Polyethylene Glycol-(N-Methylimidazolium) Hydroxide-Grafted γ-Fe2O3@HAp: A Novel Nanomagnetic Recyclable Basic Phase-Transfer Catalyst for the Synthesis of Tetrahydrobenzopyran Derivatives in Aqueous Media

Article abstract of DOI:10.1002/jccs.201700401

Polyethylene glycol-(N-methylimidazolium) hydroxide-grafted hydroxyapatite encapsulated γ-Fe₂O₃ nanoparticles, γ-Fe₂O₃@HAp@PEG(mim)OH, were prepared and characterized by FTIR, SEM, TEM, TGA, and EDAX. This nanoc

Full text of DOI:10.1002/jccs.201700401

JOURNAL OF THE CHINESE
CHEMICAL SOCIETY
Article
Polyethylene Glycol-(N-Methylimidazolium) Hydroxide-Grafted γ-Fe2O3@HAp: A Novel
Nanomagnetic Recyclable Basic Phase-Transfer Catalyst for the Synthesis of
Tetrahydrobenzopyran Derivatives in Aqueous Media
a,b
a
Hamed Talaei,a Mehdi Fallah-Mehrjardi
and Fatemeh Hakimi
*
aDepartment of Chemistry, Payame Noor University (PNU), Tehran, Iran
bResearch Center of Environmental Chemistry, Payame Noor University, Yazd, Iran
(Received: November 9, 2017; Accepted: December 25, 2017; DOI: 10.1002/jccs.201700401)
Polyethylene glycol-(N-methylimidazolium) hydroxide-grafted hydroxyapatite encapsulated
γ-Fe2O3 nanoparticles, γ-Fe2O3@HAp@PEG(mim)OH, were prepared and characterized by
FTIR, SEM, TEM, TGA, and EDAX. This nanocomposite was applied as a novel, green, nano-
magnetic, and recyclable basic phase-transfer catalyst for the synthesis of tetrahydrobenzopyrans
in high yields via the three-component reaction of aromatic aldehydes, malononitrile, and dime-
done or 1,3-cyclohexanedione in aqueous media at ambient temperature.
Keywords: Phase-transfer catalyst; γ-Fe2O3@HAp@PEG(mim)OH; Nanomagnetic basic catalyst;
Tetrahydrobenzopyrans; Green chemistry.
INTRODUCTION
Green chemistry is a concept that has been receiving
hydroxide-grafted hydroxyapatite encapsulated γ-Fe2O3
nanoparticles, which we denote as γ-Fe2O3@HAp@-
PEG(mim)OH. This novel, nanomagnetic, and recycla-
ble basic PTC was characterized with several
techniques, and, finally, its catalytic activity was tested
in the synthesis of tetrahydrobenzopyrans via one-pot
three-component reaction of aryl aldehydes, malononi-
trile, and 1,3-cyclohexadione or dimedone under aque-
ous conditions at room temperature.
great attention in recent years by chemists and
researchers. It focuses on technological approaches to pol-
lution prevention by the designing processes and products
that minimize the use and production of hazardous che-
micals, and also avoiding the use organic solvents and
using alternative safer solvents.1 One of the best solutions
to the problem of solvent toxicity and disposal is the use
of water as the medium for organic reactions.2
Since most of the organic reactants do not dissolve
in water, phase-transfer catalysts (PTCs) can be used to
overcome this problem.3 Both homogeneous and hetero-
geneous PTCs improve the contact between inorganic
reagents and organic substrates, but one of the major
problems associated with the use of homogeneous cata-
lysts is the recovery of the catalyst from the reaction
medium. Immobilization of the PTC on an insoluble
matrix can provide a simple solution to this problem.4–7
Because of the widespread application of hydroxy-
apatite as a robust material for drug and protein deliv-
ery agent and catalyst supporting material,8–12 and
based on our earlier success in the synthesis of novel
catalysts,13–16 in this study, for the first time, we pre-
RESULTS AND DISCUSSION
γ-Fe2O3@HAp@PEG(mim)OH was prepared by
the concise route outlined in Scheme 1. The addition of
Ca(NO3)2Á4H2O and (NH4)2HPO4 solutions to the Fe3O4
magnetic nanoparticles (MNPs) led to its oxidation and
coating with hydroxyapatite. Hexamethylenediisocyanate
(HMDI) was used for conjugating polyethylene glycol
monobromide onto the surface of the γ-Fe2O3@HAp
NPs. After that, N-methylimidazole was immobilized
onto the modified MNPs, leading to the formation of the
nanomagnetic PTC γ-Fe2O3@HAp@PEG(mim)Br. Ulti-
mately, a mixture of the prepared nanocomposite and
sodium hydroxide in water was stirred at room tempera-
ture, and a novel nanomagnetic basic PTC was produced.
