Synthesis, analgesic and anti-inflammatory activities of some novel pyrazolines derivatives

Article abstract of DOI:10.1016/j.bmcl.2010.04.082

In search for a new analgesic and anti-inflammatory agent with improved potency, we designed and synthesized a series of 3,2-(4,5-dihydro-5-(4- morphilinophenyl)-1H-pyarazol-3-yl)phenols 6(a-g) and its N-phenylpyrazol-1- carbothioamide 7(a-g) by Claisan-Schmidt condensation followed by the reaction of hydrazine hydrate. All the synthesized compounds were assayed for their in vivo analgesic and anti-inflammatory activities. All the compounds synthesized showed the potential to demonstrate analgesic and anti-inflammatory activity, of particular interest compounds 6a, 6b, 6g, 7a, 7d and 7g were found comparable to Diclofenac.

Full text of DOI:10.1016/j.bmcl.2010.04.082

Bioorganic & Medicinal Chemistry Letters 20 (2010) 3721–3725
Contents lists available at ScienceDirect
Bioorganic & Medicinal Chemistry Letters
journal homepage: www.elsevier.com/locate/bmcl
Synthesis, analgesic and anti-inflammatory activities of some novel
pyrazolines derivatives
*
Ratnadeep S. Joshi, Priyanka G. Mandhane, Santosh D. Diwakar, Sanjay K. Dabhade, Charansingh H. Gill
Department of Chemistry, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad 431 004, India
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 28 November 2009
Revised 8 April 2010
Accepted 19 April 2010
Available online 24 April 2010
In search for a new analgesic and anti-inflammatory agent with improved potency, we designed and
synthesized a series of 3,2-(4,5-dihydro-5-(4-morphilinophenyl)-1H-pyarazol-3-yl)phenols 6(a–g) and
its N-phenylpyrazol-1-carbothioamide 7(a–g) by Claisan–Schmidt condensation followed by the reaction
of hydrazine hydrate. All the synthesized compounds were assayed for their in vivo analgesic and anti-
inflammatory activities. All the compounds synthesized showed the potential to demonstrate analgesic
and anti-inflammatory activity, of particular interest compounds 6a, 6b, 6g, 7a, 7d and 7g were found
comparable to Diclofenac.
Keywords:
Analgesic
Anti-inflammatory activity
Pyrazolines
Ó 2010 Elsevier Ltd. All rights reserved.
N-phenylpyrazol-1-carbothioamide
Pain is a disagreeable and subjective sensation resulting from a
harmful sensorial stimulation that alerts the body about a current
or potential damage to its tissues or organs. Despite the painful
sensation, which can be efficiently solved by the removal of the
main reason, the pain-causing stimulus cannot always be either
easily defined or quickly removed. Contemporary analgesics, like
opiates and nonsteroidal anti-inflammatory drugs have some lim-
itations in clinical use, such as gastrointestinal (GI) haemorrhage
and ulceration, addiction, tolerance especially for opiates.1 There-
fore, medicinal research for the development of safer and more
effective anti-inflammatory agents are a great deal of interest for
many researchers.
2-Pyrazoline ring system has attracted significant interest in
medicinal chemistry over the past few decades. Scaffolds contain-
ing the 2-pyrazoline (4,5-dihydropyrazole) heterocyclic have dem-
onstrated a wide range of biological activity viz. anti-inflammatory
activity,2–4 anticancer activity,5 CB1 receptor antagonism for obes-
ity,6 antidepressant7 and antidiabetic.8
Literature survey revealed that many pyrazoline derivatives
have found their clinical application as NSAIDS. Antipyrine (a),
2,3-dimethyl-1-phenyl-3-pyrazolin-5-one, was the first pyrazoline
derivative used in the treatment of pain and inflammation. Phenyl
butazone (b) and its potent metabolite celocoxib (c), a prototype of
pyrazolinedione NSAIDs, are potent anti-inflammatory agents.
However their use became restricted due to their GI side effects.9
Besides these some pyrazoline derivatives (d) and (e) are also
reported in literature as having potent anti-inflammatory
activity.10,11
O
SO2NH2
O
N
N
N
N
N
N
F3C
O
(a) Antipyrine
(b) Phenyl butazone
Cl
(c) Celocoxib
H
H
H
H
H
NH
H
NH
N
N
O
O
(d)
(e)
N-Functionalized morpholine derivatives exhibit diversified
biological activities such as antidiabetic,12 antiemetic13,14 platelet
aggregation inhibitors15 inflammatory migraine and asthma.16
4-Phenyl morpholine derivatives are reported to possess antimi-
crobial,17 anti-inflammatory, central nervous system activities18
also posses the anti-Alzheimer’s diseases activity.19
In view of these observations and in continuation of our re-
search programme on the synthesis of five-membered heterocyclic
compounds,20,21 we report herein the synthesis of some new pyr-
azoline derivatives, which have been found to possess an interest-
ing profile of analgesic and anti-inflammatory activity.
The reaction of morpholine (2) with 4-fluorobenzaldehyde (1) to
gave 4-(morpholin-4-yl)benzaldehyde (3) (Scheme 1).22 (E)-1-(2-
Hydroxyphenyl)-3-(4-morpholinophenyl)prop-2-en-1-one 5(a–g)
* Corresponding author. Tel.: +91 240 2403311; fax: +91 240 2400291.
E-mail address: prof_gill@rediffmail.com (C.H. Gill).
0960-894X/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved.
doi:10.1016/j.bmcl.2010.04.082

3722
R. S. Joshi et al. / Bioorg. Med. Chem. Lett. 20 (2010) 3721–3725
R1
the synthesized compounds were characterized by their physical
R2
R3
OH
O
and spectral data (IR, 1H NMR, Mass) and confirmed the structures
of novel compounds.
