One-pot synthesis of new derivatives of pyran using N-halosulfonamide

Article abstract of DOI:10.1039/c4ra04929b

In this study N,N,N′,N′-tetrabromobenzene-1,3-disulfonamide was used as a reagent for the three-component one-pot synthesis of some novel 9-aryl-9H-2,4,5,7-tetramethyl-diuracilopyrans, which has not been published before, as well as 9-aryl-3,4,6,7-tetrahy

Full text of DOI:10.1039/c4ra04929b

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One-pot synthesis of new derivatives of pyran using
N-halosulfonamide†
Cite this: RSC Adv., 2014, 4, 33582
*
Ramin Ghorbani-Vaghei, Zahra Salimi, Seyedeh Mina Malaekehpoor, Fatemeh Eslami
and Samira Noori
In this study N,N,N0,N0-tetrabromobenzene-1,3-disulfonamide was used as a reagent for the three-
component one-pot synthesis of some novel 9-aryl-9H-2,4,5,7-tetramethyl-diuracilopyrans, which has
not been published before, as well as 9-aryl-3,4,6,7-tetrahydro-2H-pyran-1,8(5H,9H)-diones in excellent
yields. This is obtained from the condensation of aromatic and heterocyclic aldehydes and N,N-
dimethylbarbituric acid or cyclohexane-1,3-diones in ethanol at room temperature.
Received 25th May 2014
Accepted 28th July 2014
DOI: 10.1039/c4ra04929b
www.rsc.org/advances
synthesis of various important compounds which have recently
drawn great attention.
Introduction
An important challenge in organic synthesis is development of
powerful methods for the synthesis of complex heterocyclic
molecules from readily available reagents.1 Multicomponent
condensation reactions (MCRs) have recently been discovered
Results and discussion
To pursue our interest in the application of N,N,N0,N0-
tetrabromobenzene-1,3-disulfonamide [TBBDA],15 (Fig. 2) in
organic synthesis,15–20 herein we introduce a facile, three-
component one-pot synthesis of new 9-aryl-9H-2,4,5,7-
tetramethyl-diuracilopyran (route A), which has not been pub-
lished before, as well as 9-aryl-3,4,6,7-tetrahydro-2H-xanthene-
1,8(5H,9H)-dione (route B). This is obtained from the conden-
sation of various aromatic and heteroaromatic aldehydes and
N,N-dimethylbarbituric acid or cyclohexane-1,3-dione in the
presence of TBBDA as reagent in ethanol at room temperature
(Scheme 1).
It is easy to prepare TBBDA and it is stable under atmo-
spheric conditions for two months. Furthermore, TBBDA is a
non-volatile, inexpensive, and safe reagent. Aer completion of
the reaction, the sulphonamide was recovered, brominated and
used for several times.
to be
a powerful method for the synthesis of organic
compounds. High selectivity, high atom-economy, simplicity
and relatively high speed are central issues in multicomponent
reactions.2–4
In recent years, 4H-pyrans and their derivatives have attrac-
ted intense interest due to their useful biological and pharma-
cological properties, such as being anti-inammatory,5
antimicrobial,6 anticonvulsant activities,7 anticoagulant, spas-
molytic, anticancer and anti-anaphylactic agents.8 There are
widely applied in photodynamic therapy,9 and used as uores-
cent dye materials10 for visualization of biomolecules,11,12 and in
laser technology13 (Fig. 1). Furthermore, substituted 4H-pyrans
constitute a structural unit of a series of natural products.14
Especially pyran diones, that belong to the naturally-occurring
compounds, are used as reactive intermediates for the
Initial efforts were focused on optimizing conditions for the
formation of 9-(2-chlorophenyl)-9H-2,4,5,7-tetramethyl-
diuracilopyran using N,N-dimethylbarbituric acid and 2-chlor-
obenzaldehyde under various conditions (Table 1).
In this context, ethanol (EtOH) selected as best solvent for
these reactions. Reactions in EtOH are generally considered
environmentally safe, devoid of any carcinogenic effects, simple
Fig. 1 Some examples of pyran derivatives with different properties.
Department of Organic Chemistry, Faculty of Chemistry, Bu-Ali-Sina University,
Hamedan, Iran. E-mail: rgvaghei@yahoo.com; Fax: +988118380709
† Electronic supplementary information (ESI) available. See DOI:
10.1039/c4ra04929b
Fig. 2 The structure of TBBDA.