pared
polyethylene
glycol-(N-methylimidazolium)
*Corresponding author. Email: fallah.mehrjerdi@pnu.ac.ir
J. Chin. Chem. Soc. 2018
© 2018 The Chemical Society Located in Taipei & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
1

Article
Talaei et al.
OH
HO
HO
HO
OH
OH
HAp
FeCl3.6H2O
+
O
NH4OH, N2
80oC, 1 h
Ca(NO3)2.4H2O
(NH4)2HPO4
OCN(CH2)6NCO
Dry DMF, 3 h
Fe3O4
MNP
γ-Fe2O3
O
P OH
O
FeCl2.4H2O
OH
OH
HAp
NMe
O
O
O
HO
CH2CH2Br
N
N
n
γ-Fe2O3
O
P
O
N
C
CH3CN, reflux, 48 h
O
Dry DMF, 70 oC, 3 h
H
O
HAp
O
O
O
H
NMe
N
N
NaOH
H2O, r.t., 1 h
N
O
γ-Fe2O3
O
P
O
N
O
O
Br
H
n
n
O
O
HAp
O
H
N
NMe
O
γ-Fe2O3
O
P
O
N
H
OH
O
O
Scheme 1. Synthesis of γ-Fe2O3@HAp@PEG(mim)OH.
The catalyst was characterized by the various tech-
niques including Fourier transform infrared (FTIR)
spectroscopy (Figure 1), transmission electron micros-
copy (TEM, Figure 2), scanning electron microscopy
(SEM, Figure 3), energy dispersive X-ray (EDX,
Figure 4) spectroscopy, and thermogravimetric analysis
(TGA, Figure 5). According to the FTIR spectrum of
the catalyst (Figure 1), the characteristic absorption
bands due to the bending vibration mode of O─P─O
surface phosphate groups in the hydroxyapatite shell
were observed at 563 and 601 cm−1 which overlap with
the Fe─O stretching band. In addition, the absorption
Fig. 2. TEM image of γ-Fe2O3@HAp@PEG
Fig. 1. FTIR spectra of γ-Fe2O3@HAp@PEG
(mim)OH.
(mim)OH.
2
www.jccs.wiley-vch.de
© 2018 The Chemical Society Located in Taipei & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
J. Chin. Chem. Soc. 2018

JOURNAL OF THE CHINESE
CHEMICAL SOCIETY
Synthesis of Tetrahydrobenzopyrans by a Novel PTC
Fig. 3. SEM images of (a) γ-Fe2O3@HAp and (b) γ-Fe2O3@HAp@PEG(mim)OH (b).
band at 1029 cm−1 can be attributed to the stretching of
the P─O bond. The IR spectrum of the catalyst also
showed the characteristic absorption bands at 3332 and
1620 cm−1 corresponding to the NH and C═O groups.
The NHCO stretching was also observed at 1577 cm−1. It is
worth noting the disappearance of the isocyanate peak in the
IR spectrum of the catalyst at about 2200–2300 cm−1. The
introduction of PEG-substituted N-methylimidazolium on
Fig. 4. EDAX pattern of γ-Fe2O3@HAp@PEG(mim)OH.