O
CHO
These newly synthesized scaffolds were screened for analgesic
and anti-inflammatory activities against mice and rat. Compounds
6b, 6g, 7d and 7g exhibited equipotent analgesic activity as com-
pared to other tested scaffolds and 6a, 6g, 7d and 7g shows the
good anti-inflammatory activity as compared to other compounds.
Compounds 6d, 6g, 7d and 7g were halogen containing scaffold, so
we have confirmed that halogen containing derivatives shows the
better activity. We embarked on a hit-to-lead exploration program
focus on related scaffolds thus our aim was to explore SAR trends
and to find out the lead for further optimization.
The structure of 5d is interpreted from spectroscopic data. IR
spectra of compound 5d reveals absorption band in the region
3210 cmꢀ1 corresponding to –OH stretching of phenolic broad
bands because of ring closure. In the 1H NMR spectra of 5d exhibit
each of the olefinic protons as a doublet at d = 6.90–6.93 and 7.89–
7.93 regions with a mutual coupling constant value J = 15.24 Hz.
These observed coupling constant values indicate the presence of
E,E0-configuration form the structure, the two triplets at 3.29 and
3.86 of morpholine ring. The phenolic –OH is highly deshielded
and appears at 12.97 ppm.
4(a-g)
II
CHO
N
O
I
N
H
2
F
1
3
R1
R1
O
O
R2
R3
R2
R3
OH
N
OH
N
N
III
5(a-g)
O
NH
R1
O
R2
R3
OH
N
N
R1=H, R2=H, R2=H,
R1=H, R2=H, R2=CH3,
IV
R1=CH3, R2=H, R2=CH3,
R1=H, R2=H, R2=Cl,
R1=Cl, R2=H, R2=Cl,
R1=H, R2=CH3, R2=Cl,
R1=H, R2=H, R2=Br,
N
NH
S
IR spectra of compounds 6c reveals absorption band in the re-
gions 3428 cmꢀ1 corresponding to –OH stretching of phenolic
broad bands because of ring closure. The band at 1500–1600 cmꢀ1
corresponds to the –C@N stretching. 1H NMR spectra of 6c reveals
the presence of two un-equivalent protons of a methylene group at
d = 3.04–3.16 and 3.43–3.49 coupled with each other and in turn
with the vicinal methane proton (H-5) at t = 4.80–4.85. It has also
been noticed that, the up field shifted proton of methylene residue
coupled with the vicinal methane one (H-5) with a coupling con-
stant value J = 8.86–16.48 Hz indicating the presence of trans-con-
figuration. In other words, this mentioned proton is located cis to
the aryl group attached to the pyrazolines C-5. Also, the coupling
constant value between the downfield shifted proton of methylene
function and the vicinal methine proton (H-5) J = 8.76–10.6 Hz
supports this assumption.
Scheme 1. Reagents and conditions: (I) neat 100 oC; (II) ethanol, KOH at 25 oC; (III)
N2H4ꢁH2O, acetic acid, ethanol, reflux; (IV) phenylisothiocyanate, triethylamine in
diethyl ether at 25 oC.
were synthesized by Claisen–Schimdt condensation23,24 by treating
4-(morpholin-4-yl)benzaldehyde (3) with substituted 2-hydroxy
acetophenones 4(a–g) in dilute ethanolic solution of potassium
hydroxide at ambient temperature. Further 3,2-(4,5-dihydro-5-(4-
morphilinophenyl)-1H-pyarazol-3-yl)phenols 6(a–g)25 were pre-
pared by reacting (E)-1-(2-hydroxyphenyl)-3-(4-morpholinophe-
nyl)prop-2-en-1-one 5(a–g) with hydrazine hydrate in the
presence of acetic acid and ethanol, followed by the reaction of
phenylisothiocyanate at room temperature with 3,2-(4,5-dihydro-
5-(4-morphilinophenyl)-1H-pyarazol-3-yl)phenol 6(a–g) which
gave corresponding 4,5-(dihydro-3(2-hydroxyphenyl)-5-(4-mor-
phinophenyl)-N-phenylpyrazol-1-carbothioamide26,27 7(a–g). All
IR spectra of compound 7b reveals absorption bands in the re-
gion 3423 cmꢀ1 corresponding to –OH stretching of phenolic broad
band because of ring closure. Stretching frequency of –C@S bond
Table 1
Analgesic activity by acetic acid induced writhing response in mice and anti-inflammatory activity of against carrageenan induced rat paw edema model in rats of pyrazoline and
its derivatives
Entry
Number of writhings SEM
Increase in paw volume ml SEM after carrageenan administration
2 h
3 h
4 h
24 h
Control
Diclofenac
71
08
11
10
62
53
40
57
15
12
46
38
09
47
65
13
3
2
3
2
3
4
1
3
4
2
3
4
2
3
2
3
1.49 0.20
0.18 0.03
0.73 0.11
0.87 0. 14
1.38 0.18
1.52 .0.12
1.41 0.22
1.56 0.12
0.86 0.15
0.82 0.14
1.52 0.21
1.41 0.14
0.64 0.10
1.49 0.12
1.42 0.11
0.87 0.12
1.64 0.15
0.18 0.015
0.59 0.12
0.85 0.14
1.57 0.12
1.60 0.18
1.46 0.11
1.62 0.16
0.52 0.14
0.62 0.18
1.60 0.12
1.81 0.16
0.72 0.14
1.47 0.13
1.53 013
0.69 0.13
1.57 14
1.92 0.12
0.03 0.01
0.68 0.10
0.79 0.12
1.92 0.12
1.92 0.18
1.72 0.18
193 0.14
0.98 0.12
0.94 0.11
1.92 0.21
1.73 0.18
0.86 0.12
1.92 0.18
1.92 0.19
0.92 0.16
0.18 0.02
0.69 0.11
0.96 0.10
1.53 0.18
1.61 0.12
1.75 0.15
163 0.11
0.64 0.10
0.84 0.14
1.43 0.18
1.63 0.18
0.72 0.12
1.52 0/17
1.57 0.16
0.91 0.17
6a
6b
6c
6d
6e
6f
6g
7a
7b
7c
7d
7e
7f
7g
SEM—standard error mean; N = 6.
