Co(NO3)2·6H2O as a powerful and reusable catalyst for the synthesis of phenylbenzo[g]chromenes

Article abstract of DOI:10.1007/s13738-017-1200-3

An efficient and easy protocol for the one-pot three-component synthesis of phenylbenzo[g]chromenes was developed. The synthesis was achieved by the reaction of aromatic aldehydes, Meldrum’s acid, and 2-hydroxynaphthalene-1,4-dione in the presence of cata

Full text of DOI:10.1007/s13738-017-1200-3

J IRAN CHEM SOC
DOI 10.1007/s13738-017-1200-3
ORIGINAL PAPER
Co(NO3)2·6H2O as a powerful and reusable catalyst
for the synthesis of phenylbenzo[g]chromenes
Mehrnoush Kangani1 · Nourallah Hazeri1 · Malek‑Taher Maghsoodlou1
Received: 12 March 2017 / Accepted: 12 September 2017
© Iranian Chemical Society 2017
Abstract An efcient and easy protocol for the one-pot
three-component synthesis of phenylbenzo[g]chromenes
was developed. The synthesis was achieved by the reac-
tion of aromatic aldehydes, Meldrum’s acid, and 2-hydrox-
ynaphthalene-1,4-dione in the presence of catalytic amount
of Co(NO3)2·6H2O at room temperature. The important
advantages of this procedure are short reaction times, high
yields, easy work-up, reusable catalyst, and no need to col-
umn chromatography.
well-distributed in natural products with a broad spectrum
of biological activities including anti-Alzheimer”s [2],
anti-proliferative [3], anti-microbial [4], anti-cancer [5],
anti-tumor [6], TNF-α inhibitor [7] anti-viral [8, 9], anti-
Parkinson disease, anti-infammatory [10], anticonvulsant
[11], antimalarial [12, 13], anti-helminthic [14, 15], sex-
hormonal activity [16], anti-Huntington”s disease [17],
estrogenic [18] and others [19] (Fig. 1). The possibility of
wide range of biological properties make chromens as an
interesting synthetic target. Therefore, developing straight-
forward and fexible synthetic methods toward functional-
ized chromens has attracted attention from organic research-
ers [20–23]. Some methods such as microwave irradiation
[24], use of l-proline and nickel nanoparticles as catalyst
[25, 26] have been reported to facilitate the synthesis of
phenylbenzo[g]chromenes. In continuation of our research
on chromene synthesis and considering the important bio-
logical and pharmaceutical properties of these compounds
[27–29], we investigate to report an efcient approach for
the synthesis of phenylbenzo[g]chromenes via the one-pot
three-component condensation between aromatic aldehydes,
Meldrum’s acid, and 2-hydroxynaphthalene-1,4-dione in the
presence of catalytic amount of Co(NO3)2·6H2O at ambient
condition (Scheme 1).
Keywords Phenylbenzo[g]chromenes · Aromatic
aldehydes · Meldrum’s acid · 2-hydroxynaphthalene-1 ·
4-dione
Introduction
Heterocycles, an important class of organic compounds,
consist of more than 70% of promising bioactive and drug
molecules presently available in literature. Because of their
wide broad biological and natural afuence, Oxygen het-
erocycles have a special interest and pharmaceutical signif-
cance to chemists [1]. O-heterocycles, “chromene” hetero-
cyclic scafolds represent a “distinguished” structural motif
Electronic supplementary material The online version of this
article (doi:10.1007/s13738-017-1200-3) contains supplementary
material, which is available to authorized users.
