Synthesis and biological evaluation of some new pyrazoline substituted benzenesulfonylurea/thiourea derivatives as anti-hyperglycaemic agents and aldose reductase inhibitors

Article abstract of DOI:10.1016/j.ejmech.2014.04.046

Seventeen new pyrazoline substituted benzenesulfonylurea/thiourea derivatives (2a-q) were synthesized and characterized by elemental analysis and various spectroscopic techniques viz; IR, ¹H NMR, ¹³C NMR, and MS data. Thirteen compounds showed moderate to good anti-hyperglycaemic activity in glucose fed hyperglycaemic normal rats at the dose of 0.05 mM/kg b.w. On the basis of docking results nine compounds (2a, 2c, 2e, 2h, 2k, 2l, 2n, 2o and 2q) were evaluated for their ability to inhibit rat lens aldose reductase. Out of these six compounds (2h, 2k, 2l, 2n, 2o and 2q) were found more effective than the known ARI sorbinil. Five compounds (2h, 2k, 2l, 2n and 2o) showed significant dual action (anti-hyperglycaemic and aldose reductase inhibition).

Full text of DOI:10.1016/j.ejmech.2014.04.046

European Journal of Medicinal Chemistry 80 (2014) 209e217
Contents lists available at ScienceDirect
European Journal of Medicinal Chemistry
journal homepage: http://www.elsevier.com/locate/ejmech
Original article
Synthesis and biological evaluation of some new pyrazoline
substituted benzenesulfonylurea/thiourea derivatives as
anti-hyperglycaemic agents and aldose reductase inhibitors
Syed Ovais a, H. Pushpalatha b, G. Bhanuprakash Reddy b, Pooja Rathore a, Rafia Bashir a,
Shafiya Yaseen a, Alhamza Dheyaa a, Raed Yaseen a, Omprakash Tanwar c,
,
Mymoona Akthar c, Mohammed Samim a, Kalim Javed a
*
a Department of Chemistry, Faculty of Science, Jamia Hamdard (Hamdard University), New Delhi 110 062, India
b Biochemistry Division, National Institute of Nutrition, Hyderabad, India
c Drug Design and Medicinal Chemistry Lab, Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Jamia Hamdard (Hamdard University),
New Delhi, India
a r t i c l e i n f o
a b s t r a c t
Article history:
Seventeen new pyrazoline substituted benzenesulfonylurea/thiourea derivatives (2aeq) were synthe-
sized and characterized by elemental analysis and various spectroscopic techniques viz; IR, 1H NMR, 13
C
Received 24 December 2013
Received in revised form
6 March 2014
Accepted 14 April 2014
Available online 15 April 2014
NMR, and MS data. Thirteen compounds showed moderate to good anti-hyperglycaemic activity in
glucose fed hyperglycaemic normal rats at the dose of 0.05 mM/kg b.w. On the basis of docking results
nine compounds (2a, 2c, 2e, 2h, 2k, 2l, 2n, 2o and 2q) were evaluated for their ability to inhibit rat lens
aldose reductase. Out of these six compounds (2h, 2k, 2l, 2n, 2o and 2q) were found more effective than
the known ARI sorbinil. Five compounds (2h, 2k, 2l, 2n and 2o) showed significant dual action (anti-
hyperglycaemic and aldose reductase inhibition).
Keywords:
Benzenesulfonylurea/thiourea
Docking
Ó 2014 Elsevier Masson SAS. All rights reserved.
Aldose reductase inhibition
NADPH
Anti-hyperglycaemic
Anti-diabetic
1. Introduction
hyperglycaemia due to insulin resistance in liver and peripheral
tissues. It also occurs due to the high caloric intake, sedentary life
Diabetes mellitus (DM) is one of the most daunting challenges
posed by chronic diseases across the world and number of patients
is on rise. In 2011 there were 366 million people with diabetes
globally, and this is expected to rise to 552 million by 2030 [1]. Most
people with diabetes live in low- and middle-income countries like
India, and the numbers will increase drastically in next few years
[1]. The recently published ICMR-INDIAB national study reported
that there are 62.4 million people with type 2 diabetes (T2DM) and
77 million people with pre-diabetes in India [2]. These numbers
are projected to increase to 101 million by the year 2030 [1].
