined using potentiometric titration, and it was
found to be 3.1 mmol/g.
Preparation and characterization of hollow Fe3O4@
DA‑SO3H
General procedure for synthesis of 1,4‑dihydropyridine
(1,4‑DHPs) and 1,8‑dioxodecahydroacridine derivatives
As shown in Scheme 1, in the first step, hollow-Fe3O4
nanoparticles were synthesized by hydrothermal treatment
[68]. The next step involves the functionalization of hollow
Fe3O4 with dopamine [54], and finally –SO3H immobilized
on the surface of H-Fe3O4@DA through covalent binding
of sulfonic acid groups to the surface of a solid support
using ClSO3H in an ice bath.
As shown in Fig. 1, the dopamine coordinated to the sur-
face of the iron oxide nanoparticle because of the improved
orbital overlap of the five-membered ring and a reduced
steric repulsion around the iron complex [69].
The catalytic activity of H-Fe3O4@DA-SO3H was also
evaluated through condensation of various aldehyde (1)
(1 mmol), ethyl acetoacetate (2) (2 mmol) or 1,3-cyclohex-
anedione (4) (2 mmol), NH4OAc (2.5 mmol) and
H-Fe3O4@DA-SO3H (0.01 g) as catalyst at 100 °C under
solvent-free condition. After completion of the reaction
monitored by means of TLC (n-hexan: EtOAc 7:3), the
reaction mixture diluted by hot EtOH and catalyst was sep-
arated from the mixture by means of an external magnet.
The pure products were recrystallized from ethanol.
FT‑IR spectra
Spectroscopic data and physical properties of some
selected compounds Diethy-l4-(4-chlorophenyl)-1,4-di-
hydro-2,6- dimethylpyridine-3,5- dicarboxylate (3c): light
yellow solid; mp: 149 °C; IR νmax (KBr): 827, 1118, 1622,
The FT-IR spectra of H-Fe3O4, H-Fe3O4@DA and
H-Fe3O4@DA-SO3H are depicted in Fig. 2. The Fe–O
stretching vibration near 580 cm−1 was observed in all
three spectra [70]. The significant features of H-Fe3O4@
DA spectrum (Fig. 2b) are the appearance of the peaks
about 3448, 3164, 1625 and 1400 cm−1, which could
be assigned to the –NH2 and C–N stretching vibration of
1
1650, 1475, 1212, 1688, 2958.60 and 3309.62 cm−1; H
NMR (500 MHz, DMSO-D6) δ: 8.84 (1H, s, N–H), 7.30–
7.21 (2H, d, Ar–H), 7.20–7.16 (2H, d, Ar–H), 4.86 (1H,
1 3

J IRAN CHEM SOC
Fig. 2 FT-IR spectra of
H-Fe3O4@DA-SO3H
a H-Fe3O4, b H-Fe3O4@DA and c
Fig. 1 Interaction of dopamine with H-Fe3O4
dopamine related to the surface of hollow MNPs [48]. In
contrast, the grafting of acidic functional group (–SO3H) in
H-Fe3O4@DA-SO3H was confirmed by weak S–O stretch-
ing vibration at 651 cm−1 and strong O=S symmetric
stretching vibration about 1041–1072 cm−1 (Fig. 2c) [61].
The wide and strong absorbance peak at 2800–3400 cm−1
attributed to the –OH groups on the hollow MNPs’ surface
after modification and sulfonation (Fig. 2c). The increase
in intensity of this band confirms that there are more –OH
groups on the surface of final catalyst in comparison with
the spectra of unmodified magnetic particles (a, b).
