Synthesis of a novel bifunctional oxyammonium-based ionic liquid: Application for the synthesis of pyrano[4,3-b]pyrans and tetrahydrobenzo[b]pyrans

Article abstract of DOI:10.1002/jccs.201800468

In the present investigation, a novel bifunctional oxyammonium-based ionic liquid, namely, 2,2′-(ethane-1,2-diylbis[oxy])bis(ethan-1-aminium)-2,2,2-trifluoroacetate, was designed and synthesized. The structure of the titled ionic liquid was characterized

Full text of DOI:10.1002/jccs.201800468

Received: 10 December 2018
DOI: 10.1002/jccs.201800468
Revised: 3 October 2019
Accepted: 23 November 2019
A R T I C L E
Synthesis of a novel bifunctional oxyammonium-based
ionic liquid: Application for the synthesis of pyrano[4,3-b]
pyrans and tetrahydrobenzo[b]pyrans
Azra Zarei1 | Meysam Yarie1
Khodabakhsh Niknam2
| Mohammad Ali Zolfigol1
|
1Department of Organic Chemistry,
Abstract
Faculty of Chemistry, Bu-Ali Sina
University, Hamedan, Iran
In the present investigation, a novel bifunctional oxyammonium-based ionic liquid,
namely, 2,20-(ethane-1,2-diylbis[oxy])bis(ethan-1-aminium)-2,2,2-trifluoroacetate,
was designed and synthesized. The structure of the titled ionic liquid was charac-
terized using Fourier-transform infrared spectroscopy (FT-IR), proton nuclear
magnetic resonance (1HNMR), carbon nuclear magnetic resonance (13CNMR),
fluorine nuclear magnetic resonance (19FNMR), homonuclear COSY nuclear
magnetic resonance (NMR), thermogravimetry (TG), derivative thermogravimetry
(DTG) analysis, X-ray diffraction patterns (XRD), scanning electron microscopy
(SEM), and transmission electron microscopy (TEM). The described ionic liquid
demonstrated robust catalytic performance in the synthesis of pyrano[4,3-b]pyrans
and tetrahydrobenzo[b]pyran derivatives. The ionic liquid presents a high poten-
tial of recycling and reusing capability in both types of model reactions.
2Department of Chemistry, Faculty of
Sciences, Persian Gulf University,
Bushehr, Iran
Correspondence
Meysam Yarie and Mohammad Ali
Zolfigol, Department of Organic Chemistry,
Faculty of Chemistry, Bu-Ali Sina
University, Hamedan 6517838683, Iran.
Email: myari.5266@gmail.com (M. Y.);
mzolfigol@yahoo.com (M. A. Z.);
zolfi@basu.ac.ir (M. A. Z.)
Funding information
National Elites Foundation; Iran National
Science Foundation (INSF), Grant/Award
Number: 98001912; Bu-Ali Sina University
K E Y W O R D S
bifunctional ionic liquid, multicomponent reactions, oxyammonium-based ionic liquid, pyrano
[4,3-b]pyrans, tetrahydrobenzo[b]pyrans
1 | INTRODUCTION
Due to the presence of bulky and asymmetric ions
within the structure of ionic liquids, they melt at temper-
Over the routine, step-by-step sequential access to highly
valuable and complex structures, one-pot mul-
atures lower than 100ꢀC. Frequently, ionic liquids are
referred to as tunable, tailored, task-specific, or des-
ignable species. This is because the properties of ionic liq-
uids can be easily adjusted by the discreet selection of
suitable anions and cations. Currently, due to remarkable
typical characteristics such as minor vapor pressure, large
temperature window of molten state, excellent solvation
properties, high chemical and thermal stability, lack of
inflammability, wide electrochemical window, and respect-
able ion conductivity, ionic liquids emerged as an interdis-
ciplinary area and found a critical rule in different fields of
science. Compared with bulky ionic liquids, nanoionic
a
ticomponent method provides several conceptual and
synthetical merits. The privileged advantages of one-pot
multicomponent reactions are due to the rapid achieve-
ment of complexity and diversity in organic synthesis
through high practical and time-saving approaches. In
addition, this synthetic tool allows the chemists to meet
the criteria of green chemistry, such as atom and step
economy, waste prevention, saving of solvents and
reagents, avoidance of hazardous materials, uncompli-
cated purification procedures, and energy efficiency.[1–8]
© 2019 The Chemical Society Located in Taipei & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
J Chin Chem Soc. 2019;1–12.
http://www.jccs.wiley-vch.de
1

2
ZAREI ET AL.
liquids have been able to overcome disadvantages such as
high cost and viscosity and slow gas diffusivity. Hence,
novel task-specific ionic liquids for resolving the above-
mentioned drawbacks are more in demand.[9–17]
neurodegenerative diseases, such as Alzheimer's,
Huntington's, Parkinson's, and Down's syndrome and
also in the treatment of myoclonus and schizophre-
nia.[46,47] Tetrahydrobenzo[b]pyran derivatives have been
used as for diuretic, anticancer, and antianaphylactic activi-
ties and as anticoagulant agents.[48–51] In the last few years,
owing to the above-mentioned versatilities of
tetrahydrobenzo[b]pyrans, various efforts have been made
to present new procedures for their construction.[52–75]
In the present work, keeping in mind the usefulness
and efficiency of ionic liquids and the biological impor-
tance of pyrano[4,3-b]pyrans and tetrahydrobenzo[b]
pyran derivatives and following our earlier efforts of the
knowledge-based development of task-specific catalysts for
the preparation of valuable heterocyclic compounds,[76–91]
we wish to report the design, synthesis, and catalytic appli-
cation of a novel bifunctional oxyammonium-based ionic
liquid [CH2O(CH2)2NH3]2(CF3COO)2 toward the synthesis
of pyrano[4,3-b]pyrans and tetrahydrobenzo[b]pyrans
under mild reaction conditions (Schemes 1–3).
Among the biological active heterocyclic compounds,
4H-pyran structural motifs have a vital position in many
natural products and drugs and represent varied pharma-
cological properties. For example, (4-oxo-4H-pyran-2-yl)
acrylic acid esters are used as tyrosinase inhibitors,[18]
4-phenyl-4H-pyrans are IKCa channel blockers,[19] and
2-amino-4H-pyrans are applied as an antibacterial.[20]
Fused 4H-pyran derivatives, such as pyrano[4,3-b]pyran
derivatives, have been widely used in various molecules
exhibiting a broad range of pharmacological applications,
such as antiviral,[21] anticonvulsant and antimicrobial,[22]
antileishmanial,[23] antiproliferative,[24] antiviral,[25] anti-
HIV, antituberculosis, and antifungal agents.[26] There-
fore, it is expected that the preparation of these versatile
compounds is an important goal for chemists. Some previ-
ously reported methods for the synthesis of pyrano[4,3-b]
[27]
pyrans include using catalysts such as KF-Al2O3,
triethylbenzyl ammonium chloride,[28] piperidine[29] and
NH4OAc[30] magnesium oxide,[31] DBU,[32] H6P2W18
2 | RESULTS AND DISCUSSION
O62ꢁ18H2O,[33]
nanoeggshell/Cu(OH)2,
thiourea
[34]
dioxide,[35] 4-(Succinimido)-1-butane sulfonic acid,[36]
The design, synthesis, and application of multifunctional
hydrophilic ionic liquids are our main focus. With this aim,
we have applied an open-chain amine with glycolic spacers
as a suitable starting material for the synthesis of desired
ionic liquid. The bifunctional oxyammonium-based ionic
liquid [CH2O(CH2)2NH3]2(CF3COO)2 was synthesized
via a simple procedure. The described ionic liquids were
fully characterized by using various technical methods,
such as Fourier-transform infrared spectroscopy (FT-IR),
proton nuclear magnetic resonance (1HNMR), carbon
nano-CaO,[37] [BBMIm](HSO4)2,
electrocatalysis,[39]
[38]
alum[40] [18-C-6 K][OAc][41] DABCO,[42] PNO/Ag2O,[43]
(CTA)3[SiW14]-Li+-MMT,[44] and sodium ethylene diamine
tetraacetate.[45]
As in the case of pyrano[4,3-b]pyran derivatives,
tetrahydrobenzo[b]pyrans are privileged heterocyclic
structures that represent the varied scope of pharmaceuti-
cal and biological applications. These types of heterocyclic
structures have been applied in the treatment of
SCHEME 1 Preparation of
bifunctional oxyammonium-
based ionic liquid
SCHE ME 2 Synthesis of pyrano
[4,3-b]pyrans in the presence of [CH2O
(CH2)2NH3]2(CF3COO)2