J. Chin. Chem. Soc. 2018
© 2018 The Chemical Society Located in Taipei & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.jccs.wiley-vch.de
3

Article
Talaei et al.
110
100
90
The data from EDAX analysis are consistent with
our expectations and confirms the presence of carbon,
oxygen, calcium, phosphorous, iron, and nitrogen in
γ-Fe2O3@HAp@PEG(mim)OH (Figure 4).
TGA of the γ-Fe2O3@HAp@PEG(mim)OH was
investigated by raising its temperature at the rate of
80
70
60
50
−1
ꢀ
ꢀ
10 C min in air up to 800 C to analyze its thermal
decomposition behavior (Figure 5). Two main stages of
weight loss are observed. The first small weight loss of
40
30
20
0
ꢀ
100
200
300
400
500
600
700
800
11% below 280 C is due to the removal of physically
Temperature (°C)
adsorbed water as well as dehydration of the surface
OH groups; the second one in the region of 280–360 C
Fig. 5. TGA diagram of γ-Fe2O3@HAp@PEG
ꢀ
(mim)OH.
is probably due to the decomposition of the organic
groups. The curve shows a weight loss of about 52%
the surface of γ-Fe2O3@HAp was confirmed by the
C─H stretching and bending bands, which could be
observed at 2850–2950 and 1400–1500 cm−1, respec-
tively. In addition, the bands at 1620 and 1577 cm−1
were assigned to the imidazole C═N bending and ring-
stretching vibrations, respectively, which overlap with the
NHCO stretching bands. This spectrum showed a broad
peak at 3200–3600 cm−1, which includes the O─H stretch-
ing vibration.
ꢀ
from 280 to 360 C, resulting from the decomposition
of the organic spacer grafting to the magnetite surface.
After successful characterization of the catalyst, to
evaluate the catalytic activity of γ-Fe2O3@HAp@PEG
(mim)OH as a basic nanomagnetic PTC, initially a
three-component reaction of benzaldehyde, malononi-
trile, and dimedone was carried out to determine the
catalyst efficiency and to arrive at the optimized reac-
tion conditions (Table 1).
Both TEM (Figure 2) and SEM (Figure 3) results
showed that the encapsulated nanoparticles were pre-
sent as uniform particles and the size of encapsulated
nanoparticles was less than 100 nm.
After preliminary experiments, it was found that the
condensation reaction of benzaldehyde, malononitrile,
and dimedone was efficiently carried out in the presence
Table 1. Optimization of the reaction conditions for the synthesis of tetrahydrobenzopyran 1aa
O
O
CHO
CN
CN
CN
Catalyst
Base, H2O, r.t.
+
+
O
NH2
O
1a
Entry
Catalyst (g)
Base (mol%)
Time (min)
Yieldb (%)
1
2
3
4
5
6
7
8
9
–
–
NaOH (10)
K2CO3 (10)
K2CO3 (10)
K2CO3 (10)
K2CO3 (10)
K2CO3 (5)
–
90
90
90
90
20
20
90
20
90
35
30
75
80
92
91
30
92
80
γ-Fe2O3@HAp@PEG(mim)Cl (0.05)
γ-Fe2O3@HAp@PEG(mim)Br (0.05)
γ-Fe2O3@HAp@PEG(mim)OH (0.05)
γ-Fe2O3@HAp@PEG(mim)OH (0.05)
γ-Fe2O3@HAp@PEG(mim)OH (0.05)
γ-Fe2O3@HAp@PEG(mim)OH (0.04)
γ-Fe2O3@HAp@PEG(mim)OH (0.05)
K2CO3 (5)
NaOH (10)
a Reaction conditions: benzaldehyde (1 mmol), malononitrile (1 mmol), dimedone (1 mmol), water (3 mL).
b Isolated yield.