XRD spectra
Fig. 3 XRD pattern of a H-Fe3O4, b H-Fe3O4@DA and c H-Fe3O4@
DA-SO3H
The XRD analysis of H-Fe3O4, H-Fe3O4@DA, H-Fe3O4@
DA-SO3H was performed and the resulted compara-
tive spectra are depicted in Fig. 3. The XRD spectrum
of H-Fe3O4 shows the diffraction peaks at 2θ = 30.06°,
35.40°, 40.06°, 59.98°, 62.57° and 73.85° which can be
assigned to the (220), (311), (400), (422), (511) and (440)
planes of H-Fe3O4, respectively, that clearly matches with
those of the literature report [71–73]. No other diffrac-
tion peaks were obtained, indicating high purity of the as-
synthesized hollow-Fe3O4 products. However, the XRD
pattern of H-Fe3O4@DA, H-Fe3O4@DA-SO3H shows the
broadband appearing in the range from 20° to 25° that is
related to the presence of amorphous dopamine and dopa-
mine –SO3H shells formed around the magnetic hollow
sphere that are not present in hollow-Fe3O4 species. As
shown in Fig. 3b, c, there is not any considerable shift in
the positions of the peaks, indicating the structural stabil-
ity of H-Fe3O4 MNP during modification and sulfonation
processes. Meanwhile, the average crystal size of H-Fe3O4
was also determined from X-ray pattern using Debye–
Scherrer formula given as τ = K λ/β Cos θ is to be around
34.5 nm.
FE‑SEM, EDX and TEM analyses
The size and morphology of H-Fe3O4 MNPs before and
after the functionalization process were examined by
means of SEM and TEM analyses. Figure 4 shows a typi-
cal SEM image of H-Fe3O4, H-Fe3O4@DA and H-Fe3O4@
DA-SO3H, respectively, that shows the particles are spheri-
cal in shape and nearly monodisperse in size. The elemen-
tal composition of H-Fe3O4, H-Fe3O4@DA and H-Fe3O4@
DA-SO3H was also determined from EDX spectra, which
further confirmed the hollow Fe3O4 (Fig. 4d) modified
with dopamine (Fig. 4e) and functionalized with –SO3H
(Figs. 4f, 5b–g). The presence of Au element is arising
from the coating of materials by layer of Au in FE-SEM
and EDX analyses.
The hollow structure was confirmed by TEM as
shown in Fig. 5. In addition, a strong contrast between
the dark edges and the pale center confirms the creation
of hollow structures. The average diameter of core/shell
1 3

J IRAN CHEM SOC
particles is around 500 nm, which is in agreement with
SEM (Fig. 4c), indicating that the dopamine sulfonic
acid shell covered hollow particles completely. As shown
in Fig. 5, the sphere morphology is well preserved after
modification.
from BET) and specific surface area SA (m2 g−1) (obtained
from BJH) [63]. Therefore, the ρshell value was calculated
as follow: 4.73 g.cm−3
.
4π{(r + t)2 + r2}
(4/3)πρshell{(r + t)3 − r3}
SA =
TGA analysis
The magnetite’s density is established at 5.18 g.cm−3
[76, 77], so the as-synthesized hollow spheres have lower
density than solid sphere-like Fe3O4. It can be important for
potential applications in industrial fields.
Thermal gravimetric analysis (TGA) of H-Fe3O4,
H-Fe3O4@DA and H-Fe3O4@DA-SO3H was used to con-
firm the successful preparation and thermal stability of
catalyst as outlined in Fig. 6. The TGA curves present dif-
ferent mass loss range. In all three curves, a weight loss
(about 10%) in the temperature range from 35 to 150 °C
is attributed to the removal of the surface adsorbed water.
In Fig. 6b, the weight loss (about 20%) up to 250 °C is
related to removal of organic groups on the surface. The
TGA curve for the H-Fe3O4@DA-SO3H exhibits three-
weight loss steps, which are assigned to the loss of water,
decomposition of sulfamic acid and loss of organic groups.
Based on these results, the successful grafting of dopamine
sulfamic acid onto the surface of hollow Fe3O4 is verified.
The catalytic activity of H‑Fe3O4@DA‑SO3H
at different one‑pot multi‑ component reactions
Having synthesized and characterized the H-Fe3O4@
DA-SO3H, its role as a heterogeneous magnetically acid
catalyst was then evaluated in the course of the synthesis
of 1,4-dihydropyridine (1,4-DHPs) and 1,8-dioxodecahy-
droacridine derivatives. In order to optimize reaction con-
ditions, the reaction of benzaldehyde (1 mmol) with ethyl
acetoacetate (2 mmol) or dimedone (2 mmol) in the pres-
ence of NH4OAc (2.5 mmol) to afford the corresponding
products (3a and 5a) was selected as the model reactions.