ZAREI ET AL.
3
SCHEME 3 Synthesis of
tetrahydrobenzo[b]pyrans in the
presence of [CH2O
(CH2)2NH3]2(CF3COO)2
SCHEME 4 Optimal reaction
condition for the synthesis of target
molecule 1a
nuclear magnetic resonance (13CNMR), fluorine nuclear
magnetic resonance (19FNMR), homonuclear COSY
nuclear magnetic resonance (NMR), thermogravimetry
(TG), derivative thermogravimetry (DTG), X-ray diffrac-
tion (XRD), scanning electron microscopy (SEM), and
transmission electron microscopy (TEM). All of the used
methods confirmed the successful synthesis of the titled
catalyst. Details are discussed in the electronic supporting
information.
outcome data imply that a solvent-free condition at 80ꢀC
in the presence of 7 mol% of ionic liquid catalyst
(Table 1, Entry 10) is the optimal reaction condition. The
related data are presented in Table 1.
After determination of the optimal reaction parameters
for the synthesis of target molecule 1a, aromatic aldehydes
bearing either electron-withdrawing or electron-donating
substituents were tested using the optimal reaction condi-
tions to yield the desired molecules 1a–n. From the
achieved experimental results, the reactions for all sub-
strates were found to proceed smoothly toward the desired
pyrano[4,3-b]pyran derivatives in short reaction times
with excellent yields (Scheme 2 and Table 2).
2.1 | Catalytic performance of the novel
ionic liquid in multicomponent reactions
The promising obtained result from the catalytic
application of ionic liquid encouraged us to test its cata-
lytic performance in the synthesis of tetrahydrobenzo[b]
pyrans as biological active target structures. In the case of
tetrahydrobenzo[b]pyrans, the best reaction condition
scrutinized over the reaction of 4-chlorobenzaldehyde,
malononitrile and dimedone (Scheme 5). Respect to
green nature, reaction time and yield of the desired mole-
cule 2a, the best experimental data were obtained in the
presence of 7 mol% of ionic liquid at 70 oC undersolvent-
free condition (Table 3, Entry 8).
Afterward, as in the case of pyrano[4,3-b]pyrans, the
generality and scope of the presented method was investi-
gated regarding the green synthesis of tetrahydrobenzo
[b]pyran derivatives. For this goal, with optimal reaction
conditions in hand, the varied aromatic aldehyde with
electron-withdrawing and electron-releasing groups was
After verification of the formation of the titled ionic liq-
uid catalyst using the above-discussed methods, due to
the pharmaceutical versatilities of the pyrano[4,3-b]
pyrans and tetrahydrobenzo[b]pyrans, we were encour-
aged to study the catalytic activity of the described
ionic liquid toward the synthesis of these heterocyclic
scaffolds.
In an initial endeavor, in the case of pyrano[4,3-b]
pyrans, the reaction between equivalent amounts of
4-chlorobenzaldehyde, malononitrile, and 4-hydroxy-
6-methyl-2H-pyran-2-one was selected as a test reaction
(Scheme 4). Using model reaction, effective reaction
parameters, including solvents, the load of catalyst, and
operational reaction temperature, were checked thor-
oughly. With respect to the reaction time and yield of the
desired compound under different conditions, the

4
ZAREI ET AL.
TABLE 1 Optimization of reaction conditions for the synthesis of desired molecule 1aa
Entry
1
Solvent
—
Load of catalyst (mol%)
Temperature (ꢀC)
Time (min.)
Yield (%)b
10
10
10
10
10
10
5
r.t.
50
60
70
80
90
80
80
80
80
80
80
80
80
80
80
240
60
20
18
13
13
25
30
300
13
30
35
100
80
80
90
—
80
87
90
93
93
88
85
—
92
90
87
85
83
60
80
2
—
3
—
4
—
5
—
6
—
7
—
8
—
3
9
—
—
7
10
11
12
13
14
15
16
—
EtOH
H2O
CH3CN
n-hexane
EtOAc
THF
7
7
7
7
7
7
Note: The bold values represent optimized reaction conditions.
aReaction conditions: 4-chlorobenzaldehyde (1 mmol, 0.140 g), malononitrile (1 mmol, 0.066 g), 4-hydroxy-6-methyl-2H-pyran- 2-one (1 mmol, 0.126 g).
bIsolated yield.
TABLE 2 Synthesis of target molecules 1a–n in the presence of novel bifunctional oxyammonium-based ionic liquid catalysta
Entry
Product
1a
R
Time (min)
Yield (%)b
Melting point (ꢀC), found [lit.]ref.
219–222 [220–222]77
226–228 [207–209]77
246–248 [250–252]77
228–230 [232–234]77
215–217 [222–224]41
240–244 [243–245]41
178–180 [new]
219–221[212–215]77
238–240 [not reported]34
258–260 [262–264]77
227–229 [not reported]42
244–246 [new]
1
4-cl
13
18
15
20
12
25
25
15
30
17
30
18
20
25
92
88
85
89
93
85
86
92
84
91
87
93
91
84
2
1b
4-me
3
1c
H
4
1d
3-NO2
5
1e
Pyridine-3-carbaldehyde
6
1f
2-OMe
7
1g
α-Methyl cinnamaldehyde
8
1h
1i
4-Br
9
4-OH
10
11
12
13
14
1j
2-cl
1k
1l
3,4,5-(OMe)3
3,5-F2
1m
1n
3,5-(CF3)2
4-isopropyl
248–250 [new]
225–227 [new]
aReaction conditions: aryldehyde (1 mmol), malononitrile (1 mmol, 0.066 g), 4-hydroxy-6-methyl-2H-pyran- 2-one (1 mmol, 0.126 g).
bIsolated yields.
subjected to the reaction with malononitrile and
dimedone or cyclohexane-1,3-dione. The achieved experi-
mental data for the synthesis of tetrahydrobenzo[b]
pyrans were collected in Table 4. All the reactions can
lead to the desired molecules in short reaction times with
excellent yields (Scheme 3, Table 4).
A typical plausible mechanistic process for the syn-
thesis of the desired compound 1b is illustrated in
Scheme 6. The dual-role ionic liquid catalyst simulta-
neously activates both benzaldehyde and malononitrile
to initiate the mechanistic process. A nucleophilic attack
from malononitrile on activated benzaldehyde yields

