A highly flexible green synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10- dione derivatives with CuI nanoparticles as catalyst under solvent-free conditions

Article abstract of DOI:10.1016/j.cclet.2013.11.046

CuI nanoparticles as an efficient catalyst have been used for the preparation of 1H-pyrazolo[1,2-b]phthalazine-5,10-diones by the four-component condensation reaction of phthalic anhydride, hydrazine monohydrate, aromatic aldehydes and malononitrile or ethyl cyanoacetate under solvent-free conditions in good to excellent yields, short reaction times and environmentally benign, milder reaction conditions.

Full text of DOI:10.1016/j.cclet.2013.11.046

Chinese Chemical Letters 25 (2014) 401–405
Contents lists available at ScienceDirect
Chinese Chemical Letters
journal homepage: www.elsevier.com/locate/cclet
Original article
A highly flexible green synthesis of 1H-pyrazolo[1,2-b]phthalazine-
5,10-dione derivatives with CuI nanoparticles as catalyst under
solvent-free conditions
*
Javad Safaei-Ghomi , Hossein Shahbazi-Alavi, Abolfazl Ziarati, Raheleh Teymuri,
Mohammad Reza Saberi
Department of Organic Chemistry, Faculty of Chemistry, University of Kashan, Kashan 51167, Iran
A R T I C L E I N F O
A B S T R A C T
Article history:
CuI nanoparticles as an efficient catalyst have been used for the preparation of 1H-pyrazolo[1,2-
b]phthalazine-5,10-diones by the four-component condensation reaction of phthalic anhydride,
hydrazine monohydrate, aromatic aldehydes and malononitrile or ethyl cyanoacetate under solvent-
free conditions in good to excellent yields, short reaction times and environmentally benign, milder
reaction conditions.
Received 13 August 2013
Received in revised form 11 November 2013
Accepted 13 November 2013
Available online 28 November 2013
ß 2013 Javad Safaei-Ghomi. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights
reserved.
Keywords:
Nanoparticles
Multi-component reactions
Solvent-free
Pyrazolophthalazine
1. Introduction
core structures can be created through MCR synthesis [22–26].
Consequently, MCRs have been paid much attention by synthetic
Among a large diversity of heterocyclic compounds, bridgehead
hydrazine heterocycles have attracted considerable attention
because they show some pharmacological properties and biologi-
cal activities [1–5]. Among which, pyrazole derivatives are
acknowledged to possess a wide range of bioactivities and exhibit
important biological properties such as anti-inflammatory [6],
antifungal [7], anticancer [8], antiviral [9], antitumor [10],
anticoagulant [11] antibacterial (inhibitory activity against Escher-
ichia coli FabH) [12], and antihypoglycemic activity [13,14].
Phthalazine derivatives were reported to possess a multiplicity
of pharmacological properties including antimicrobial [15],
anticonvulsant [16], antifungal [17], anticancer [18], cardiotonic
[19], vasorelaxant [20] activities. Pyrazolo[1,2-b]phthalazine-
dione derivatives have been described as anti-inflammatory,
analgesic, anti-hypoxic, and anti-pyretic agents [21] and therefore,
the development of simple methods for the synthesis of
pyrazolo[1,2-b]phthalazine-5,10-diones is considered very impor-
tant. Multi-component reactions (MCRs) constitute a very power-
ful tool to synthesize diverse and complex heterocyclic
compounds. Meanwhile, more classical drug-like, heterocyclic
organic chemists worldwide due to the effectiveness of multiple
component reactions at building functionalized, drug-likes struc-
tures from different families of compounds in a single step and
thus we believe that discovering and developing new and novel
ones is an important pursuit in academic chemistry [27,28].
Similarly nanoparticles have undergone extensive examination
in the past decade. Recent advances in nanoscience and
nanotechnology have led to new research interests in using
nanometer-sized particles as an alternative matrix for catalytic
reactions. Among various nanoparticles, copper nanoparticles have
received considerable attention because of their unique properties
and potential applications in diverse fields [29]. Recently, copper
nanoparticles were used as a suitable catalyst in many reactions
including synthesis of alkyne-azide cycloadditions [30], the
Mannich reaction [31], aza-Michael reactions [32], hydroxylation
of phenol [33], 1,4-dihydropyridines [34], polyfunctionalized
pyridine derivatives [35], and functionalized tricarboxamides [36].
The synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-dione
derivatives via the three-component coupling of aldehydes, mal-
ononitrile or ethyl cyanoacetate and phthalhydrazide has been
reported using MCRs in the presence of diverse catalysts including
PTSA/[Bmim]Br (100 8C, 3 h) [37], Et3N/EtOH (50 8C, 1 h, sonochem-
istry) [38], [Bmim]OH/MW (100 W, 45 8C, 4–5 min) [39], 1,8-
diazabicyclo[5,4,0]-undec-7-en-8-ium acetate, (DBU[CH3COO],
*
Corresponding author.
E-mail address: safaei@kashanu.ac.ir (J. Safaei-Ghomi).
1001-8417/$ – see front matter ß 2013 Javad Safaei-Ghomi. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
http://dx.doi.org/10.1016/j.cclet.2013.11.046

402
J. Safaei-Ghomi et al. / Chinese Chemical Letters 25 (2014) 401–405
R
O
R
O
O
CN
CuI NP
S
+
O
.
+
+
NH -NH H O
2
2
2
N
N
X
solvent-free
X
O
CHO
X= CN, COOEt
H N
2
1
2
3
4
5
Scheme 1. Synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-dione derivatives.
(solvent-free) [40], AL-KIT-6(ethanol, 60 8C, 4 h) [41], NiCl2ꢀ6H2O
(ethanol/reflux) [42] InCl3 [43].
mp 247–249 8C, IR (KBr, cmꢁ1):
1H NMR (400 MHz, DMSO-d6):
n
d
max 3383, 3300, 2207, 1659, 1603;
2.43 (3H, s, CH3), 6.30 (1H, s, CH),
Herein, we report the use of CuI nanoparticles as an efficient
catalyst for the preparation of 1H-pyrazolo[1,2-b]phthalazine-
5,10-diones by the four-component condensation reactions of
phthalic anhydride, hydrazine monohydrate, aromatic aldehydes
and malononitrile or ethyl cyanoacetate under solvent-free
conditions in good to excellent yields (Scheme 1).
7.17–7.28 (4H, m, Ar), 7.96–8.25 (6H, m, Ar and NH2); 13C NMR
(100 MHz, DMSO-d6): d 18.65, 61.2, 62.5, 122.0, 126.8, 127.2, 127.8,
128.0, 128.3, 128.5, 128.7, 130.5, 133.8, 134.8, 135.2, 136.5, 153.7,
154.2, 156.6. Anal. Calcd. for C19H14N4O2: C 69.09, H 4.27, N 16.95,
Found: C 68.98, H 4.25, N 16.98, MS (EI) (m/z): 330.
3-Amino-1-(3-methylphenyl)-5,10-dihydro-5,10-dioxo-1H-
pyrazolo[1,2-b]phthalazine-2-carbonitrile (5b): Yellow powder;
mp 250–252 8C, IR (KBr, cmꢁ1):
1H NMR (400 MHz, DMSO-d6):
nmax 3361, 3259, 2194, 1658, 1570;
2. Experimental
d
2.27 (3H, s, CH3), 6.05 (1H, s, CH),
7.12–7.24 (4H, m, Ar), 7.96–8.26 (6H, m, Ar and NH2); 13C NMR
2.1. Preparation of CuI nanoparticles
(100 MHz, DMSO-d6): d 24.0, 61.3, 63.2, 122.1, 122.3, 127.2, 127.4,
127.8, 128.2, 128.6, 128.9, 131.4, 134.0, 134.6, 135.6, 136.3, 154.0,
154.5, 157.3. Anal. Calcd. for C19H14N4O2: C 69.09, H 4.27, N 16.95,
Found: C 69.15, H 4.15, N 16.87, MS (EI) (m/z): 330.