In this regard, various reaction parameters such as solvent,
temperature and the amount of catalyst should be consid-
ered (Scheme 2).
In addition, with respect to the green chemistry consid-
erations, the model reactions were carried out in solvent-
free condition, too (Table 1). As Table 1 shows, in the
absence of the catalyst, a low yield of the products has been
obtained (Table 1, entry 8).
A variety of aromatic aldehydes bearing electron-donat-
ing or electron-withdrawing groups (Table 2, entries 1–9),
aliphatic aldehyde (Table 2, entry 10) and heteroaromatic
aldehyde (Table 2, entry 11) smoothly reacted with ethyl-
acetoacetate and ammonium acetate to give the correspond-
ing 1,4-DHPs in good-to-high yields and short reaction
times. We also tested aromatic aldehydes with substituent
in different positions (Table 2, entries 6–8). To our delight,
ortho- and meta- substituted aromatic aldehydes were
also very reactive and gave high yields of corresponding
products.
Magnetization study
The magnetic properties of H-Fe3O4, H-Fe3O4@DA and
H-Fe3O4@DA-SO3H were studied by vibrating sample mag-
netometer (VSM) at room temperature and are presented
in Fig. 7. The curves show no remnant magnetization or
coercivity, indicating three samples are super-paramagnetic
at room temperature. In addition, H-Fe3O4 shows relative
high-saturation magnetization. So, H-Fe3O4 has super-para-
magnetic behavior and high saturation magnetization prop-
erties, simultaneously [72, 74]. Considering the curves a, b
and c in the Fig. 6, it is found that the saturation magnetiza-
tion values of H-Fe3O4, H-Fe3O4@DA and H-Fe3O4@DA-
SO3H are 70.66, 50.85 and 37.35 emu/g, respectively. The
decrease in the saturation magnetization of H-Fe3O4@DA
and H-Fe3O4@DA-SO3H is attributed to the contribution
of the non-magnetic materials. The results indicated that the
obtained catalyst would respond fast under external magnet.
Calculation of H‑Fe3O4 density
Encouraged by these results, the optimized condition
was also attempted to the synthesis a variety of 1,8-diox-
odecahydroacridine derivatives (Table 3). Therefore, the
reaction of different aldehydes with ammonium acetate
and dimedone or 1,3-cyclohexanedione resulted in the
formation of the corresponding products. The reactions
were clean and the products result in high yield (94–80%)
in reaction times ranging from 25 to 55 min. This method
is equally effective with aldehydes bearing electron-
withdrawing (Table 3, entries 2–8, 14–16 and 18–19),
It is important to determine the physical property of shell
in hollow sphere particles, because it is the most consider-
able factor, which directly affects functionality of the final
catalyst. So, in this study the shell density was determined
using specific surface area and shell thickness as reported
earlier in the literature [75].
The ρshell was calculated with shell thickness of “t” (nm)
(obtained from XRD), inner radius of “r” (nm) (obtained
1 3

J IRAN CHEM SOC
Fig. 4 FE-SEM–EDS analysis of H-Fe3O4 (a, d), H-Fe3O4@DA (b, e) and H-Fe3O4@DA-SO3H (c, f)
electron-donating groups (Table 3, entries 9–11, 17 and 20)
and aromatic rings containing bulky substituents (Table 3,
entry 12).However, aliphatic aldehydes have no reaction
activity in the novel method.
The comparison of the catalytic activity of H-Fe3O4@
DA-SO3H with various catalysts at different reaction con-
ditions for synthesis of (3a) and (5a) compounds is listed
in Table 4. The collected data clearly indicate that this new
synthesized catalyst has many advantages in various fields
such as reaction time, yield and catalytic activity.