ZAREI ET AL.
5
SCHEME 5 Optimal reaction
condition for the synthesis of target
molecule 2a
TABLE 3 Optimization of reaction conditions for the synthesis of desired molecule 2aa
Entry
Solvent
—
Load of catalyst (mol%)
Temperature (ꢀC)
Time (min)
Yield (%)b
1
10
10
10
10
5
r.t.
50
70
80
70
70
70
70
70
70
70
70
70
70
120
60
15
15
25
35
240
15
25
30
90
60
60
60
80
87
95
95
88
80
60
95
93
87
87
83
60
90
2
—
3
—
4
—
5
—
6
—
3
7
—
—
7
8
—
9
EtOH
H2O
CH3CN
n-hexane
EtOAc
THF
7
10
11
12
13
14
7
7
7
7
7
aReaction conditions: 4-chlorobenzaldehyde (1 mmol, 0.140 g), malononitrile (1 mmol, 0.066 g), dimedone (1 mmol, 0.140 g).
bIsolated yield.
Knoevenagel intermediate 2 after dehydration. In the
next step, the Knoevenagel intermediate 2 acts as a
Michael acceptor and is subjected to the reaction with
the activated 4-hydroxy-6-methyl-2H-pyran-2-one, which
produces the intermediate 3. Afterward, intermediate 4
formed from an intramolecular nucleophilic attack by
the oxygen atom on the nitrile group. In the presence of
the catalyst, this intermediate tautomerized to the desired
molecule 1b.
In the case of tetrahydrobenzo[b]pyran derivatives,
compound 2b was selected as a model, and the suggested
mechanism is as depicted in Scheme 7. Similar to a plau-
sible mechanism for compound 1b, in the presence of
ionic liquid catalyst, Knoevenagel intermediate 2 was
generated from the reaction of benzaldehyde and
malononitrile. This intermediate is exposed to a nucleo-
philic attack from the enol form of dimedone. This reac-
tion generates intermediate 5, which undergoes an
intramolecular nucleophilic attack to yield the
corresponding intermediate 6. Finally, the desired
product 2b was obtained using a tautomerization process
in the presence of catalyst (Scheme 7).
2.2 | Recyclability of the novel ionic
liquid
In another investigation, catalyst recovery and reuse as a
very important issue from the viewpoint of green chemistry
principals were inspected in both types of multicomponent
reactions. The results were quite satisfactory. After comple-
tion of each run, to separate the catalyst, 5 ml of distillated
water was added to the reaction mixture and stirred for
5 min. The ionic liquid catalyst was dissolved in distillated
water, while the product and unreacted starting materials
did not dissolve. Through simple filtration and evaporation
of the solvent, the catalyst was recovered and preserved for
the next run. The recovered ionic liquid catalyst could be
reused for three runs in both cases of the reactions. In
both cases of the multicomponent reactions, the recovery

6
ZAREI ET AL.
TABLE 4 Synthesis of target molecules 2a–v in the presence of novel bifunctional oxyammonium-based ionic liquid catalysta
Entry
1
Product
2a
R1
R2
Time (min)
Yield (%)b
Melting point (ꢀC), found [lit.]ref.
4-cl
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
H
15
20
20
18
15
15
18
20
22
25
15
15
10
18
20
15
16
18
12
13
15
20
95
90
92
92
94
93
95
90
91
90
95
96
96
93
90
93
94
91
93
92
93
90
192–202 [210–212]82
219–223 [215–217]82
187–190 [227–229]82
190–194 [195–197]82
191–202 [212–214]82
197–201 [205–207]82
174–177 [180–182]82
203–207 [196–197]74
219–222 [218–220]75
229–232 [205–206]69
185–188 [215–218]71
209–213 [211–213]82
184–187 [255–256]70
204–207 [207–209]67
198–202 [203–205]68
225–227 [new]
2
2b
2c
4-me
3
H
4
2d
2e
4-OMe
5
2-cl
6
2f
4-Br
7
2g
4-NO2
8
2h
2i
4-isopropyl
3-OEt-4-OH
3-OH
9
10
11
12
13
14
15
16
17
18
19
20
21
22
2j
2k
2l
Cinnamaldehyde
3-NO2
2m
2n
2o
2p
2q
2r
Pyridine-3-carboxaldehyde
α-Methyl cinnamaldehyde
2-OMe
3,5-F2
4-CF3
217–219 [218–219]69
232–236 [169–170]73
184–188 [new]
239–241 [250–252]72
209–212 [210–212]72
256–259 [new]
3,5-(CF3)2
3,4-F2
2s
2t
3,5-F2
2u
2v
4-CF3
H
3,5-(CF3)2
H
aReaction conditions: aryldehyde (1 mmol), malononitrile (1 mmol, 0.066 g), dimedone or cyclohexane-1,3-dione (1 mmol).
bIsolated yield.
and reusability test was examined over the reaction of
4-chlorobenzaldehyde, malononitrile, and 4-hydroxy-
6-methyl-2Hpyran-2-one or dimedone in the related optimal
reaction conditions as depicted in Scheme 8.
afford a pure ionic liquid catalyst as desired product. All
obtained data confirmed the successful formation of the
catalyst.
3.2 | General method for the synthesis of
pyrano[4,3-b]pyrans in the presence of
novel bifunctional ionic liquid catalyst
3 | EXPERIMENTAL
3.1 | General method for the synthesis of
novel bifunctional ionic liquid catalyst
At the optimal reaction conditions depicted in Table 1 (sol-
vent free, 80ꢀC, 7 mol% of ionic liquid), a mixture of aro-
matic aldehydes (1 mmol), malononitrile (1 mmol,
0.066 g), and 4-hydroxy-6-methyl-2H-pyran-2-one (1 mmol,
0.126 g) was subjected to the reaction for proper times as
given in Table 2. After completion of the reaction as
monitored by TLC, in order to separate the ionic liquid
catalyst, 5 ml of distillated water was added to the mixture
and stirred for 5 min. The catalyst was removed from the
reaction mixture by simple filtration. Through evaporation
of the solvent, the catalyst was recovered and preserved for
The novel bifunctional oxyammonium-based ionic liquid cat-
alyst was synthesized as follows: 10 mmol (1.14 g, 0.77 ml)
of trifluoracetic acid was added dropwise to a round-bottom
flask containing 5 mmol (0.74 g, 0.73 ml) of 1,8-diamino-
3,6-dioxaoctane under neat conditions at ambient tempera-
ture. During the addition of acid to base, the mixture was
stirred vigorously. After the addition was completed, the
mixture was stirred for 2 hr. The obtained thick precipitate
was washed thoroughly with diethyl ether (3 × 10 ml) to