The CuI nanoparticles were prepared according to the proce-
dure reported in the literature [44]. Where the catalyst was
prepared by ultrasonic irradiation approach. Firstly, the copper
substrate (CuSO4) (1 mmol) is cleaned ultrasonically for 20 s in
acetone and then in a 2 mol/L HCl solution, followed by repeated
rinsing with distilled water. After drying, the substrate is dipped
slowly into a solution of KI (2 mmol) in 40 mL of distilled water,
sonicated and allowed to react for 30 min. When the reaction was
completed, a gray precipitate was obtained. The solid was filtered
and washed with distilled water, ethanol and dried at room
temperature for 48 h.
3-Amino-1-(4-methylphenyl)-5,10-dihydro-5,10-dioxo-1H-
pyrazolo[1,2-b]phthalazine-2-carbonitrile (5c): Yellow powder;
mp 253–255 8C, IR (KBr, cmꢁ1):
1H NMR (400 MHz, DMSO-d6):
n
d
max 3361, 3259, 2196, 1656, 1569;
2.28 (3H, s, CH3), 6.07 (1H, s, CH),
7.14–7.33 (4H, m, Ar), 7.94–8.25 (6H, m, Ar and NH2); 13C NMR
(100 MHz, DMSO-d6):
d 21.2, 62.3, 64.0, 123.1, 1234, 127.4, 127.6,
127.9, 128.1, 128.7, 130.2, 130.8, 133.3, 134.6, 135.0, 136.5, 153.0,
154.7, 157.0. Anal. Calcd. for C19H14N4O2: C 69.09, H 4.27, N 16.95,
Found: C 69.11, H 4.19, N 16.90, MS (EI) (m/z): 330.
3-Amino-1-(4-isopropylphenyl)-5,10-dihydro-5,10-dioxo-1H-
pyrazolo[1,2-b]phthalazine-2-carbonitrile (5d): Yellow powder;
2.2. General procedure for the preparation of 1H-pyrazolo[1,2-
b]phthalazine-5,10-dione derivatives
mp 265–267 8C, IR (KBr, cmꢁ1):
1H NMR (400 MHz, DMSO-d6):
nmax 3368, 3264, 2191, 1659, 1569;
d
1.18 (6H, d, J = 6.8 Hz), 2.92 (1H,
Hydrazine monohydrate (1 mmol) and phthalic anhydride
(1 mmol) were mixed at 70 8C (15 min). Then, aromatic aldehydes
(1 mmol), malononitrile or ethyl cyanoacetate (1 mmol) and CuI
nanoparticles (10% mol), as catalyst, was added and stirred at 70 8C
under solvent-free conditions for the specific time (Table 1). After
completion of the reaction, the reaction mixture was recrystallized
from MeOH to afford the pure product.
m), 6.09 (1H, s, CH), 7.23–7.35 (4H, m, Ar), 7.95–8.24 (6H, m, Ar and
NH2); 13C NMR (100 MHz, DMSO-d6):
24.3, 33.6, 61.3, 63.4, 116.1,
d
126.9, 127.32, 127.7, 129.1, 133.6, 134.21, 148.4, 150.6, 153.4,
156.8. Anal. Calcd. for C21H18N4O2: C 70.36, H 5.06, N 15.63, Found:
C 70.29, H 4.99, N 15.67, MS (EI) (m/z): 358.
3-Amino-1-(4-hydroxyphenyl)-5,10-dihydro-5,10-dioxo-1H-
pyrazolo[1,2-b]phthalazine-2-carbonitrile (5e): Yellow powder;
3-Amino-1-(2-methylphenyl)-5,10-dihydro-5,10-dioxo-1H-
pyrazolo[1,2-b]phthalazine-2-carbonitrile (5a): Yellow powder;
mp 270–272 8C, IR (KBr, cmꢁ1):
1H NMR (400 MHz, DMSO-d6):
J = 8 Hz, Ar), 7.22–7.24 (2H, d, J = 8 Hz, Ar), 7.95–8.24 (6H, m, Ar
and NH2), 9.51 (1H, s, OH); 13C NMR (100 MHz, DMSO-d6):
61.4,
nmax 3372, 3259, 2197, 1663, 1568;
d
6.02 (1H, s), 6.70–6.72 (2H,d,
Table 1
The model reaction was carried out by various catalystsa
d
62.6, 115.0, 116.2, 126.6, 127.3, 128.3, 128.6, 128.8, 133.6, 134.5,
150.5, 153.5, 156.6, 157.6. Anal. Calcd. for C18H12N4O3: C 65.06, H
3.64, N 16.85, Found: C 64.98, H 3.57, N 16.80, MS (EI) (m/z): 332.