33582 | RSC Adv., 2014, 4, 33582–33586
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otherwise stated. 1H and 13C-NMR spectra were recorded on
Bruker Advance 400 FT NMR spectrometers (undertaken at
University of Mazandaran, Iran). Infrared (IR) spectroscopy was
performed on a Perkin Elmer GX FT-IR spectrometer. Mass
spectra were recorded on a 5973 Network Mass Selective
Detector Mass Spectrometer (undertaken at University of Teh-
ran, Iran). Elemental analyses (C, H, N) were performed with a
Elemental Combustion System 4010 (undertaken at University
of Tehran, Iran).
Scheme 1 Synthesis of new derivatives of pyran using TBBDA.
Typical procedure for the preparation of 9-(2-chlorophenyl)-
9H-2,4,5,7-tetramethyl-diuracilopyran (Table 2, entry 4)
Table 1 Optimization of reaction conditions for the synthesis of 9-(2-
chlorophenyl)-9H-2,4,5,7-tetramethyl-diuracilopyrana
A mixture of N,N-dimethylbarbituric acid (0.312 g, 2 mmol), 2-
chlorobenzaldehyde (0.140 g, 1 mmol), ethanol (2 mL) and
TBBDA (0.1 g, 0.18 mmol) was stirred at room temperature for
60 min. The progress of the reaction was monitored by TLC
[acetone/n-hexane (3 : 10)]. Aer completion of the reaction, the
reaction mixture was ltered and washed with ethanol. The
crude product was recrystallized from hot ethanol to afford the
pure product as a white powder (91%). Aer evaporation of the
ethanol, cold methylene dichloride (2 mL) was added, and
reagent was recovered by ltration.
Amount of TBBDA
(g)
Entry
Solvent
Time (min)
Yield (%)
1
2
3
4
5
6
7
Ethanol
Ethanol
Ethanol
Ethanol
No solvent
Acetone
H2O
0
60
60
60
60
60
30
30
23
62
91
85
41
33
42
0.05
0.1
0.15
0.1
0.1
0.1
a
Experimental conditions: 2-chlorobenzaldehyde (1 mmol) and N,N-
dimethylbarbituric acid (2 mmol).
9-(2-Chlorobenzo[h]quinoline)-9H-2,4,5,7-tetramethyl-
diuracilopyran (Table 2, entry 1); white powder 88%; m.p. 273–
ꢀ
275 C; elem. anal. found: C, 59.94; H, 3.35; N, 13.08 calc. for
C
26H20ClN5O5: C, 60.29; H, 3.89; N, 13.52%. IR (KBr, nmax/cmꢁ1):
to handle, cheaper to operate and especially important in
industry.
3450, 3053, 2956, 1724, 1650; 1H-NMR (400 MHz, DMSO-d6) dH
(ppm): 2.44 (s, 3H, OMe), 3.14 (s, 3H, OMe), 3.27 (s, 3H, OMe),
3.47 (s, 3H, OMe), 5.45 (s, 1H, CH), 7.80–7.90 (m, 5H, ArH), 8.46
(s, 1H, ArH), 8.99–9.01 (q, 1H, ArH); 13C-NMR (100 MHz, DMSO-
d6) dC (ppm): 28.2, 28.2, 29.3, 30.3, 52.8, 85.6, 89.2, 124.4, 125.2,
125.6, 127.2, 128.2, 128.7, 129.2, 129.5, 129.9, 134.2, 141.5,
145.6, 148.4, 150.6, 151.4, 158.5, 163.2, 163.4, 165.8; MS m/z: 517
(M+).
We found that the reaction was rapid when using N,N,N0,N0-
tetrabromobenzene-1,3-disulfonamide [TBBDA] (0.1 g, 60 min,
entry 3). We then examined a wide variety of aromatic aldehyde
and we observed that they successfully react with N,N-dimethyl-
barbituric acid or cyclohexane-1,3-dione. This clearly estab-
lishes the scope and generality of this method. As it is shown in
Table 2, the electron withdrawing or donating groups on the
phenyl rings did not have an inuence on the reaction.
The probable mechanism of this reagent is that it releases
Br+ in situ, which can act as an electrophilic species.15–20
Therefore, the mechanism shown in Scheme 2 may be sug-
gested for the conversion of the various aldehyde, N,N-dimethyl-
barbituric acid, cyclohexane-1,3-dione to pyran derivatives.