Experimental
General
* Mehrnoush Kangani
mehrnooshkangani@gmail.com
Melting points and IR spectra were measured on an Elec-
trothermal 9100 apparatus and a JASCO FT/IR-460 plus
spectrometer. The 1H and 13C NMR spectra were recorded
on a Bruker DRX-300 Advance instrument with CDCl3 and
DMSO as solvent at 300 and 75 MHz, respectively. The
* Nourallah Hazeri
n_hazeri@chem.usb.ac.ir
1
Department of Chemistry, University of Sistan
and Baluchestan, P.O. Box 98135-674, Zahedan, Iran
Vol.:(0123456789)
1 3

J IRAN CHEM SOC
Fig. 1 Some bioactive
NH2
O
chromenes heterocycles
Z
O
NC
CN
NO2
Br
Ph
O
NH2
O
O
O
OEt
Z=O,S,NH
antitumor agent
antibacterial
anticancer
and antibacterial
O
O
O
O
O
O
O
HO
HO
O
O
O
O
O
anti-inflammatory
anti-HIV
activity against leukemia cell L1210
mass spectra were recorded on an Agilent Technology (HP)
mass spectrometer, operating at an ionization potential of
70 eV. Aromatic aldehydes, Meldrum’s acid, and 2-hydrox-
ynaphtalene-1, 4-dion were obtained from Merck (Darm-
stadt, Germany), Aldrich and Fluka (Buchs, Switzerland),
and used without further purifcation.
MS (EI, 70 eV) m/z (%): 334 (M+, 59), 306 (100), 277 (94),
249 (15), 228 (24), 189 (16), 165 (47), 134 (34), 104 (73),
76 (80), 43 (23).
3 , 4 ‑ D i hy d ro ‑ 4 ‑ ( 4 ‑ f l u o ro p h e nyl ) b e n z o [ g ]
chromene‑2,5,10‑trione (4b) IR (KBr, cm−1): 2921,
2843, 1782, and 1686. 1H NMR (300 MHz, CDCl3) δ (ppm):
3.07–3.13 (m, 2H), 4.68 (dd, J = 6.0, 2.7 Hz, 1H), 7.04 (t,
J = 8.4 Hz, 2H,Ar), 7.28–7.29 (m, 2H, Ar), 7.79–7.783 (m,
2H, Ar), 8.09–8.23 (m, 2H, Ar). 13C NMR (75 MHz, CDCl3)
δ (ppm): 34.5, 35.3, 116.4 (d, J = 21.75 Hz), 125.4, 126.7,
126.9, 128.5 (d, J = 7.8 Hz), 130.8, 131.2, 134.2, 134.5,
134.5, 134.6, 151.3, 160.7, 163.7 (d, J = 228.0 Hz), 164.0
(C=O), 177.2 (C=O), 182.6 (C=O). MS (EI, 70 eV) m/z
(%): 322 (M+, 81), 294 (4), 272 (3), 251 (70), 224 (16), 196
(27), 170 (13), 133 (30), 104 (96), 76 (100), 50 (30).
General procedure for the synthesis of (4a–g)
2-Hydroxynaphtalen-1, 4-dion (1.0 mmol) was added
to the stirred solution of aromatic aldehydes (1.0 mmol)
and Meldrum’s acid (1.0 mmol) in EtOH (3 mL). Then,
Co(NO3)2·6H2O (5 mol%) was added to the above mixture.
The reaction mixture was stirred for the time indicated in
Table 2. The progress of the reaction was monitored by thin-
layer chromatography (TLC). After the completion of the
reaction, the thick precipitation was fltered of and washed
with ethanol (3 × 2 cm3) to remove the catalyst. The solid
was purifed by recrystallization from ethanol to give prod-
uct 4a–g.
3, 4‑Dihydro‑4‑(2‑methoxyphenyl)benzo[g]
chromene‑2,5,10‑trione (4c) IR (KBr, cm−1): 2998, 2823,
1784, and 1680. 1H NMR (300 MHz, CDCl3) δ (ppm): 3.12
(d, J = 4.8 Hz, 2H), 3.79 (s, 3H, OCH3), 4.64 (t, J = 4.2 Hz,
1H), 6.80–6.84 (m, 3H, Ar), 7.22–7.29 (m, 1H, Ar),
7.55–7.81 (m, 2H, Ar), 8.07–8.20 (m, 2H, Ar). 13C NMR
(75 MHz, CDCl3) δ (ppm): 35.1, 35.2, 55.2, 113.0, 113.2,
118.7, 125.5, 126.7, 126.8, 130.5, 130.8, 131.3, 134.1,
134.5, 140.2, 151.4, 160.2, 163. 9 (C=O), 177.3 (C=O),
182.6 (C=O). MS (EI, 70 eV) m/z (%): 334 (M+, 30), 306
(11), 277 (16), 251 (25), 228 (3), 207 (11), 178 (12), 149
(36), 127 (10), 104 (59), 76 (18), 43 (100).