T2DM is the most common form of diabetes and has been found 90%
of all diabetes [3]. It is a debilitating disease characterized by
styles and lack of exercise. Patients with diabetes mellitus are at
high risk for developing long term complications including neu-
ropathy, nephropathy, retinopathy and cataract [4,5]. Although
strict glycemic control is expected to prevent diabetic complications
but perfect glycemic control is not always possible.
Aldose reductase (AR), the key enzyme of the polyol pathway,
has been demonstrated to play important roles in the pathogenesis
of the diabetic complications such as neuropathy, nephropathy,
retinopathy and cataract [4,5]. In hyperglycaemic conditions, aldose
reductase catalyzes an NADPH-dependent reduction of glucose to
sorbitol, which in turn is oxidised to fructose by an NADþ-depen-
dent sorbitol dehydrogenase (Fig. 1). Once sorbitol is accumulated
inside the cells, it cannot diffuse easily across the cell membrane as
a result osmotic pressure increases causing cellular damage.
Moreover depletion of NADPH and NADþ cofactors compromises
body’s anti-oxidant defence system. In addition, high blood levels
of fructose may account for increased glycation and accelerating
* Corresponding author.
E-mail addresses: kjaved@jamiahamdard.ac.in, kjavedchem@yahoo.co.in
(K. Javed).
http://dx.doi.org/10.1016/j.ejmech.2014.04.046
0223-5234/Ó 2014 Elsevier Masson SAS. All rights reserved.

210
S. Ovais et al. / European Journal of Medicinal Chemistry 80 (2014) 209e217
animals [9] and there are evidences that blockage of AR can have
beneficial effect in diabetic complications [10,11].
NADP+
NADPH
NADP+ NADH
Variety of structurally different compounds have been identified
as potent in vitro ARIs and a number of them are in clinical trials to
test their efficacy in the prevention and treatment of peripheral
neuropathy in diabetes [5,12]. They can be classified into various
groups based on their structures: acetic acid derivatives (e.g.
epalrestat, Imirestat), cyclic imides (especially spirohydantoins, e.g.
sorbinil, fidarestat) (Fig. 2) etc. Despite being structurally different,
all ARIs possess two peculiar pharmacophoric elements: i) an acidic
moiety which is able to interact with the “anion-binding site” of the
catalytic site, and ii) a lipophilic scaffold which can bind to the
highly flexible specificity pocket of the catalytic site [13]. Our in-
terest in studying the molecular determinants for binding to the
aldose reductase inhibitor site led us to study the aldose reductase
inhibitory activity of target compounds possessing benzenesulfo-
nylurea/thiourea as carboxylic acid surrogates. Besides this ben-
zenesulfoanmide derivatives have been already reported as ARI
[14,15]. The SO2 group of the benzenesulfonamide forms the
hydrogen bond with the amino acid residues of the anionic binding
site of the AR enzyme [16].
Glucose
Sorbitol
Fructose
Aldose
reductase
Sorbitol
dehydrogenase
Increased
osmotic pressure
and oxidative stress
Increased
glycation and aging
Fig. 1. Schematic diagram for polyol pathway and its side effects.
ageing [6,7] (Fig. 1). Thus inhibition of AR is one of the important
targets and its inhibition could be the key for the treatment of many
diabetic complications [8]. Aldose reductase inhibitors (ARIs) have
been shown to reduce tissue sorbitol accumulation in diabetic
Fig. 2. Structure of anti-diabetic drugs (1e7), ARIs (8e12) and pyrazoline derivatives patented as anti-diabetic and anti-obesity agents (13). Rationally designed template for
targeted compound (2aeq).

