Application of biological-based nano and nano magnetic catalysts in the preparation of arylbispyranylmethanes

Article abstract of DOI:10.1039/c6ra18719f

Herein, the utilization of 2-carbamoylhydrazine-1-sulfonic acid, carbamoylsulfamic acid and their related nano magnetic core-shell catalysts were described as biological-based nano catalysts with a urea moiety in the synthesis of arylbispyranylmethane der

Full text of DOI:10.1039/c6ra18719f

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Application of biological-based nano and nano magnetic catalysts
in the preparation of arylbispyranylmethanes
Received 00th January 20xx,
Accepted 00th January 20xx
Mohammad Ali Zolfigol,* Monireh Navazeni, Meysam Yarie, Roya Ayazi-Nasrabadi*
DOI: 10.1039/x0xx00000x
Herein, the utilization of 2-carbamoylhydrazine-1-sulfonic acid, carbamoylsulfamic acid and their related nano magnetic
core-shell catalysts were described as biological-based nano catalysts with urea moiety in the synthesis of
arylbispyranylmethane derivatives under mild and eco-friendly reaction conditions. A good range of aromatic aldehydes
were treated with 4-hydroxy-6-methyl-2-pyrone to give arylbispyranylmethane derivatives through a tandem Knoevenagel
condensation and Michael addition procedure in relatively short reaction times with high yields. The presented protocols
have merits like the eco-friendly nature, high efficiency, simple operational procedures and benign reaction conditions.
www.rsc.org/
O
O
Introduction
HN
N
HN
N
OAc
OAc
O
O
In the modern era in the field of organic chemistry, the
enhancement of the reaction efficacy, improvement of the atom
and step economy, construction of the complex molecules in a
simple manner, the reduction of waste production and avoidance of
utilization of a large amount of unsafe organic solvents have
become crucial objectives [1]. The aforementioned concerns can be
resolved in the case of using one-pot multi component reactions as
a premium strategy compared to the conventional step wise
organic reactions [2-5]. Therefore, by keeping these merits in mind,
the designing and applying a one-pot multi component reaction
strategy for the preparation of the biologically active compounds is
desired.
O
O
O
O
O
O
OAc
OAc
O
O
O
O
Me
O
Me
Me
Me
OH OH
Scheme 1: 5-Substituted pyrimidine nucleosides with potential antiviral
activities
catalysis of organic bases [8-9], Ionic liquid mediated [6b] and using
AcOH and piperidine [9], have been investigated for the synthesis of
arylbispyranylmethane derivatives. By the way, all of the presented
protocols suffer from one or more serious drawbacks like
employing hazardous and unsafe solvents, acidic or basic media,
lengthen reaction times, harsh reaction conditions and tedious
work up. Therefore, due to the high importance role of the green
chemistry in the domain of organic synthesis, the development of
more eco-friendly and environmentally benign procedures for the
synthesis of arylbispyranylmethanes is desirable.
Among the heterocyclic compounds, the arylbispyranylmethane
derivatives present
a
wide variety of therapeutic and
pharmaceutical properties as they can be utilized as anticoagulant
agents, similar to the structurally related anticoagulant agent 3,3'-
methylenebis (4-hydroxycoumarin) [6]. Also, these compounds are
related to similar structural motifs that exhibit anti-inflammatory
activities and can be used as an inhibitor for mPGES-1 and 5-LO [7].
In addition, 5-substituted pyrimidine nucleoside derivatives of the
arylbispyranylmethanes have potential antiviral activities (Scheme
1) [6b].
The catalytic active species with small metal-free organic molecules
entitled “organocatalysts” found their key roles as promoter and
established highly dynamic area in the academic and also industrial
sectors in the past few years and the organocatalysis has grown
dramatically [10]. A striking advantage of organocatalysts is their
high surface to volume ratio which can intensify the possibility of
the interaction between reactants and catalyst and lead to
multiplying the catalytic performance of the applied
organocatalysts [11-13]. Nowadays, the applications of magnetic
nano-sized particles as versatile inorganic support for organic and
inorganic species have appeared as a potent branch in the field of
green chemistry. Utilizing of the magnetic nano particles as
supports for immobilization of organocatalysts can add varied
Despite of above mentioned biological merits of this versatile
heterocyclic scaffold, only a few methods, including under the
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merits to homogeneous nature of them and make them powerful
and easy recoverable heterogeneous active catalysts [14].