*
**
p <0.05.
p <0.01.
***p <0.001.

R. S. Joshi et al. / Bioorg. Med. Chem. Lett. 20 (2010) 3721–3725
3723
appears at 1200–1300 cmꢀ1
.
1H NMR spectra of the compound 7b
N-substituted pyrazolines were found to be comparable with
Diclofenac. 3-(5-Chloro-2-hydroxyphenyl)-4,5-(dihydro-5-(4-mor-
phinophenyl)-N-phenylpyrazol-1-carbothio-amide (7d) was found
to be equipotent with Diclofenac. All data were analyzed by
one-way ANOVA test followed by Dunnet’s test in the acetic acid
induced writhing model.
HA, HB and HX protons of pyrazoline ring were observed as doublet
of doublet at 3.12–3.26 (JAB: 17.8 Hz), 3.87–3.90 (JAX: 11.48 Hz) and
6.07–6.11 ppm (JBX: 11.36–11.4 Hz), respectively. An N–H proton
of the thiocarbonyl group was observed at 9.4 ppm generally as
broad band.
To determine the analgesic activity28 by using acetic acid in-
duced writhing response in mice.29 All the compounds were tested
with the control sample and reference drug Diclofenac. Analgesic
activity was expressed as pain response in the mice as the number
of writhing. These compounds inhibited the peripheral pain re-
sponse in the mice as the number of writhing was found to be less
than the control group of vehicle treated animals.
The result is summarized in Table 1 and Figure 1. In tested com-
pounds compound 6a, 6b, 6g, 7a, 7d and 7g were found to be active
after comparing with Diclofenac. Compounds 6a, 6b and 6g having
pyrazoline derivative and compounds 7a, 7d and 7g having
To determine the anti-inflammatory activity by using carra-
geenan induced rat paw edema in rats.30 The effect of synthesized
compounds and reference drug on paw edema induced by carra-
geen have shown in Table 1 and Figure 2. The subplantar injection
of carrageenan in control rats induced in increase paw volume over
24 h. The change in paw volume in the rats injected with carra-
geenan indicates that these four compounds were able to inhibit
the change in paw volume at third and fourth hour after the carra-
geenan injection providing an innuendo towards its probable
mechanism of action. Since prostaglandins are secreted at the third
and fourth hour after the injection of carrageenan, it may be
Figure 1. Effect of 6(a–g) and 7(a–h) on acetic acid induced writhing response in mice. All data were analyzed by one-way ANOVA followed by Dunnet’s test in the acetic acid
** ***
*
induced writhing model ( p <0.05, p <0.01,
p <0.001).
Figure 2. Effect of 6(a–g) and 7(a–g) on carrageenan induced rat paw edema in rats. All data were analyzed by two-way ANOVA followed by Bonferroni multiple comparison
** ***
*
test in the carrageenan induced rat paw edema model ( p <0.05, p <0.01, p <0.001).

3724
R. S. Joshi et al. / Bioorg. Med. Chem. Lett. 20 (2010) 3721–3725
15. Manfred, R.; Michael, R. S.; Wolfgang, G.; Eckhard, R. Ger. Offen DE
3729285:17, 1989; Chem. Abstr. 1989, 111, 134172.
16. (a) Varma, R. S.; Prakash, R.; Prasad, C. R. J. Chem. Soc. Pak. 1986, 8, 17; (b)
Hester, J. B.; Nidy, E. G.; Perricone, S. C.; Poel, T. J. PCT Int. Appl. 2001,
W00144188.
17. (a) Misra, V. S.; Singh, S.; Agarwal, R.; Chaudhary, K. C. J. Chem. Soc. Pak. 1981, 3,
209; (b) Verma, M. G.; Sharma, V. R.; Saxena, A. K.; Bhalla, T. N.; Sinha, J. N.;
Bhargava, K. P. Pharmacol. Res. Commun. 1984, 16, 9.
18. (a) Agarwal, R.; Agarwal, C.; Singh, S.; Misra, V. S. J. Chem. Soc. Pak. 1984, 6, 84;
(b) Agarwal, R.; Chaudhary, K. C.; Misra, V. S. J. Indian Chem. 1983, 22B, 308; (c)
Varma, R. S.; Prakash, C.; Prasad, R. J. Chem. Soc. Pak. 1986, 8, 117.
19. Ucar, G.; Gohanb, N.; Yesilada, A.; Altan, B. A. Neurosci. Lett. 2005, 382, 327.
20. (a) Joshi, R. S.; Mandhane, P. G.; Diwakar, S. D.; Gill, C. H. Ultrason. Sonochem.
2010, 17, 298; (b) Kale, R. P.; Jadhav, G. R.; Shaikh, M. U.; Gill, C. H. Tetrahedron
Lett. 2009, 50, 1780; (c) Jadhav, G. R.; Kale, R. P.; Shaikh, M. U.; Gill, C. H. Chin.
Chem. Lett. 2009, 20, 292; (d) Jadhav, G. R.; Kale, R. P.; Shaikh, M. U.; Gill, C. H.
Chin. Chem. Lett. 2009, 20, 535.
21. (a) Diwakar, S. D.; Bhagwat, S. S.; Shingare, M. S.; Gill, C. H. Bioorg. Med. Chem.
Lett. 2008, 18, 4678; (b) Jadhav, G. R.; Shaikh, M. U.; Shingare, M. S.; Gill, C. H. J.
Heterocycl. Chem. 2008, 45, 1287; (c) Jadhav, G. R.; Shaikh, M. U.; Kale, R. P.;
Ghawalkar, A. R.; Nagargoje, D. R.; Shiradkar, M.; Gill, C. H. Bioorg. Med. Chem.
Lett. 2008, 16, 6244; (d) Jadhav, G. R.; Shaikh, M. U.; Kale, R. P.; Shiradkar, M.;
Gill, C. H. Eur. J. Med. Chem. 2009, 44, 2930.