Recyclability of catalyst
The reusability and recovery of the catalyst are important
issues for the catalytic reactions, which make the method
economically cheap, industrially profitable and environ-
mentally sustainable. So, the reaction between benzalde-
hyde (1 mmol) and dimedone (2 mmol) under optimal reac-
tion condition was selected to investigate the constancy of
the catalyst activity for this model reaction. After comple-
tion of the reaction, hot ethanol was added to the reaction
1 3

J IRAN CHEM SOC
Fig. 5 TEM of H-Fe3O4@
DA-SO3H (a) and elemental
mapping data of H-Fe3O4@DA-
SO3H (b–g)
Fig. 7 Magnetization curves for H-Fe3O4 (a), H-Fe3O4@DA (b) and
H-Fe3O4@DA-SO3H (c)
Fig. 6 TGA of a H-Fe3O4, b H-Fe3O4@DA and c H-Fe3O4@DA-
SO3H
mixture and the catalyst was easily separated using an
external magnet. It was washed with ethanol, dried at 70 °C
and used for the next cycle. The recovered catalyst could be
added to fresh substrates of mentioned reaction for at least
6 times without any noticeable reduction in catalytic activ-
ity (Fig. 8).
1 3

J IRAN CHEM SOC
Scheme 2 Model reactions for
optimization of reaction condi-
tion for synthesis of 3a and 5a
O
O
O
O
O
O
OEt
CHO
O
EtO
OEt
O
+ NH4OAc
N
H
N
H
(5a)
Reaction condition
Reaction condition
(3a)
Table 1 Optimization of
No.
Catalyst (g)
Condition
Time (min)
Yield (%)a
8a
reaction condition for synthesis
of 1,4-dihydropyridine and
1,8-dioxodecahydroacridine
8a
9a
9a
1
0.005
Solvent free/80 °C
Solvent free/80 °C
Solvent free/90 °C
Solvent free/90 °C
Solvent free/100 °C
Solvent free/100 °C
Solvent free/100 °C
Solvent free/100 °C
Solvent free/100 °C
Solvent free/100 °C
Solvent free/100 °C
50
45
45
40
40
40
25
60
40
40
40
45
40
45
40
40
40
35
60
40
40
40
75
80
80
85
85
90
90
90
2
0.01
75
3
0.005
80
4
0.01
80
5
0.01
85
6
0.02
85
7
0.04
85
8
–
Trace
54
9
Fe3O4(0.01 g)
Fe3O4@DA (0.01 g)
DA (0.01 g)
55
45
10
11
32
Trace
Reaction condition: benzaldehyde (1 mmol), ethyl acetoacetate or dimedone (2 mmol), NH4OAc
(2.5 mmol)
a
Isolated yield
Table 2 Synthesis of 1,4-dihydropyridine derivatives
No.
Aldehyde
Product
Time (min)
Yield (%)a
M.P. (°C)
1
OHC–C6H5
3a
3b
3c
3d
3e
3f
40
25
45
30
25
35
40
45
25
25
20
85
92
88
85
84
87
85
83
85
79
86
157–158 [78]
126–128 [79]
149 [80]
2
2-Cl–C6H4–CHO
4-Cl–C6H4–CHO
4-Br–C6H4–CHO
4-F–C6H4–CHO
3
4
165–167 [78]
147-148 [80]
162–164 [81]
160–161 [82]
129–130 [78]
157–158 [80]
139–140 [80]
169–170 [82]
5
6
2-O2N–C6H4–CHO
3-O2N–C6H4–CHO
4-O2N–C6H4–CHO
4-MeO–C6H4–CHO
Cinnamaldehyde
Thiophen-2-carbaldehyde
7
3 g
3 h
3i
8
9
10
11
3j
3 k
Reaction condition: aldehyde (1 mmol), ethyl acetoacetate (2 mmol), NH4OAc (2.5 mmol), H-Fe3O4@DA-SO3H (0.01 g), under solvent-free
condition at 100 °C
a
Isolated yield
1 3

J IRAN CHEM SOC
Table 3 Synthesis of 1,8-dioxodecahydroacridine derivatives
No.