3-Amino-1-(4-chlorophenyl)-5,10-dihydro-5,10-dioxo-1H-pyr-
azolo[1,2-b]phthalazine-2-carbonitrile (5g): Yellow powder; mp
Entry
Catalyst
Mol%
Time (min)
Yieldb (%)
1
2
FeCl3
MgO
15
10
10
20
10
10
15
5
80
80
40
50
35
45
55
61
75
82
93
92
3
GaCl3
Et3N
100
180
45
4
5
CuCl
270–272 8C, IR (KBr, cmꢁ1):
NMR (400 MHz, DMSO-d6):
n
d
max 3375, 3259, 2194, 1659, 1655; 1H
6.14 (1H, s, CH), 7.39–7.52 (4H, m, Ar),
6
CuBr
45
7
CuI
40
7.94–8.26 (6H, m, Ar and NH2); 13C NMR (100 MHz, DMSO-d6):
d
8
CuI NPs
CuI NPs
CuI NPs
25
61.3, 62.8, 116.3, 127.2, 127.7, 128.8, 129.3, 133.3, 134.3, 135.1,
137.9, 151.2, 154.1, 157.2. Anal. Calcd. for C18H11N4O2Cl: C 61.64,
H 3.16, N 15.97, Found: C 61.51, H 3.13, N 16.01, MS (EI) (m/z): 350.
Ethyl 3-amino-5,10-dihydro-1(4-isopropylphenyl)-5,10-dioxo-
1H-pyrazolo[1,2-b]phthalazine-2-carboxylate (5i): Yellow powder;
9
10
15
25
10
25
a
Phthalic anhydride (1 mmol), hydrazine monohydrate (1 mmo1), benzaldehyde
(1 mmol) and malononitrile (1 mmol).
b
Isolated yield.

J. Safaei-Ghomi et al. / Chinese Chemical Letters 25 (2014) 401–405
403
Fig. 1. SEM images of CuI NPs before use (a), after reuse of three times (b).
mp 231–233 8C, IR (KBr, cmꢁ1):
1H NMR (400 MHz, DMSO-d6):
6H, J = 8 Hz, 2CH3), 2.69–2.82 (m, 1H, CH), 3.97 (m, 2H, CH2), 6.03 (s,
1H), 7.13–7.36 (4H, m, Ar),7.94–8.25 (6H, m); 13C NMR (100 MHz,
n
max 3432, 3324, 1699,1665, 1530;
determined the best level for the synthesis of 1H-pyrazolo[1,2-
b]phthalazine-5,10-dione derivatives was using CuI nanoparticles
at 10 mol% which gave excellent yields of product. When 5, 10 and
15 mol% of CuI nanoparticles were used, the yields were 82%, 92%
and 90%, respectively. Therefore, 10 mol% of CuI nanoparticle was
suitable and an excessive amount of catalyst did not increase the
yields significantly. The effect of temperature was also evaluated
for the model reaction (Table 3). Almost all reactions worked well
with a variety of aromatic aldehydes and the desired compounds
were obtained in good to high yields within short reaction time
(Table 4).
d
1.00 (t, 3H, J = 8 Hz, CH3), 1.14 (d,
DMSO-d6):
d 14.1, 23.8, 33.0, 58.4, 62.9, 81.7, 125.6, 126.6, 127.2,
128.6, 128.8, 133.5, 134.5, 137.1, 147.6, 153.0, 156.7, 164.3. Anal.
Calcd. for C23H23N3O4: C 68.14, H 5.71, N 10.36, Found: C 68.10, H
5.67, N 10.29, MS (EI) (m/z): 405.
3. Results and discussion
To optimize the experiment temperature, the mixture was
heated at different temperatures ranging from 30 8C to 80 8C
(Table 3). The time of reaction was decreased when the reaction
temperature was raised from 30 8C to 70 8C. Therefore, 70 8C was
chosen as the reaction temperature for all subsequent reactions.