S. Ovais et al. / European Journal of Medicinal Chemistry 80 (2014) 209e217
211
In curing diabetes sulfonylureas and biguanides have repre-
sented the backbone of oral therapy in non-insulin dependent
diabetes mellitus (NIDDM) for more than 30 years [17]. An NIDDM
patient is characterized by a low response in insulin secretion to-
ward increased blood glucose levels. Sulfonylureas directly interact
thioureido group, keeping the core structure intact (Fig. 2). These
compounds (2aeq) were evaluated for anti-hyperglycaemic effects
in glucose fed hyperglycaemic normal rats. In silico molecular dock-
ing studies of these compounds (2aeq) were performed with respect
to aldose reductase. Compounds showing good docking results were
evaluated for their ability to inhibit rat lens aldose reductase.
with the
b-cells of Langerhans islets which results in increased
insulin secretion [18]. However, the main side effect of the sulfo-
nylurea therapy is weight gain [19,20].
2. Chemistry
Pyrazolines are well known and important nitrogen containing
five membered heterocyclic compounds. Pyrazolines have been
reported to show a wide range of biological activities like anti-
inflammatory, anti-cancer, anti-microbial etc [21]. Apart from
these biological activities pyrazoline derivatives have been re-
ported to possess anti-diabetic [22e24] and anti-obesity activities
[25,26].
The targeted compounds (2aeq) were synthesised by
condensing appropriate pyrazoline bearing benzenesulphonamide
with appropriate isocyanate or isothiocyanate by refluxing in
acetone containing dry K2CO3 (Scheme 1). The pyrazoline
substituted benzenesulfonamides (1aeg) weresynthesized through
reported method [27].
In the view of the above fact, we report the synthesis of new
pyrazoline substituted benzenesulfonylurea/thiourea derivatives
(2aeq) incorporating with known bioactive moieties highlighted in
Fig. 2. In the context to increase the efficacy we have introduced va-
riety of diaryl substituted pyrazoline moiety at para position of
benzenesulphonamide and variety of substitutions (benzyl, butyl
and cyclohexyl groups) were made at N2 position of the uriedoi/
3. Pharmacology
Newly synthesised compounds (2aeq) were evaluated for anti-
hyperglycaemic effects at the dose of 0.05 mM/kg b.w. in glucose-
fed hyperglycaemic normal rats [28]. The marketed sulfonylurea
drug gliclazide was used as positive control. Docking studies were
CH3
N
CH3
CH3
N
N
Ar
H3C
a
H3C
H3C
b
+
ArCHO
CH3
O
O
HN NH HCl
2
c
O
S O
NH
2
CH3
CH3
N
N
H3C
H3C
Ar
S
Ar
S
d
N
N
N
N
O
O
O
O
NH
NH
NH
2
R
X
1a-g
2a-q
2a: Ar = Phenyl, X = O, R = C6H5-CH2-
2b: Ar = 4-Chlorophenyl, X = O, R = C6H5-CH2-
2d: Ar = 4-Methylphenyl, X = O, R = C6H5-CH2-
2f: Ar = 3,4-Dimethoxyphenyl, X = O, R = C6H5-CH2-
2c: Ar = 4-Methoxyphenyl, X = O, R = C6H5-CH2-
2e: Ar = 2-Chlorophenyl, X = O, R = C6H5-CH2-
2g:Ar = 3,4,5-Trimethoxyphenyl, X = O, R = C6H5-CH2- 2h: Ar = Phenyl, X=S, R= C6H5-CH2-
2i: Ar = 4-Chlorophenyl, X=S, R= C6H5-CH2-
2k: Ar = 4-Methylphenyl, X=S, R= C6H5-CH2-
2m: Ar = 3,4,5-Trimethoxyphenyl, X=S, R= C6H5-CH2-
2o: Ar = 4-Chlorophenyl, X=S, R= C4H9-
2q: Ar = Phenyl, X=S, R= C6H11-
2j: 4-Methoxyphenyl, X=S, R= C6H5-CH2-
2l: Ar = 2-Chlorophenyl, X=S, R= C6H5-CH2-
2n: Ar = Phenyl, X=S, R= C4H9-
2p: Ar = 4-Methoxyphenyl, X=S, R= C4H9-
Scheme 1. Synthesis of pyrazoline based benzenesulfonylurea/thiourea derivatives (2aeq). Reagents and conditions: (a) CH3COCl, CH2Cl2, AlCl3; (b) ClaiseneSchmidt Reaction,
NaOH; (c) Absolute alcohol, Reflux 12e18 h; (d) Appropriate isocyanate and isothiocyanate, K2CO3, dry acetone, reflux 24e72 h.