Aldehyde
R1
Product
Time (min)
Yield (%)a
M.P. (°C)
1
OHC–C6H5
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
H
5a
5b
5c
5d
5e
5f
40
35
40
35
25
45
45
40
30
40
40
40
50
45
35
35
35
40
40
55
90
88
92
90
90
85
90
94
85
90
90
85
89
85
90
92
92
90
85
80
290–291 [34]
225–227 [34]
297–299 [34]
312–313 [34]
292–293 [34]
284–286 [34]
282–284 [34]
302–303 [34]
265–267 [34]
268–270 [34]
269–271 [34]
264–266 [34]
279–280 [34]
295–298 [83]
280–281 [34]
295–296 [83]
253–254 [34]
295–296 [34]
310–311 [34]
302–304 [34]
2
2-Cl–C6H4–CHO
4-Cl–C6H4–CHO
4-Br–C6H4–CHO
4-F–C6H4–CHO
3
4
5
6
2-O2N–C6H4–CHO
3-O2N–C6H4–CHO
4-O2N–C6H4–CHO
4-(CH3)2N–C6H4–CHO
4-Me–C6H4–CHO
4-MeO–C6H4–CHO
2-Naphtaldehyde
OHC–C6H5
7
5 g
5 h
5i
8
9
10
11
12
13
14
15
16
17
18
19
20
5j
5 k
5 l
6a
6b
6c
6d
6e
6f
2-O2N–C6H4–CHO
3-O2N–C6H4–CHO
4-O2N–C6H4–CHO
4-Me–C6H4–CHO
4-Cl–C6H4–CHO
4-Br–C6H4–CHO
4-MeO–C6H4–CHO
H
H
H
H
H
H
6 g
6 h
H
Reaction condition: aldehyde (1 mmol), dimedone or 1,3-cyclohexanedione (2 mmol), NH4OAc (2.5 mmol), H-Fe3O4@DA-SO3H (0.01 g),
under solvent-free condition at 100 °C
a
Isolated yield
Table 4 Comparison of the
catalytic activity of H-Fe3O4@
No. Catalyst
Condition
Product Time (min) Yield (%)
DA-SO3H with various catalysts
1
TiO2 NPs
Fe-TDU-1
n-FTSAa
n-ZrSAb
EtOH/reflux
EtOH/80 °C
3a
3a
135
300
50
45
15
20
180
20
5
92 [78]
76 [84]
95 [85]
91 [34]
89 [86]
90 [87]
61 [88]
93 [89]
92 [39]
85c
2
3
Solvent free/110 °C 5a
Solvent free/100 °C 5a
4
5
Benzyltrimethylammoniumfluoride hydrate Solvent free/70 °C 3i
6
Chitosan
Solvent free/80 °C 3a
Solvent free/80 °C 3a
Solvent free/80 °C 5a
Solvent free/80 °C 5a
Solvent free/100 °C 3a
Solvent free/100 °C 5a
7
Dimethyl phosphate ionic liquids
Vanadatesulfuric acid
Fe3O4 (0.024 g)
8
9
10
11
H-Fe3O4@DA-SO3H (0.01 g)
H-Fe3O4@DA-SO3H (0.01 g)
40
40
90c
a
Nano-Fe3O4–TiO2–SO3H
Nano-ZrO2–SO3H
This work
b
c
1 3

J IRAN CHEM SOC
15. M. Sasidharan, S. Anandhakumar, P. Bhanja, A. Bhaumik, J.
Mol. Catal. A: Chem. 411, 87 (2016)
16. C. Deng, X. Ge, H. Hu, L. Yao, C. Han, D. Zhao, Cryst. Eng.
Comm. 16, 2738 (2014)
17. J.Y. Kim, J.C. Park, H. Kang, H. Song, K.H. Park, Chem. Com-
mun. 46, 439 (2010)
18. J. Chattopadhyay, T.S. Pathak, R. Srivastava, A.C. Singh, Elec-
trochim. Acta 167, 429 (2015)
19. H. Lv, G. Ji, W. Liu, H. Zhanga, Y. Dub, J. Mater. Chem. C. 3,
10232 (2015)
20. Y. Yang, W. Zhang, Y. Zhang, A. Zheng, H. Sun, X. Li, S. Liu, P.
Zhang, X. Zhang, Nano Res. 8, 3404 (2015)