All the reactions reached completion within 25–35 min and
afforded good yields of products. As represented in Table 4, all
aldehydes gave the expected products at high yields, either bearing
electron-withdrawing groups or electron-donating groups under
solvent-free conditions.
The morphology and particle size of copper(I) iodide nano-
particles, was investigated by scanning electron microscopy (SEM)
before use and after reuse of three times with images shown in
Fig. 1. The SEM images show particles with diameters in the range
of nanometers. The XRD pattern of the CuI nanoparticles is shown
in Fig. 2. The results show that spherical CuI nanoparticles were
obtained with an average diameter of 10–30 nm as confirmed by
XRD analysis.
Initially, we had explored and optimized different reaction
parameters for the synthesis of 1H-pyrazolo[1,2-b]phthalazine-
5,10-diones by the four-component condensation reaction of
phthalic anhydride, hydrazine monohydrate, benzaldehyde and
Table 2
The test reaction using different solvents with CuI nanoparticles.a
malononitrile as
a model reaction. Several reactions were
Entry
Condition
Time (min)
Yieldb (%)
scrutinized using different catalysts and various solvents, such
as ethanol, acetonitrile, water, dichloromethane and solvent-free
conditions (Tables 1 and 2). Under solvent-free conditions, we
1
2
3
4
5
EtOH (reflux)
H2O (reflux)
CH3CN (reflux)
CH2Cl2
50
120
50
62
25
57
53
92
50
Solvent-free
25
a
Phthalic anhydride (1 mmol), hydrazine monohydrate (1 mmo1), benzaldehyde
(1 mmol) and malononitrile (1 mmol).
b
Isolated yield.
Table 3
Effects of temperature variation on the yield and time of the model reaction.a
Entry
Temperature (8C)
Time (min)
Yieldb (%)
1
2
3
4
5
30
40
60
70
80
180
120
45
20
35
70
90
90
25
25
a
Phthalic anhydride (1 mmol), hydrazine monohydrate (1 mmo1), benzaldehyde
(1 mmol) and malononitrile (1 mmol), under solvent-free conditions.
b
Fig. 2. The XRD pattern of CuI(I) nanoparticles (NP).
Isolated yield.

404
J. Safaei-Ghomi et al. / Chinese Chemical Letters 25 (2014) 401–405
Table 4
Synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-diones.a
Products
Aldehydes
X
Time (min)
Yield (%)
Mp (8C) [Ref]
5a
5b
5c
5d
5e
5f
2-Me-C6H4
3-Me-C6H4
4-Me-C6H4
4-iso-propyl-C6H4
4-OH-C6H4
2-thiophene
4-Cl-C6H4
CN
29
26
27
28
35
25
25
27
28
26
29
30
87
89
88
90
82
86
93
91
90
91
88
88
248–250 [40]
250–252b
CN
CN
253–255 [45]
264–266 [43]
270–272 [43]
244–246 [43]
270–272 [37]
276–278 [37]
231–233 [43]
201–203b
CN
CN
CN
5g
5h
5i
CN
C6H5
CN
4-iso-propyl-C6H4
2-Me-C6H4
4-Me-C6H4
3-Me-C6H4
COOEt
COOEt
COOEt
COOEt
5j
5k
5l
204–206 [37]
206–208b
a
Phthalic anhydride (1 mmol), hydrazine monohydrate (1 mmo1), aromatic aldehydes (1 mmol) and malononitrile or ethyl cyanoacetate (1 mmol), under solvent-free
conditions with CuI NPs.
b
The product was prepared and reported for the first time.
[14] K. Dugi, M. Mark, F. Himmelsbach, Pharmaceutical composition comprising a
4. Conclusion
pyrazole-O-glucoside derivative, WO 2009022009 A 1.
[15] S.S. El-Saka, A.H. Soliman, A.M. Imam, Synthesis, antimicrobial activity and
In this research, we described an efficient and one-pot synthesis
of 1H-pyrazolo[1,2-b]phthalazine-5,10-diones by the four-com-
ponent condensation reaction of phthalic anhydride, hydrazine
monohydrate, aromatic aldehydes and malononitrile or ethyl
cyanoacetate under solvent-free conditions. The advantages
offered by this method include, short reaction times, excellent
yields, a simple procedure, easy workup and the employment of a
cost-effective catalyst.
electron impact of mass spectra of phthalazine-1,4-dione derivatives, Afinidad
66 (2009) 167–172.