ZAREI ET AL.
7
SCHEME 6 A plausible mechanism for the synthesis of desired compound 1b
the next run. The filtrated crude product was washed with
hot ethanol and air dried to yield the desired molecules.
3.4 | Selected spectral data
3.4.1 | Spectral data of the bifunctional
oxyammonium-based ionic liquid
3.3 | General method for the synthesis of
tetrahydrobenzo[b]pyrans in the presence
of novel bifunctional ionic liquid catalyst
2,20-(Ethane-1,2-diylbis[oxy])bis(Ethan-1-aminium)
2,2,2-trifluoroacetate
1
Melting point: 90–92ꢀC; H NMR (300 MHz): δppm 8.03
(bs, 6H, NH), 3.61 (t, J = 3 Hz, 4H, CH2), 3.58 (s, 4H,
CH2), 2.98 (t, J = 3 Hz, 4H, CH2); 13C NMR (75 MHz):
δppm 158.6 (q, J = 23.3 Hz, C=O), 117.1 (q, J = 222.7 Hz,
CF3), 69.4, 66.6, 38.5, 19F NMR (282 MHz): δppm − 73.8.
At 70ꢀC, 7 mol% of ionic liquid was added to a round-
bottom flask containing a mixture of aromatic aldehydes
(1 mmol), malononitrile (1 mmol, 0.066 g), and
dimedone or cyclohexane-1,3-dione (1 mmol) as a cata-
lyst. The resulting mixture was stirred for the appropriate
times as given in Table 4. The progress of the reaction
was monitored by TLC. After completion of the reac-
tion, water (5 ml) was added to the reaction mixture,
and the catalyst was removed from the reaction mix-
ture and recovered for the next run. The reaction mix-
ture was filtered, and residue was purified by washing
with hot ethanol and air dried to yield the desired
structures.
3.4.2 | Selected spectral data of the
prepared structures
2-Amino-7-methyl-5-oxo-4-(pyridin-3-yl)-4H,5H-pyrano
[4,3-b]pyran-3-carbonitrile (1e)
Melting point: 215–217ꢀC. FT-IR (KBr, ν, cm−1): 3,410,
1
3,127, 2,192, 1,704, 1,668, 1,647, 1,621, 1,379, 1,258. H

8
ZAREI ET AL.
SCHEME 7 A plausible mechanism for the synthesis of desired compound 2c
SCHEME 8 Reusing test in both cases of multicomponent reactions
NMR (300 MHz, DMSO) δppm 8.49–8.45 (m, 2H, Aro-
matic), 7.65–7.61 (m, 1H, Aromatic), 7.39–7.33 (m, 3H,
Aromatic and NH2), 6.31 (s, 1H, Olefinic), 4.40 (s, 1H,
CH), 2.24 (s, 3H, CH3). 13C NMR (75 MHz, DMSO) δppm
163.7, 161.8, 159.0, 158.7, 149.5, 148.7, 139.4, 135.7, 124.2,
119.6, 100.2, 98.5, 57.4, 34.5, 19.8.
2-Amino-7-methyl-5-oxo-4-(3,4,5-trimethoxyphenyl)-
4H,5H-pyrano[4,3-b]pyran-3-carbonitrile (1k)
Melting point: 227–229ꢀC. FT-IR (KBr, ν, cm−1): 3,498,
1
3,367, 2,195, 1,696, 1,669, 1,640, 1,589, 1,380, 1,130. H
NMR (300 MHz, DMSO) δppm 7.21 (s, 2H, NH2), 6.47 (s,
2H, Aromatic), 6.29 (s, 1H, Olefinic), 4.29 (s, 1H, CH),