In continuation of our previously research interest related to the
maturation of the design, construction, applications and
knowledge-based development of solid acids [15] and inorganic
acidic salts [16] for the organic functional group interconversion
and also in order to find the new synthetic organic methods in
competence with principles of green chemistry, we wish to report
the more applications of our previously reported nano organo solid
acid catalysts namely, 2-carbamoylhydrazine-1-sulfonic acid 1,
carbamoylsulfamic acid 2 and their related nano magnetic core-
shell catalysts 3 and 4, as biological-based, efficient and mild
nanocatalysts for the preparation of the arylbispyranylmethane
derivatives under benign and solvent free reaction conditions as
portrayed in Scheme 2.
Me
O
O
Me
O
O
R
OH
O
OH
O
Cat. 1-4
Solvent free, Thermal
OH
OH
O
H
Me
Me
O O
R
Figure 1: Recorded TEM images of four biological based nano and
nanomagnetic catalysts 1-4
5a-l
R= H, 4-Cl, 4-NO2, 4-Me, 4-OH, 2,4-Cl2, 2-Cl, 4-F, 4-OMe, 4-Br, 3-NO2, 4-CN
Before all else, in order to find the best promoter for the synthesis
of arylbispyranylmethane derivatives, due to the structural
similarity, the catalytic activity of the two biological-based nano
organo solid acid catalysts and their nano magnetic core-shell
equivalents of them (Scheme 3), were investigated at the synthesis
of target molecule 5a. The obtained data were embedded in Table
1.
Scheme 2: The preparation of the arylbispyranylmethanes in the presence of
biological-based nano solid acid catalysts
O
O
O
S
H
O
S
O
N
O
H2N
N
H
H2N
O
N
H
OH
OH
1
2
SiO2
SiO2
O
O
H2
N
H2
N
H
Si
N
Si
SO3H
O
O
Fe3O4
Fe3O4
SO3H
N
N
H
H
O
O
O
Cl
Cl
3
4
Table 1: Screening of different catalysts at the synthesis of
compound 5a*
Scheme 3: The structure of applied biological-based nano solid acid catalysts
with urea moiety for the synthesis of arylbispyranylmethanes
Catalyst
Load of
catalyst
Temperature
( oC)
Time
(min)
Yield
(%)**
Results and discussion
Catalyst 1
Catalyst 2
Catalyst 3
Catalyst 4
15 mol%
10 mol%
7 mg
80
25
20
20
16
92
90
93
95
100
100
100
The 2-carbamoylhydrazine-1-sulfonic acid 1 and carbamoylsulfamic
acid
2
and their related nano magnetic core-shell catalysts
and
{Fe3O4@SiO2@(CH2)3Semicarbazide-SO3H/HCl}
3
5 mg
{Fe3O4@SiO2@(CH2)3-Urea-SO3H/HCl} 4, as biological-based nano
solid acid catalysts with urea moiety were prepared according to
our previously reported methods (Scheme 3) [11, 17, 18].
*Reaction condition: benzaldehyde (1 mmol, 0.106 g), 4-hydroxy-
6-methyl-2-pyrone (2 mmol, 0.252 g), **Isolated yields
In order to study the morphology and particles size of our
previously reported biological based catalysts 1-4, the transmission
electron microscopy (TEM) images of the catalysts were prepared
and portrayed in Figure 1. The TEM micrographs confirmed that the
all presented catalysts are in nano meter scale as reported in the
literatures [11, 17, 18].
From the achieved data in the screening of the catalysts (Table 1), it
can be inferred that the all tested catalysts can act as excellent
promoter for the synthesis of compound 5a. Therefore, the catalytic
application of four biological-based nano catalysts were explored at
the synthesis of a good range of arylbispyranylmethane under mild
and solvent free conditions (Scheme 2).
2 | J. Name., 2012, 00, 1-3
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In continue, to find the best experimental conditions for the It is worthy to mention that in the case of nano organocatalysts 1
preparation of the 3,3'-(phenylmethylene)bis(4-hydroxy-6-methyl- and 2, increasing in the load of catalysts or temperatures did not
2H-pyran-2-one) in the presence of 2-carbamoylhydrazine-1- effect in the yields or reaction times for the synthesis of target
sulfonic acid 1, the optimal reaction temperature, amount of the compounds. Also, the resulting from solvents screening, did not
catalyst and different solvents were scrutinized upon the reaction show more positive effect over solvent free condition.
of benzaldehyde and 4-hydroxy-6-methyl-2-pyrone. The attained
Table 3: Optimization of reaction conditions for the synthesis of
data have revealed that the best results were obtained in the
arylbispyranylmethanes in the presence of 2- carbamoylsulfamic
acid 2 *
presence of a catalytic amount of catalyst 1 under solvent free
conditions at 80 °C (Table 2, Entry 3).