4
www.jccs.wiley-vch.de
© 2018 The Chemical Society Located in Taipei & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
J. Chin. Chem. Soc. 2018

JOURNAL OF THE CHINESE
CHEMICAL SOCIETY
Synthesis of Tetrahydrobenzopyrans by a Novel PTC
Table 2. Synthesis of 4H-tetrahydrobenzopyrans catalyzed by γ-Fe2O3@HAp@PEG(mim)OH in watera
O
Ar
O
CN
CN
CN
γ-Fe2O3@HAp@PEG(mim)OH
+
+
ArCHO
K2CO3 (5 mol%), H2O, r.t.
R
R
O
NH2
O
R
R
R = H or Me
M.p. (ꢀC)
Entry
Ar
R
Time (min)
Product
Yield (%)b
Found
229–231
Reportedref.
1
2
3
4
5
6
7
8
C6H5
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
H
H
H
H
H
H
H
H
20
35
50
45
30
40
20
40
60
30
30
55
30
40
65
50
40
50
40
40
1a
1b
1c
1d
1e
1f
1g
1h
1i
1j
1k
1l
2a
2b
2c
2d
2e
2f
92
90
87
88
85
86
89
85
83
89
91
84
88
91
90
88
89
87
85
89
231–23217
197–19918
219–22119
208–21020
226–22720
217–21920
201–20320
226–22819
210–21219
210–21217
–
4-MeOC6H4
4-MeC6H4
2-ClC6H4
3-ClC6H4
4-ClC6H4
4-BrC6H4
4-HOC6H4
4-Me2NC6H4
3-O2NC6H4
2,5-(MeO)2C6H3
2-Furyl
192–193
215–216
204–206
226–228
214–215
202–204
225–237
209–211
211–212
171–173
219–221
237–240
195–197
160–162
206–208
224–227
236–237
225–227
220–222
9
10
11
12
13
14
15
16
17
18
19
20
220–22219
238–24017
192–19317
–
C6H5
4-MeOC6H4
4-MeC6H4
2-ClC6H4
–
4-ClC6H4
224–22617
238–24018
229–23018
–
4-BrC6H4
3-O2NC6H4
2,5-(MeO)2C6H3
2g
2h
a Reaction conditions: aryl aldehyde (1 mmol), malononitrile (1 mmol), 1,3-dicarbonyl (1 mmol), K2CO3 (5 mol%), PTC
(0.04 g), water (3 mL), room temperature.
b Isolated yield.
of 0.04 g of γ-Fe2O3@HAp@PEG(mim)OH and 5 mol%
of potassium carbonate in water at room temperature to
producedgive 2-amino-3-cyano-7,7-dimethyl-4-(4-methyl
phenyl)-5-oxo-4H-5,6,7,8-tetrahydrobenzo-pyran (1a) in
excellent yield in a short reaction time (Table 1, entry 8).
Lower amounts of catalyst gave 4H-pyranin lower yield,
while higher amounts of the catalyst or base had no
marked effect on the reaction time and yield (Table 1,
entries 5 and 6). The reaction in the presence of NaOH
and K2CO3 (10 mol%) without the catalyst led to the for-
mation of the corresponding product in low yield after a
long reaction time (Table 1, entries 1 and 2). Additionally,
the reaction in the absence of the base (Table 1, entry 7)
or in the presence of NaOH (Table 1, entry 9) did not
reach completetion even after much longer reaction time.
This coupling reaction in the presence of the chloride and
bromide forms of the PTC gave the corresponding prod-
uct in lower yields with longer reaction times (Table 1,
entries 3 and 4).
Subsequently, the generality and synthetic scope
of this three-component protocol for synthesizing a
series of tetrahydrobenzopyrans were demonstrated by
the reaction of various aryl aldehydes with malononi-
trile and dimedone or 1,3-cyclohexadione under
optimal conditions (Table 2). As shown in Table 2,
yields of products are good to excellent for aromatic
aldehydes bearing both electron-donating and electron-
withdrawing groups.
