Synthesis and characterization of bromine source immobilized on diethylenetriamine-functionalized magnetic nanoparticles: A novel, versatile and highly efficient reusable catalyst for organic synthesis

Article abstract of DOI:10.1002/aoc.3687

Bromine source immobilized on magnetic nanoparticles functionalized with diethylenetriamine was successfully synthesized and characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, vibrating sample magnetometry, thermogravimetric analysis and X-ray diffraction. The catalytic activity in the synthesis of 2,3-dihydroquinazoline-4(1H)-one and polyhydroquinoline derivatives and in Knoevenagel condensation was studied. The bromine catalyst can be magnetically recovered and reused several times without significant loss of its catalytic activity. All products were obtained in high to excellent yields.

Full text of DOI:10.1002/aoc.3687

Received: 7 September 2016
DOI 10.1002/aoc.3687
Revised: 17 October 2016
Accepted: 18 October 2016
F U L L PA P E R
Synthesis and characterization of bromine source immobilized on
diethylenetriamine‐functionalized magnetic nanoparticles: A
novel, versatile and highly efficient reusable catalyst for organic
synthesis
Lotfi Shiri1 | Sadegh Rahmati2 | Zahra Ramezani Nejad1 | Mosstafa Kazemi1
1 Department of Chemistry, Faculty of Basic
Bromine source immobilized on magnetic nanoparticles functionalized with
diethylenetriamine was successfully synthesized and characterized using Fourier
transform infrared spectroscopy, scanning electron microscopy, vibrating sample
magnetometry, thermogravimetric analysis and X‐ray diffraction. The
catalytic activity in the synthesis of 2,3‐dihydroquinazoline‐4(1H)‐one and
polyhydroquinoline derivatives and in Knoevenagel condensation was studied. The
bromine catalyst can be magnetically recovered and reused several times without
significant loss of its catalytic activity. All products were obtained in high to excel-
lent yields.
Sciences, Ilam University, PO Box 69315‐516
Ilam, Iran
2 Department of Chemistry, Payame Noor
University (PNU), PO Box 19395‐3697 Tehran,
Iran
Correspondence
Lotfi Shiri, Department of Chemistry, Faculty of
Basic Sciences, Ilam University, PO Box 69315‐
516, Ilam, Iran.
Email: lshiri47@gmail.com
KEYWORDS
2,3‐dihydroquinazoline‐4(1H)‐one, bromine source, Knoevenagel condensation,
magnetic nanoparticles, magnetic separation, polyhydroquinoline
1
|
INTRODUCTION
acid[24] have been recently reported in the literature. Despite
the great importance of these strategies, most of them suffer
2,3‐Dihydroquinazoline‐4(1H)‐ones and polyhydroquino-
lines are two important classes of nitrogen‐containing
heterocyclic compounds that have attracted much attention
in medicinal chemistry, because their structural motifs (as
intermediates) play a pivotal role in the synthesis of natural
products and active molecules with valuable antioxidant and
pharmacological properties.[1–6] Recent literature clearly
from various drawbacks such as unsatisfactory yields, forma-
tion of undesirable di‐substituted products, long reaction
times, high temperatures, tedious work‐up, use of hazardous
and carcinogenic solvents as reaction media as well as use
of toxic, expensive and non‐reusable catalysts. Therefore,
the design and development of new, clean and efficient
synthetic strategies (using reusable catalysts and green
solvents) for the synthesis of these valuable derivatives is still
an important challenge from environmental, practical and
economic points of view.
shows
that
2,3‐dihydroquinazoline‐4(1H)‐one
and
polyhydroquinoline have a broad spectrum of biological
and pharmacological activities such as antitumor, anticancer,
antibiotic, antidiabetic, antibacterial, antidefibrillatory,
antipyretic and anticonvulsant activities.[7–10] In view of their
tremendous importance, for the synthesis of 2,3‐dihydro-
quinazoline‐4(1H)‐one and polyhydroquinoline frameworks,
a variety of catalysts and promoters such as ammonium
chloride,[11] iodine,[12] ionic liquids,[13,14] Brønsted acids,[15]
phosphoric acid,[16] copper chloride,[17] tetrabutylammonium
The design and development of new strategies for the
heterogenization of homogeneous catalysts on solid supports
is an important challenge in modern catalysis research.[25]
Nowadays, magnetic nanoparticles (MNPs), especially
Fe3O4 nanoparticles, have emerged as popular heterogeneous
supports for the immobilization of homogeneous catalysts,
because these MNPs (after completion of reactions) can be
readily separated from the reaction using an eternal
bromide,[18] TMSCl‐NaI,[19] heteropolyacid,[20] nickel nano-
particles,[21] MCM‐41,[22] ZrCl4
and p‐toluenesulfonic
[23]
magnet.[26–28] In fact, MNPs are
a bridge between
Appl Organometal Chem 2017; e3687;
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Copyright © 2017 John Wiley & Sons, Ltd.
1 of 10
DOI 10.1002/aoc.3687

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SHIRI ET AL.
heterogeneous and homogeneous catalysts and also magnetic
separation is a promising alternative to filtration or centrifu-
gation because it prevents loss of catalyst and increases
reusability.[29,30]
chloroform at ambient temperature led to the corresponding
MNPs‐DETA tribromide.
MNPs‐DETA tribromide was characterized using Fourier
transform infrared (FT‐IR) spectroscopy, scanning electron
microscopy (SEM), vibrating sample magnetometry (VSM),
X‐ray diffraction (XRD) and thermogravimetric analysis
(TGA).
Up to now, a diverse range of synthetic protocols have
been developed for the construction of organic compounds
and synthetic intermediates using molecular bromine.[31] To
decrease the impact of the toxicity of molecular bromine,
during recent decades a series of tribromide‐containing com-
pounds have been prepared and successfully applied as cata-
lysts for organic reactions to obtain the corresponding target
synthetic products.[32,33] The immobilization of N‐tribromide
reagents on MNPs can be regarded as an efficient and
fascinating catalytic strategy. Inspired by this catalytic strat-
egy, herein we report magnetic Fe3O4 nanoparticle‐supported
diethylenetriamine/tribromide source as a new, eco‐friendly
and magnetically recoverable catalyst for the synthesis of
2,3‐dihydroquinazoline‐4(1H)‐one and polyhydroquinoline
derivatives.
The FT‐IR spectrum of MNPs‐DETA tribromide is shown
in Figure 1, which clearly differs from those of non‐function-
alized Fe3O4 MNPs and CPTMS‐MNPs. The FT‐IR spectrum
of Fe3O4 nanoparticles shows a stretching vibration at
3440 cm−1 which incorporates the contributions from both
symmetric and asymmetric modes of the O─H bonds that
are attached to the surface iron atoms (Figure 1a). The
presence of Fe3O4 is shown by the strong absorption band at
around 560 cm−1, which is attributed to the Fe─O bond of
Fe3O4.[15] The CPTMS anchored on Fe3O4 is confirmed
by C─H stretching vibrations that appear at 2855–
2956 cm−1 (Figure 1b). Also the absorption around at 1000
and 1044 cm−1 corresponds to Si─O stretching vibration.[16]
As shown in Figure 1c, the functionalized DETA instead of
Cl is confirmed by N─H stretching vibration that appears at
2
| RESULTS AND DISCUSSION
3446 cm−1 [34]
In the FT‐IR spectrum of MNPs‐DETA‐
.