[16] L. Zhang, L.P. Guan, X.Y. Sun, et al., Synthesis and anticonvulsant activity of 6-
alkoxy-[1,2,4]triazolo[3,4-a]phthalazines, Chem. Biol. Drug Des. 73 (2009) 313–
319.
[17] C.K. Ryu, R.E. Park, M.Y. Ma, J.H. Nho, Synthesis and antifungal activity of 6-
arylamino-phthalazine-5,8-diones and 6,7-bis(arylthio)-phthalazine-5,8-diones,
Bioorg. Med. Chem. Lett. 17 (2007) 2577–2580.
[18] J. Li, Y.F. Zhao, X.Y. Yuan, J.X. Xu, P. Gong, Synthesis and anticancer activities of
novel 1,4-disubstituted phthalazines, Molecules 11 (2006) 574–582.
[19] Y. Nomoto, H. Obase, H. Takai, et al., Studies on cardiotonic agents. II. Synthesis of
novel phthalazine and 1,2,3-benzotriazine derivatives, Chem. Pharm. Bull.
(Tokyo) 38 (1990) 2179–2183.
Acknowledgment
[20] N. Watanabe, Y. Kabasawa, Y. Takase, et al., 4-Benzylamino-1-chloro-6-substi-
tuted phthalazines: synthesis and inhibitory activity toward phosphodiesterase
5, J. Med. Chem. 41 (1998) 3367–3372.
The authors are grateful to University of Kashan for supporting
this work (No. 159196/XIIV).
[21] F. Al’-Assar, K.N. Zelenin, E.E. Lesiovskaya, I.P. Bezhan, B.A. Chakchir, Synthesis and
pharmacological activity of 1-hydroxy, 1-amino-, and 1-hydrazino-substituted
2,3-dihydro-1H-pyrazolo[1,2-a]pyridazine-5,8-diones and 2,3-dihydro-1H-pyra-
zolo[1,2-b]phthalazine-5,10-diones, J. Pharm. Chem. 36 (2002) 598–603.
[22] J. Sinkkonen, V. Ovcharenko, K.N. Zelenin, et al., 1H and 13C NMR study of 1-
hydrazino-2,3-dihydro-1H-pyrazolo[1,2-a]pyridazine-5,8-diones and 1H-pyra-
zolo[1,2-b]phthalazine-5,10-diones and their ring-chain tautomerism, Eur. J.
Org. Chem. 13 (2002) 2046–2053.
[23] R.P. Jain, J.C. Vederas, Structural variations in keto-glutamines for improved
inhibition against hepatitis A virus 3C proteinase, Bioorg. Med. Chem. Lett. 14
(2004) 3655–3658.
[24] A. Kumar, M.K. Gupta, M. Kumar, L-Proline catalysed multicomponent synthesis of
3-amino alkylated indoles via a Mannich-type reaction under solvent-free con-
ditions, Green Chem. 14 (2012) 290–295.
[25] I. Ugi, A. Do¨mling, W. Ho¨rl, Multicomponent reactions in organic chemistry,
Endeavour 18 (1994) 115–122.
[26] M.M. Heravi, B. Baghernejad, H.A. Oskooie, A novel three-component reaction for
the synthesis of N-cyclohexyl-3-aryl-quinoxaline-2-amines, Tetrahedron Lett. 50
(2009) 767–769.
[27] J. Gerencser, G. Dormon, F. Darvas, Meldrum’s acid in multicomponent reaction:
applications to combinatorial and diversity-oriented synthesis, QSAR Comb. Sci.
25 (2006) 439–448.
[28] D.J. Ramon, M. Yus, Asymmetric multicomponent reactions (AMCRs): the new
frontier, Angew. Chem. Int. Ed. 44 (2005) 1602–1634.
References
[1] W.R. Vaughan, The chemistry of the phthalazines, Chem. Rev. 43 (1948) 447–508.