ZAREI ET AL.
9
3.75 (s, 6H, OCH3), 3.66 (s, 3H, OCH3), 2.25 (s, 3H, CH3).
13C NMR (75 MHz, DMSO) δppm 163.3, 161.9, 158.7,
158.6, 153.3, 139.8, 137.0, 119.8, 105.2, 101.0, 98.5, 60.4,
58.3, 56.3, 36.9, 19.8.
2-Amino-4-(2-methoxyphenyl)-7,7-dimethyl-5-oxo-
5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile (2o)
Melting point: 194–204ꢀC. FT-IR (KBr, ν, cm−1): 3,397,
1
3,331, 2,189, 1,687, 1,655, 1,607, 1,371, 1,141, 1,017. H
NMR (300 MHz, DMSO) δppm 7.18 (td, 1H, Aromatic,
J = 7.5 Hz), 7.03–6.96 (m, 2H, Aromatic), 6.90–6.85 (m,
3H, Aromatic and NH2), 4.50 (s, 1H, CH), 3.77 (s, 3H,
OCH3), 2.60–2.44 (AB system, 2H, J = 15 Hz), 2.30–2.06
(AB system, 2H, J = 15 Hz), 1.06 (s, 3H, CH3), 0.99 (s,
3H, CH3). 13C NMR (75 MHz, DMSO) δppm 196.0, 163.6,
159.5, 157.3, 132.7, 129.0, 128.3, 120.8, 120.3, 112.4, 112.0,
57.9, 56.1, 50.5, 32.3, 30.8, 29.1, 27.1.
2-Amino-4-(3,5-difluorophenyl)-7-methyl-5-oxo-4H,5H-
pyrano[4,3-b]pyran-3-carbonitrile (1l)
Melting point: 244–246ꢀC. FT-IR (KBr, ν, cm−1): 3,404,
1
3,330, 2,194, 1,708, 1,676, 1,645, 1,615, 1,382, 1,262. H
NMR (300 MHz, DMSO) δppm 7.33 (s, 2H, NH2), 7.12 (tt,
1H, Aromatic, J = 3 Hz), 7.01–6.94 (m, 2H, Aromatic),
6.30 (s, 1H, Olefinic), 4.43 (s, 1H, CH), 2.25 (s, 3H, CH3).
13C NMR (75 MHz, DMSO) δppm 163.8, 162.8 (dd,
J = 240 Hz, J = 12.8 Hz), 161.8, 159.2, 158.7, 148.7
2-Amino-4-(3,5-difluorophenyl)-7,7-dimethyl-5-oxo-
5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile (2p)
Melting point: 225–227ꢀC. FT-IR (KBr, ν, cm−1): 3,393,
(t,
J
= 8.25 Hz), 119.5, 111.3 (dd,
J
= 24 Hz,
J = 7.25 Hz),103.0 (t, J = 25.5 Hz), 99.9, 98.6, 57.3,
36.5, 19.8.
1
3,327, 2,198, 1,682, 1,661, 1,602, 1,375, 1,307, 1,119. H
NMR (300 MHz, DMSO) δppm 7.16 (s, 2H, NH2), 7.08 (tt,
1H, Aromatic, J = 3 Hz), 6.92–6.85 (m, 2H, Aromatic),
4.30 (s, 1H, CH), 2.64–2.47 (AB system, 2H, CH2,
J = 18 Hz), 2.30–2.16 (AB system, 2H, CH2, J = 18 Hz),
1.05 (s, 3H, CH3), 1.00 (s, 3H, CH3). 13C NMR (75 MHz,
DMSO) δppm 196.2, 163.7, 162.8 (dd, J = 240 Hz,
J = 12.8 Hz), 159.1, 150.0 (t, J = 8.3 Hz), 119.8, 112.02,
110.8 (dd, J = 24.7, J = 7.5 Hz), 102.7 (t, J = 25.5 Hz),
57.6, 50.7, 40.1, 35.8, 32.3, 28.5, 27.6.
2-Amino-4-(3,5-bis[trifluoromethyl]phenyl)-7-methyl-
5-oxo-4H,5H-pyrano[4,3-b]pyran-3-carbonitrile (1m)
Melting point: 248–250ꢀC. FT-IR (KBr, ν, cm−1): 3,421,
3,339, 2,194, 1,721, 1,675, 1,646, 1,611, 1,384, 1,284. 1H NMR
(300 MHz, DMSO) δppm 8.02 (s, 1H, Aromatic), 7.96 (s, 2H,
Aromatic), 7.41 (s, 2H, NH2), 6.33 (s, 1H, Olefinic), 4.72
(s, 1H, CH), 2.25 (s, 1H, CH3). 13C NMR (75 MHz, DMSO)
δppm 164.0, 161.9, 159.3, 158.8, 147.3, 130.7 (q, J = 32.3),
129.2, 125.6, 122.0, 121.5, 119.4, 99.4, 98.7, 56.8, 36.4, 19.8.
2-Amino-7,7-dimethyl-5-oxo-4-(4-[trifluoromethyl]
phenyl)-5,6,7,8-tetrahydro-4H-chromene-
3-carbonitrile (2q)
2-Amino-4-(4-isopropylphenyl)-7-methyl-5-oxo-4H,5H-
pyrano[4,3-b]pyran-3-carbonitrile (1n)
Melting point: 222–225ꢀC. FT-IR (KBr, ν, cm−1): 3,370,
Melting point: 217–219ꢀC. FT-IR (KBr, ν, cm−1): 3,394,
1
1
3,302, 2,203, 1,716, 1,671, 1,641, 1,617, 1,377, 1,264. H
3,323, 2,190, 1,683, 1,658, 1,371, 1,324, 1,119, 1,067. H
NMR (300 MHz, DMSO) δppm 7.21–7.19 (m, 3H, Aro-
matic and NH2), 7.12 (d, 2H, Aromatic, J = 9 Hz), 6.29 (s,
1H, Olefinic), 4.26 (s, 1H, CH), 2.86 (s, 1H, CH, J = 6 Hz),
NMR (300 MHz, DMSO) δppm 7.69 (d, 2H, aromatic,
J = 6 Hz), 7.41 (d, 2H, aromatic, J = 6 Hz), 7.16 (s, 2H,
NH2), 4.33 (s, 1H, CH), 2.62–2.52 (m, 2H, CH2), 2.31–2.11
(AB system, 2H, CH2, J = 15 Hz), 1.06 (s, 3H, CH3), 0.98 (s,
3H, CH3). 13C NMR (75 MHz, DMSO) δppm 196.2, 163.4,
159.0, 128.6, 128.0, 127.5, 126.6, 125.8 (q, J = 3.75 Hz),
123.0, 120.0, 112.5, 57.9, 50.4, 40.2, 36.1, 32.3, 28.8, 27.4.
2.23 (s, 3H, CH3), 1.21 (s, 3H, CH3), 1.19 (s, 3H, CH3). 13
C
NMR (75 MHz, DMSO) δppm 163.3, 161.9, 158.6, 158.6,
147.5, 141.5, 127.9, 126.8, 119.9, 101.4, 98.4, 58.5, 36.3,
33.5, 24.3, 24.3, 19.8.
2-Amino-4-(4-isopropylphenyl)-7,7-dimethyl-5-oxo-
5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile (2h)
Melting point: 203–207ꢀC. FT-IR (KBr, ν, cm−1): 3,370,
2-Amino-4-(3,5-bis[trifluoromethyl]phenyl)-
7,7-dimethyl-5-oxo-5,6,7,8-tetrahydro-4H-chromene-
3-carbonitrile (2r)
1
3,311, 2,186, 1,682, 1,653, 1,370, 1,214, 1,137, 1,034. H
Melting point: 232–236ꢀC. FT-IR (KBr, ν, cm−1): 3,405,
1
NMR (300 MHz, DMSO) δppm 7.18 (d, 2H, aromatic,
J = 9 Hz), 7.07 (d, 2H, Aromatic, J = 9 Hz), 6.99 (s, 2H,
NH2), 4.16 (s, 1H, CH), 2.86 (s, 1H, CH, J = 6 Hz),
2.53–2.52 (m, 2H, CH2), 2.30–2.11 (AB system, 2H, CH2,
J = 15 Hz), 1.20 (d, 6H, CH3, J = 6 Hz) 1.06 (s, 3H, CH3),
0.99 (s, 3H, CH3). 13C NMR (75 MHz, DMSO) δppm 196.2,
163.0, 158.9, 147.0, 142.7, 127.5, 126.8, 120.3, 113.3, 59.0,
50.5, 40.2, 35.6, 33.5, 32.3, 28.9, 27.4, 24.4, 24.3.
3,334, 2,200, 1,683, 1,659, 1,374, 1,281, 1,131, 1,038. H
NMR (300 MHz, DMSO) δppm 7.99 (s, 1H, Aromatic),
7.85 (s, 2H, Aromatic), 7.25 (s, 2H, NH2), 4.57 (s, 1H,
CH), 2.58 (brs 2H, CH2), 2.32–2.10 (AB system, 2H, CH2,
J = 15 Hz), 1.06 (s, 3H, CH3), 0.96 (s, 3H, CH3). 13C NMR
(75 MHz, DMSO) δppm 196.33, 164.1, 159.4, 148.7, 130.7
(q, J = 32.3 Hz), 129.2, 128.5, 125.6, 121.0, 122.10, 119.7,
111.7, 57.3, 50.3, 40.1, 35.8, 32.3, 28.9, 26.9.