22. Synthesis of 4-(morpholin-4-yl)benzaldehyde (3): The mixture of 4-
fluorobenzaldehyde (0.8113 mol) was refluxed at 120 °C in the appropriate
amount of the morpholine; the progress of the reaction was monitor by TLC.
After completion of the reaction, the reaction mass was poured on ice cold
water (50 ml) to give white solid, which was filtered, dried and recrystallized
in ethanol give the pure solid; yield: 78% (white solid); mp 132–133 °C; FTIR
(KBr) cmꢀ1: 3050 (Ar C–H); 2980 (aldehyde stretching –CHO); 1695 (CH@O);
1153 (C–O–C); 1H NMR chemical shifts at (400 MHz, CDCl3, d ppm): 3.42 (t, 4H,
CH2); 3.92 (t, 4H, CH2); 6.78 (dd, 2H, Ar-H); 7.52 (dd, 2H, Ar-H); ES-MI (m/z)
192 (M+).
postulated that the compounds may act through inhibition of the
arachidonic acid pathway. The obtained results were subjected to
statistical analysis by two-way ANOVA followed by Bonferroni
multiple comparison test in the carrageenan induced rat paw ede-
ma model. Results revealed that all the tested compounds showed
a variant significant anti-inflammatory activity at the administered
dose (1000 mg/kg po) compared to Diclofenac. It is obvious that
most of the tested N-phenylpyrazol-1-carbothioamide 7a–g re-
vealed relatively higher activities than their starting pyrazolines
6a–g.
The results also revealed that in some cases, the presence of the
plane pyrazolines and N-phenylpyrazol-1-carbothioamide having
the anti-inflammatory activity. Also the 2-(4,5-dihydro-5-(4-mor-
philinophenyl)-1H-pyarazol-3-yl)-4-methylphenol and 3-(5-chloro-
2-hydroxyphenyl)-4,5-(dihydro-5-(4-morphinophenyl)-N-phenyl-
pyrazol-1-carbothioamide having enhance the anti-inflammatory
activity. The R3 of Br having the better activity in pyrazoline and
N-phenylpyrazol-1-carbothioamide. It is obvious that, there is no
direct correlation between enhancement of the anti-inflammatory
activity and the presence of electron donating and electron with-
drawing group.
We have synthesized a series of morpholine bearing pyrazo-
lines, and N-phenylpyrazol-1-carbothioamide. The investigation
of analgesic and anti-inflammatory screening data reveals that
among the 14 compounds screened six compounds showed good
analgesic and anti-inflammatory inhibition almost equivalent to
the standard. Hence, it is concluded that there is ample scope for
further study in developing these as good lead compounds.
23. (a) Dawey, W.; Tivey, D. J. J. Chem. Soc. 1958, 16, 1320; (b)Organic Synthesis;
Gillman, H., Blatt, A. H., Eds.; Wiley: New York, 1967; Vol. I, p 78; (c) Mehra, H.
S. J. Indian Chem. Soc. 1968, 45, 178.
24. Synthesis of substituted (E)-1-(2-hydroxyphenyl)-3-(4-morpholinophenyl)prop-2-
en-1-one: Aqueous KOH (1.23 g, 0.0022 mol) was added to a suspension of
1-(2-hydroxyphenyl)ethanone 4(a–g) (1 g, 0.0037 mol) and 4-(morpholin-4-
yl)benzaldehyde 3 (1.44 g, 0.0037 mol) in 10 ml ethanol. The mixture was
stirred at 25 °C temperature for overnight and further the mixture was poured
into water and acidified with HCl (2 M) till, pH 4. The solid product separated
out was filtered off and recrystallized from ethanol. Compound 5a: yield: 67%
(yellow solid); mp 117–118 °C; FTIR (KBr) cmꢀ1: 3233 (Ar-OH); 1688 (–CO–);
1211 (C–O–C); 1H NMR chemical shifts at (400 MHz, CDCl3, d ppm): 2.32 (s,
3H); 3.30 (t, 4H, CH2); 3.88 (t, 4H, CH2); 6.89 (dd, J = 5.6 Hz, 3H, Ar-H); 7.305
(dd, J = 2, 1H, Ar-H); 7.52 (d, J = 15.4 Hz, 1H, olefinic); 7.62 (d, J = 8.4 Hz, 2H, Ar-
H); 7.68 (s, 1H, Ar-H); 7.90 (d, J = 15.6 Hz, 1H, olefinic); 12.84 (s, 1H, Ar-OH);
ES-MI (m/z) 324 (M+). Compound 5d: yield: 65% (yellow solid); mp 110–
111 °C; FTIR (KBr) cmꢀ1: 3210 (Ar-OH); 1680 (–CO–); 763 (Ar-Cl); 1143 (C–O–
C); 1H NMR chemical shifts at (400 MHz, CDCl3, d ppm): 3.29 (t, 4H, CH2); 3.86
(t, 4H, CH2); 6.90 (d, J = 2.54 and 11.44 Hz, 2H, Ar-H); 6.98 (d, J = 8.92 and
18.88 Hz, 1H, olefinic); 7.42 (t, J = 2.04 and 8.44 Hz, 2H, Ar-H); 7.63 (d, J = 2.72
and 9.88 Hz, 2H, Ar-H); 7.86 (d, J = 2.56, 1H, Ar-H); 7.93 (d, J = 15.24 Hz, 1H,
olefinic); 12.97 (s, 1H, Ar-OH); ES-MI (m/z) 342 (M+).
Acknowledgments
The authors are thankful to University Grants Commission, New
Delhi, for financial support and to the Head, Department of Chem-
istry, Dr. Babasaheb Ambedkar Marathwada University, Auranga-
bad, for his valuable support and laboratory facilities, and
Principal, Maulana Azad College, Aurangabad for pharmacological
study.