3 , 4 ‑ D i hy d ro ‑ 4 ‑ ( 4 ‑ m et h ox y p h e nyl ) b e n z o [ g ]
chromene‑2,5,10‑trione (4a) IR (KBr, cm−1): 2966,
2842, 1782, and 1742. 1H NMR (300 MHz, CDCl3) δ (ppm):
3.10 (d, J = 4.2 Hz, 2H), 3.78 (s, 3H, OCH3), 4.63 (s, 1H),
6.86 (d, J = 8.4 Hz, 2H, Ar), 7.20 (d, J = 8.1 Hz, 2H, Ar),
7.79–7.80 (m, 2H, Ar), 8.19–8.22 (m, 2H, Ar). 13C NMR
(75 MHz, CDCl3) δ (ppm): 34.4, 35.4, 55.3, 114.7, 125.9,
126.7, 126.8, 127.9, 130.7, 130.8, 131.3, 134.1, 134.5,
151.1, 159.3, 164.0 (C=O), 177.3 (C=O), 182.7 (C=O).
1 3

J IRAN CHEM SOC
R
O
O
H
R
O
O
O
O
O
Co(NO3)2. 6H2O (5 mol%)
EtOH, r.t
+
+
O
O
O
O
OH
4a-g
2
3
1
OMe
F
OMe
O
MeO
O
OMe
O
OMe
O
O
O
O
O
O
O
O
O
O
O
O
O
4a
4b
4c
4d
Cl
NO2
O
O
O
O
OMe
O
O
O
O
O
O
O
O
4e
4f
4g
Scheme 1 Synthesis of phenylbenzo[g]chromene derivatives
3, 4‑Dihydro‑4‑(3, 4, 5‑trimethoxyphenyl) benzo[g]
chromene‑2, 5, 10‑trione (4d) IR (KBr, cm−1): 2941,
Ar), 7.35–7.31 (m, 1H, Ar), 7.38 (d, J = 7.5 Hz, 1H, Ar),
7.72–7.76 (m, 2H, Ar), 8.02–8.20 (m, 2H, Ar). 13C NMR
(75 MHz, CDCl3) δ (ppm): 33.5, 35.3, 54.3, 110.8, 120.9,
122.8, 126.5, 126.7, 127.0, 129.4, 130.5, 130.8, 131.5,
133.8, 134.3, 151.1, 157.2, 163.7 (C=O), 177.7 (C=O),
183.1 (C=O). MS (EI, 70 eV) m/z (%): 334 (M+, 93), 306
(66), 278 (15), 247 (95), 218 (9), 189 (26), 165 (34), 134
(50), 104 (78), 76 (100), 43 (32).
1
2844, 1708, and 1669. H NMR (300 MHz, CDCl3) δ
(ppm): 3.11–3.13 (m, 2H), 3.81 (s, 3H, OCH3), 3.84 (s, 6H,
2OCH3), 4.62 (dd, J = 6.0, 3 Hz, 1H), 6.49 (s, 2H, Ar),
8.11–8.14 (m, 2H, Ar), 8.20–8.23 (m, 2H, Ar). 13C NMR
(75 MHz, CDCl3) δ (ppm): 35.1, 35.3, 56.2 (2OCH3), 60.8
(OCH3), 103.9, 125.6, 126.7, 126.9, 130.8, 131.3, 134.2,
134.4, 134.6, 137.8, 151.1, 153.8, 164.2 (C=O), 177.3
(C=O), 182.7 (C=O). MS (EI, 70 eV) m/z (%): 349 (M+,
91), 366 (25), 336 (4), 307 (21), 277 (10), 251 (19), 223
(15), 176 (20), 146 (7), 104 (86), 76 (100), 43 (80).