Br (Figure 1d), the presence of the anchored benzyl
groups are confirmed by C─H stretching vibration that
appears at 2960 cm−1 and also C═C stretching vibration
2.1 | Preparation and characterization of catalyst
Bromine source immobilized on magnetic Fe3O4 nanoparti-
cles functionalized with diethylenetriamine (MNPs‐DETA
tribromide) was successfully synthesized using a surface
modification strategy as depicted in Scheme 1. The Fe3O4
MNPs were prepared by the chemical co‐precipitation
method[2] and coated with 3‐chloropropyltrimethoxysilane
(CPTMS) via covalent bonds.[6] The reaction of the sup-
ported CPTMS with diethylenetriamine (DETA) in toluene
under reflux conditions for 42 h produced DETA‐functional-
ized Fe3O4 nanoparticles (MNPs‐DETA). Finally, the
reaction of DETA‐Fe3O4 bromide, formed via the reaction
of MNPs‐DETA and benzyl bromide, with Br2 in
mode as a broad band that appears at 1648 cm−1 [35]
.
The particle morphology and textural properties of the
nanocatalyst were studied using SEM. The SEM images of
MNPs‐DETA tribromide nanoparticles at different magnifi-
cations are displayed in Figure 2. The SEM images of the
synthesized nanocatalyst confirm the formation of nanoparti-
cles with spherical shapes. From this analysis, it is evident
that the catalyst is made up of uniform particles and the
average size of MNPs‐DETA tribromide is about 18 nm.
SCHEME
1
General route for the synthesis of DETA tribromide
FIGURE 1 FT‐IRspectraof(a)MNPs,(b)CPTMS‐MNPs,(c)DETA‐MNPs,
(d) MNPs‐DETA‐Br and (e) MNPs‐DETA tribromide
immobilized on magnetic nanoparticles

SHIRI ET AL.
3 of 10
FIGURE
4
Magnetization curves for MNPs (red) and MNPs‐DETA
tribromide (green) at room temperature
XRD is an effective technique for the investigation of the
major properties of magnetite structures. In fact, the
formation of magnetite crystal phase in the nanomagnetic
catalyst in aggregate powder form can be well identified
using XRD. The XRD spectrum of MNPs‐DETA tribromide
is displayed in Figure 5. The XRD pattern of the catalyst
shows several peaks at 2θ values of 35.1°, 41.5°, 50.6°,
63.1°, 67.5° and 74.6°, which are related to crystal planes
in the MNP cubic lattice.[2]
FIGURE 2 SEM images of MNPs‐DETA tribromide
TGA was used to determine the amount of functional
groups chemisorbed onto the surface of MNPs. Figure 3
shows the TGA curves for bare MNPs, MNPs‐CPTMS,
MNPs‐DETA and MNPs‐DETA tribromide. The TGA curves
of the samples show a small weight loss below 200 °C due to
desorption of physically adsorbed solvents and surface
hydroxyl groups.[17] Organic groups have been reported to
desorb at temperatures above 260 °C. The organic groups
on the catalyst are found to have a mass percentage loss of
about 15%, while MNPs‐CPTMS and MNPs‐DETA have
mass losses of 5 and 9%, respectively. As shown in
Figure 3, the catalyst is stable even at 200 °C.
The magnetic properties of MNPs and MNPs‐DETA
tribromide were characterized using VSM. The room temper-
ature magnetization curves of MNPs and MNPs‐DETA
tribromide are shown in Figure 4. As can be seen, the
saturation magnetization of MNPs‐DETA tribromide is about
17 emu g−1, which is much lower than that of bare MNPs
(about 55 emu g−1).
2.2 | Catalytic study
2.2.1
| 2,3‐dihydroquinazoline‐4(1H)‐ones
After successful characterization of the prepared nanosolid
catalyst, the catalytic activity of MNPs‐DETA tribromide in
the synthesis of 2,3‐dihydroquinazoline‐4(1H)‐ones was
studied. To standardize the reaction conditions, the impact
of a series of parameters (such as catalyst concentration,
solvent nature and reaction temperature) on the
cyclocondensation of anthranilamide with 4‐chloroben-
zaldehyde as model substrates was investigated. According to
Table 1, the highest yield and shortest reaction time of prod-
uct 2a are obtained in the presence of 15 mg of MNPs‐DETA
tribromide in water (2 ml) at 70 °C (Table 1, entry 3).
To investigate the generality of the catalytic protocol, we
extended the reaction to a broad spectrum of aromatic
aldehydes under the optimized reaction conditions
(Scheme 2). The results are summarized in Table 2. In
FIGURE 3 TGA curves of bare MNPs (black), MNPs‐CPTMS (blue),
MNPs‐DETA (green) and MNPs‐DETA tribromide (red)
FIGURE 5 XRD pattern of MNPs‐DETA tribromide

4 of 10
SHIRI ET AL.
TABLE 1 Optimization of reaction conditionsa
2.2.2 | Polyhydroquinolines
Following our successful synthesis of 2,3‐dihydroqui-
nazoline‐4(1H)‐one derivatives, we decided to evaluate the
activity of the MNPs‐DETA tribromide catalyst in the synthe-
sis of polyhydroquinolines. The reaction of 4‐choloro-
benzaldehyde, ethyl acetoacetate, dimedone and ammonium
acetate was chosen as a model reaction to determine the
optimum reaction conditions, and the effects of various
parameters such as catalyst concentration, solvent nature
and temperature on the model reaction were tested. The
results are summarized in Table 3. The best results (highest
yield and shortest reaction time) for product 4a are obtained
when 15 mg of magnetic nanocatalyst is used in the absence
of solvent at 90 °C (Table 3, entry 3).
With the optimized reaction conditions in hand, to explore
the scope and limitation of this catalytic system, a library of
aromatic aldehydes was subjected to reaction with ethyl
acetoacetate, dimedone and ammonium acetate (Scheme 3).
The results are summarized in Table 4. Various functional
groups are tolerated under this catalytic system, and aromatic
aldehydes bearing electron‐deficient or electron‐rich substitu-
ents on the aromatic ring in the ortho, meta and para positions
are successfully subjected to the same reaction and the corre-
sponding 1,4‐substituted derivatives are obtained in excellent
yields (91–99%) in short reaction times (less than 30 min).