10
ZAREI ET AL.
2-Amino-4-(3,4-difluorophenyl)-7,7-dimethyl-5-oxo-
5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile (2s)
Melting point: 184–188ꢀC. FT-IR (KBr, ν, cm−1): 3,394,
1,2-diylbis[oxy])bis(ethan-1-aminium)-2,2,2-trifluoroacetate
was designed, synthesized, and characterized using various
techniques. The titled ionic liquid presents robust catalytic
performance in the synthesis of pyrano[4,3-b]pyran deriva-
tives and tetrahydrobenzo[b]pyrans. In addition, the ionic
liquid presents a high potential of recycling and reusing
capability in both types of the investigated reactions. The
present work can open up new and promising insights into
the course of rational design, synthesis, and applications of
task-specific multifunctional hydrophilic ionic liquids for
various purposes.
1
3,324, 2,188, 1,674, 1,638, 1,516, 1,365, 1,246, 1,214. H
NMR (300 MHz, DMSO) δppm 7.42–7.33 (m, 1H, Aromatic),
7.24–7.17 (m, 1H, Aromatic), 7.12 (s, 2H, NH2), 7.05–7.01
(m, 1H, Aromatic), 4.26 (s, 1H, CH), 2.60–2.47 (AB system,
2H, CH2, J = 18 Hz), 2.29–2.13 (AB system, 2H, CH2,
J = 15 Hz), 1.05 (s, 3H, CH3), 0.98 (s, 3H, CH3). 13C NMR
(75 MHz, DMSO) δppm 196.2, 163.3, 159.0, 149.6 (dd,
J = 247.5, J = 12.8), 148.6 (dd, J = 247.5, J = 12.8) 143.1 (t,
J = 3.8 Hz), 124.3–124.4 (m), 120.0, 117.2 (dd, J = 90 Hz,
J = 17.3), 112.5, 58.0, 50.4, 40.1, 35.4, 32.3, 28.6, 27.5.
ACKNOWLEDGMENTS
We thank Bu-Ali Sina University, Iran National Science
Foundation (INSF) (Grant Number: 98001912) and the
National Elites Foundation for financial support of our
research groups. We are also thankful to Prof Michael
Greaney's research group at the School of Chemistry,
Manchester University, for running NMR and mass
spectroscopy.
2-Amino-4-(3,5-difluorophenyl)-5-oxo-
5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile (2t)
Melting point: 239–241ꢀC. FT-IR (KBr, ν, cm−1): 3,406,
3,332, 2,192, 1,683, 1,657, 1,463, 1,367, 1,122, 1,004. 1H
NMR (300 MHz, DMSO) δppm 7.15 (s, 2H, NH2), 7.07 (tt,
1H, Aromatic, J = 3 Hz), 6.94–6.88 (m, 2H, Aromatic), 4.29
(s, 1H, CH), 2.74–2.60 (m, 2H, CH2), 2.34–2.30 (m, 2H,
CH2), 2.01–1.92 (m, 2H, CH2). 13C NMR (75 MHz, DMSO)
ORCID
δppm 196.4, 165.8, 162.8 (dd, J = 240 Hz, J = 12.8 Hz) 159.0,
Meysam Yarie https://orcid.org/0000-0002-7129-0776
150.0 (t, J = 8.3 Hz), 119.9, 113.0, 110.8 (dd, J = 24 Hz,
J = 9.8 Hz),102.6 (t, J = 25.5), 57.5, 36.7, 35.8, 27.0, 20.2.
REFERENCES
[1] R. C. Cioc, E. Ruijter, R. V. A. Orru, Green Chem. 2014, 16,
2958.
[2] S. Garbarino, D. Ravelli, S. Protti, A. Basso, Angew. Chem., Int.
Ed. 2016, 55, 15476.
[3] R. Kakuchi, Angew. Chem., Int. Ed. 2014, 53, 46.
[4] L. Levi, T. J. J. Muller, Chem. Soc. Rev. 2016, 45, 2825.
[5] T. Ahmadi, G. Mohammadi Ziarani, P. Gholamzadeh,
H. Mollabagher, Tetrahedron: Asymmetry 2017, 28, 708.
[6] J. A. Filho, B. C. Lemos, A. S. de Souza, S. Pinheiro,
S. J. Greco, Tetrahedron 2017, 73, 6977.
2-Amino-5-oxo-4-(4-[trifluoromethyl]phenyl)-
5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile (2u)
Melting point: 209–212ꢀC. FT-IR (KBr, ν, cm−1): 3,430,
1
3,335, 2,197, 1,683, 1,658, 1,597, 1,422, 1,367, 1,105. H
NMR (300 MHz, DMSO) δppm 7.68 (d, 2H, Aromatic,
J = 9 Hz), 7.42 (d, 2H, Aromatic, J = 9 Hz), 7.14 (s, 2H,
NH2), 4.33 (s, 1H, CH), 2.73–2.57 (m, 2H, CH2), 2.40–2.22
(m, 2H, CH2), 2.04–1.87 (m, 2H, CH2). 13C NMR
(75 MHz, DMSO) δppm 196.4, 165.4, 159.0, 149.9, 130.2,
128.6, 127.7 (q, J = 31.5 Hz), 126.6, 125.8 (q, J = 3.8 Hz),
123.0, 120.0, 119.4, 113.5, 57.9, 57.8, 36.7, 36.1, 27.0, 20.2.
[7] I. A. Ibarra, A. Islas-Jácome, E. González-Zamora. Org. Biomol.
Chem. 2018, 16, 1402.
[8] T. Zarganes-Tzitzikas, A. L. Chandgude, A. Dömling, Chem.
Rec. 2015, 15, 981.
[9] R. Hayes, G. G. Warr, R. Atkin, Chem. Rev. 2015, 115, 6357.
[10] S. Zhang, J. Zhang, Y. Zhang, Y. Deng, Chem. Rev. 2017, 117,
6755.
[11] S. Das, S. Santra, P. Mondal, A. Majee, A. Hajra, Synthesis
2016, 48, 1269.
[12] K. L. Luska, P. Migowski, W. Leitner, Green Chem. 2015, 17,
3195.
[13] L. C. Brown, J. M. Hogg, M. Swadzba-Kwasny, Top. Curr.
Chem. 2017, 375, 78.
[14] P. Virtanen, E. Salminen, J.-P. Mikkola, Ind. Eng. Chem. Res.
2017, 56, 12852.
[15] V. Campisciano, F. Giacalone, M. Gruttadauria, Chem. Rec.
2017, 17, 1.
[16] A. Kausar, Polym. Plast. Technol. Eng. 2017, 56, 1823.
[17] a Y. Zhu, N. S. Hosmane, Eur. J. Inorg. Chem. 2017, 2017,
2-Amino-4-(3,5-bis[trifluoromethyl]phenyl)-5-oxo-
5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile (2v)
Melting point: 256–259ꢀC. FT-IR (KBr, ν, cm−1): 3,407, 3,335,
2,195, 1,682, 1,657, 1,372, 1,282, 1,171, 1,124. 1H NMR
(300 MHz, DMSO) δppm 7.98 (s, 1H, Aromatic), 7.87 (s, 2H,
Aromatic), 7.24 (s, 2H, NH2), 4.56 (s, 1H, CH), 2.75–2.58 (m,
2H, CH2), 2.39–2.24 (m, 2H, CH2), 2.02–1.89 (m, 2H, CH2).
13C NMR (75 MHz, DMSO) δppm 196.6, 166.0, 159.0, 148.7,
130.7 (q, J = 33.0 Hz), 129.2, 128.6 (q, J = 2.3 Hz), 125.6,
122.0, 121.1, 119.7, 118.4, 112.6, 57.1, 36.7, 35.9, 27.1, 20.2.
4 | CONCLUSIONS
In summary,
a
novel hydrophilic bifunctional
4369.
b A. H. Jadhav, A. Chinnappan, R. H. Patil,
oxyammonium-based ionic liquid, namely, 2,20-(ethane-
S. V. Kostjuk, H. Kim, Chem. Eng. J. 2014, 240, 228.