To investigate the reusability of the catalyst, it
was recovered from the reaction mixture using an exter-
nal magnet (Figure 6) and washed with acetone or
methanol and dried in air. It was then reused for
J. Chin. Chem. Soc. 2018
© 2018 The Chemical Society Located in Taipei & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.jccs.wiley-vch.de
5

Article
Talaei et al.
CONCLUSION
In conclusion, we described the synthesis and
characterization of a novel nanomagnetic basic PTC,
γ-Fe2O3@HAp@PEG(mim)OH and the catalytic activ-
ity of this magnetically separable catalyst in the one-pot
three-component synthesis of tetrahydrobenzopyrans
under aqueous media at room temperature. This novel
catalytic method offers several advantages including
environmental friendliness, high yield, short reaction
time, the use of mild reaction conditions involving a
simple work-up procedure, ease of separation, and recy-
clability of the magnetic catalyst. The immobilized cat-
alyst could be easily recovered by easy magnetic
decantation and reused at least five times without
noticeable loss of activity. So this procedure can be con-
sidered a new and suitable addition to the present meth-
odologies in this area.
Fig. 6. Image showing the catalyst separation by an
applied magnetic field.
EXPERIMENTAL
Materials and methods
subsequent experiments (up to five cycles) under similar
reaction conditions. It was observed that the yields of
the product remained comparable in these experiments
(Figure 7), thereby establishing the recyclability and the
reusability of the catalyst without any significant loss of
activity.
Comparison of the catalytic strength of
γ-Fe2O3@HAp@PEG(mim)OH in the three-component
condensation of benzaldehyde, malononitrile, and
dimedone to produce the corresponding 4H-pyran with
some of methods reported in the literature is given in
Table 3. The results show that our procedure provides
high yields of the products in short reaction times under
mild and green conditions.
All materials and reagents were purchased from
Fluka and Merck and used without further purification.
Products were characterized by comparison of their phys-
ical data as well as IR, 1H-NMR, and 13C-NMR spectra
with those of known samples. NMR spectra were
recorded in DMSO-d6 on a Bruker Advance DPX
400 MHz spectrometer with TMS as the internal stan-
dard. IR spectra were recorded on a BOMEM MB-Series
1998 FTIR spectrometer. The purity determination of
the products and reaction monitoring were accomplished
by TLC on silica gel PolyGram SILG/UV 254 plates.
TGA curve of the catalyst was recorded on a BAHR
SPA 503 at heating rates of 10 ꢀC min−1 under air atmo-
sphere, over the temperature range 25–800 ꢀC. SEM-
EDAX analyses were carried out using a Philips XL30
instrument. The TEM images were recorded using a
Zeiss-EM10C-80 kV miroscope.
Conversion (%)
Time (min)
100
80
60
40
20
Synthesis of polyethylene glycol-(N-methylimidazolium)
bromide-grafted hydroxyapatite encapsulated γ-Fe2O3
nanoparticles
0
γ-Fe2O3@HAp30 and HO-PEG-Br31 were prepared
according to reported methods. To introduce isocyanate
groups, the γ-Fe2O3@HAp core–shell nanoparticles
(0.5 g) were dispersed in 15 mL dry DMF by sonication
(30 min), and then HMDI (8 mmol, 1.28 mL) diluted in
5 mL dry DMF was added dropwise to the mixture.
1
2
3
Run
4
5
1
2
3
4
5
Conversion (%)
Time (min)
100
100
100
100
100
20
20
20
22
23
Fig. 7. Recovery and reusability of the catalyst.