9-(2-Chloroquinolin-3-yl)-9H-2,4,5,7-tetramethyl-diuracilo-
pyran (Table 2, entry 2); opalescent powder 85%; m.p. 265–267
ꢀC; elem. anal. found: C, 56.43; H, 3.59; N, 14.78 calc. for
C
22H18ClN5O5: C, 56.48; H, 3.88; N, 14.97%. IR (KBr, nmax/cmꢁ1):
3406, 3063, 2955, 1676, 1646; 1H-NMR (400 MHz, DMSO-d6) dH
(ppm): 2.44 (s, 3H, OMe), 2.89 (s, 3H, OMe), 3.11 (s, 3H, OMe),
3.13 (s, 3H, OMe), 3.21 (s, 3H, OMe), 3.25 (s, 3H, OMe), 3.45 (s,
3H, OMe), 3.49 (s, 3H, OMe), 5.11 (s, 1H, CH), 5.39 (s, 1H, CH),
7.58–7.61 (t, J 7.2, 1H, ArH), 7.67–7.71 (t, J 7.6, 1H, ArH), 7.78–
7.81 (t, J 7.6, 1H, ArH), 7.84–7.86 (d, J 7.6, 1H, ArH), 7.88–7.92 (t,
J 7.2, 1H, ArH), 7.96–7.98 (d, J 8.4, 1H, ArH), 8.01–8.04 (t, J 7.6,
2H, ArH), 8.32 (s, 1H, ArH), 8.43 (s, 1H, ArH); 13C-NMR (100
MHz, DMSO-d6) dC (ppm): 28.2, 28.2, 29.3, 29.6, 30.3, 35.1, 52.8,
55.6, 85.6, 86.1, 89.2, 126.3, 127.0, 127.1, 127.7, 128.0, 128.3,
128.5, 128.7, 131.5, 132.3, 139.2, 141.9, 147.0, 149.2, 150.6,
151.4, 158.5, 161.5, 163.1, 165.7; MS m/z: 467 (M+).
Conclusions
In this study, we have developed a green one-pot synthesis of
pyrans derivatives using [TBBDA] as new reagent. The condi-
tions are mild and a wide range of functional groups can be
tolerated. This method offers several advantages such as inex-
pensive reagent, short reaction times, easy synthetic procedure,
good to high yields, simple work-up procedure and easy
isolation.
9-(4-Methoxyphenyl)-9H-2,4,5,7-tetramethyl-diuracilopyran
ꢀ
(Table 2, entry 3); white powder 85%; m.p. 246–248 C; elem.
anal. found: C, 51.91; H, 4.09; N, 12.4 calc. for C20H20N4O6: C,
Materials and equipment
53.25; H, 4.89; N, 13.59%. IR (KBr, nmax/cmꢁ1): 3451, 2964, 1715,
All commercially available chemicals were obtained from Merck 1674; 1H-NMR (400 MHz, DMSO-d6) dH (ppm): 2.46 (s, 3H,
and Fluka and used without further purication unless OMe), 3.11 (s, 3H, OMe), 3.21 (s, 3H, OMe), 3.39 (s, 3H, OMe),
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Table 2 Synthesis of new derivatives of pyran using TBBDA
Entry
Aldehyde
Product
Time (min)
Yielda (%)
M.P. (ꢀC)
1
60
88
273–275
2
30
85
265–267
3
4
5
100
85
91
82
246–248
199–201
258–259
60
25
6
7
120
120
61
66
266–268
199–201
8
180
63
268–269
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Table 2 (Contd.)
Entry
Aldehyde
Product
Time (min)
180
Yielda (%)
M.P. (ꢀC)
9
73
232–233
10
120
120
79
75
259–261
252–254
11
a
Isolated yield.
131.9, 133.3, 150.5, 151.3, 158.4, 163.0, 163.3, 165.9; MS m/z: 415
(M+-1).