Amount of catalyst
Time Yield (%)b
(min)
Entry
(mg)
Solvent (temp., °C)
1
5
H2O (70)
H2O (70)
100
80
50
50
50
50
60
80
75
50
120
90
94
2
10
15
20
15
15
15
15
15
15
—
3
H2O (70)
97
4
H2O (70)
97
5
CH3CN (70)
EtOH (70)
DMF (70)
95
6
92
7
94
8
H2O–EtOH (1:1) (70)
H2O (C)
91
9
95
10
11
H2O (C)
97
H2O (C)
Trace
aReaction conditions: anthranilamide (1.05 mmol) and 4‐chlorobenzaldehyde
(1 mmol) in the presence of catalyst and solvent (2 ml).
bIsolated yield.
2.2.3
| Knoevenagel condensation
Knoevenagel condensation is an important carbon–carbon
bond forming reaction in organic synthesis. Knoevenagel
products, namely α,β‐unsaturated products or synthesized
alkenes, play and a key role in the synthesis of fine
chemicals,[42] therapeutic drugs,[43] natural products,[44]
functional polymers,[45] cosmetics[46] and perfumes,[47] in
hetero Diels–Alder reactions[48] and in the synthesis of carbo-
cyclic as well as heterocyclic compounds of biological signif-
icance.[49] In general, this type of condensation is catalysed
SCHEME
2
MNPs‐DETA tribromide‐catalysed cyclocondensation of
anthranilamide with aromatic aldehydes
general, the reactions are clean, and the corresponding
products (2,3‐dihydroquinazoline‐4(1H)‐ones) are obtained
in excellent yields (91–97%). In contrast, aromatic aldehydes
having groups like Cl, F, Me, OMe and OH show better
reactivity, and the reactions are completed in shorter times.
TABLE 2 MNPs‐DETA tribromide‐catalysed one‐pot synthesis of 2,3‐dihydroquinazolin‐4(1H)‐ones in H2O at 70 °C
Entry
R
R′
Product
Time (min)
Yield (%)a
M.p. (°C)
1
4‐ClC6H5CHO
4‐MeC6H5CHO
4‐FC6H5CHO
H
H
H
H
H
H
H
H
H
H
H
H
H
H
2a
2b
2c
50
55
97
94
90
93
94
93
94
96
90
95
98
93
96
91
201–204[7]
227–230[6]
194–198[6]
198–200[33]
196–198[6]
218–222[19]
218–220[6]
200–202[34]
180–182[34]
140–144[35]
198–200[34]
188–190[6]
202–206[36]
208–212[6]
2
3
90
4
4‐NO2C6H5CHO
4‐BrC6H5CHO
4‐(Me2)NC6H5CHO
C6H5CHO
2d
2e
250
180
160
50
5
6
2f
7
2 g
2 h
2i
8
3‐NO2C6H5CHO
3‐BrC6H5CHO
3‐OMeC6H5CHO
3‐OHC6H5CHO
2‐NO2C6H5CHO
2‐ClC6H5CHO
160
140
55
9
10
11
12
13
14
2j
2 k
2 l
2 m
2n
55
180
55
3,4‐(OMe)2C6H5CHO
60
aIsolated yield.

SHIRI ET AL.
5 of 10
TABLE 3 Optimization of reaction conditionsa
Entry
Catalyst (mg)
Solvent
Temperature (°C)
Time (min)
Yield (%)b
1
5
Solvent‐free
Solvent‐free
Solvent‐free
Solvent‐free
CH3CN
90
90
35
25
95
97
2
10
15
20
15
15
15
15
15
15
15
15
—
3
90
10
99
4
90
10
98
5
Reflux
Reflux
Reflux
Reflux
80
240
240
240
240
240
25
80
6
THF
60
7
H2O
35
8
EtOH
85
9
H2O–EtOH (1:1)
Solvent‐free
Solvent‐free
Solvent‐free
Solvent‐free
65
10
11
12
13
70
94
80
18
97
100
90
10
99
120
Trace
aReaction conditions: aldehyde (1 mmol), dimedone (1 mmol), ethyl acetoacetate (1 mmol) and ammonium acetate (1.2 mmol).
bIsolated yield.
purpose, a screening was carried out in order to optimize
catalyst loading, solvent nature and reaction temperature for
the condensation of malononitrile with 4‐chlorobenzaldehyde
as model substrates (Table 5). First, to study the effect of
catalyst loading, the model reaction was studied by varying
the amount of MNPs‐DETA tribromide in water at 70 °C
(Table 5, entries 1–4). The results show that 15 mg of
MNPs‐DETA tribromide is the optimal amount of catalyst
for all subsequent condensations. To cheek the effect of sol-
vent on product yield and reaction time, the model reaction
was carried out with 15 mg of catalyst in several solvents such
as CH3CN, EtOH, CH2Cl2 and H2O–EtOH (1:1) (Table 5,
entries 5–8). The results show that water is the most effective
solvent, because the reaction proceeds smoothly giving the
SCHEME
3
MNPs‐DETA
tribromide‐catalysed
synthesis
of
polyhydroquinolines
TABLE 4 MNPs‐DETA tribromide‐catalysed synthesis of
polyhydroquinolines at 90 °C under solvent‐free conditions
Time
Entry
Aldehyde
Product (min) Yield (%)a
M.p. (°C)
1
4‐ClC6H5CHO
4‐MeC6H5CHO
4‐FC6H5CHO
4a
4b
4c
10
15
7
99
95
97
91
96
98
98
93
93
97
98
98
233–236[37]
258–260[37]
186–189[37]
241–243[38]
250–253[37]
230–232[38]
180–182[37]
205–208[37]
228–232[38]
172–175[38]
207–210[38]
206–209[38]
TABLE 5 Optimization of reaction conditionsa
2
3
4
4‐NO2C6H5CHO
4‐BrC6H5CHO
4‐(Me2)NC6H5CHO
4‐OEtC6H5CHO
C6H5CHO
4d
4e
15
10
20
15
10
5
5
6
4f
Time Yield (%)b
(min)
7
4 g
4 h
4i
Amount of catalyst
(mg)
Entry
Solvent (temp., °C)
8
9
3‐BrC6H5CHO
3‐NO2C6H5CHO
2‐ClC6H5CHO
2‐NO2C6H5CHO
1
5
H2O (reflux)
H2O (reflux)
60
45
90
93
96
96
84
91
58
94
89
92
5
10
11
12
4j
20
15
30
2
10
15
20
15
15
15
15
15
15
—
4 k
4 l
3
H2O (reflux)
25
4
H2O (reflux)
25
aIsolated yield.
5
CH3CN (reflux)
EtOH (reflux)
CH2Cl2 (reflux)
H2O–EtOH (1:1) (80)
H2O (90)
120
75
6
7
180
60
by organic bases and their salts such as ethylenediamine,
dimethylaminopyridine and guanidine in an organic solvent
or a liquid‐phase system.[50] In these cases, the recovery of
the catalyst is very difficult and their utilization is not ideal
from the economic point of view. With these considerations
in mind, we were interested in studying the catalytic activity
of MNPs‐DETA tribromide in the Knoevenagel condensation
of aldehydes and active methylene compounds. For this
8
9
80
10
11
H2O (80)
45
H2O (reflux)
300
aReaction conditions: malononitrile (1.05 mmol) and 4‐chlorobenzaldehyde
(1 mmol) in the presence of catalyst and solvent (2 ml).
bIsolated yield.