6
www.jccs.wiley-vch.de
© 2018 The Chemical Society Located in Taipei & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
J. Chin. Chem. Soc. 2018

JOURNAL OF THE CHINESE
CHEMICAL SOCIETY
Synthesis of Tetrahydrobenzopyrans by a Novel PTC
Table 3. Comparison of synthesis of tetrahydrobenzopyrans with different methods
Entry
Base or/and catalyst
Solvent
Condition
Time (min)
Yield (%)
Ref.
21
22
23
24
25
26
27
28
29
1
2
3
4
5
6
7
8
9
10
Yb(PFO)3
TBAF
MgO
EtOH
H2O
EtOH, H2O
Neat
EtOH
EtOH
PEG, H2O
H2O
EtOH
H2O
60 ꢀC
Reflux
Reflux
r.t.
r.t.
60 ꢀC
r.t.
300
30
30
5
25
15
15
20
60
20
90
97
92
70
94
94
95
92
85
92
[H3N+CH2CH2OH][HCO2
SiO2 NPs
]
−
MSNs
MNPs-Guanidine
K2CO3, [DiEG(mim)2][OH]2
Cs2CO3
K2CO3, γ-Fe2O3@HAp@PEG(mim)OH
r.t.
Visible light
r.t.
Present work
After mechanical stirring of the mixture for 3 h, to graft
PEG onto the surface, HO-PEG-Br (2 g) dissolved in dry
DMF (5 mL) was added dropwise to the reaction mix-
ture and stirred at 70 ꢀC for 3 h. The precipitate was sep-
arated by magnetic decantation and washed with CCl4
several times. N-Methylimidazole (40 mmol, 3.28 g) in
30 mL acetonitrile was added to the obtained nanocom-
posite and stirred for 48 h under reflux condition. The
solid was washed with CH2Cl2 and dried at room
temperature.
(5 mol%, 6.9 mg) in water (3 mL). The reaction mixture
was stirred at ambient temperature for an appropriate
time as shown in Table 2. After completion of the reac-
tion according to TLC analysis (n-hexane: ethyl acetate;
7:1), the mixture was filtered off in the presence of a
magnet to separate the catalyst and the filtrate was
washed with cool ethanol to obtain the corresponding
4H-pyrans. The crude products were purified by recrys-
tallization from ethanol.
2-Amino-3-cyano-7,7-dimethyl-4-(4-methylphenyl)-5-
oxo-4H-5,6,7,8-tetrahydrobenzopyran (1c)
Synthesis of polyethylene glycol-(N-methylimidazolium)
hydroxide-grafted hydroxyapatite encapsulated γ-Fe2O3
nanoparticles
A mixture of the nanocomposite (0.5 g) and
sodium hydroxide (10 mmol, 0.4 g) in water (20 mL)
was stirred at room temperature for 1 h. The produced
precipitate was separated using an external magnet,
washed with ethanol (3 × 10 mL), and dried in an oven
at 80 ꢀC to give γ-Fe2O3@HAp@PEG(mim)OH.
M.p. 215–216 ꢀC; IR (KBr): ν = 3425, 3329, 2956,
2191, 1674, 1637, 1600 cm−1 (Figure S1, Supporting
information); 1H NMR (400 MHz, DMSO-d6):
δ = 0.96 (s, 3H, CH3), 1.04 (s, 3H, CH3), 2.07 (d,
J = 16.0 Hz, 1H, CH-8), 2.23 (d, J = 16.0 Hz, 1H,
CH-8), 2.27 (s, 3H, CH3), 3.37 (m, 2H, CH-6), 4.14 (s,
1H, CH-4), 6.98 (s, 2H, NH2), 7.04 (d, J = 8.0 Hz, 2H,
ArH), 7.10 (d, J = 8.0 Hz, 2H, ArH) (Figure S2); 13C
NMR (100 MHz, DMSO-d6): δ = 20.56, 26.73, 28.39,
31.75, 35.15, 49.96, 58.43, 112.85, 119.73, 127.05,
128.84, 135.59, 141.79, 158.41, 162.25, 195.59
(Figure S3).