9-(2,4-Dichlorophenyl)-9H-2,4,5,7-tetramethyl-diuracilopyran
(Table 2, entry 5); white powder 82%; m.p. 258–259 ꢀC; elem.
anal. found: C, 48.82; H, 2.93; N, 12.22 calc. for C19H16Cl2N4O5:
C, 50.57; H, 3.57; N, 12.42 IR (KBr, nmax/cmꢁ1): 3446, 3099, 2957,
1765, 1708, 1670; 1H-NMR (400 MHz, DMSO-d6) dH (ppm): 2.59
(s, 3H, OMe), 3.11 (s, 6H, 2 OMe), 3.40 (s, 3H, OMe), 5.23 (s, 1H,
CH), 7.29–7.40 (m, 2H, ArH), 7.68–7.68 (d, J 2, 1H, ArH); 13C-NMR
(100 MHz, DMSO-d6) dC (ppm): 28.1, 28.2, 28.3, 28.4, 28.9, 29.2,
30.2, 52.2, 85.4, 89.1, 122.5, 127.1, 128.0, 128.7, 128.9, 128.9,
131.3, 132.1, 133.2, 133.3, 134.1, 134.3, 134.6, 135.9, 149.8, 150.5,
151.3, 158.4, 163.1, 163.2, 165.7, 166.3; MS m/z: 449 (M+-1).
9-(4-Fluorophenyl)-3,4,6,7-tetrahydro-2H-pyran-1,8(5H,9H)-
ꢀ
dione (Table 2, entry 6); white powder 61%; m.p. 266–268 C;
Scheme 2 Suggested mechanism for synthesis of pyran derivatives.
elem. anal. found: C, 72.75; H, 5.30; calc. for C19H17FO3: C,
73.06; H, 5.49%. IR (KBr, nmax/cmꢁ1): 2955, 1721, 1655; 1H-NMR
(400 MHz, DMSO-d6) dH (ppm): 1.80–1.89 (m, 2H, CH2), 1.91–
1.98 (m, 2H, CH2), 2.21–2.34 (m, 4H, 2CH2), 2.55–2.70 (m, 4H,
2CH2), 4.56 (s, 1H, CH), 7.00–7.04 (t, J 8.8, 2H, ArH), 7.19–7.22
(q, 2H, ArH); 13C-NMR (100 MHz, DMSO-d6) dC (ppm): 20.3,
26.8, 30.7, 36.8, 114.9, 115.1, 115.7, 130.2, 130.3, 141.1, 141.1,
159.8, 162.2, 165.3, 196.8; MS m/z: 312 (M+).
3.73 (s, 3H, OMe), 5.05 (s, 1H, CH), 6.82–7.07 (s, 4H, ArH); 13C-
NMR (100 MHz, DMSO-d6) dC (ppm): 28.1, 28.2, 29.4, 30.1, 55.6,
56.0, 86.0, 90.6, 113.8, 126.7, 130.3, 150.571, 151.3, 158.6, 159.8,
162.6, 163.6, 166.0; MS m/z: 412 (M+).
9-(2-Chlorophenyl)-9H-2,4,5,7-tetramethyl-diuracilopyran
ꢀ
(Table 2, entry 4); white powder 91%; m.p. 199–201 C; elem.
9-(3-Methoxyphenyl)-3,4,6,7-tetrahydro-2H-pyran-1,8(5H,9H)-
ꢀ
anal. found: C, 52.97; H, 3.54; N, 12.70 calc. for C19H17ClN4O5:
C, 53.75; H, 4.11; N, 13.44%. IR (KBr, nmax/cmꢁ1): 3415, 3069,
2959, 1766, 1702, 1693, 1667; 1H-NMR (400 MHz, DMSO-d6) dH
(ppm): 2.51 (s, 3H, OMe), 3.11 (s, 3H, OMe), 3.20 (s, 3H, OMe),
3.40 (s, 3H, OMe), 5.26 (s, 1H, CH), 7.23–7.37 (m, 3H, ArH), 7.46–
7.48 (d, J 8, 1H, ArH); 13C-NMR (100 MHz, DMSO-d6) dC (ppm):
28.1, 28.2, 29.2, 30.2, 52.8, 85.5, 89.3, 127.7, 129.4, 130.9, 131.9,
dione (Table 2, entry 7); white powder 66%; m.p. 199–201 C;
elem. anal. found: C, 74.01; H, 6.07; calc. for C20H20O4: C, 74.06;
H, 6.21%. IR (KBr, nmax/cmꢁ1): 3434, 2969, 2935, 2835, 1670,
1654; 1H-NMR (400 MHz, DMSO-d6) dH (ppm): 1.82–1.87 (m, 2H,
CH2), 1.92–1.98 (m, 2H, CH2), 1.98–2.35 (m, 4H, 2CH2), 2.56–
2.70 (m, 4H, 2CH2), 3.69 (s, 3H, OCH3), 4.56 (s, 1H, CH), 6.68–
6.71 (q, 2H, ArH), 6.73–6.75 (d, J 8, 1H, ArH), 7.10–7.14 (t, J 10,
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1H, ArH); 13C-NMR (100 MHz, DMSO-d6) dC (ppm): 20.3, 26.8,
31.1, 36.8, 55.2, 111.3, 114.8, 115.8, 120.5, 129.4, 146.4, 159.3,
165.3, 196.7; MS m/z: 324 (M+).