[2] H.W. Heine, R. Henrie, L. Heitz, S.R. Kovvali, Diaziridines III. Reactions of some 1-
alkyl- and 1,1-dialkyl-1H-diazirino[1,2-b]phthalazine-3,8-diones, J. Org. Chem.
39 (1974) 3187–3191.
[3] S. Rostamizadeh, M. Nojavan, R. Aryan, H. Sadeghian, M. Davoodnejad, A novel and
efficient synthesis of pyrazolo[3,4-d]pyrimidine derivatives and the study of their
anti-bacterial activity, Chin. Chem. Lett. 24 (2013) 629–632.
[4] N.K. Terrett, A.S. Bell, D. Brown, P. Ellis, Sildenafil (VIAGRATM), a potent and
selective inhibitor of type 5cGMP, phosphodiesterase with utility for the treat-
ment of maleerectile dysfunction, Bioorg. Med. Chem. Lett. 6 (1996) 1819–1824.
[5] S.K. Singh, P.G. Reddy, K.S. Rao, et al., Polar substitutions in the benzenesulfona-
mide ring of celecoxib afford a potent 1,5-diarylpyrazole class of COX-2 inhibitors,
Bioorg. Med. Chem. Lett. 14 (2004) 499–504.
[6] T. Nakamura, M. Sato, H. Kakinuma, et al., Pyrazole and isoxazole derivatives as
new, potent, and selective 20-hydroxy-5,8,11,14-eicosatetraenoic acid synthase
inhibitors, J. Med. Chem. 46 (2003) 5416–5427.
[7] O. Prakash, R. Kumar, V. Parkash, Synthesis and antifungal activity of some new 3-
hydroxy-2-(1-phenyl-3-aryl-4-pyrazolyl)chromones, Eur. J. Med. Chem. 43
(2008) 435–440.
[8] M.A.F. Vera-DiVaio, A.C.C. Freitas, H.C.A. Castro, et al., Synthesis, antichagasic in
vitor evaluation, cytotoxicity assays, molecular modeling and SAR/QSAR studies
of a 2-phenyl-3-(1-phenyl-1H-pyrazol-4-yl) acrylic acid benzylidene-carbohy-
drazide series, Bioorg. Med. Chem. 17 (2009) 295–302.
[9] M.J. Genin, C. Biles, B.J. Keiser, et al., Novel 1,5-diphenylpyrazole nonnucleoside
HIV-1 reverse transcriptase inhibitors with enhanced activity versus the dela-
virdine-resistant P236L mutant: lead identification and SAR of 3-and 4-substitut-
ed derivatives, J. Med. Chem. 43 (2000) 1034–1040.
[10] F. Wei, B.X. Zhao, B. Huang, et al., Design, synthesis, and preliminary biological
evaluation of novel ethyl 1-(20-hydroxy-30-aroxypropyl)-3-aryl-1H-pyrazole-5-
carboxylate, Bioorg, Med. Chem. Lett. 16 (2006) 6342–6347.
[11] Y. Xia, Z.W. Dong, B.X. Zhao, et al., Synthesis and structure-activity relationships
of novel 1-arylmethyl-3-aryl-1H-pyrazole-5-carbohydrazide derivatives as po-
tential agents against A549 lung cancer cells, Bioorg. Med. Chem. 15 (2007) 6893–
6899.
[29] L. Lu, M.L. Sui, K. Lu, Superplastic extensibility of nanocrystalline copper at room
temperature, Science 287 (2000) 1463–1466.
[30] Y.J. Song, C. Yoo, J.T. Hong, et al., Nanocrystalline copper oxide(II)-catalyzed
alkyne-azide cycloadditions, Bull. Korean Chem. Soc. 29 (2008) 1561–1564.
[31] M. Kidwai, N.K. Mishra, V. Bansal, A. Kuma, S. Mozumdar, Novel one-pot Cu-
nanoparticles-catalyzed Mannich reaction, Tetrahedron Lett. 50 (2009) 1355–
1358.
[32] A.K. Verma, R. Kumar, P. Chaudhary, et al., Cu-nanoparticles: a chemoselective
catalyst for the aza-Michael reactions of N-alkyl and N-arylpiperazines with
acrylonitrile, Tetrahedron Lett. 46 (2005) 5229–5232.