6 of 10
SHIRI ET AL.
plate after 300 min. Accordingly, after a comprehensive
screening of the process parameters, the highest yield and
shortest reaction time for product 6a are obtained with 15 mg
of MNPs‐DETA tribromide inwater at 70 °C (Table 5, entry 3).
In order to explore the scope and generality of this
catalytic system, the Knoevenagel condensations of two types
of active methylene compounds (malononitrile and ethyl
cyanoacetate) with various aldehydes were tested under the
optimized conditions (Scheme 4). The results of this study
are summarized in Table 6. A broad spectrum of Knoevenagel
products is obtained in satisfactory times with excellent
yields. These results demonstrate well that malononitrile
(Table 6, entries 1–10) is more reactive than ethyl
cyanoacetate (Table 6, entries 11–16), because the reactions
complete faster and the products achieved in higher yields
when malononitrile is used as active methylene compound.
SCHEME 4 Knoevenagel condensation of active methylene compounds
with aromatic aldehydes catalysed by MNPs‐DETA tribromide
maximum yield. From a comparison of the obtained results
(Table 5, entries 9 and 10 versus entry 3), we find that the
product yield and reaction time are not improved when the
reaction temperature decreases from reflux temperature to
80 °C. To clarify the role of MNPs‐DETA tribromide, the pro-
cess was conducted under catalyst‐free conditions (Table 5,
entry 6), and a product yield of only 5% is observed on TLC
TABLE 6 MNPs‐DETA tribromide‐catalyed one‐pot Knoevenagel condensation in water at reflux temperature
Entry
Substrate
X/Y
Product
Time (min)
Yield (%)a
M.p. (°C)
1
4‐ClC6H5CHO
4‐OMeC6H5CHO
4‐MeC6H5CHO
4‐FC6H5CHO
4‐(Me)2NC6H5CHO
4‐BrC6H5CHO
C6H5CHO
CN/CN
CN/CN
6a
6b
6c
25
290
45
96
97
90
85
93
92
98
93
95
95
92
85
90
88
91
95
159–161[48]
110–112[48]
132–134[48]
122–125[49]
178–181[49]
155–157[49]
80–82[48]
169–172[18]
103–106[50]
89–92[51]
85–87[49]
86–88[52]
88–91[49]
85–89[49]
2
3
CN/CN
4
CN/CN
6d
6e
25
5
CN/CN
180
90
6
CN/CN
6f
7
CN/CN
6 g
6 h
6i
40
8
4‐OEtC6H5CHO
3‐OMeC6H5CHO
2‐ClC6H5CHO
4‐ClC6H5CHO
4‐FC6H5CHO
4‐BrC6H5CHO
4‐MeC6H5CHO
C6H5CHO
CN/CN
120
240
50
9
CN/CN
10
11
12
13
14
15
16
CN/CN
6j
CN/CO2Et
CN/CO2Et
CN/CO2Et
CN/CO2Et
CN/CO2Et
CN/CO2Et
6 k
6 l
6 m
6n
6o
6p
180
35
210
90
60
52–53[48]
53–55[53]
2‐ClC6H5CHO
75
aIsolated yield.
TABLE 7 Comparison of activity of various catalysts in the synthesis of products 2a (entries 1–5), 4a (entries 6–10) and 6a (entries 11–15)
Entry
Catalyst
Conditions
Time (min)
Yield (%)
Ref.
[54]
1
KAl(SO4)2.E12H2O
Glycerosulfonic acid
Silica sulfuric acid
SBNPSA
EtOH, reflux
Glycerol, 80 °C
H2O,80 °C
300
360
180
150
50
80
97
81
87
97
87
80
98
95
99
90
88
94
95
96
[55]
2
[56]
3
[57]
4
EtOH, reflux
5
MNPs‐DETA tribromide
PdCl2
H2O, 70 °C
This work
[3]
6
THF, reflux
240
30
[58]
[37]
[59]
7
K7[PW11CoO40
Cu‐SPATB/Fe3O4
[TBA]2[W6O19
]
CH3CN, reflux
PEG‐400, 80 °C
Solvent‐free, 110 °C
Solvent‐free, 90 °C
EtOH, reflux
8
65
9
]
20
10
11
12
13
14
15
MNPs‐DETA tribromide
PVC‐TEPA
10
This work
[60]
60
[61]
[62]
[48]
SO42−/ZrO2
Solvent‐free, reflux
DMSO, 35 °C
acetone, r.t.
120
720
60
Lipase
NP‐SnO2
MNPs‐DETA tribromide
H2O, reflux
25
This work

SHIRI ET AL.
7 of 10
synthetic strategy for the preparation of pharmaceutically
and biologically active molecules.
4
| EXPERIMENTAL
4.1 | Materials
Chemicals were purchased from Fisher and Merck. The
reagents and solvents used were obtained from Sigma‐
Aldrich, Fluka or Merck and used without further purifica-
tion. Nanostructures were characterized using a Holland
Philips X'pert powder X‐ray diffractometer (Co Kα radiation;
0.154056 nm), at a scanning speed of 2° min−1 from 10° to
100°. The particle size and morphology were investigated
with a JEOL JEM‐2010 scanning electron microscope, at an
accelerating voltage of 200 kV. The FT‐IR spectra of samples
were recorded in KBr discs using a Nicolet Impact 410
spectrometer. TGA curves were recorded using a PL‐STA
1500 device (Thermal Sciences). Superparamagnetic proper-
ties of the catalyst were measured using VSM (MDKFD).
FIGURE 6 Reusability of MNPs‐DETA tribromide in the syntheses of
products 2a, 4a and 6a
In order to show the efficiency of the present system
under investigation, the results obtained for the synthesis of
products 2a, 4a and 6a were compared with those of
previously reported procedures (Table 7). As evident from
Table 7, the present catalytic system is superior to some of
those reported previously in terms of reaction conditions,
reaction time and percentage yields.
2.2.4
| Recovery and reusability
The recovery and reusability of catalysts are valuable advan-
tages in modern catalysis research, which makes them very
favourable from commercial and economic points of view.
In this respect, the reusability of MNPs‐DETA tribromide in
the syntheses of products 2a, 4a and 6a (as model reactions)
was investigated. At the end of the process, MNPs‐DETA
tribromide was readily separated from the reaction mixture
using an external magnet, washed several times with ethanol
and dried to remove residual product. Then, the recovered
catalyst was reused for a subsequent fresh batch of the
reaction. The catalytic activity was studied for several succes-
sive runs, showing similar activity (Figure 6). Accordingly,
one of the fascinating advantages of this new catalytic system
is the simple, rapid and efficient separation of the catalyst
using a suitable external magnet, which minimizes the loss
of catalyst during separation.