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S. Ovais et al. / European Journal of Medicinal Chemistry 80 (2014) 209e217
performed by using Glide module of the Schrodinger-9 software in
order to get better comprehension of the aldose reductase inhibi-
tory potency of the newly synthesised compounds (2aeq) at mo-
lecular level. On the basis of the docking studies nine synthesized
compounds (three benzenesulfonylurea 2a, 2c, 2e and six benze-
nesulfonylthiourea 2h, 2k, 2l, 2n, 2o, 2q) were evaluated in vitro for
their ability to inhibit activity of partially purified rat lens aldose
reductase (AR) [29]. Their effectiveness was evaluated with respect
to known ARI sorbinil.
the activity (2b vs 2a, 2e vs 2a, 2i vs 2h and 2l vs 2h). Similarly
introduction of methyl group at C-4 position of 5-phenyl ring of
pyrazoline decreases the activity (2d vs 2a and 2k vs 2h). It is
interesting to note that in case of benzenesulfonylurea derivatives
increase in the number of methoxyl groups on 5-phenyl ring of
pyrazoline increases the activity (2c vs 2a, 2f vs 2c, 2g vs 2f). 2i and
2j derivatives consisting benzyl unit at thiouredo group were found
less effective than corresponding 2o and 2p derivatives having
butyl chain (Table 1). No SAR could be developed when benzene-
sulfonylurea derivatives were compared to their corresponding
benzenesulfonylthiourea derivatives.
4. Result and discussion
As the compounds evaluated for the anti-hyperglycaemic ac-
tivity have structural resemblances with the clinically used sulfo-
nylureas based anti-diabetic drugs. Therefore, it may be assumed
that compounds (2aeq) interact with the receptors which exist on
4.1. Chemistry
The structure of newly synthesised benzenesulfonylurea/thio-
the ATP-sensitive Kþ channel on the pancreatic
b-cell membrane
urea derivatives (2aeq) were determined on the basis of elemental
surface. This interaction inhibits Kþ efflux, causing membrane de-
polarization followed by an increase in Ca2þ influx through voltage-
dependent Ca2þ channels. The increase in cytoplasmic Ca2þ con-
centration eventually triggers insulin secretion from pancreatic
islets. However this needs further exploration.
analysis and various spectroscopic methods such as IR, 1H NMR, 13
C
NMR and MS. Elemental analysis (C, H, N and S) data were within
ꢀ0.5% of the theoretical values. All the peaks corresponding to IR,
1H NMR and 13C NMR were observed at expected positions in
respective spectra (for details see experimental section).
4.2.2. Docking
4.2. Pharmacology
Docking studies of the newly synthesised compounds (2aeq)
were performed in order to get better comprehension of the aldose
reductase inhibitory potency at molecular level and to shed light on
the interactions in the active site of aldose reductase. Docking
studies were performed using Glide module of the Schrodinger-9
software on the falcipain-2 receptor (PDB id: 1EL3, 1USO, 2FZD,
2PDK). Themostrelevantposes were obtainedwithPDB id:1EL3 and
1USO. However, the docking studies were performed with PDB id:
1El3 because this structure is bound with IDD384, which is a sul-
phonamide derivative and is relevant with our study. The re-docking
of reference ligand (IDD384) into active site of ALR2 reveals that it
occupies the same binding pocket with root mean square deviation
4.2.1. Blood glucose lowering effect
In the present study, oral anti-hyperglycaemic effects of
seventeen compounds (2aeq) were assessed in glucose-fed
hyperglycaemic normal rats at the dose of 0.05 mM/kg b.w. The
marketed sulfonylurea drug gliclazide at the dose 0.05 mM/kg b.w.
was used as positive control. The results are summarized in Table 1.
Quantitative glucose tolerance of each animal was calculated by
area under curve (AUC) method by using prism software.