3 , 4 ‑ D i h y d r o ‑ 4 ‑ ( 4 ‑ n i t r o p h e n y l ) b e n z o [ g ]
chromene‑2,5,10‑trione (4f) IR (KBr, cm−1): 2937, 2862,
1
1783, and 1680. H NMR (300 MHz, CDCl3, DMSO) δ
(ppm): 2.96 (d, J = 16.2 Hz, 1H), 3.41 (d, 1H), 4.74 (d,
J = 8.4 Hz, 1H), 7.50–8.14 (m, 8H, Ar). 13C NMR (75 MHz,
CDCl3, DMSO) δ (ppm): 34.9, 35.2, 123.3, 124.2, 124.4,
125.9, 126.5, 126.5, 128.5, 129.1, 131.0, 131.3, 133.1,
134.4, 134.7, 152.3, 164.4 (C=O), 177.2 (C=O), 182.5
(C=O). MS (EI, 70 eV) m/z (%): 349 (M+, 30), 3 246 (21),
3 , 4 ‑ D i hy d ro ‑ 4 ‑ ( 2 ‑ m et h ox y p h e nyl ) b e n z o [ g ]
chromene‑2,5,10‑trione (4e) IR (KBr, cm−1): 2931,
2883, 1783, and 1680. 1H NMR (300 MHz, CDCl3) δ (ppm):
2.96–3.13 (m, 2H), 3.77 (s, 3H, OCH3), 4.67 (d, J = 8.4 Hz,
1H), 6.90 (d, J = 8.1 Hz, 1H, Ar), 6.95 (t, J = 7.5 Hz, 1H,
1 3

J IRAN CHEM SOC
Scheme 2 Model reaction
for optimization amount of
catalyst for the synthesis of
phenylbenzo[g]chromenes
OMe
O
H
O
O
O
O
O
Co(NO3)2. 6H2O (5 mol%)
EtOH, r.t
+
+
O
O
O
O
OH
O
OMe
4a-g
2
3
1
Table 1 Optimization conditions for the synthesis of phenylbenzo[g]
82), 310 (40), 282 (58), 254 (11), 233 (40), 205 (12), 176
(38), 138 (60), 104 (82), 76 (100), 43 (41).
chromenes
Entry Catalyst
Solvent Time Isolated yield (%)
1
2
3
–
EtOH 48
EtOH 48
EtOH 12 h
–
Result and discussion
Fe (NO3)3·9H2O
p-toluene sulfonic
Knovenogel product
40
The reaction conditions were optimized using 4-meth-
oxybenzaldehyde, Meldrum’s acid, and 2-hydroxynaph-
thalene-1,4-dion in equimolar amounts as a model system
(Scheme 2). Initially, the control experiment confrmed that
the reaction did not proceed without the catalyst (Table 1,
Entries 1). The model reaction was then performed in the
presence of different catalysts such as Fe(NO3)3·9H2O,
p-toluene sulfonic acid and lactic acid at room temperature.
As it can be seen in Table 1, the best reaction condition was
obtained at room temperature in the presence of 5 mol% of
Co(NO3)2·6H2O (Table 1, Entry 7). The increasing amount
of catalyst did not have any efect on the yield and time of
reaction. With respect to green chemistry concept, we did
not try other organic solvents for this synthesis.
acid
4
5
6
7
8
Lactic acid (5 mol%) EtOH 24 h
ZrCl4
HClO4–SiO2
KHSO4
Co(NO3)2·6H2O
40
50
60
50
EtOH 18 h
EtOH 9 h
EtOH 7 h
EtOH 50 min 30
EtOH 10 min 90
EtOH 10 min 90
(3 mol%)
9
Co(NO3)2·6H2O
(5 mol%)
Co(NO3)2·6H2O
10
(10 mol%)
221 (16), 293 (31), 218 (7), 189 (34), 149 (38), 127 (10),
104 (73), 76 (100), 43 (66).
Using these optimized experimental conditions, a wide
verity of products 4a–g were synthesized via the reaction of
aromatic aldehydes, Meldrum’s acid and 2-hydroxynaphtha-
lene-1, 4-dion (Table 2).