4.2 | Preparation of MNPs
A mixture of FeCl3⋅6H2O (5.838 g, 0.0216 mol) and
FeCl2⋅4H2O (2.147 g, 0.0108 mol) was dissolved in 100 ml
of deionized water in a three‐necked flask (250 ml) under
nitrogen atmosphere. After that, 10 ml of NH3 was added into
the solution within 30 min with vigorous mechanical stirring.
After being rapidly stirred for 30 min, the resultant black
dispersion was heated to 80 °C for 30 min. The black precip-
itate formed was isolated by magnetic decantation, washed
with double‐distilled water until neutrality, and further
washed twice with ethanol and dried at room temperature.
4.3 | Preparation of MNPs‐CPTMS
The obtained Fe3O4 MNPs (1.5 g) were dispersed in 250 ml
of ethanol–water (1:1 v/v) by sonication for 30 min, and then
CPTMS (2.5 ml) was added to the reaction mixture. The
reaction mixture was mechanically stirred under nitrogen
atmosphere at 40 °C for 8 h. Then, the nanoparticles were
re‐dispersed in ethanol by sonication five times and separated
through magnetic decantation. The nanoparticle product
(MNPs‐CPTMS) was dried at room temperature.
3
| CONCLUSIONS
In summary, we developed a versatile protocol for the
synthesis of 2,3‐dihydroquinazoline‐4(1H)‐one and
polyhydroquinoline derivatives and Knoevenagel products
using MNPs‐DETA tribromide as bromine source catalyst.
It is noteworthy that all products were obtained in good to
excellent yields. Simple preparation of the catalyst from
commercially available materials, high catalytic activity,
simple operation, high yields, use of water as solvent,
reactions occurring under solvent‐free conditions, easy
magnetic separation and reusability of the catalyst with
unaltered activity make our protocol a green and feasible
synthetic strategy. As a result of this study, we believe that
this protocol will open up a new practical and efficient
4.4 | Preparation of MNPs‐DETA
MNPs‐CPTMS (1.5 g) was dispersed in toluene (50 ml) in an
ultrasonic bath for 10 min. DETA (2 ml) was added and
stirred at 100 °C for 30 h under nitrogen atmosphere. Then,
the prepared functionalized MNPs were separated by
magnetic decantation and washed three times with ethanol
to remove the unattached substrates. The resulting product
was dried at room temperature.

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SHIRI ET AL.
4.5 | Preparation of MNPs‐DETA bromide
acetate (3 × 5 ml) was added to the reaction mixture and
the catalyst was separated using an external magnet. Ethyl
acetate was evaporated under reduced pressure to afford the
crude products. The obtained crude products were further
recrystallized from ethanol to afford the pure final products
(88–98%).
The obtained MNPs‐DETA (1 g) was added to a mixture of
K2CO3 (3 mmol) and benzyl bromide (5 ml) in
dimethylformamide (DMF). The mixture was then stirred at
80 °C for 5 h under nitrogen atmosphere. The resulting
powder was separated by magnetic decantation. The
magnetic powder was washed with ethanol and dried at room
temperature.
4.10 | Spectroscopic data
All the products reported here are known compounds and the
spectroscopic data were matched literature values. Data for
some of the compounds are given below.
4.6 | Preparation of MNPs‐DETA tribromide catalyst
MNPs‐DETA bromide (0.5 g) was dispersed in CCl4 (5 ml)
in an ultrasonic bath for 10 min. Subsequently, Br2 (2.5 ml)
was added and the mixture was stirred for 8 h at room temper-
ature. Then, the final product was separated by magnetic
decantation and washed with CCl4 to remove unattached
substrates. The product (MNPs‐DETA tribromide) was stored
in a refrigerator until use.
4.10.1
(2a)
| 2‐(4‐Chlorophenyl)‐2,3‐dihydroquinazolin‐4(1H)‐one
1H NMR (400 MHz, DMSO‐d6, δH, ppm): 5.79 (s, 1H), 6.70
(t, J = 7.6 Hz, 1H, Ar‐H), 6.76 (d, J = 8 Hz, 1H, Ar‐H), 7.16
(brs, 1H, N─H), 7.24–7.29 (td, J = 7.6, 1.6 Hz, 1H, Ar‐H),
7.48 (dt, J = 8.8, 2 Hz, 2H, Ar‐H), 7.52 (dt, J = 8.4, 2 Hz,
2H, Ar‐H), 7.62 (dd, J = 7.6, 1.6 Hz, 1H, Ar‐H), 8.35 (brs,
1H, N─H). 13C NMR (100 MHz, DMSO‐d6, δC, ppm):
66.3, 114.9, 115.4, 117.8, 127.9, 128.8, 129.2, 133.5,
133.9, 141.1, 148.1, 164.
4.7 | General procedure for synthesis of 2,3‐
dihydroquinazolin‐4(1H)‐ones
A mixture of anthranilamide (1.05 mmol, 142 mg), aldehyde
or ketone and MNPs‐DETA tribromide (15 mg) in water
(2 ml) was stirred at 70 °C. The progress of the reaction
was monitored by TLC (acetone–n‐hexane, 2:8). After the
time specified in Table 2, the reaction was allowed to cool
to room temperature. CH2Cl2 (3 × 5 ml) was added to the
reaction mixture and the catalyst was separated using an
external magnet. CH2Cl2 was evaporated under reduced
pressure to afford the crude products. The obtained crude
products were further recrystallized from ethanol to afford
the pure 2,3‐dihydroquinazolin‐4(1H)‐ones (91–97%).
4.10.2
(2b)
| 2‐(4‐Methylphenyl)‐2,3‐dihydroquinazolin‐4(1H)‐one
1H NMR (400 MHz, DMSO‐d6, δH, ppm): 2.31 (s, 3H, CH3),
5.73 (s, 1H), 6.68 (t, J = 7.6 Hz, 1H, Ar‐H), 6.75 (d, J = 8.4 Hz,
1H, Ar‐H), 7.07 (brs, 1H, N─H), 7.20–7.27 (m, 3H, Ar‐H),
7.39 (d, J = 8 Hz, 2H, Ar‐H), 7.62 (dd, J = 7.6, 1.2 Hz,
1H, Ar‐H), 8.25 (brs, 1H, N─H). 13C NMR (100 MHz,
DMSO‐d6, δC, ppm): 21.2, 66.9, 114.9, 115.5, 117.5,
127.3, 127.8, 129.3, 133.7, 138.2, 139.1, 148.4, 164.1.