References and notes
1. Vongtau, H. O.; Abbah, J.; Mosugu, O.; Chindo, B. A.; Ngazal, I. E.; Salawu, A. O.;
Kwanashie, H. O.; Gamaniel, K. S. J. Ethnopharmacol. 2004, 92, 317.
2. Flora, F. B.; Hanaa, M. H.; Adel, S. G. Bioorg. Med. Chem. 2006, 14, 3929.
3. Bansal, E.; Srivatsava, V. K.; Kumar, A. Eur. J. Med. Chem. 2001, 36, 81.
4. (a) Rathish, I. G.; Javed, K.; Ahmad, S.; Bano, S.; Alam, M. S.; Pillai, K. K.; Singh,
S.; Bagchi, V. Bioorg. Med. Chem. Lett. 2009, 19, 255; (b) Amir, M.; Kumar, H.;
Khan, S. A. Bioorg. Med. Chem. Lett. 2008, 18, 918.
5. Coleman, P. J.; Schreier, J. D.; Cox, C. D.; Fraley, M. E.; Garbaccio, R. M.; Buser, C.
A.; Walsh, E. S.; Hamilton, K.; Lobell, R. B.; Rickert, K.; Tao, W.; Diehl, R. E.;
South, V. J.; Davide, J. P.; Kohl, N. E.; Yan, Y.; Kuo, L.; Prueksaritanont, T.; Li, C.;
Mahan, E. A.; Fernandez-Metzler, C.; Salata, J. J.; Hartman, G. D. Bioorg. Med.
Chem. Lett. 2007, 17, 5390.
6. Lange, J. H. M.; Van Stuivenberg, H. H.; Veerman, W.; Wals, H. C.; Stork, B.;
Coolen, H. K. A. C.; McCreary, A. C.; Adolfs, T. J. P.; Kruse, C. G. Bioorg. Med. Chem.
Lett. 2005, 15, 4794.
7. Chimenti, F.; Maccioni, E.; Secci, D.; Bolasco, A.; Chimenti, P.; Granese, A.;
Befani, O.; Turini, P.; Alcaro, S.; Ortuso, F.; Cirilli, R.; La Torre, F.; Cardia, M. C.;
Distinto, S. J. Med. Chem. 2005, 48, 7113.
8. (a) Jovanovic, S. V.; Steenken, S.; Tosic, M.; Marjanovic, B.; Simic, M. G. J. Am.
Chem. Soc. 1994, 116, 4846; (b) Bors, W.; Heller, W.; Michel, C.; Stettmaier, K. In
Handbook of Antioxidants; Adenas, E., Packer, L., Eds.; Marcel Dekker: New York,
1996; p 409.
9. William, D. A.; Lemke, T. L. Foye’s Principle of Medicinal Chemistry, 5th ed.;
Williams and Wilkins: Lippincott, Philadelphia, 2002. p 751.
10. Khode, S.; Maddi, V.; Aragade, P.; Palkar, M.; Ronad, P. K.; Mamledesai, S.;
Thippeswamy, A. H. M.; Satyanarayana, D. Eur. J. Med. Chem. 2009, 44, 1682.
11. Mohammad, A.; Amir, A. Bioorg. Med. Chem. Lett. 2006, 16, 2812.
12. Manfred, R.; Michael, M.; Robert, S.; Wolfgang, G. Eur. Patent. Appl EP
334146:28, 1989; Chem. Abstr. 1989, 112, 178999.
25. Synthesis of substituted 3,2-(4,5-dihydro-5-(4-morphilinophenyl)-1H-pya-
razol-3-yl)phenol: (0.1 g, 0.00028 mol) of chalcones 5(a–g) was dissolved in
5 ml of ethanol. To this reaction mixture, (0.1 ml, 0.0031 mol) of hydrazine
hydrate was added. The reaction mass was heated at reflux for 3 h and then
1 ml gl. acetic acid was added and heating was continued further for 2 h. After
completion of reaction (monitor by TLC), reaction mixture was cooled to room
temperature. At the end 10 ml cold water was slowly added to the flask and the
separated product was filtered off and washed with cold water for several
times. The final compound was recrystallized from ethanol. Compound 6a:
yield: 78% (white solid); mp 143–144 °C. FTIR (KBr) cmꢀ1: 3387 (Ar-OH); 1530,
1480 (C@N); 1209 (C–O–C); 1H NMR chemical shifts at (400 MHz, CDCl3, d
ppm): 3.22 (dd, J = 9.2 and 15.8 Hz, 1H, CH2 pyrazoline); 3.12 (t, 4H, CH2); 3.49
(dd, J = 9.2 and 15.8 Hz, 1H, CH2 pyrazoline); 3.76 (t, 4H, CH2); 4.62 (t, J = 2.8
and 11.2 Hz, 1H, C5H); 6.27 (br s, 1H, NH); 7.10 (d, J = 12.1 Hz, 2H, Ar-H); 7.21
(d, J = 9.8 Hz, 1H, Ar-H); 7.32 (d, J = 2.8 Hz, 1H, Ar-H); 7.42 (t, J = 2.8 and 9.2 Hz,
2H, Ar-H); 7.42 (s, 1H, Ar-H); 11.00 (s, 1H, Ar-OH); ES-MI (m/z) 324 (M+1).