21. M. Chen, L. Wu, S. Zhou, B. You, Adv. Mater. 18, 801 (2006)
22. C. Zhou, K. Huang, L. Yuan, W. Feng, X. Chu, Z. Geng, X. Wu,
L. Wang, S. Feng, N. J. Chem. 39, 2413 (2015)
23. Z. Teng, X. Su, Y. Zheng, J. Zhang, Y. Liu, S. Wang, J. Wu, G.
Chen, J. Wang, D. Zhao, G. Lu, J. Am. Chem. Soc. 137, 7935
(2015)
Fig. 8 Catalyst recyclability experiment
Conclusions
24. M.K. Kim, D.W. Kim, D.W. Shin, S.J. Seo, H.K. Chung, J.B.
Yoo, Phys. Chem. Chem. Phys. 17, 2416 (2015)
25. M. Ohnishi, Y. Kozuka, Q.L. Ye, H. Yoshikawa, K. Awaga, R.
Matsuno, M. Kobayashi, A. Takahara, T. Yokoyama, S. Bandow,
S. Iijima, J. Mater. Chem. 16, 3215 (2006)
26. M. Chen, L. Wu, S. Zhou, B. You, Adv. Mater. 18, 801 (2006)
27. M.M. Titirici, M. Antonietti, A. Thomas, Chem. Mater. 18, 3808
(2006)
In summary, the new hollow-Fe3O4-supported dopamine
sulfamic acid was introduced as an efficient and low-
density catalyst for different multi-component organic
reactions including synthesis of 1,4-dihydropyridine and
1,8-dioxodecahydroacridine derivatives under solvent-free
condition. The novel catalyst could be recovered in a fac-
ile manner from the reaction mixture and a good yield was
observed even after the catalyst was recycled six times.
28. M. Shokouhimehr, J.E. Lee, S.I. Hana, T. Hyeon, Chem. Com-
mun. 49, 4779 (2013)
29. Z. Wang, M. Chen, L. Wu, Chem. Mater. 20, 3251 (2008)
30. Y. Zhao, J. Zhang, W. Li, C. Zhang, B. Han, Chem. Commun.
2365 (2009)
Acknowledgements The authors gratefully acknowledge Semnan
University Research Council for financial support of this work.
31. B. Liu, H.C. Zeng, Small 1, 566 (2005)
32. J. Li, H.C. Zeng, J. Am. Chem. Soc. 129, 15839 (2007)
33. Z. Wang, L. Wu, M. Chen, S. Zhou, J. Am. Chem. Soc. 131,
11276 (2009)
References
34. A. Amoozadeh, S. Rahmani, B. Bitaraf, F. Bolghan Abadi, E.
Tabrizian, N. J. Chem. 40, 770 (2016)
1. J. Shin, R.M. Anisur, M.K. Ko, G.H. Im, J.H. Lee, I.S. Lee,
Angew. Chem. Int. Ed. 48, 321 (2009)
2. J.F. Chen, H.M. Ding, J.X. Wang, L. Shao, Biomaterials 25, 723
(2004)
35. N. Koukabi, E. Kolvari, M.A. Zolfigol, A. Khazaei, B. Sagha-
semi, B. Fasahati, Adv. Synth. Catal. 354, 2001 (2012)
36. E. Kolvari, N. Koukabi, M.M. Hosseini, M. Vahidian, E. Gho-
badi, RSC Adv. 6, 7419 (2016)
3. J. Gao, J. Chen, X. Li, M. Wang, X. Zhang, F. Tan, S. Xu, J. Liu,
37. M. A. Zolfigol, M. Yarie, Appl. Organometal. Chem. (2016).
J. Colloid Interface Sci. 444, 38 (2015)
doi:10.1002/aoc.3598
4. S. Ameen, M.S. Akhtar, H.K. Seoa, H. Shina, Chem. Eng. J. 270,
564 (2015)
5. X. Lai, J.E. Halpert, D. Wang, Energy Environ. Sci. 5, 5604
(2012)
6. G. Duan, W. Cai, Y. Luo, F. Sun, Adv. Funct. Mater. 17, 644
(2007)
38. K. Debnath, K. Singha, A. Pramanik, RSC Adv. 5, 31866 (2015)
39. M. Nasr-Esfahani, S.J. Hoseini, M. Montazerozohori, R. Meh-
rabi, H. Nasrabadi, J. Mol. Catal. A: Chem. 382, 99 (2014)
40. T. Yao, H. Wang, Q. Zuo, J. Wu, B. Xin, F. Cui, T. Cui, J. Colloid
Interface Sci. 450, 366 (2015)