Load of
Temperature Time
Table 2: Optimization of reaction conditions for the synthesis of
arylbispyranylmethanes in the presence of 2-carbamoylhydrazine-1-
sulfonic acid 1*
Entry Solvent
catalyst
(mol%)
Yield (%)**
(oC)
(min)
1
2
-
-
-
-
-
-
-
-
15
15
15
15
15
5
r.t.
54
100
67
Trace
69
Load of
Temperature Time
Entry Solvent
catalyst
(mol%)
Yield (%)**
(oC)
(min)
3
80
30
68
4
100
113
100
100
100
100
Reflux
26
93
1
2
-
15
15
15
15
5
r.t.
54
60
85
Trace
42
5
26
75
-
6
26
87
3
-
80
25
92
7
10
20
-
20
90
4
-
100
80
25
90
8
15
78
5
-
30
89
9
227
30
53
6
-
-
10
20
-
80
23
78
10
EtOH
10
82
7
80
20
88
8
-
80
110
130
120
Trace
85
11
CH3CN
10
Reflux
125
93
9
H2O
EtOH
15
15
Reflux
Reflux
12
13
n-Hexan
10
10
Reflux
Reflux
85
55
72
91
10
89
EtOAc
11
12
CH3CN
15
15
Reflux
Reflux
30
50
86
63
*Reaction conditions: benzaldehyde (1 mmol, 0.106 g), 4-hydroxy-6-
methyl-2-pyrone (2 mmol, 0.252 g), **Isolated yields.
n-Hexan
As in the case of two biologically-based organocatalysts, the
*Reaction conditions: benzaldehyde (1 mmol, 0.106 g), 4-hydroxy-6-
methyl-2-pyrone (2 mmol, 0.252 g), **Isolated yields.
optimal
reaction
conditions
for
the
synthesis
of
arylbispyranylmethanes were inspected in the presence of their
nano magnetic core-shell equivalents 3 and 4 of them. In the case
of nano catalyst 3, the reaction between 4-chlorobenzaldehyde and
4-hydroxy-6-methyl-2-pyrone was selected as a model reaction to
afford 3,3'-((4-chlorophenyl)methylene)bis(4-hydroxy-6-methyl-2H-
pyran-2-one) and the attained data for the study of different
amount of the catalyst, temperatures and solvents were embedded
in Table 4. The best reaction conditions are in the presence of 7 mg
nano magnetic core-shell catalyst at 100 oC under solvent free
conditions (Table 4, Entry 3).
In another study, the application of the carbamoylsulfamic acid 2 as
an effective biological-based nano organocatalysts with urea moiety
was inspected in the synthesis of 3,3'-(phenylmethylene)bis(4-
hydroxy-6-methyl-2H-pyran-2-one). At the beginning, to exploration
of the best experimental conditions, the reaction of benzaldehyde
and 4-hydroxy-6-methyl-2-pyrone was picked up as a test reaction.
The achieved data for the investigation of different loads of the
catalyst 2, operational temperatures and solvents are indexed in
Table 4. The attained results show that the best condition for the
model reaction, were attain when the reaction was performed
using catalytic load of the catalyst 2 under solvent free conditions at
100 oC (Table 3, Entry 7).
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Table 4: Optimization of reaction conditions for the synthesis of
Table 5: Optimization of reaction conditions for the synthesis of
arylbispyranylmethanes in the presence of Cat. 4
arylbispyranylmethanes in the presence of Cat. 3
Load of
Load of
Temperature Time
Temperature Time
Entry
Solvent
catalyst
(mg)
Yield (%)** Entry Solvent
catalyst
(mg)
Yield (%)**
(oC)
(min)
(oC)
(min)
1
2
-
7
7
r.t.