Comparing AUC of experimental and control groups determined
the percentage anti-hyperglycaemic activity. Statistical comparison
was made by Dunnett’s test. Samples showing significant inhibition
(p < 0.05) on postprandial hyperglycaemia (AUC) were considered
as active samples. Thirteen compounds showed moderate to good
activity in the range of 10e29.3%. Compounds 2g and 2m showed
anti-hyperglycaemic activity comparable to the standard drug
gliclazide.
ꢀ
(RMSD) of 0.56 A which further validates the present docking pro-
tocol (Fig. 3A and B). Docking results reveal that the compounds 2o
and 2q bound tightly in the active site of aldose reductase (ALR2).
These compounds (2o and 2q) well occupied in the receptor cavity
and forms hydrogen bonds and hydrophobic interactions (Fig. 3C
and D). The sulphonamide group of 2o and 2q is anchored into the
anion binding site formed by Tyr48, His110 and Trp111 and forms
hydrogen-bonding with Trp111, which is key residue in binding and
catalysis [30,31]. The pyrazoline ring core gets tightly trapped in the
hydrophobic pocket formed by Phe122, Leu300, Leu301, Trp219, and
With relation to SAR we observed that introduction of chlorine
atom at C-4/C-2 position of 5-phenyl ring of pyrazoline decreases
Table 1
Trp295. The 3-phenyl ring of pyrazoline ring forms
p interaction
Effect of pyrazolines based benzenesulfonylurea/thiourea (0.05 mM/kg) on blood
glucose levels in glucose (3 g/kg) fed normal hyperglycaemic rats.
withTrp219. In additiontothese interactions, thealiphaticsidechain
(2o) and cyclohexyl ring (2q) also show some important interaction
as they area ligand into the small hydrophobic pocket formed by
Val47, Tyr48, Trp20, Trp219, Pro218 and Phe122.
Group no.
Treatment (0.05 mmol/kg)
% Activity
Significance
I
II
III
Control
Gliclazide
2a
0.0
25.4
15.5
6.7
17.5
12.0
4.7
18.0
29.3
24.2
4.2
11.7
21.7
15.3
28.6
10.5
18.9
17.2
2.7
e
P < 0.05
P < 0.05
P > 0.05
P < 0.02
P < 0.05
P > 0.05
P < 0.05
P < 0.02
P < 0.05
P > 0.05
P < 0.05
P < 0.05
P < 0.05
P < 0.05
P < 0.02
P < 0.05
P < 0.05
P > 0.05
The binding pose of compound 2a (Fig. 3E) reveals why it is
inactive. It does not fit well in the receptor binding site and does not
show hydrogen bonding like 2o and 2q. This may be explained on
the basis that the sulphonamide attached to the thiourea moiety
attains more planner structure than sulphonamide attached to the
urea moiety. Moreover, all other groups attached to the pyrazoline
ring show different posses when compared to the 2o and 2q
(Fig. 3F). Therefore it misses all the important interactions required
for ALR2 inhibition. The fact is also validated by Fig. 3F, where 2a
was superimposed on 2o and it is clear that compound 2o has more
relaxed conformation that compound 2a.
IV
2b
V
2c
VI
2d
VII
VIII
IX
2e
2f
2g
X
2h
XI
2i
XII
XIII
XIV
XV
XVI
XVII
XVIII
XIX
2j
2k
2l
2m
2n
2o
2p
2q
4.2.3. Aldose reductase inhibition
Nine synthesized compounds (three benzenesulfonylurea 2a,
2c, 2e and six benzenesulfonylthiourea 2h, 2k, 2l, 2n, 2o, 2q) were

S. Ovais et al. / European Journal of Medicinal Chemistry 80 (2014) 209e217
213
Fig. 3. Ligands are shown as ball and stick (carbon as green, oxygen as red, sulphur as yellow and nitrogen as blue), Hydrogen bonding shown as yellow lines, (A, B): Crystal pose of
IDD384 and Ligplot picture of IDD384 obtained from Protein databank, (CeE): Docking pose of compounds 2o, 2q and 2a, (F): Superimposed pose of 2a (carbon as ice blue) and 2o
(carbon as green). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)
evaluated in vitro for their ability to inhibit activity of partially
Table 2
purified rat lens aldose reductase (AR). It has been shown that there
is an approximately 85% sequence similarity between rat lens and
human aldose reductase (ALR2), while the proposed active sites of
both enzymes are identical [32]. The performed assay was based on
a spectrometric measurement, which is proven to be a reliable
method [33], with DL-glyceraldehyde as the substrate and NADPH
as the cofactor. Sorbinil, a known ARI was used as a positive control.