Basic capacity of the catalyst
To determine the basicity of the catalyst,
γ-Fe2O3@HAp@PEG(mim)OH (0.1 g) was added to
25 mL of NaCl aqueous solution (1 M, pH = 5.9) and
stirred for 24 h. The pH of the solution was increased
to 9.76, which is equal to a basic capacity of
3.1 × 10−4 mmol basic sites/g of the catalyst.
2-Amino-3-cyano-7,7-dimethyl-4-(furan-2-yl)-5-oxo-4H-
5,6,7,8-tetrahydrobenzopyran (1l)
ꢀ
M.p. 219–221 C; IR (KBr): ν = 3398, 3325, 2951,
2187, 1678, 1651, 1604 cm−1 (Figure S4); 1H NMR
(400 MHz, DMSO-d6): δ = 0.99 (s, 3H, CH3), 1.05 (s,
3H, CH3), 2.15 (d, 1H, J = 16.0 Hz, CH-8), 2.27 (d, 1H,
J = 16.0 Hz, CH-8), 2.47–2.55 (m, 2H, CH-6), 4.33 (s,
1H, CH-4), 6.05 (m, 1H, ArH), 6.32 (m, 1H, ArH), 7.08
(s, 2H, NH2), 7.48 (s, 1H, ArH) (Figure S5); 13C NMR
General procedure for the synthesis of
tetrahydrobenzopyrans
The basic PTC (40 mg) was added to a mixture of
aromatic aldehydes (1 mmol), malononitrile (1 mmol),
1,3-cyclohexadione or dimedone (1 mmol), and K2CO3
J. Chin. Chem. Soc. 2018
© 2018 The Chemical Society Located in Taipei & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.jccs.wiley-vch.de
7

Article
Talaei et al.
10. Y.-H. Yang, C.-H. Liu, Y.-H. Liang, F.-H. Lin, K. C.-
W. Wu, J. Mater. Chem. B 2013, 1, 2447.
11. B. P. Bastakoti, Y.-C. Hsu, S.-H. Liao, K. C.-W. Wu,
M. Yusa, S. Inuoe, K. Nakashima, Y. Yamauchi, Chem.
Asian J. 2013, 8, 1301.
12. H. R. Ali, H. H. El-Maghrabi, F. Zahran,
Y. M. Moustafa, Appl. Surf. Sci. 2017, 426, 56.
13. A. R. Kiasat, M. Fallah-Mehrjardi, J. Braz. Chem. Soc.
2008, 19, 1595.
14. A. R. Kiasat, M. Fallah-Mehrjardi, Synth. Commun.
2010, 40, 1551.
15. A. R. Kiasat, M. Zayadi, F. Mohammad-Taheri,
M. Fallah-Mehrjardi, Iran. J. Chem. Chem. Eng. 2011,
30, 37.
(100 MHz, DMSO-d6): δC = 26.52, 28.39, 28.95, 31.78,
46.43, 49.86, 55.36, 105.03, 110.32, 110.42, 119.53,
141.72, 155.69, 159.28, 163.24, 195.41 (Figure S6).
2-Amino-3-cyano-4-phenyl-5-oxo-4H-5,6,7,8-
tetrahydrobenzopyran (2a)
ꢀ
M.p. 237–240 C; IR (KBr): ν = 3394, 3325, 3209,
2962, 2885, 2198, 1678, 1600 cm−1 (Figure S7); 1H NMR
(400 MHz, DMSO-d6): δ = 1.95–2.00 (m, 2H, CH2–6),
2.25–2.35 (m, 2H, CH2–8), 2.61–2.64 (m, 2H, CH2–7),
4.20 (s, 1H, CH-4), 7.00 (s, 2H, NH2), 7.16–7.20 (m, 3H,
ArH), 7.27–7.31 (m, 2H, ArH) (Figure S8); 13C NMR
(100 MHz, DMSO-d6): δC = 19.77, 26.43, 35.41, 36.29,
58.18, 113.76, 119.75, 126.49, 127.09, 128.30, 144.76,
158.45, 164.44, 195.82 (Figure S9).