ZAREI ET AL.
11
[18] S. S. Kang, H. J. Kim, C. Jin, Y. S. Lee, Bioorg. Med. Chem. Lett.
2009, 19, 188.
[51] L. Bonsignore, G. Loy, D. Secci, A. Calignano, J. Org. Chem.
1993, 28, 517.
[19] K. Urbahns, E. Horváth, J. P. Stasch, F. Mauler, Bioorg. Med.
Chem. Lett. 2003, 13, 2637.
[20] D. Kumar, V. B. Reddy, S. Sharad, U. Dube, S. Kapur, Eur.
J. Med. Chem. 2009, 44, 3805.
[21] M. J. Perez-Perez, J. Balzarini, J. Rozenski, E. De Clercq,
P. Herdewijn, Bioorg. Med. Chem. Lett. 1995, 5, 1115.
[22] M. D. Aytemir, U. Calis, M. Ozalp, Arch. Pharm. 2004,
337, 281.
[23] X. Fan, D. Feng, Y. Qu, X. Zhang, J. Wang, P. M. Loiseau,
G. Andrei, R. Snoeck, E. De Clercq, Bioorg. Med. Chem. Lett.
2010, 20, 809.
[52] N. M. A. El-Rahman, R. M. Borik, World Appl. Sci. J. 2014, 31, 1.
[53] S. Nemouchi, R. Boulcina, B. Carboni, A. Debache, C. R. Chim.
2012, 15, 394.
[54] J. T. Li, W. Z. Xu, L. C. Yang, T. S. Li, Synth. Commun. 2004,
34, 4565.
[55] B. Boumoud, A. A. Yahiaoui, T. Boumoud, A. Debache,
J. Chem. Pharm. Res. 2012, 4, 795.
[56] R. S. Bhosale, C. V. Magar, K. S. Solanke, S. B. Mane,
S. S. Choudhary, R. P. Pawar, Synth. Commun. 2007, 37, 4353.
[57] R. Hekmatshoar, S. Majedi, K. Bakhtiari, Catal. Commun.
2008, 9, 307.
[24] a C. P. Dell, C. W. Smith, Eur. Pat. Appl., EP 537, 949. b
C. P. Dell, C. W. Smith, Chem. Abstr. 1993, 119, 139102d.
[25] A. G. Martinez, L. J. Marco, Bioorg. Med. Chem. Lett. 1997, 7,
3165.
[26] L. Abrunhosa, M. Costa, F. Areias, A. Venâncio, F. Proenca,
J. Ind. Microbiol. Biotechnol. 2007, 34, 787.
[58] B. Maleki, S. S. Ashrafi, RSC Adv. 2014, 4, 42873.
[59] D. Azarifar, S. M. Khatami, R. Nejat-Yami, J. Chem. Sci. 2014,
126, 95.
[60] I. Devi, P. J. Bhuyan, Tetrahedron Lett. 2004, 45, 8625.
[61] A. A. Mohammadi, M. R. Asghariganjeh, A. Hadadzahmatkesh,
Arab. J. Chem. 2017, 10, 2213.
[27] X. S. Wang, J. X. Zhou, Z. S. Zeng, Y. L. Li, D. Q. Shi, S. J. Tua,
Arkivoc 2006, xi, 107.
[28] D. Q. Shi, L. H. Niu, Q. Y. Zhuhang, Chin. J. Org. Chem. 2008,
28, 1633.
[29] E. V. Stoyanov, I. C. Ivanov, D. Heber, Molecules 2000, 5, 19.
[30] D. Rajguru, B. S. Keshwal, S. Jain, Med. Chem. Res. 2013, 22, 5934.
[31] M. Seifi, H. Sheibani, Catal. Lett. 2008, 126, 275.
[32] J. M. Khurana, B. Nand, P. Saluja, Tetrahedron 2010, 66, 5637.
[33] D. Rajguru, B. S. Keshwal, S. Jain, Chin. Chem. Lett. 2013, 24,
1033.
[62] S. Rathod, B. Arbad, M. Lande, Chin. J. Catal. 2010, 31, 631.
[63] H. R. Safaei, M. Shekouhy, A. Shirinfeshan, S. Rahmanpur,
Mol. Divers 2012, 16, 669.
[64] E. Sheikhhosseini, D. Ghazanfari, V. Nezamabadi, Iran.
J. Catal. 2013, 3, 197.
[65] M. Esmaeilpour, J. Javidi, F. Dehghani, F. Nowroozi-Dodeji,
RSC Adv. 2015, 5, 26625.
[66] X. S. Wang, D. Q. Shi, S. J. Tu, C. S. Yao, Synth. Commun.
2003, 33, 119.
[67] J. Rakhtshah, S. Salehzadeh, M. A. Zolfigol, S. Baghery,
Appl. Organometal. Chem. 2017, 31, e3690. https://doi.org/
10.1002/aoc.3690.
[34] E. Mosaddegh, A. Hassankhani, H. Karimi-Maleh, Mater. Sci.
Eng., C 2015, 46, 264.
[35] M. Ghashang, S. Sheik Mansoor, K. Aswin, Chin. J. Catal.
2014, 35, 127.
[68] D. Azarifar, Y. Abbasi, Synth. Commun. 2016, 46, 745.
[69] R.-Y. Guo, Z.-M. An, L.-P. Mo, R.-Z. Wang, H.-X. Liu, S.-
X. Wang, Z.-H. Zhang, ACS Comb. Sci. 2013, 15, 557.
[70] Y. Rena, W. Zhang, J. Lub, K. Gaoa, X. Liaoa, X. Chen, RSC
Adv. 2015, 5, 79405.
[36] N. Ghaffari Khaligh, Chin. Chem. Lett. 2015, 26, 26.
[37] E. Mosaddegh, A. Hassankhani, Chin. J. Catal. 2014, 35, 351.
[38] N. G. Khaligh, Monatsh. Chem. 2014, 145, 1643.
[39] M. N. Elinson, R. F. Nasybullin, G. I. Nikishin, Electrocatalysis
2013, 4, 56.
[71] A. Khazaei, F. Gholami, V. Khakyzadeh, A. R. Moosavi-Zare,
J. Afsar, RSC Adv. 2015, 5, 14305.
[40] D. Rajguru, B. S. Keshwal, S. Jain, V. W. Bhagwat, Monatsh.
Chem. 2013, 144, 1411.
[72] A. Thakur, M. Tripathi, U. C. Rajesh, D. S. Rawat, RSC Adv.
2013, 3, 18142.
[41] M. Abaszadeh, M. Seifi, Res. Chem. Intermed. 2015, 41, 7715.
[42] R. Hariri, Z. Afshar, M. Mahdavi, M. Safavi, M. Saeedi,
Z. Najafi, R. Sabourian, E. Karimpour-Razkenari, N. Edraki,
F. Homayouni Moghadam, A. Shafiee, M. Khanavi,
T. Akbarzadeh, Arch. Pharm. Chem. Life Sci. 2016, 349, 915.
[43] M. Beerappa, K. Shivashankar, RSC Adv. 2015, 5, 30364.
[44] E. Abbaspour-Gilandeh, M. Aghaei-Hashjin, A. Yahyazadeh,
H. Salemi, RSC Adv. 2016, 6, 55444.
[45] L. Chen, J. Lin, B. Chen, L. Zhao, Res. Chem. Intermed. 2017,
43, 6691.
[46] C. S. Konkoy, D. B. Fick, S. X. Cai, N. C. Lan, J. F. W. Keana,
Chem. Abstr. 2000, 134, 29313a.
[73] H.-Y. Zhou, F.-Q. Dong, X.-L. Du, Z.-K. Zhou, H.-R. Huo, W.-
H. Wang, H.-D. Zhan, Y.-F. Dai, J. Meng, Y.-P. Sui, J. Li,
F. Sui, Y.-H. Zhai, Bioorg. Med. Chem. Lett. 2016, 26, 3876.
[74] a R. M. N. Kalla, A. Varyambath, M. R. Kim, I. Kim, Appl.
Catal. A. Gen. 2017, 538, 9. b F. Naghiyev, I. Mamedov,
V. Khrustalev, N. Shixaliyev, A. Maharramov, J. Chin. Chem.
Soc. 2019, 66, 253.
[75] M. A. Zolfigol, N. Bahrami-Nejad, F. Afsharnadery,
S. Baghery, J. Mol. Liq. 2016, 221, 851.
[76] M. A. Zolfigol, M. Yarie, RSC Adv. 2015, 5, 103617.
[77] M. A. Zolfigol, M. Yarie, S. Baghery, A. Khoshnood,
D. A. Alonso, Res. Chem. Intermed. 2017, 43, 3291.
[78] M. Yarie, M. A. Zolfigol, Y. Bayat, A. Asgari, D. A. Alonso,
A. Khoshnood, RSC Adv. 2016, 6, 82842.
[47] C. S. Konkoy, D. B. Fick, S. X. Cai, N. C. Lan, J. F. W. Keana,
PCT Int. Appl. 2000, WO 00 75, 123.
[48] Y. L. Zhang, B. Z. Chen, K. Q. Zheng, M. L. Xu, X. H. Lei,
Y. Xue, X. Bas, Chem. Abstr. 1982, 17, 17.
[49] L. L. Andreani, E. Lepi, Bull. Chim. Farm. 1960, 99, 583.
[50] W. O. Foye, Prinicipi di Chemico Farmaceutica, Piccin, Padova,
Italy 1991, p. 416.
[79] M. A. Zolfigol, M. Navazeni, M. Yarie, R. Ayazi-Nasrabadi,
Appl. Organometal. Chem. 2016, 31, e3633. https://doi.org/10.
1002/aoc.3633.
[80] M. A. Zolfigol, M. Navazeni, M. Yarie, R. Ayazi-Nasrabadi,
RSC Adv. 2016, 6, 92862.