[33] A.K. Edward, L.M. Anton, S.K. Yulia, et al., Copper nanoparticles as active catalysts
in hydroxylation of phenol by hydrogen peroxide, Appl. Catal. A: Gen. 385 (2010)
62–72.
[34] J. Safaei-Ghomi, A. Ziarati, R. Teymuri, CuI nanoparticles as new, efficient and
reusable catalyst for the one-pot synthesis of 1,4-dihydropyridines, Bull. Korean
Chem. Soc. 33 (2012) 2679–2682.
[12] P.C. Lu¨, J. Sun, Y. Luo, Y. Yang, H.L. Zhu, Design, synthesis, and structure activity
relationships of pyrazole derivatives as potential FabH inhibitors, Bioorg. Med.
Chem. Lett. 20 (2010) 4657–4660.
[13] N. Cho, M. Kamaura, T. Yogo, H. Imoto, Preparation of pyrazole derivatives as
improvement of insulin resistance, WO 2009139340.
[35] J. Safaei-Ghomi, M.A. Ghasemzadeh, CuI nanoparticles: a highly active and easily
recyclable catalyst for the synthesis of 2-amino-3,5-dicyano-6-sulfanyl pyridines,
J. Sulfur Chem. 34 (2013) 233–241.

J. Safaei-Ghomi et al. / Chinese Chemical Letters 25 (2014) 401–405
405
[36] A. Ziarati, J. Safaei-Ghomi, S. Rohani, Pseudo five-component process for the
synthesis of functionalized tricarboxamides using CuI nanoparticles as reusable
catalyst, Chin. Chem. Lett. 24 (2013) 195–198.
[37] R. Ghahremanzadeh, G. Imani Shakibaei, A. Bazgir, An efficient one-pot synthesis of
1H-pyrazolo[1,2-b]phthalazine-5,10-dionederivatives,Synlett8(2008) 1129–1132.
[38] M.R. Nabid, S.J. Tabatabaei Rezaei, R. Ghahremanzadeh, A. Bazgir, Ultrasound-
assisted one-pot, three-component synthesis of 1H-pyrazolo[1,2-b]phthalazine-
5,10-diones, Ultrason. Sonochem. 17 (2010) 159–161.
synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-dione carbonitriles and carbox-
ylates, J. Mol. Catal. A: Chem. 361–362 (2012) 58–67.
[42] S.H. Song, J. Zhong, Y.H. He, Z. Guan, One-pot four-component synthesis of 1H-
pyrazolo[1,2-b]phthalazine-5,10-dione derivatives, Tetrahedron Lett. 53 (2012)
7075–7077.
[43] M. Veeranarayana Reddy, Y. Tae Jeeong, InCl3-catalyzed green synthesis of 1H-
pyrazolo[1,2-b]phthalazine-5,10-diones under solvent-free conditions, Tetrahe-
dron Lett. 54 (2013) 3546–3549.
[39] D.S. Raghuvanshi, K.N. Singh, A highly efficient green synthesis of 1H-pyra-
zolo[1,2-b]phthalazine-5,10-dione derivatives and their photophysical studies,
Tetrahedron Lett. 52 (2011) 5702–5705.
[44] Y. Jiang, S.Y. Gao, Z.D. Li, X.X. Jia, Y.L. Chen, Cauliflower-like CuI nanostructures:
green synthesis and applications as catalyst and adsorbent, Mater. Sci. Eng. B 176
(2011) 1021–1027.
[40] H.R. Shaterian, M. Mohammadnia, Mild basic ionic liquids catalyzed new four-
component synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-diones, J. Mol. Liq.
173 (2012) 55–61.
[41] G. Karthikeyan, A. Pandurangan, Post synthesis alumination of KIT-6 materials
with la3d symmetry and their catalytic efficiency towards multicomponent
[45] A. Azarifar, R. Nejat-Yami, D. Azarifar, Nano-ZnO: an efficient and reusable
catalyst for one-pot synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-diones
and pyrazolo[1,2-a][1,2,4]triazole-1,3-diones, J. Iran. Chem. Soc. 10 (2013)
297–306.