Compound 6b: yield: 78% (white solid); mp 92–93 °C; FTIR (KBr) cmꢀ1: 3387
(Ar-OH); 1567, 1509 (C@N); 1132 (C–O–C); 1H NMR chemical shifts at
(400 MHz, CDCl3, d ppm): 2.33 (s, 3H); 3.07 (dd, J = 8.32 and 16.48 Hz, 1H,
CH2 pyrazoline); 3.15 (t, 4H, CH2); 3.52 (dd, J = 10.8 and 16.4 Hz, 1H, CH2
pyrazoline); 3.86 (t, 4H, CH2); 4.82 (t, J = 8.4 and 10.4 Hz, 1H, C5H); 5.86 (br s,
1H, NH); 6.70 (d, J = 8.0 Hz, 1H, Ar-H); 6.86 (s, 1H, Ar-H); 6.88 (d, J = 8.4 Hz, 2H,
Ar-H); 7.02 (d, J = 8.0 Hz, 1H, Ar-H); 7.33 (t, J = 3.2 and 8.8 Hz, 2H, Ar-H); 10.98
(s, 1H, Ar-OH); ES-MI (m/z) 338 (M+). Compound 6c: yield: 80% (white solid);
mp 98–99 °C; FTIR (KBr) cmꢀ1: 3428 (OH); 1543, 1505 (C@N); 1220 (C–O–C);
1H NMR chemical shifts at (400 MHz, CDCl3, d ppm): 2.33 (s, 6H); 3.04 (dd,
J = 8.32 and 16.48 Hz, 1H, CH2 pyrazoline); 3.16 (t, 4H, CH2); 3.43 (dd, J = 8.32
and 16.48 Hz, 1H, CH2 pyrazoline); 3.87 (t, 4H, CH2); 4.85 (t, J = 8.86 and
18.88 Hz, 1H, C5H); 5.94 (br s, 1H, NH); 6.90 (t, J = 8.6 and 12.84 Hz, 3H, Ar-H);
7.25 (d, J = 1.36 and 10.08 Hz, 3H, Ar-H); 10.89 (s, 1H, Ar-OH); ES-MI (m/z) 371
13. Hale, J. J.; Mills, S. G.; MacCross, M.; Dorn, C. P.; Finke, P. E.; Budhu, R. J. J. Med.
Chem. 2000, 43, 1234.
14. Dorn, C. P.; Hale, J. J.; MacCoss, M.; Mills, S. G. U.S. Patent 5,691,336:82, 1997;
Chem. Abstr. 1997, 128, 48231.
(M+). Compound 6d: yield: 78% (white solid); mp 107–109 °C; FTIR (KBr) cmꢀ1
:

R. S. Joshi et al. / Bioorg. Med. Chem. Lett. 20 (2010) 3721–3725
3725
3430 (Ar-OH); 1570, 1512 (C@N); 778 (Ar-Cl); 1165 (C–O–C); 1H NMR
chemical shifts at (400 MHz, CDCl3, d ppm): 3.12 (dd, J = 10.8 and 16.8 Hz,
1H, CH2 pyrazoline); 3.16 (t, 4H, CH2); 3.44 (dd, J = 10.8 and 16.8 Hz, 1H, CH2
pyrazoline); 3.84 (t, 4H, CH2); 4.87 (t, J = 2.4 and 10.8 Hz, 1H, C5H); 5.97 (br s,
1H, NH); 6.83 (d, J = 11.6 Hz, 2H, Ar-H); 6.94 (d, J = 9.2 Hz, 1H, Ar-H); 7.17 (d,
J = 2.4 Hz, 1H, Ar-H); 7.19 (t, J = 2.8 and 9.2 Hz, 2H, Ar-H); 6.86 (s, 1H, Ar-H);
11.00 (s, 1H, Ar-OH); ES-MI (m/z) 358 (M+) 360 (M+2). Compound 6e: yield:
78% (white solid); mp 124–125 °C; FTIR (KBr) cmꢀ1: 3450 (Ar-OH); 1544
(C@N); 787 (Ar-Cl); 1298 (C–O–C); 1H NMR chemical shifts at (400 MHz, CDCl3,
d ppm): 3.18 (dd, J = 8.2 and 16.3 Hz, 1H, CH2 pyrazoline); 3.25 (t, 4H, CH2);
3.48 (dd, J = 10.2 and 15.9 Hz, 1H, CH2 pyrazoline); 3.76 (t, 4H, CH2); 4.72 (t,
J = 2.6 and 10.2 Hz, 1H, C5H); 6.21 (br s, 1H, NH); 6.90 (d, J = 10.8 Hz, 1H, Ar-H);
7.02 (d, J = 9.6 Hz, 1H, Ar-H); 7.12 (d, J = 2.6 Hz, 1H, Ar-H); 7.25 (t, J = 2.3 and
8.5 Hz, 1H, Ar-H); 7.86 (s, 1H, Ar-H); 10.67 (s, 1H, Ar-OH); ES-MI (m/z) 392 (M+)
394 (M+2). Compound 6f: yield: 82% (white solid); mp 135–136 °C; FTIR
(KBr) cmꢀ1: 3456 (Ar-OH); 1544 (C@N); 1338 (C–O–C); 762 (Ar-Cl); 1H NMR
chemical shifts at (400 MHz, CDCl3, d ppm): 1.95 (s, 3H, Ar-CH3); 3.12 (dd,
J = 7.65 and 15.98 Hz, 1H, CH2 pyrazoline); 3.34 (t, 4H, CH2); 3.54 (dd, J = 10.56
and 15.93 Hz, 1H, CH2 pyrazoline); 3.84 (t, 4H, CH2); 4.85 (t, J = 3.12 and
10.56 Hz, 1H, C5H); 6.1 (br s, 1H, NH); 7.05 (d, J = 10.22 Hz, 1H, Ar-H); 7.14 (d,
J = 1.12 Hz, 1H, Ar-H); 7. 20 (d, J = 3.25 Hz, 1H, Ar-H); 7.30 (t, J = 2.42 and
9.12, Hz, 1H, Ar-H); 7.92 (s, 1H, Ar-H); 11.24 (s, 1H, Ar-OH); ES-MI (m/z) 372
(M+) 374 (M+2). Compound 6g: yield: 75% (white solid); mp 146–147 °C; FTIR
(KBr) cmꢀ1: 3469 (Ar-OH); 1580 (C@N); 1342 (C–O–C); 794 (Ar-Cl); 1H NMR
chemical shifts at (400 MHz, CDCl3, d ppm): 3.22 (t, 4H, CH2); 3.29 (dd, J = 3.45
and 16.29 Hz, 1H, CH2 pyrazoline); 3.72 (t, 4H, CH2); 4.15 (dd, J = 10.22 and
16.29 Hz, 1H, CH2 pyrazoline); 4.54 (t, J = 7.86 and 10.46 Hz, 1H, C5H); 6.65 (br
s, 1H, NH); 7.10 (d, J = 10.21 Hz, 1H, Ar-H); 7.20 (d, J = 2.23 Hz, 1H, Ar-H); 7. 34
(d, J = 3.40 Hz, 1H, Ar-H); 7.49 (t, J = 2.46, 2H, Ar-H); 7.87 (s, 1H, Ar-H); 12.30 (s,
1H, Ar-OH); ES-MI (m/z) 402 (M+) 404 (M+2).