80
360
30
60
85
93
92
85
90
53
77
72
1
2
3
4
5
6
7
8
9
-
10
10
10
15
7
80
100
45
15
12
30
16
16
23
20
102
85
90
66
53
77
95
94
93
79
-
-
3
-
7
100
20
-
110
4
-
7
110
17
-
80
5
-
-
5
100
30
-
-
100
6
10
-
100
25
5
100
7
-
100
227
20
-
3
100
9
H2O
EtOH
7
Reflux
Reflux
H2O
EtOH
5
Reflux
Reflux
10
7
100
5
11
CH3CN
7
Reflux
60
47
10
CH3CN
5
Reflux
40
78
12
13
EtOAc
7
7
Reflux
Reflux
85
50
7
11
12
EtOAc
5
5
Reflux
Reflux
190
160
38
42
n-Hexan
120
n-Hexan
*Reaction conditions: 4-Chlorobenzaldehyde (1 mmol, 0.140 g), 4- *Reaction conditions: benzaldehyde (1 mmol, 0.106 g), 4-hydroxy-6-
hydroxy-6-methyl-2-pyrone (2 mmol, 0.252 g), **Isolated yields. methyl-2-pyrone (2 mmol, 0.252 g), **Isolated yields.
In the case of nano magnetic core-shell catalyst 4, the reaction of In attempting to confirm the applicability and efficacy of the
benzaldehyde and 4-hydroxy-6-methyl-2-pyrone was picked up for presented protocols for the arylbispyranylmethanes synthesis, a
optimizing of the reaction conditions to yield 3,3'- good range of aromatic aldehydes (containing those bearing
(phenylmethylene)bis(4-hydroxy-6-methyl-2H-pyran-2-one).
The electron-withdrawing, electron-releasing groups and halogens)
resulting data inserted in Table 5, indicate that the optimized were reacted with 4-hydroxy-6-methyl-2-pyrone in the presence of
reaction conditions obtained when the reaction carried out under 2-carbamoylhydrazine-1-sulfonic acid 1, carbamoylsulfamic acid 2
solvent free conditions in the presence of 5 mg of nano magnetic and their related nano magnetic core-shell catalysts 3 and 4 as
catalyst 4 at 100 oC (Table 5, Entry 6). The obtained data were biological-based nano catalysts with urea moiety at their optimal
collected in Table 5.
reaction conditions as embedded in Table 2-5. The obtained data
have illustrated that the starting materials were reacted with each
other to afford the desired products in good to excellent yields in
Similar to nano organocatalysts 1 and 2, as indicated in Tables 4 and
5, in the case of nano magnetic core-shell catalysts 3 and 4,
performing the reactions in various solvents or increasing the
amount of catalyst and elevated temperature did not present any
short
reaction
times
(Table
6).
progress in the yield or reaction time
Table 6: Synthesis of the arylbispyranylmethane derivatives in the presence of four nano solic acid catalystsa
Cat. 1 Cat. 2 Cat. 3 Cat. 4
Time
.
Product
5a
R
M. p (oC) found [Lit]ref
213-216 [214-215]9
Time
(min)
Yield
Time
(min)
Yield
(%)b
Time
(min)
Yield
(%)b
Yield
(%)b
(%)b
(min)
H
25
92
20
90
18
90
16
95
4 | J. Name., 2012, 00, 1-3
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5b
ARTICLE
4-Cl
40
90
62
38
33
33
46
30
35
65
30
75
93
94
98
90
95
93
87
89
77
94
62
85
70
42
48
50
70
40
57
28
90
86
95
91
98
84
94
90
95
84
95
95
20
20
28
47
13
40
45
37
38
38
55
93
92
96
90
89
98
91
96
92
73
92
30
25
35
45
37
43
30
35
60
23
43
95
96
88
88
76
94
91
91
96
72
98
202-206 [205-207]9
232-234 [214-217]9
219-221 [202-204]7b
202 [new]
5c
5d
5e
5f
4-NO2
4-F
4-OH
4-Me
3-NO2
2,4-Cl2
2-Cl
183-185 [186-187]7b
200-204 [193-194]10
244-246 [226-229]20
155-158 [155-156]10
174-176 [174-176]9
212-215 [207-208]20
223-225 [201-203]7b
5g
5h
5i
5j
4-OMe
4-Br
5k
5l
4-CN
aReaction condition: arylaldehydes ( 1 mmol), 4-hydroxy-6-methyl-2-pyrone (2 mmol, 0.252 g), bRefers to isolated yields
To the best of our knowledge, recyclability and reusability can
be considered as one of the major factors which should be
8
considered for applying of catalysts in the chemical processes. A
7
comparison between the catalysts 1-4 on the basis of their
6
recyclability and reusability, have shown that nano magnetic
5
catalysts 3-4 are more better than the described catalysts 1-2.