3 , 4 ‑ D i h y d r o ‑ 4 ‑ ( 4 ‑ c h l o r o p h e n y l ) b e n z o [ g ]
chromene‑2,5,10‑trione (4g) IR (KBr, cm−1): 3024,
2959, 1741, and 1680. 1H NMR (300 MHz, CDCl3) δ (ppm):
2098–3.06 (m, 2H), 4.57 (dd, J = 6.0, 2.7 Hz, 1H), 7.12 (d,
J = 8.4 Hz, 2H, Ar), 7.23 (d, J = 8.4 Hz, 2H, Ar), 7.68–7.72
(m, 2H, Ar), 7.99–8.13 (m, 2H, Ar). 13C NMR (75 MHz,
CDCl3) δ (ppm): 34.6, 35.1, 125.1, 126.7, 126.1, 126.7,
126.9, 127.1, 128.2, 128.8, 129.6, 130.8, 131.2, 134.2,
134.2, 134.6, 151.4, 163.9 (C=O), 177.1 (C=O), 182.5
(C=O). MS (EI, 70 eV) m/z (%): 340 (M+2, 32), 338 (M+,
Table 2 Interestingly, diferent aryl aldehydes includ-
ing electron withdrawing or releasing substituents (ortho-,
meta-, and para-substituted) participated well in this reaction
and gave the phenylbenzo[g]chromene derivatives in good-
to-excellent yield. The structures of the products 4a–g were
detected from IR, 1H and 13C NMR, and mass spectra. The
mass spectrum of these compounds displayed molecular ion
peaks with appropriate m/z values. Any initial fragmentation
Table 2 Synthesis of
Entry
Aldehyde
Product
Time (min)
Yield (%)
M.p °C
Lit. M.p °C
phenylbenzo[g]chromene
derivatives
1
2
3
4
5
6
7
4-OMe–C6H4
4-F–C6H4
3-OMe–C6H4
3,4,5-(OMe)2–C6H2
2-OMe–C6H4
4-NO2–C6H4
4-Cl–C6H4
4a
4b
4c
4d
4e
4f
10
15
15
20
20
10
10
90
95
85
90
85
90
85
200–202
210–212
201–203
202–204
204–205
219–221
222–224
191–192 [24]
210–212 [25]
191–192 [24]
203–206 [25]
–
219–221 [25]
224–227 [25]
4g
1 3

J IRAN CHEM SOC
Table 3 Comparison of the efciency of Co(NO3)2·6H2O with other
involves the loss of the C=O moieties. The assignments of
IR, 1H, 13C NMR are given in the experimental section.
According to the literature [24, 25], a mechanistic expla-
nation for the formation of phenylbenzo[g]chromenes is
shown in Scheme 3. First, formation of arylidene Meldrum’s
acid A by the Knoevenagel condensation between an alde-
hyde 1 and Meldrum’s acid. Then, in addition to arylidene
Meldrum’s acid, 2-hydroxynaphtalene-1,4-dione undergoes
a Michael-type A to give intermediate B which undergoes
cyclization with concomitant loss of acetone and carbon
dioxide to aford the desired product.
reported catalysts in literature
Entry Catalyst/condition
Time Yield (%) References
1
2
3
4
HOAc/MWI
l-prolin/H2O, refux
PEG-Ni nps/EG, r.t
4 min 93
4 h 73
10 min 79
[24]
[25]
[26]
[Present wok]
Co(NO3)2·6H2O/EtOH, r.t 10 min 90
4-methylbenzaldehyde, Meldrum’s acid, and 2-hydrox-
ynaphthalene-1,4-dione. After completion of the reac-
tion, the thick precipitation was fltered of and washed
with ethanol (3 × 2 cm3) to remove the catalyst. The
Co(NO3)2·6H2O was dissolved in EtOH and fltered for
separation of the crude product. The separated product
was washed twice with EtOH (2 × 5 mL). The result-
ing product subsequently recrystallized from hot ethanol
to give the pure solid. In order to recover the catalyst,
since Co(NO3)2·6H2O is soluble in EtOH, the fltrate was
extracted with diethyl ether. The aqueous layer was sepa-
rated, and its solvent was evaporated under reduced pres-
sure and Co(NO3)2·6H2O was recovered and reused. The
catalytic system worked well up to fve catalytic runs. The
In order to assess the efciency and generality of this
methodology, the result from the reaction of 4-chloroben-
zaldehyde and Meldrum’s acid with 2-hydroxynaphtalene-
1,4-dione by this method has been compared with those of
the previously reported methods [24–26] (Table 3). Accord-
ing to the green chemistry, if possible, synthetic methods
should be conducted at room temperature and pressure [30].