Acknowledgements
We would like to thank Bu-Ali Sina University, Center of
Excellence in Development of Environmentally Friendly
Methods for Chemical Synthesis (CEDEFMCS) for nancial
support of this study. Also, we would like to thank Zohreh Sal-
imi for editing the manuscript.
9-(1H-Indole-3-yl)-3,4,6,7-tetrahydro-2H-pyran-1,8(5H,9H)-
dione (Table 2, entry 8); opalescent powder 63%; m.p. 268–
ꢀ
269 C; elem. anal. found: C, 74.94; H, 5.49; N, 3.83; calc. for
C
21H19NO3: C, 75.66; H, 5.74; N, 4.20%.IR (KBr, nmax/cmꢁ1):
3415, 3058, 2946, 2895, 1676, 1656; 1H-NMR (400 MHz, DMSO-
d6) dH (ppm): 1.79 (broad, 2H, CH2), 1.92 (broad, 2H, CH2), 2.24
(m, 4H, 2CH2), 2.64–2.65 (m, 4H, 2CH2), 4.87 (s, 1H, CH), 6.94–
6.95 (t, J 7.2, 1H, ArH), 7.00 (m, 2H, ArH), 7.25–7.27 (d, J 8, 1H,
ArH), 7.55–7.57 (d, J 8, 1H, ArH), 10.79 (s, 1H, NH); 13C-NMR
(100 MHz, DMSO-d6) dC (ppm): 20.4, 22.3, 26.9, 36.9, 111.8,
116.2, 118.5, 118.7, 119.3, 120.9, 124.2, 126.1, 136.6, 164.7,
196.8; MS m/z: 333 (M+).
Notes and references
1 P. Laszlo, in Organic Reactions: Simplicity and Logic, Wiley-
VCH, New York, 1995.
2 C. O. Kappe, Curr. Opin. Chem. Biol., 2002, 6, 314.
3 A. Domling and I. Ugi, Angew. Chem., Int. Ed., 2000, 39, 3168.
4 J. Zhu and H. Bienayme, Multicomponent Reactions, Wiley-
VCH, Weinheim, 2005.
5 J. P. Poupelin, G. Saint-Rut, O. Foussard-Blanpin,
G. Narcisse, G. Uchida-Ernouf and R. Lacroix, Eur. J. Med.
Chem., 1978, 13, 67–71.
6 S. C. Kuo, L. J. Huang and H. Nakamura, J. Med. Chem., 1984,
27, 539.
9-(5-Methylthiophen-2-yl)-3,4,6,7-tetrahydro-2H-pyran-
1,8(5H,9H)-dione (Table 2, entry 9); pale yellow powder 73%;
ꢀ
m.p. 232–233 C; elem. anal. found: C, 68.44; H, 5.73; S, 9.11;
calc. for C18H18O3S: C, 68.76; H, 5.77; O, 15.27; S, 10.20%. IR
(KBr, nmax/cmꢁ1): 3313, 2957, 2936, 2892, 2818, 1671, 1618; 1H-
NMR (400 MHz, DMSO-d6) dH (ppm): 1.85–1.93 (m, 2H, CH2),
1.95–2.01 (m, 2H, CH2), 2.29 (s, 3H, CH3), 2.32–2.35 (m, 4H,
2CH2), 2.55–2.68 (m, 4H, 2CH2), 4.79 (s, 1H, CH), 6.47–6.50 (q,
2H, ArH); 13C-NMR (100 MHz, DMSO-d6) dC (ppm): 15.3, 20.3,
25.8, 26.8, 36.8, 115.5, 124.3, 125.1, 137.7, 146.1, 165.5, 196.6;
MS (m/z): 314 (M+).
7 A. H. Bedair, N. A. El-Hady, M. S. A. El-Latif, A. H. Fakery and
A. M. El-Agrody, Farmaco, 2000, 55, 708.
8 L. Loy, G. Bonsignore, D. Secci and A. Calignano, Eur. J. Med.
Chem., 1993, 28, 517.