4.8 | General procedure for synthesis of
polyhydroquinolines
4.10.3
(2d)
| 2‐(4‐Nitrophenyl)‐2,3‐dihydroquinazolin‐4(1H)‐one
1H NMR (400 MHz, DMSO‐d6, δH, ppm): 5.94 (t, J = 2 Hz,
1H, CH), 6.71 (t, J = 7.6 Hz, 1H, Ar‐H), 6.79 (d, J = 7.6 Hz,
1H, Ar‐H), 7.26–7.30 (td, J = 7.6, 1.6 Hz, 1H, Ar‐H), 7.35
(brs, 1H, N─H), 7.62–7.65 (dd, J = 8, 1.6 Hz, 1H, Ar‐H),
7.75–7.79 (dt, J = 8.8, 2 Hz, 2H, Ar‐H), 8.26–8.30 (dt, J = 9.2,
2 Hz, 2H, Ar‐H), 8.55 (brs, 1H, N─H). 13C NMR (100 MHz,
DMSO‐d6, δC, ppm): 66.8, 115, 115.4, 118, 124.1, 127.9,
128.5, 134.1, 147.7, 147.9, 149.8, 163.8.
A mixture of aldehyde (1 mmol), dimedon (1 mmol), ethyl
acetoacetate (1 mmol), ammonium acetate (1.2 mmol) and
MNPs‐DETA tribromide (15 mg) was stirred at 90 °C under
solvent‐free conditions. The progress of the reaction was
monitored by TLC (acetone–n‐hexane, 3:7). After comple-
tion of the reaction, the catalyst was separated using an
external magnet and washed with ethyl acetate. Then, the
solvent was evaporated and all products were recrystallized
from ethanol. The pure polyhydroquinoline derivatives were
obtained in excellent yields (91–99%).
4.10.4
| 2‐Phenyl‐2,3‐dihydroquinazolin‐4(1H)‐one (2 g)
1H NMR (400 MHz, DMSO‐d6, δH, ppm): 5.77 (s, 1H), 6.69
(t, J = 8 Hz, 1H, Ar‐H), 6.77 (d, J = 7.6 Hz, 1H, Ar‐H), 7.13
(brs, 1H, N─H), 7.26 (td, J = 8, 1.6 Hz, 1H, Ar‐H), 7.34–
7.43 (m, 3H, Ar‐H), 7.51 (dd, J = 6.8, 1.2 Hz, 2H, Ar‐H),
7.63 (dd, J = 7.6, 1.2 Hz, 1H, Ar‐H), 8.31 (brs, 1H, N‐H).
13C NMR (100 MHz, DMSO‐d6, δC, ppm): 67.1, 114.9,
115.4, 117.6, 127.4, 127.9, 128.8, 129, 133.8, 142.1, 148.4,
164.1.
4.9 | General procedure for Knoevenagel condensation
A mixture of aldehyde (1 mmol), activated methylene
compound (1.05 mmol) and MNPs‐DETA tribromide
(15 mg) in water (2 ml) was stirred at reflux temperature.
The progress of the reaction was monitored by TLC
(acetone–n‐hexane, 3:7). After the time specified in Table 6,
the reaction was allowed to cool to room temperature. Ethyl

SHIRI ET AL.
9 of 10
4.10.5
(2 h)
|
2‐(3‐Nitrophenyl)‐2,3‐dihydroquinazolin‐4(1H)‐one
32.6, 36.6, 50.6, 59.6, 103.5, 109.9, 121.5, 127, 129, 130.6,
130.9, 146.1, 150.3, 150.7, 167, 194.8.
1H NMR (400 MHz, DMSO‐d6, δH, ppm): 5.98 (s, 1H), 6.72
(t, J = 8 Hz, 1H, Ar‐H), 6.82 (d, J = 8 Hz, 1H, Ar‐H), 7.29
(td, J = 6.8, 1.6 Hz, 1H, Ar‐H), 7.38 (brs, 1H, N─H),
7.65 (dd, J = 8, 1.6 Hz, 1H, Ar‐H), 7.71 (t, J = 8 Hz, 1H,
Ar‐H), 7.97 (d, J = 7.6 Hz, 1H, Ar‐H), 8.23 (dq, J = 8,
1.6 Hz, 1H, Ar‐H), 8.39 (t, J = 2 Hz, 1H, Ar‐H), 8.57
(brs, 1H, N─H). 13C NMR (100 MHz, DMSO‐d6, δC,
ppm): 65.7, 115.1, 115.4, 118, 122.1, 123.8, 127.9, 130.5,
133.8, 134.1, 144.7, 147.8, 148.2, 163.9.
4.10.10
| 2‐(4‐Chlorobenzylidene)malononitrile (6a)
1H NMR (400 MHz, DMSO‐d6, δH, ppm): 7.74 (d, J = 8.8 Hz,
2H), 7.97 (d, J = 8.8 Hz, 2H), 8.73 (s, 1H). 13C NMR
(100 MHz, DMSO‐d6, δC, ppm): 82.7, 113.5 (CN), 114.5
(CN), 115.7 (2C), 130.5, 132.6 (2C), 139.5, 160.6.
4.10.11
| 2‐(4‐Methoxybenzylidene)malononitrile (6b)
1H NMR (400 MHz, DMSO‐d6, δH, ppm): 7.21 (d, J = 7.2 Hz,
2H), 7.99 (d, J = 7.2 Hz, 2H), 8.41 (s, 1H). 13C NMR
(100 MHz, DMSO‐d6, δC, ppm): 56.4, 114.4 (CN), 115.3
(CN), 115.7 (2C), 124.6, 133.8 (2C), 160.9, 164.8.
4.10.6
| Ethyl‐4‐(4‐fluorophenyl)‐2,7,7‐trimethyl‐5‐oxo‐1,4,5,
6,7,8‐hexahydroquinoline‐3‐carboxylate (4c)
1H NMR (400 MHz, DMSO‐d6, δH, ppm): 0.85 (s, 3H), 1.02
(s, 3H), 1.13 (t, J = 7.2 Hz, 3H), 1.99 (d, J = 16 Hz, 1H),
2.18 (d, J = 16 Hz, 1H), 2.28–2.32 (m, 4H), 2.43
(d, J = 16.8 Hz, 1H), 3.98 (q, J = 7.2 Hz, 2H), 4.87 (s,
1H), 6.99–7.20 (m, 4H, Ar‐H), 9.11 (brs, 1H, N─H). 13C
NMR (100 MHz, DMSO‐d6, δC, ppm): 14.6, 18.8, 26.7,
29.6, 32.6, 35.8, 50.7, 59.5, 103.9, 110.4, 114.7, 129.6,
144.3, 145.7, 149.95, 159.7, 167.2, 194.7.
4.10.12
| 2‐(4‐Ethoxybenzylidene)malononitrile (6 h)
1H NMR (400 MHz, DMSO‐d6, δH, ppm): 1.37 (t, J = 7.2 Hz,
3H), 4.19 (q, J = 7.2 Hz, 2H), 7.19 (d, J = 9.2 Hz, 2H), 7.98
(d, J = 9.2 Hz, 2H), 8.41 (s, 1H). 13C NMR (100 MHz,
DMSO‐d6, δC, ppm): 14.8, 64.5, 77.1, 114.4 (CN), 115.3
(CN), 116 (2C), 124.5, 133.9 (2C), 160.9, 164.2.