This methodology was performed at room temperature for
economic and environmental impacts.
Recovery of the catalysts is important in green organic
synthesis. Thus, we also for recyclability of the cata-
lysts, investigated the recycling of Co(NO3)2·6H2O under
reaction conditions using a selected model reaction of
Scheme 3 The proposed
O
O
mechanism for the synthesis of
O
O
O
O
Knoevenagel
phenylbenzo[g]chromenes
+
O
O
O
Ar
H
Ar
O
1
2
A
O
O
O
O
Ar
O
O
Ar
O
Co(NO3)2.6H2O
O
+
O
OH
O
O
OH
A
B
O
-
-
CO2
O
Ar
O
O
O
4
1 3

J IRAN CHEM SOC
6. D.R. Anderson, S. Hegde, E. Reinhard, L. Gomez, W.F. Vernier,
L. Lee, S. Liu, A. Sambandam, P.A. Sinder, L. Masih, Bioorg.
Med. Chem. Lett. 15, 1587 (2005)
90
85
80
75
7. J.F. Cheng, A. Ishikawa, O. Yoshinori, T. Arrhenius, A. Nadzan,
Bioorg. Med. Chem. Lett. 13, 3647 (2003)
8. P.W. Smith, S.L. Sollis, P.D. Howes, P.C. Cherry, I.D. Starkey,
K.N. Cobley, H. Weston, J. Scicinski, A. Merritt, A. Whittington,
P. Wyatt, N. Taylor, D. Green, R. Bethell, S. Madar, R.J. Fenton,
P.J. Morley, T. Pateman, A. Beresford, J. Med. Chem. 41, 787
(1998)
9. A.G. Martinez, L. Marck, J. Bioorg. Med. Chem. Lett. 7, 3165
(1997)
Run 1
90
Run 2
90
Run 3
85
Run 4
83
Run 5
80
10. L.L. Andreani, E. Lapi, Bull. Chim. Farm. 99, 583 (1960)
11. M.A. Bhat, N. Siddiqui, S.A. Khan, Acta Pol. Pharm. 65, 235
(2008)
Yield
12. V.F. De Andrade-Neto, M.O.F. Goulart, J.F. Da Silva Filho, M.J.
Da Silva, M.D.C.F.R. Pinto, A.V. Pinto, M.G. Zalis, L.H. Car-
valho, A.U. Krettli, Bioorg. Med. Chem. Lett. 14, 1145 (2004)
13. P.S. Elisa, E.B. Ana, A.G. Ravelo, D.J. Yapu, A.G. Turba, Chem.
Biodivers. 2, 26 (2005)
Fig. 2 Results of recycling over fve consecutive recycling experi-
ments
recovered catalyst was reused fve times without any loss
14. R.P. Tripathi, A.P. Bhaduri, S.N. Singh, R.K. Chatterjee, P.K.
Murthy, Acta Tropica 76, 101 (2000)
of its activities (Fig. 2).
15. B.N. Sudha, C. Sridhar, V.G. Sastry, Y.S.R. Reddy, O. Sreevi-
dya, S. Lavanya, V.A. Jyothi, V. Nagesh, S. Sen, R. Chakraborty,
Indian J. Chem. 52B, 422 (2013)
Conclusion
16. S.J. Mohr, M.A. Chirigios, F.S. Fuhrman, J.W. Pryor, Cancer Res.
35, 3750 (1975)
In conclusion, Co(NO3)2·6H2O is a simple and efcient cata-
lyst for the three-component synthesis of medicinally rel-
evant phenylbenzo[g]chromenes. The reaction is performed
under mild conditions. The procedure utilizes the simple
equipment and easily carried out. It is also valuable from
the viewpoint of diversity-oriented large-scale processes.