chemical shifts at (400 MHz, CDCl3, d ppm): 2.36 (s, 6H); 3.01 (t, 4H, CH2); 3.16
(dd, J = 3.48 and 16.6 Hz, 1H, CH2 pyrazoline); 3.53 (t, 4H, CH2); 3.82 (t,
J = 10.88 and 16.6 Hz, 1H, C5H); 6.22 (dd, J = 3.86 and 12.46 Hz, 1H, CH2
pyrazoline); 6.90 (t, J = 8.32 Hz, 2H, Ar-H); 7.04 (d, J = 8.8 Hz, 2H, Ar-H); 7.30
(dd, J = 7.2 and 8.29 Hz, 3H, Ar-H); 7.56 (t, J = 2.2 and 8.9 Hz, 1H, Ar-H); 7.77 (t,
J = 7.76 and 11.9 Hz, 2H, Ar-H); 10.23 (br s, 1H, NH); 12.02 (s, 1H, Ar-OH); ES-
MI (m/z) 506 (M+) and 505 (M). Compound 7d: yield: 75% (white solid); mp
156–157 °C. FTIR (KBr) cmꢀ1: 3354 (Ar-OH); 2987 (N–H); 1533 (C@N); 1227
(C@S); 1139 (C–O–C), 1H NMR chemical shifts at (400 MHz, CDCl3, d ppm): 3.09
(dd, J = 3.10 and 15.9 Hz, 1H, CH2 pyrazoline); 3.18 (t, 4H, CH2); 3.36 (dd,
J = 3.10 and 15.9 Hz, 1H, CH2 pyrazoline); 3.65 (t, 4H, CH2); 4.12 (t, J = 10.76
and 16.56 Hz, 1H, C5H); 6.98 (t, J = 8.32 Hz, 2H, Ar-H); 7.12 (d, J = 8.44 Hz, 2H,
Ar-H); 7.30 (dd, J = 8.43 and 8.88 Hz, 3H, Ar-H); 7.39 (t, J = 2.10 and 8.13 Hz,
2H, Ar-H); 7.67 (t, J = 7.34 and 11.9 Hz, 3H, Ar-H); 10.10 (br s, 1H, NH); 11.56 (s,
1H, Ar-OH); ES-MI (m/z) 494 (M+) and 496 (Mꢀ). Compound 7e: yield: 76%
(white solid); mp 149–149 °C; FTIR (KBr) cmꢀ1: 3410 (Ar-OH); 2946 (N–H);
1497 (C@N); 1234 (C@S); 1109 (C–O–C); 1H NMR chemical shifts at (400 MHz,
CDCl3, d ppm): 3.02 (dd, J = 3.12 and 16.13 Hz, 1H, CH2 pyrazoline); 3.30 (t, 4H,
CH2); 3.52 (dd, J = 3.12 and 16.13 Hz, 1H, CH2 pyrazoline); 3.61 (t, 4H, CH2);
3.98 (t, J = 10.67 and 16.32 Hz, 1H, C5H); 6.78 (t, J = 7.90 Hz, 2H, Ar-H); 6.92 (d,
J = 8.54 Hz, 2H, Ar-H); 7.02 (dd, J = 8.2 and 8.80 Hz, 3H, Ar-H); 7.35 (t, J = 2.40
and 8.51 Hz, 2H, Ar-H); 7.73 (t, J = 8.14 and 12.67 Hz, 2H, Ar-H); 9.56 (br s, 1H,
NH); 12.23 (s, 1H, Ar-OH); ES-MI (m/z) 527 (M+) and 529 (M+2). Compound 7f:
yield: 70% (white solid); mp 156–157 °C; FTIR (KBr) cmꢀ1: 3435 (Ar-OH); 2896
(NH); 1523 (C@N); 1215 (C@S); 1123 (C–O–C); 1H NMR chemical shifts at
(400 MHz, CDCl3, d ppm): 1.82 (s, 3H, Ar-CH3);3.09 (t, 4H, CH2); 3.21 (dd,
J = 3.23 and 15.97 Hz, 1H, CH2 pyrazoline); 3.97 (t, 4H, CH2); 4.03 (dd, J = 3.15
and 16.24 Hz, 1H, CH2 pyrazoline); 4.28 (t, J = 10.65 and 16.54 Hz, 1H, C5H);
6.12 (t, J = 7.92 Hz, 2H, Ar-H); 7.22 (d, J = 8.58 Hz, 2H, Ar-H); 7.38 (dd, J = 8.12
and 8.65 Hz, 3H, Ar-H); 7.51 (t, J = 2.21 and 8.87 Hz, 2H, Ar-H); 7.89 (t, J = 8.45
and 12.14 Hz, 2H, Ar-H); 10.54 (br s, 1H, NH); 12.14 (s, 1H, Ar-OH); ES-MI (m/z)
507 (M+) and 509 (M+2). Compound 7g: yield: 73% (white solid); mp 164–
165 °C; FTIR (KBr) cmꢀ1: 3425 (Ar-OH); 2898 (NH); 1526 (C@N); 1214 (C@S);
1163 (C–O–C); 1H NMR chemical shifts at (400 MHz, CDCl3, d ppm): 2.97 (t, 4H,
CH2); 3.13 (dd, J = 3.31 and 16.27 Hz, 1H, CH2 pyrazoline); 4.06 (t, 4H, CH2);
4.21 (dd, J = 12.65 and 15.78 Hz, 1H, CH2 pyrazoline); 4.32 (t, J = 10.25 and
15.86 Hz, 1H, C5H); 6.21 (t, J = 7.96 Hz, 2H, Ar-H); 7.23 (d, J = 8.65 Hz, 1H, Ar-
H); 7.65 (dd, J = 8.25 and 8.75 Hz, 3H, Ar-H); 7.64 (t, J = 2.25 and 8.98 Hz, 2H,
Ar-H); 7.98 (t, J = 8.35 and 12.46 Hz, 2H, Ar-H); 10.52 (br s, 1H, NH); 12.35 (s,
1H, Ar-OH); ES-MI (m/z) 537 (M+) and 539 (M+2).