4
Therefore, the recyclability and reusability of the two nano
3
2
1
magnetic core-shell catalysts 3 and 4, for the preparation of
arylbispyranylmethane derivatives were successfully explored
for eight times. After performance of each run, hot ethanol was
added to the reaction mixture to dissolve the desired target
molecules and unreacted starting materials (the examined
catalysts were not dissolved in hot ethanol). Then, the used
nano magnetic catalysts were separated from the reaction
mixture by applying a simple external magnet and washed
repetitively with ethanol and preserved for next attempt. The
0
10 20 30 40 50 60 70 80 90 100
1
2
3
4
5
6
7
8
Cat. 4
95
94
93
93
93
91
91
91
Cat. 3 93
93
93
93
93
93
92
92
reusability
test
and
recycling
possibility
of
Figure 2: The recycling possibility and reusability of the two nano
magnetic core-shell catalysts 3 and 4 at the synthesis of desired target
molecules 5b.
the{Fe3O4@SiO2@(CH2)3Semicarbazide-SO3H/HCl}
3
and
{Fe3O4@SiO2@(CH2)3-Urea-SO3H/HCl} 4, as biological-based
nano magnetic solid acid catalysts were probed at the reaction
of 4-chlorobenzaldehyde and 4-hydroxy-6-methyl-2-pyrone
under optimal reaction conditions in constant times 20 and 30
minutes, respectively. The attained data as indicated in Figure 2,
demonstrate that the catalytic activity of the two nano magnetic
solid acidic catalysts were conserved after eight times without
any considerable amount of loss in their initial catalytic
performance.
The manner of the catalytic performance of the biological-based
nano catalysts 1-4 with urea moiety and the formation of the
various arylbispyranylmethanes could be rationalized as follows
(Scheme 4). Initially, the activated aromatic aldehydes were
subjected in to the reaction with 4-hydroxy-6-methyl-2-pyrone
and the related Knovengel adduct A was generated through
dehydration. Subsequently, in the presence of the nano
catalysts, the intermediate A acts as a Michael acceptor and by
the reaction with the second molecule of the 4-hydroxy-6-
methyl-2-pyrone, the intermediate B is formed. Eventually, the
tautomerization of the intermediate B offers the full conjugated
corresponding target product 5a-l.
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Synthesis of arylbispyranylmethane derivatives in the
presence of biological-based nano solid acid catalysts 1
and 2: A typical procedure
To a round bottom flask containing a mixture of aromatic
aldehydes (1 mmol) and 4-hydroxy-6-methyl-2-pyrone (2 mmol,
0.252 g), and 2-carbamoylhydrazine-1-sulfonic acid 1 (0.0184 g,
15 mol%), 2- carbamoylsulfamic acid 2 (0.0108 g, 10 mol%), as
catalysts was added. Afterwards, the obtained reaction mixture
o
was placed in an oil bath at 80 C (in the case of organo catalyst
1) or 100 oC (in the case of organo catalyst 2) and was vigorously
stirred for appropriated times as indicated in their related Table
6. The reaction progress was checked using TLC technical skill
with a mixture of n-hexane and ethyl acetate as the eluent. After
performance of the reaction, the mixture was cooled to ambient
temperature. Then, in the case of organo catalyst 1 and 2 in
order to removing of the used catalyst, 5 mL of distillated water
were added and the mixture was stirred for addition 5 minutes
and decanted. Finally, the crude products were recrystallized
from ethanol which to afford pure target molecules in good to
high yields as depicted in Table 6.
Scheme 4: The plausible mechanism for the preparation of the
arylbispyranylmethanes in the presence of the described biological-
based nano catalysts 1-4.
Conclusion
In conclusion, in this investigation, we have explored the
catalytic applicability of the biological-based nano catalysts with
urea moiety in the synthesis of arylbispyranylmethane
derivatives. The benefits of these procedures are the reducing of
the reaction times, improving of the yields, benign and eco-
friendly reaction conditions, step and atom viability, easy work-
up and purification of the desired products. Since that the
recyclability and reusability is a major factor for influencing the
suitability of any catalyst, we observed that the nano magnetic
catalysts 3-4 are more recyclable than the described
organocatalysts 1-2. Finally, on the basis of our observations and
the above mentioned advantages, herein, we thought that all of
the described biological-based nano solid acids and/or catalysts
have potential for industrial production.