41. P. Wang, H. Zhu, M. Liu, J. Niu, B. Yuan, R. Li, J. Ma, RSC Adv.
7. P. Wang, H. Zhu, M. Liu, J. Niu, B. Yuan, R. Li, J. Ma, RSC Adv.
4, 28922 (2014)
4, 28922 (2014)
42. S. Xuan, W. Jiang, X. Gong, Y. Hu, Z. Chen, J. Phys. Chem. C
113, 553 (2009)
43. H. Liu, P. Wang, H.Yang, J. Niu, J. Ma, N. J. Chem. 39, 4343 (2015)
44. M.B. Gawande, P.S. Brancoa, R.S. Varma, Chem. Soc. Rev. 42,
3371 (2013)
8. J. Niu, M. Liu, P. Wang, Y. Long, M. Xie, R. Li, J. Ma, N. J.
Chem. 38, 1471 (2014)
9. H. Kang, H. Lee, J. Park, H. Song, K. Park, Top. Catal. 53, 523
(2010)
10. F. Zhang, Y. Wei, X. Wu, H. Jiang, W. Wang, H. Li, J. Am. Chem.
Soc. 136, 13963 (2014)
45. H. Peng, X. Zhang, K. Huang, H. Xu, J. Wuhan. Univ. Technol.
Mat. Sci. Ed. 23, 480 (2008)
11. X. Wu, L. Tan, D. Chen, X. Meng, F. Tang, Chem. Commun. 50,
539 (2014)
46. B. Mirzayi, A. Nematollahzadeh, S. Seraj, Powder Technol. 270,
185 (2015)
12. H. Li, Z. Zhu, J. Liu, S. Xie, H. Li, J. Mater. Chem. 20, 4366
(2010)
13. Y. Guo, Y.T. Xu, G.H. Gao, T. Wang, B. Zhao, X.Z. Fu, R. Sun,
C.P. Wong, Catal. Commun. 58, 40 (2015)
14. C.C. Nguyen, N.N. Vu, T.O. Do, J. Mater. Chem. A 4, 4413
(2016)
47. M. Martın, P. Salazar, R. Villalonga, S. Campuzano, J.M. Pingar-
ron, J. Gonzalez-Mora, J. Mater. Chem. B 2, 739 (2014)
48. V. Polshettiwar, B. Baruwati, R.S. Varma, Green Chem. 11, 127
(2009)
49. V. Polshettiwar, M.N. Nadagouda, R.S. Varma, Chem. Commun.
6318 (2008)
1 3

J IRAN CHEM SOC
50. B.R. Vaddula, A. Saha, J. Leazer, R.S. Varma, Green Chem. 14,
2133 (2012)
70. S.P. Pawar, D.A. Marathe, K. Pattabhi, S. Bose, J. Mater. Chem.
A 3, 656 (2015)
51. A. Saha, J. Leazer, R.S. Varma, Green Chem. 14, 67 (2012)
52. D. Losic, Y. Yu, M.S. Aw, S. Simovic, B. Thierry, J. Addai-Men-
sah, Chem. Commun. 46, 6323 (2010)
53. R.B. Nasir Baig, R.S. Varma, Chem. Commun. 48, 2582 (2012)
54. D. Guin, B. Baruwati, S.V. Manorama, Org. Lett. 9, 1419 (2007)
55. O. Gleeson, R. Tekoriute, Y.K. Gun,ko, S.J. Connon, Chem. Eur.
J. 15, 5669 (2009)
71. J. Niu, M. Xie, X. Zhu, Y. Long, P. Wang, R. Li, J. Mol. Catal. A:
Chem. 392, 247 (2014)
72. A. Naghipour, A. Fakhri, Catal. Commun. 73, 39 (2016)
73. J. Safari, Z. Zarnegar, J. Mol. Catal. A: Chem. 379, 269 (2013)
74. W. Cheng, K. Tang, Y. Qi, J. Sheng, Z. Liu, J. Mater. Chem. 20,
1799 (2010)
75. C. Takai, H. Watanabe, T. Asai, M. Fuji, Colloids. Surf. A: Phys-
icochem. Eng. Aspects 404, 101 (2012)