4.10.13
(6n)
| Ethyl (E)‐2‐cyano‐3‐(4‐methylphenyl)‐2‐propenoate
1H NMR (400 MHz, DMSO‐d6, δH, ppm): 1.26 (t, J = 7.2 Hz,
3H), 2.4 (s, 3H), 3.54 (q, J = 7.2 Hz, 2H), 7.1 (d, J = 8 Hz,
2H), 7.45–7.47 (d, J = 8 Hz, 2H), 8.03 (s, 1H). 13C NMR
(100 MHz, DMSO‐d6, δC, ppm): 15.24 (CH3), 55.31
(CH3O), 65.39 (O─CH2), 102.33 (C─CN), 113.77 (CN),
121.36, 126.51, 132.22, 139.33, 152.57, 162.26 (C═O).
4.10.7
| Ethyl‐4‐(4‐bromophenyl)‐2,7,7‐trimethyl‐5‐oxo‐1,4,5,
6,7,8‐hexahydroquinoline‐3‐carboxylate (4e)
1H NMR (400 MHz, DMSO‐d6, δH, ppm): 0.85 (s, 3H), 1.02
(s, 3H), 1.13 (t, J = 7.2 Hz, 3H), 1.99 (d, J = 16 Hz, 1H), 2.18
(d, J = 16 Hz, 1H), 2.27–2.31 (m, 4H), 2.43 (d, J = 17.2 Hz,
1H), 3.98 (q, J = 7.2 Hz, 2H), 4.85 (s, 1H), 7.11–7.14 (m, 2H,
Ar‐H), 7.38–7.41 (m, 2H, Ar‐H), 9.13 (brs, 1H, N─H). 13C
NMR (100 MHz, DMSO‐d6, δC, ppm): 14.6, 18.8, 26.9,
29.6, 32.6, 36.2, 50.6, 59.6, 103.5, 110.1, 119.19, 130.2,
131.1, 145.9, 147.5, 150.1, 167.1, 194.7.
ACKNOWLEDGEMENT
This work was supported by the research facilities of Ilam
University, Ilam, Iran.
REFERENCES
4.10.8
| Ethyl‐2,7,7‐trimethyl‐5‐oxo‐1,4,5,6,7,8‐hexahydro-
[1] A. Ghorbani‐Choghamarani, P. Zamani, J. Iran. Chem. Soc. 2012, 9, 607.
[2] A. Ghorbani‐Choghamarani, M. Norouzi, J. Mol. Catal. A. 2014, 395, 172.
[3] M. Saha, A. K. Pal, Tetrahedron. Lett. 2011, 52, 4872.
quinoline‐3‐carboxylate (4 h)
1H NMR (400 MHz, DMSO‐d6, δH, ppm): 0.86 (s, 3H), 1.02
(s, 3H), 1.14 (t, J = 7.2 Hz, 3H), 1.99 (d, J = 16 Hz, 1H),
2.18 (d, J = 16 Hz, 1H), 2.29–2.33 (m, 4H), 2.44
(d, J = 17.2 Hz, 1H), 3.99 (q, J = 7.2 Hz, 2H), 4.88
(s, 1H), 7.06–7.21 (m, 5H, Ar‐H), 9.07 (brs, 1H, N─H).
13C NMR (100 MHz, DMSO‐d6, δC, ppm): 14.6, 18.8,
26.9, 29.6, 32.6, 36.4, 50.7, 59.5, 104.1, 110.5, 126.1,
127.9, 128.145.5, 148.1, 150, 167.3, 194.7.
[4] K. A. Undale, T. S. Shaikh, D. S. Gaikwad, D. M. Pore, C. R. Chim. 2011,
14, 511.
[5] J. Safari, S. Gandomi‐Ravandi, C. R. Chim. 2013, 16, 1158.
[6] A. Rostami, A. Tavakoli, Chin. Chem. Lett. 2011, 22, 1317.
[7] A. Ghorbani‐Choghamarani, G. Azadi, RSC. Adv. 2015, 5, 9752.
[8] K. Sirisha, G. Achaiah, V. M. Reddy, Arch. Pharm. 2010, 343, 342.
[9] J. L. Donelson, R. A. Gibbs, S. K. De, J. Mol. Catal. A. 2006, 256, 309.
[10] A. Heydari, S. Khaksar, M. Tajbakhsh, H. R. Bijanzadeh, J. Fluorine. Chem.
2009, 130, 609.
4.10.9
| Ethyl‐4‐(3‐bromophenyl)‐2,7,7‐trimethyl‐5‐oxo‐1,4,5,
6,7,8‐hexahydroquinoline‐3‐carboxylate (4i)
[11] A. Shaabani, A. Maleki, H. Mofakham, Synth. Commun. 2008, 38, 3751.
[12] L. Y. Zeng, C. J. Cai, J. Heterocycl. Chem. 2010, 47, 1035.
[13] J. X. Chen, W. K. Su, H. Y. Wu, M. C. Liu, C. Jin, Green. Chem. 2007, 9, 972.
[14] S. J. Ji, Z. Q. Jiang, J. Lu, T. P. Loh, Synlett. 2004, 831.
1H NMR (400 MHz, DMSO‐d6, δH, ppm): 0.87 (s, 3H), 1.03
(s, 3H), 1.14 (t, J = 7.2 Hz, 3H), 2.01 (d, J = 16 Hz, 1H),
2.19 (d, J = 16 Hz, 1H), 2.31–2.34 (m, 4H), 2.45
(d, J = 17.2 Hz, 1H), 4.0 (q, J = 7.2 Hz, 2H), 4.85 (s, 1H),
7.15–7.31 (m, 4H, Ar‐H), 9.16 (brs, 1H, N─H). 13C NMR
(100 MHz, DMSO‐d6, δC, ppm): 14.6, 18.8, 26.8, 29.6,
[15] M. Rueping, A. P. Antonchick, E. Sugiono, K. Grenader, Angew. Chem. Int.
Ed. 2009, 48, 908.
[16] X. Cheng, S. K. Vellalath, R. Goddard, J. Am. Chem. Soc. 2008, 130, 15786.

10 of 10
SHIRI ET AL.
[17] R. J. Abdel‐Jalil, W. Voelter, M. Saeed, Tetrahedron. Lett. 2004, 45, 3475.
[47] N. Yu, J. M. Aramini, M. W. Germann, Z. Huang, Tetrahedron. Lett. 2000,
41, 6993.
[18] A. Davoodnia, S. Allameh, A. R. Fakhari, N. Tavakoli‐Hoseini, Chin. Chem.
Lett. 2010, 21, 550.
[48] I. Kim, S. G. Kim, J. Choi, G. H. Lee, Tetrahedron. 2008, 64, 664.
[49] L. F. Tietze, Chem. Rev. 1996, 96, 115.
[19] G. Sabitha, G. S. K. K. Reddy, C. S. Reddy, J. S. Yadav, Tetrahedron. Lett.