The catalyst shows an environmental-friendly feature which
is inexpensive, clean, safe, nontoxic, reusable and easily
obtained. Moreover, the procedure ofers several advantages
including high yields, operational simplicity, clean reaction
conditions, and the minimum pollution of the environment,
which make it a useful and attractive process for the synthe-
sis of these compounds.
17. Y.L. Zhang, B.Z. Chen, K.Q. Zheng, M.L. Xu, X.H. Lei, X.B.
Yaoxue, Chem. Abstr. 96, 135383e (1982)
18. N. Jain, J. Xu, R.M. Kanojia, F. Du, G. Jian-Zhong, E. Pacia, M.
Lai, A. Musto, G. Allan, M. Reuman, X. Li, D. Hahn, M. Cous-
ineau, S. Peng, D. Ritchie, R. Russell, S. Lundeen, Z. Sui, J. Med.
Chem. 52, 7544 (2009)
19. G. Brahmachari, Handbook of Pharmaceutical Natural Products,
vol. 1, 1st edn. (Wiley, Weinheim, 2010), p. 112
20. S.R. Yetra, T. Roy, A. Bhunia, D. Porwal, A.T. Biju, J. Org. Chem.
79, 4245 (2014)
21. D.S. Gaikwad, K.A. Undale, T.S. Shaikh, D.M. Pore, C. R. Chim
14, 865 (2011)
22. R.M.N. Kalla, S.J. Byeon, M.S. Heo, I. Kim, Tetrahedron 69,
10544 (2013)
23. M.N. Elinson, A.I. Ilovaisky, V.M. Merkulova, T.A. Zaimovskaya,
G.I. Nikishin, Mendeleev Commun. 21, 122 (2011)
24. P. Wei, X. Zhang, S. Tu, S. Yan, H. Ying, P. Ouyang, Bioorg. Med.
Chem. Lett. 19, 828 (2009)
Acknowledgements We gratefully acknowledge fnancial support
from the Research Council of the University of Sistan and Baluchestan.
25. H. Mofakham, R. Ghadari, A. Shaabani, M. Pedarpour, S. Gha-
semi, J. Iran. Chem. Soc. 1, 307 (2013)
26. J.M. Khurana, K. Vij, Tetrahedron Lett. 52, 3666 (2011)
27. N. Hazeri, M.T. Maghsoodlou, F. Mir, M. Kangani, H. Saravani,
E. Molashahi, Chin. J. Catal. 35, 391 (2014)
References
28. N. Hazeri, M.T. Maghsoodlou, M.R. Mousavi, J. Aboonajmi, M.
Safarzaei, Res. Chem. Intermed. 41, 169 (2015)
29. Z. Vafajoo, N. Hazeri, M.T. Maghsoodlou, H. Veisi, Chin. Chem.
Lett. 26, 973 (2015)
1. L. Sujay, B. Goutam, J. Org. Biomol. Chem. 2, 1 (2014)
2. W.O. Foye, Principi di Chemico Farmaceutica, Piccin: Padora,
Italy, p. 416 (1991)
3. G. Bianchi, A. Tava, Agric. Biol. Chem. 51, 2001 (1987)
4. M.M. Khafagy, A.H.F.A. El-Wahas, F.A. Eid, A.M. El-Agrody,
Farmaco 57, 715 (2002)
30. P.T. Anastas, J.C. Warner, Principles of green chemistry. Green
Chem. Theory Pract. 29, 29–56 (1998)
5. M. Ough, A. Lewis, E.A. Bey, J. Gao, J.M. Ritchie, W. Bornmann,
D.A. Boothman, L.W. Oberley, J.J. Cullen, Cancer Biol. Ther. 4,
95 (2005)
1 3