9-p-Tolyl-3,4,6,7-tetrahydro-2H-pyran-1,8(5H,9H)-dione
(Table 2, entry 10); white powder 79%; m.p. 259–261 ꢀC; elem.
anal. found: C, 77.99; H, 6.63 calc. for C20H20O3: C, 77.90; H,
6.54%. IR (KBr, nmax/cmꢁ1): 3032, 2954, 2893, 1656, 1617; 1H-
NMR (400 MHz, DMSO-d6) dH (ppm): 1.78–1.88 (m, 2H, CH2),
1.92–1.97 (m, 2H, CH2), 2.20 (s, 3H, CH3), 2.22–2.33 (m, 4H,
2CH2), 2.56–2.69 (m, 4H, 2CH2), 4.54 (s, 1H, CH), 6.99–7.01
(d, J 8, 2H, Ph), 7.05–7.07 (d, J 8, 2H, ArH); 13C-NMR
(100 MHz, DMSO-d6) dC (ppm): 20.3, 21.0, 26.8, 30.8,
36.8, 116.1, 128.3, 128.9, 135.6, 142.1, 165.1, 196.7; MS (m/z):
308 (M+).
9 S. M. Menchen, S. C. Benson, J. Y. L. Lam, W. Zhen, D. Sun,
B. B. Rosenblum, S. H. Khan and M. Taing, U.S. Patent,
US6583168, 2003, Chem. Abstr., 2003, 139, 54287f.
10 V. V. Rostovtsev, L. G. Green, V. V. Fokin and K. B. Sharpless,
Angew. Chem., Int. Ed., 2002, 41, 2596.
11 O. Sirkeeioglu, N. Talinli and A. Akar, J. Chem. Res., 1995,
502–506.
12 C. G. Knight and T. Stephens, Biochem. J., 1989, 258, 683–687.
13 M. Ahmad, T. A. King, D.-K. Ko, B. H. Cha and J. Lee, J. Phys.
D: Appl. Phys., 2002, 35, 1473–1476.
14 S. Hatakeyama, N. Ochi, H. Numata and S. Takano, J. Chem.
Soc., Chem. Commun., 1988, 1202.
15 R. Ghorbani-Vaghei and H. Jalili, Synthesis, 2005, 7, 1099.
16 R. Ghorbani-Vaghei, M. Amiri, R. Karimi-Nami and
Z. Salimi, RSC Adv, 2013, 3, 25924.
9-(4-Nitrophenyl)-3,4,6,7-tetrahydro-2H-pyran-1,8(5H,9H)-
dione (Table 2, entry 11); white powder 75%; m.p. 252–254 ꢀC;
elem. anal. found: C, 67.18; H, 4.91; N, 3.85; calc. for
C
19H17NO5: C, 67.25; H, 5.05; N, 4.13%. IR (KBr, nmax/cmꢁ1):
1
3071, 2949, 2874, 1660, 1617; H-NMR (400 MHz, DMSO-d6)
dH (ppm): 1.86–1.91 (m, 2H, CH2), 1.93–1.99 (m, 2H, CH2),
2.22–2.36 (m, 4H, 2CH2), 2.58–2.71 (m, 4H, 2CH2), 4.66 (s, 1H,
CH), 7.47–7.49 (d, J 8.4, 2H, ArH), 8.07–8.09 (d, J 8.4, 2H,
ArH); 13C-NMR (100 MHz, DMSO-d6) dC (ppm): 20.2, 26.9,
32.0, 36.7, 114.8, 123.6, 129.9, 146.3, 152.4, 165.8; MS (m/z):
339 (M+).
17 R. Ghorbani-Vaghei, H. Shahbazee and H. Veisi, Tetrahedron
Lett., 2012, 53, 2325.
18 R. Ghorbani-Vaghei, R. Karimi-Nami, Z. Toghraei-Semiromi,
M. Amiri, Z. Salimi and M. Ghavidel, C. R. Chim., 2014, 17, 324.
19 R. Ghorbani-Vaghei, R. Karimi-Nami, Z. Toghraei-Semiromi,
M. Amiri and M. Ghavidel, Tetrahedron, 2011, 67, 1930.
20 M. A. Zolgol, R. Ghorbani-Vaghei, S. Mallakpour,
G. Chehardoli, A. Ghorbani-Choghamani and A. Hosain
Yazdi, Synthesis, 2006, 10, 1631.
33586 | RSC Adv., 2014, 4, 33582–33586
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