Synthesis of arylbispyranylmethane derivatives in the
presence of biological-based nano magnetic solid acid
catalysts 3 and 4: A typical procedure
To a round bottom flask containing a mixture of aromatic
aldehydes (1 mmol) and 4-hydroxy-6-methyl-2-pyrone (2 mmol,
0.252 g), and {Fe3O4@SiO2@(CH2)3Semicarbazide-SO3H/HCl} 3 (7
mg) and {Fe3O4@SiO2@(CH2)3-Urea-SO3H/HCl}
4 (5 mg) as
catalysts were added. Afterwards, the obtained reaction mixture
was placed in an oil bath at 100 oC and was vigorously stirred for
appropriated times as indicated in their related Table 6. The
reaction progress was checked using TLC technical skill with a
mixture of n-hexane and ethyl acetate as the eluent. After
performance of the reaction, the mixture was cooled to ambient
temperature. Then, in the case of nano magnetic solid acid
catalyst 3 and 4, hot EtOH, was added to the mixture and the
catalyst were separated using an external magnet. Finally, the
crude products were recrystallized from ethanol which to afford
pure target molecules in good to high yields as depicted in Table
6.
Experimental
General
All reagents and starting materials were obtained from Merck
chemical company and employed without further purification.
The known target molecules were identified by comparison of
their physical properties and spectral data with their reported
authentic samples in the literatures. The reaction progress and
the purity of the compounds were verified using TLC skill
performed with silica gel SIL G/UV 254 plates. NMR spectra were
recorded on a Bruker Ultrashield 400 spectrometer, 1H NMR
(400.13) and 13C NMR (100.62). The data for 1H NMR are
reported as follows: chemical shift (ppm), integration,
multiplicity (s, singlet; d, doublet; t, triplet; q, quartet; m,
multiplet; and br, broad) and coupling constant (Hz). Melting
points were recorded on Buchi B-545 apparatus in open capillary
tubes. A neodymium block magnet (1.18 T) was used for
separation of the catalyst from the reaction mixture.
Selected spectral data
As it can be seen in ESI, for example in the case of compound
3,3'-((2,4-dichlorophenyl)methylene)bis(4-hydroxy-6-methyl-2H-
pyran-2-one) (5h), the FT-IR spectrum shows a broad peak at
3423 cm-1 which can be attributed to the OH functional groups
in the structure. Also, the vibration mode of C=O functional
groups appear at 1678 cm-1. In addition C=C stretching mode
1
observed at 1633 cm-1. In H NMR spectrum, a signal appears as
a broad singlet at 11.22 ppm is related to -OH functional groups.
The three aromatic protons can be found in the aromatic region
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as three separated coupled peaks. Also, due to the structural
symmetry, the two olefinic protons resonate at 5.94 ppm as a
singlet. A singlet peak at 5.56 ppm can be ascribed to the
tertiary proton in the structure and finally, a singlet peak
appears at 2.15 ppm is related to the 6 protons of two methyl
groups in the structure of the target compound 5h. In 13C NMR
spectrum, all predicted carbon atoms are appeared in the
related regions. For example the carbon and methyl groups are
resonated at 34.7 and 19.2 ppm respectively. Also, the carbons
of carbonyl functional groups are appeared at 166.2 ppm. It is
worthy to mention that, the used FT-IR, 1H NMR and 13C NMR
spectrums confirmed the formation of the target molecules 5a-l.
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3,3'-((4-hydroxyphenyl)methylene)bis(4-hydroxy-6-
methyl-2H-pyran-2-one) (5e)
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Melting point = 202 oC
FT-IR (KBr): ν (cm-1)= 3423, 1680, 1603, 1591, 1385, 833.
1H NMR (400 MHz, DMSO) δ (ppm) = 11.62 (brs, 2H, OH), 6.78
(d, J = 8.6 Hz, 2H), 6.63 (d, J = 8.6 Hz, 2H), 6.09 (s, 2H), 5.89(s,
1H), 2.20 (s, 6H).
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13C NMR (101 MHz, DMSO) δ (ppm) = 167.9, 166.4, 161.1, 155.3,
129.0, 127.4, 114.9, 102.0, 101.3, 100.1, 88.1, 32.9, 19.1.
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3,3'-((2,4-dichlorophenyl)methylene)bis(4-hydroxy-6-
methyl-2H-pyran-2-one) (5h)
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743.