2003, 44, 4129.
[50] A. V. Narsaiah, A. K. Basak, B. Visali, K. Nagaiah, Synth. Commun. 2004,
34, 2893.
[20] M. M. Heravi, K. Bakhtiari, V. Zadsirjan, M. Saeedi, F. F. Bamoharram,
Iran. J. Org. Chem. 2010, 2, 298.
[51] H. Sharghi, S. E. Moghaddam, R. Memarzadeh, S. Javadpour, J. Iran. Chem.
Soc. 2013, 10, 141.
[21] S. B. Sapkal, K. F. Shelke, B. B. Shingate, M. S. Shingare, Tetrahedron. Lett.
2009, 50, 1754.
[52] L. Muralidhar, C. R. Girija, J. Saudi. Chem. Soc. 2014, 18, 541.
[53] M. L. Kantam, B. Bharathi, Catal. Lett. 1998, 55, 235.
[54] R. Pal, T. Sarkar, Int. J. Org. Chem. 2014, 4, 106.
[22] L. Nagarapu, M. D. Kumari, N. V. Kumari, S. Kantaveri, Catal. Commun.
2007, 8, 1871.
[23] C. S. Reddy, M. Raghu, Indian. J. Chem. 2008, 47, 1578.
[24] A. Kumar, R. A. Maurya, Synlett. 2008, 883.
[55] S. Qi, S. Lan‐Xiang, G. Ze‐Mei, C. Tie‐Ming, L. Run‐Tao, Chin. J. Chem.
2005, 23, 745.
[25] L. Shiri, A. Ghorbani‐Choghamarani, M. Kazemi, Aust. J. Chem. 2016, DOI:
[56] J. S. Yadav, B. V. S. Reddy, A. K. Basak, B. Visali, A. V. Narsaiah, K.
10.1071/CH16318
Nagaiah, Eur. J. Org. Chem. 2004, 3, 546.
[26] D. Wang, D. Astruc, Chem. Rev. 2014, 114, 6949.
[57] G. Li, J. Xiao, W. Zhang, Green. Chem. 2012, 14, 2234.
[27] J. Lu, E.‐Q. Ma, Y.‐H. Liu, Y.‐M. Li, L.‐P. Mo, Z.‐H. Zhang, RSC. Adv.
2014, 4, 59167.
[58] H. A. Oskooie, M. M. Heravi, F. Derikvand, M. Khorasani, Synth. Commun.
2006, 36, 2819.
[28] J. Lu, X.‐T. Li, E.‐Q. Ma, L.‐P. Mo, Z.‐H. Zhang, Chem. Cat. Chem 2014, 6,
[59] M. Dabiri, P. Salehi, S. Otokesh, M. Baghbanzadeh, G. Kozehgary, A. A.
2854.
Mohammadi, Tetrahedron. Lett. 2005, 46, 6123.
[29] A. Ghorbani‐Choghamarani, L. Shiri, G. Azadi, RSC. Adv. 2016, 6, 32653.
[60] M. Hajjami, F. Bakhti, E. Ghiasbeygi, Croat. Chem. Acta. 2015, 88, 197.
[61] S. Bonollo, D. Lanari, L. Vaccaro, Eur. J. Org. Chem. 2011, 14, 2587.
[62] K. Niknam, N. Jafarpour, E. Niknam, Chin. Chem. Lett. 2011, 22, 69.
[30] L. Shiri, A. Ghorbani‐Choghamarani, M. Kazemi, Aust. J. Chem. 2016, 69,
585.
[31] A. T. Khan, M. Lal, M. M. Khan, Tetrahedron. Lett. 2010, 51, 4419.
[32] A. Ghosh, A. T. Khan, Tetrahedron Lett. 2014, 55, 2006.
[63] M. M. Heravi, K. Bakhtiari, N. M. Javadi, F. F. Bamoharram, M. Saeedi, J.
Mol. Catal. A. 2007, 264, 50.
[33] A. Ghorbani‐Choghamarani, H. Goudarziafshar, P. Zamani, Chin. Chem.
Lett. 2011, 22, 1207.
[64] A. Davoodnia, M. Khashi, N. Tavakoli‐Hoseini, Chin. J. Catal. 2013, 34,
1173.
[34] F. M. Moghaddam, N. Masoud, B. K. Foroushani, S. Saryazdi, N. Ghonouei,
[65] F. Dong, Y. Q. Li, R. F. Dai, Chin. Chem. Lett. 2007, 18, 266.
E. Daemi, Scientia. Iranica. 2013, 20, 598.
[66] B. M. Reddy, M. K. Patil, K. N. Rao, G. K. Reddy, J. Mol. Catal. A. 2006,
258, 302.
[35] A. Rostami, Y. Navasi, D. Moradi, A. Ghorbani‐Choghamarani, Catal.
Commun. 2014, 43, 16.
[67] Y. Ding, X. Ni, M. Gu, S. Li, H. Huang, Y. Hu, Catal. Commun. 2015, 64, 101.
[36] J. Safari, S. Gandomi‐Ravandi, J. Mol. Catal. A. 2014, 390, 1.
[37] M.‐J. Hour, L.‐J. Huang, S.‐C. Kuo, Y. Xia, K. Bastow, Y. Nakanishi,
E. Hamel, K.‐H. Lee, J. Med. Chem. 2000, 43, 4479.
SUPPORTING INFORMATION
Additional Supporting Information may be found online in
the supporting information tab for this article.
[38] V. B. Labade, P. V. Shinde, M. S. Shingare, Tetrahedron. Lett. 2013, 54,
5778.
[39] M. Desroses, M. Scobie, T. Helleday, New. J. Chem. 2013, 37, 3595.
[40] A. Ghorbani‐Choghamarani, B. Tahmasbi, P. Moradi, N. Havasi, Appl.
Organometal. Chem. 2016, 30, 619.
How to cite this article: Shiri L, Rahmati S,
Ramezani Nejad Z, Kazemi M. Synthesis and
characterization of bromine source immobilized on
diethylenetriamine‐functionalized magnetic nanoparti-
cles: A novel, versatile and highly efficient reusable
catalyst for organic synthesis. Appl Organometal
Chem. 2017;e3687. doi: 10.1002/aoc.3687
[41] M. Tajbakhsh, H. Alinezhad, M. Norouzi, S. Baghery, M. Akbari, J. Mol.
Liq. 2013, 177, 44.
[42] F. Freeman, Chem. Rev. 1980, 80, 329.
[43] G. A. Kraus, M. E. Krolski, J. Org. Chem. 1986, 51, 3347.
[44] L. F. Tietze, N. Rackelmann, Pure Appl. Chem. 2004, 76, 196.
[45] F. Liang, Y.‐J. Pu, T. Kurata, J. Kido, H. Nishide, Polymer. 2005, 46, 3767.
[46] F. Bigi, L. Chesini, R. Maggi, G. Sartori, J. Org. Chem. 1999, 64, 1033.