16. A. R. Kiasat, N. Ayashi, M. Fallah-Mehrjardi, J. Iran.
Chem. Soc. 2013, 10, 1175.
17. Y. B. Wagh, Y. A. Tayade, S. A. Padvi, B. S. Patil,
N. B. Patil, D. S. Dalal, Chin. Chem. Lett. 2015,
26, 1273.
ACKNOWLEDGMENTS
We are grateful to the Research Council of
Payame Noor University for financial support.
18. O. H. Qareaghaj, S. Mashkouri, M. R. Naimi-Jamal,
G. Kaupp, RSC Adv. 2014, 4, 48191.
19. M. G. Dekamin, M. Eslami, A. Maleki, Tetrahedron
2013, 69, 1074.
20. F. Shirini, M. Makhsous, M. Seddighi, Iran. J. Catal.
2017, 7, 21.
Supporting information
Additional supporting information is available in
the online version of this article.
21. L. M. Wang, J. H. Shao, H. Tian, Y. H. Wang, B. Liu,
J. Fluor. Chem. 2006, 127, 97.
REFERENCES
1. M. Doble, A. K. Kruthiventi, Green Chemistry and Engi-
22. S. Gao, C. H. Tsai, C. Tseng, C. F. Yao, Tetrahedron
2008, 64, 9143.
neering, Elsevier: Burlington, 2007.
2. D. Dallinger, C. O. Kappe, Chem. Rev. 2007, 107, 2563.
3. S. D. Naik, L. K. Doraiswamy, AIChE J. 1998,
44, 612.
23. M. Seifi, H. H. Sheibani, Catal. Lett. 2008, 126, 275.
24. H. R. Shaterian, M. Arman, F. Rigi, J. Mol. Liq. 2011,
158, 145.
4. C. Yuan, Z. Huang, J. Chen, Catal. Commun. 2012,
24, 56.
25. S. Banerjee, A. Horn, H. Khatri, G. Sereda, Tetrahedron
Lett. 2011, 52, 1878.
5. B. M. Godajdar, A. R. Kiasat, M. M. Hashemi, J. Mol.
Liq. 2013, 183, 14.
26. Y. Sarrafi, E. Mehrasbi, A. Vahid, M. Tajbakhsh, Chin.
J. Catal. 2012, 33, 1486.
6. A. R. Kiasat, S. Nazari, J. Davarpanah, J. Serbian,
Chem. Soc. 2014, 79, 401.
27. A. Rostami, B. Atashkar, H. Gholami, Catal. Commun.
2013, 37, 69.
7. M. Abbasi, J. Chin. Chem. Soc. 2017, 64, 896.
8. Y.-H. Liang, C.-H. Liu, S.-H. Liao, Y.-Y. Lin, H.-
W. Tang, S.-Y. Liu, I.-R. Lai, K. C.-W. Wu, ACS Appl.
Mater. Interfaces 2012, 4, 6720.
28. K. Niknam, M. Khataminejad, F. Zeyaei, Tetrahedron
Lett. 2016, 57, 361.
29. V. T. Kamble, M. Sadaf, B. S. Samer, Iran. Chem. Com-
mun. 2017, 5, 167.
9. B. P. Bastakoti, M. Inuoe, S. Yusa, S.-H. Liao, K. C.-
W. Wu, K. Nakashima, Y. Yamauchi, Chem. Commun.
2012, 48, 6532.
30. S. Igder, A. R. Kiasat, M. R. Shushizadeh, Res. Chem.
Intermed. 2015, 41, 7227.
31. S. Grinberg, E. Shaubi, Tetrahedron 1991, 47, 2895.
8
www.jccs.wiley-vch.de
© 2018 The Chemical Society Located in Taipei & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
J. Chin. Chem. Soc. 2018