26. Zuhal, O.; Zdemir, H.; Burak, K.; Bulent, G. U.; Sansal, C.; Alisx, A.; Altan, B. Eur.
J. Med. Chem. 2007, 42, 373.
27. Synthesis of substituted 4,5-(dihydro-3(2-hydroxyphenyl)-5-(4-morphilino-
phenyl)-N-phenylpyrazol-1-carbothioamide (7a–g): (0.20 g, 0.00061 mol) of
3,2-(4,5-dihydro-5-(4-morphilinophenyl)-1H-pyarazol-3-yl)phenol
6(a–g)
was dissolved in 5 ml of dry diethyl ether. To this reaction mixture, (0.083 g,
0.0061 mol) of phenylisothiocyanate was added and the reaction mass was
stirred at 25 oC temperature and then 4–5 drops of triethylamine was added
and stirred further for 4 h after completion of reaction (monitor by TLC). The
mixture was evaporated to dryness and the residue was recrystallized from
ethyl acetate. Compound 7a: yield: 72% (white solid); mp 145–146 oC. FTIR
(KBr) cmꢀ1: 3398 (Ar-OH); 2945 (N–H); 1517 (C@N); 1217 (C@S); 1126 (C–O–
C); 1H NMR chemical shifts at (400 MHz, CDCl3, d ppm): 3.08 (t, 4H, CH2); 3.12
(dd, J = 2.98 and 16.8 Hz, 1H, CH2 pyrazoline); 3.91 (t, 4H, CH2); 3.98 (t,
J = 12.18 and 16.23 Hz, 1H, C5H); 6.23 (dd, J = 2.98 and 16.8 Hz, 1H, CH2
pyrazoline); 6.92 (t, J = 8.32 Hz, 3H, Ar-H); 7.34 (dd, J = 8.14 and 8.98 Hz, 3H,
Ar-H); 7.47 (t, J = 2.11 and 9.23 Hz, 3H, Ar-H); 7.56 (t, J = 8.34 and 11.9 Hz, 2H,
Ar-H); 7.97 (d, J = 7.8 Hz, 2H, Ar-H); 9.78 (br s, 1H, NH); 10.34 (s, 1H, Ar-OH);
ES-MI (m/z) 458 (M+). Compound 7b: yield: 80% (white solid); mp 171–172 °C;
FTIR (KBr) cmꢀ1: 3423 (Ar-OH); 2980 (N–H); 1512 (C@N); 1287 (C@S) 1189
(C–O–C); 1H NMR chemical shifts at (400 MHz, CDCl3, d ppm): 2.15 (s, 3H);
3.09 (t, 4H, CH2); 3.22 (dd, J = 8.36 and 17.8 Hz, 1H, CH2 pyrazoline); 3.79 (t,
4H, CH2); 3.90 (t, J = 11.48 and 17.8 Hz, 1H, C5H); 6.11 (dd, J = 8.36 and 17.8 Hz,
1H, CH2 pyrazoline); 6.82 (t, J = 8.72 Hz, 3H, Ar-H); 7.19 (dd, J = 7.4 and 8.68 Hz,
3H, Ar-H); 7.34 (t, J = 1.8 and 9.2 Hz, 3H, Ar-H); 7.49 (t, J = 7.52 and 12.36 Hz,
2H, Ar-H); 9.45 (br s, 1H, NH); 9.74 (s, 1H, Ar-OH); ES-MI (m/z) 472 (M+).
Compound 7c: yield: 73% (white solid); mp 154–155 °C. FTIR (KBr) cmꢀ1: 3398
(Ar-OH); 3024 (N–H); 1576 (C@N); 1227 (C@S); 1223 (C–O–C); 1H NMR
28. Pharmacology: The solvents and chemicals were purchased and used as
received. Carrageenan (Sigma, St. Louis, Missouri, USA), acetic acid (S.D. Fine
chemicals, Mumbai), Diclofenac sodium (Gift sample from Symed
Pharmaceuticals, Hyderabad). Male Wistar rats (200–220 g) and Swiss albino
mice (18–22 g) were used for experiments. All animals were maintained in
standard laboratory conditions in the animal house at (temperature) 24 1 °C)
in a 12-h light:12-h dark cycle. They were fed with laboratory diet and tap
water. All experiments were carried out using six animals per group. The
compounds were tested for toxicity according to the OECD guidelines and LD50
was determined by AOT 425 guideline. The compounds were found to be safe
up to a dose of 1000 mg/kg po hence a dose of 30 mg/kg po was selected as the
therapeutic dose and all the pre clinical models were performed by
administering this dose.
29. Collier, H. D. J.; Dinnin, L. C.; Jonhson, C. A.; Scheinder, C. Br. J. Pharmacol. 1968,
32, 295.
30. (a) Henriques, M. G.; Silva, P. M.; Martins, M. A.; Flores, C. A.; Cunha, F. Q.;
Assey-Filho, J.; Cordeiro, R. S. Braz. J. Med. Biol. Res. 1987, 20, 243; (b)
Mujumdar, A. M.; Misar, A. V. J. Ethnopharmacol. 2004, 90, 11.