[13] G. K. S. Prakash, C. Panja, C. Do, T. Mathew, G. A. Olah,
Synlett, 2007, 2395.
Melting point = 244-246 oC
FT-IR (KBr): ν (cm-1)= 3423, 1678, 1633, 1575, 1385, 866.
1H NMR (400 MHz, DMSO) δ (ppm) = 11.22 (brs, 2H, OH), 7.42
(d, J = 2.2 Hz, 1H), 7.27 (dd, J = 8.5, 2.2 Hz, 1H), 7.12 (d, J = 8.5
Hz, 1H), 5.94 (s, 2H), 5.56 (s, 1H), 2.15 (s, 6H).
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ChemCatChem., 2014, 6, 3312. (j) M. Mokhtary, J. Iran. Chem.
Soc., 2016, doi: 10.1007/s13738-016-0900-4.
13C NMR (101 MHz, DMSO) δ (ppm) = 166.2, 164.0, 160.5, 138.8,
133.4, 131.5, 130.7, 127.8, 126.3, 100.3, 100.2, 34.7, 19.2.
3,3'-((2-chlorophenyl)methylene)bis(4-hydroxy-6-
methyl-2H-pyran-2-one) (5i)
Melting point = 155-158 oC
FT-IR (KBr): ν (cm-1)= 3440, 1683, 1617, 1571, 1407, 745.
1H NMR (400 MHz, DMSO) δ (ppm) = 11.40 (brs, 2H, OH), 7.50-
7.48 (m, 1H), 7.40-7.32 (m, 3H), 6.16 (s, 2H) 5.86 (s, 2H), 2.36 (s,
6H).
[15] (a) P. Salehi, M. A. Zolfigol, F. Shirini, M. Baghbanzadeh,
Curr. Org. Chem., 2006, 10, 2171; (b) M. Daraei, M. A. Zolfigol, F.
Derakhshan-Panah, M. Shiri, H. G. Kruger, M. Mokhlesi, J. Iran.
Chem. Soc, 2015, 12, 855. (c), D. Azarifar, S. M. Khatami, M. A.
Zolfigol, R. Nejat-Yami, J. Iran. Chem. Soc, 2014, 11, 1223., (d) M.
Safaiee, M. A. Zolfigol, M. Tavasoli, M. Mokhlesi, J. Iran. Chem.
Soc, 2014, 11, 1593. (e) M. A. Zolfigol and M. Yarie, RSC Adv.,
2015, 5, 103617., (f) M. A. Zolfigol, M. Kiafar, M. Yarie, A. (A.)
Taherpour, M. Saeidi-Rad, RSC Adv., 2016, 6, 50100.
[16] See our review: F. Shirini, M. A. Zolfigol, P. Salehi, M.
Abedini, Curr. Org. Chem., 2008, 12, 183.
13C NMR (101 MHz, DMSO) δ (ppm) =166.5, 164.4, 160.4, 139.2,
132.7, 130.1, 128.6, 127.2, 126.2, 100.5, 34.9, 19.1.
Acknowledgements
We thank Bu-Ali Sina University and Iran National Science
Foundation (INSF) for financial support (The Grant of Allameh
Tabataba'i's Award, Grant Number: BN093) to our research
group.
[17] M. A. Zolfigol, R. Ayazi-Nasrabadi, S. Bagheri, Appl.
Organomet. Chem. 2016, 30, 500.
References
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[18] M. A. Zolfigol, R. Ayazi-Nasrabadi, S. Bagheri, Appl.
Organomet. Chem. 2016, 30, 273.
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Application of biological-based nano and nano magnetic catalysts in
the preparation of arylbispyranylmethanes
Mohammad Ali Zolfigol,* Monireh Navazeni, Meysam Yarie, Roya Ayazi-Nasrabadi*
Department of Organic Chemistry, Faculty of Chemistry, Bu-Ali Sina University, Hamedan, Po. Box: 6517838683,
Iran. E-mail: zolfi@basu.ac.ir, mzolfigol@yahoo.com & r.ayazi.86@gmail.com, Fax: +98 8138380709; Tel: +98
8138282807
Nano 2-carbamoylhydrazine-1-sulfonic acid, carbamoylsulfamic acid and their related nano
magnetic core-shell catalysts as biological-based nano catalysts with urea moiety were used in
the synthesis of arylbispyranylmethanes.