12
ZAREI ET AL.
[81] M. Aghayee, M. A. Zolfigol, H. Keypour, M. Yarie,
L. Mohammadi, Appl. Organometal. Chem. 2016, 30, 612.
[82] M. A. Zolfigol, M. Yarie, S. Baghery, J. Mol. Liq. 2016,
222, 923.
[91] K. Niknam, M. Khataminejad, F. Zryaei, Tetrahedron Lett.
2016, 57, 361.
[83] M. A. Zolfigol, M. Navazeni, M. Yarie, R. Ayazi-Nasrabadi,
Can. J. Chem. 2017, 95, 1248.
[84] M. A. Zolfigol, M. Yarie, S. Baghery, Synlett 2016, 27, 1418.
[85] M. A. Zolfigol, M. Yarie, Appl. Organometal. Chem. 2017, 31,
e3598.
SUPPORTING INFORMATION
Additional supporting information may be found online
in the Supporting Information section at the end of this
article.
[86] M. A. Zolfigol, M. Kiafar, M. Yarie, A. A. Taherpour,
M. Saeidi-Rad, RSC Adv. 2016, 6, 50100.
How to cite this article: Zarei A, Yarie M,
Zolfigol MA, Niknam K. Synthesis of a novel
bifunctional oxyammonium-based ionic liquid:
Application for the synthesis of pyrano[4,3-b]
pyrans and tetrahydrobenzo[b]pyrans. J Chin
Chem Soc. 2019;1–12. https://doi.org/10.1002/jccs.
201800468
[87] M. Yarie, M. A. Zolfigol, M. Saeidi-Rad, J. Mol. Liq. 2018,
249, 144.
[88] M. Yarie, M. A. Zolfigol, S. Baghery, D. A. Alonso,
A. Khoshnood, M. Kalhor, Y. Bayat, A. Asgari, New J. Chem.
2017, 41, 4431.
[89] M. A. Zolfigol, F. Karimi, M. Yarie, M. Torabi, Appl. Organo-
metal. Chem. 2018, 32, e4063.
[90] L. Mohammadi, M. A. Zolfigol, A. Khazaei, M. Yarie, S. Ansari,
S. Azizian, M. Khosravi, Appl. Organometal. Chem. 2018, 32, e3933.