56. M. Hajjami, A. Ghorbani-Choghamarani, R. Ghafouri-Nejad, B.
Tahmasbi, N. J. Chem. 40, 3066 (2016)
76. Z.R. Marand, M.H.R. Farimani, N. Shahtahmasebi, Nanomed. J.
57. Ch. Lei, F. Han, D. Li, W.-C. Li, Q. Sun, X.-Q. Zhang, A.-H. Lu,
Nanoscale. 5, 1168 (2013)
1, 238 (2014)
77. L. Blaney, Lehigh Univ. 15, 33 (2007)
58. L.X. Chen, T. Liu, M.C. Thurnauer, R. Csencsits, T. Rajh, J.
78. M. Tajbakhsh, E. Allaee, H. Alinezhad, M. Khanian, F. Jahani,
S. Khaksar, P. Rezaee, M. Tajbakhsh, Chin. J. Catal. 33, 1517
(2012)
79. Y.L.N. Murthy, A. Rajack, M.T. Ramji, J.J. Babu, C. Praveen,
K.A. Lakshmi, Bioorg. Med. Chem. Lett. 22, 6016 (2012)
80. E. Priede, A. Zicmanis, Helvetica Chim. Acta 98, 1095 (2015)
81. S. Wang, Z. Li, J. Zhang, J. Li, Ultrason. Sonochem. 15, 677
(2008)
Phys. Chem. B 106, 8539 (2002)
59. F. Nemati, M.M. Heravi, A. Elhampour, RSC Adv. 5, 45775
(2015)
60. F. Nemati, A. Elhampour, H. Farrokhi, M.B. Natanzi, Catal.
Commun. 66, 15 (2015)
61. F. Nemati, S. Sabaqian, J. Saudi Chem. Soc. (2014).
doi:10.1016/j.jscs.2014.04.009
62. F. Nemati, M.M. Heravi, R. Saeedirad, Chin. J. Catal. 33, 1825
(2012)
63. A. Elhampour, M. Malmir, E. Kowsari, F. Boorboor ajdarib, F.
82. J. Safari, F. Azizi, M. Sadeghi, N. J. Chem. 39, 1905 (2015)
83. M. Nasr-Esfahani, M. Montazerozohori, T. Abdizadeh, C. R.
Chimie. 18, 547 (2015)
Nemati, RSC Adv. 6, 96623 (2016)
84. V.V. Srinivasan, M.P. Pachamuthu, R. Maheswari, J. Porous
64. F. Nemati, R. Saeedirad, Chin. Chem. Lett. 24, 370 (2013)
65. F. Nemati, A. Elhampour, S. Zulfaghari, Phosphorus, Sulfur Sili-
con Relat. Elem. 190, 692 (2015)
Mater. 22, 1187 (2015)
85. A. Amoozadeh, S. Golian, S. Rahmani, RSC Adv. 5, 45974
(2015)
66. F. Nemati, A. Elhampour, M.B. Natanzi, S. Sabaqian, J. Iran.
86. A. Khaskel, P. Barman, Heteroat. Chem. 27, 114 (2016)
87. J. Safari, F. Azizi, M. Sadeghi, New J. Chem. 39, 1905 (2015)
88. E. Priede, A. Zicmanis, Helv. Chim. Acta 98, 1095 (2015)
89. M. Nasr-Esfahani, M. Montazerozohori, T. Abdizadeh, C. R.
Chimie 18, 547 (2015)
Chem. Soc. 13, 1045 (2016)
67. F. Nemati, A. Elhampour, Sci. Iranica C 19, 1594 (2012)
68. Q.Q. Xiong, J.P. Tu, Y. Lu, J. Chen, Y.X. Yu, Y.Q. Qiao, X.L.
Wang, C.D. Gu, J. Phys. Chem. C 116, 6495 (2012)
69. M.D. Shultz, J.U. Reveles, S.N. Khanna, E.E. Carpenter, J. Am.
Chem. Soc. 129, 2482 (2007)
1 3