Results are presented in Table 2.
Benzenesulfonylthiourea derivatives (2h, 2k, 2l, 2n, 2o and 2q)
displayed good activity with IC50 ranging from 0.0178 to 0.090 mM
(Table 2). These compounds were found more effective than the
known ARI sorbinil. Among these benzenesulfonylthiourea de-
rivatives compounds 2o showed maximum inhibition with the
Aldose reductase (AR) inhibitory activity data.
Treatment
IC50 (m
M)a
2a
2c
2e
n.a.b
n.a.
n.a.
2h
2k
2l
2n
2o
2q
Sorbinil
0.0901
0.0699
0.0850
0.0430
0.0175
0.0178
8
a
IC50 values, represent the concentration required
to produce 50% enzyme inhibition.
b
IC50 values equal to 0.0175
mM followed by 2q, 2n, 2k, 2l, and 2h
n.a.: not active.
with 0.0175, 0.0430, 0.0699, 0.0850 and 0.0901
mM, respectively.
With regard to SAR of benzenesulfonylthiourea derivatives we
observed that replacement of benzyl group by butyl chain or
cyclohexyl ring at thiouredio group increased the activity (2h vs
2n and 2q).
Interestingly benzenesulfonylurea derivatives (2a, 2c and 2e)
did not show ARI activity at all. This may be attributed to the wrong
pose due to which they do not fit well in the receptor binding site.
5. Conclusion
In the present study seventeen novel pyrazoline substituted
benzenesulfonylurea/thiourea derivatives (2aeq) were synthe-
sized. The synthesized compounds are well supported by the
spectroscopic data and elemental analysis. Thirteen compounds

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S. Ovais et al. / European Journal of Medicinal Chemistry 80 (2014) 209e217
showed moderate to good anti-hyperglycaemic activity in glucose
fed hyperglycaemic normal rats at the dose of 0.05 mM/kg b.w.
ranging from 10 to 29.3%. Two compounds 2g and 2m showed anti-
hyperglycaemic activity comparable to the standard drug gliclazide.
On the basis of docking results nine compounds (2a, 2c, 2e, 2h, 2k,
2l, 2n, 2o and 2q) were selected for evaluating their ability to
inhibit rat lens AR. Out of these six compounds (2h, 2k, 2l, 2n, 2o
and 2q) were found more effective than the known ARI sorbinil.
Five compounds (2h, 2k, 2l, 2n and 2o) showed significant dual
action (anti-hyperglycaemic and aldose reductase inhibition).
17.6 Hz, H-4 cis (pyrazoline)], 4.09e4.11 (2H, m, eCH2ePhenyl),
5.52 [1H, dd, J ¼ 4.8 Hz, J ¼ 11.6 Hz, H-5 (pyrazoline)], 6.68 (1H, brs,
SO2NH), 6.71 (2H, d, J ¼ 8.8 Hz, H-30, H-50), 6.92 (2H, d, J ¼ 8.0 Hz, H-
20’’, H-60’’), 7.13e7.20 (5H, m, H-30’’, H-40’’, H-50’’, H-20’, H-60’), 7.41
(2H, d, J ¼ 8.0 Hz, H-2, H-6), 7.55 (2H, d, J ¼ 8.0 Hz, H-3ʺ, H-5ʺ), 7.60
(2H, d, J ¼ 8.4 Hz, H-20, H-60); 13C NMR (75 MHz, DMSO-d6,
d): 43.65
(CH2NH), 66.90 (C-5 pyrazoline), 151.62 (C-3 pyrazoline), 153.35
(C]O); MALDI (m/z): 588 [Mþ], 589 [Mþ1], 590 [Mþ2], 586 [Mꢂ2];
CHNS Analysis for C31H30ClN5O3S Found (Calculated) C: 63.33
(63.31), H: 5.71 (5.14), N: 11.89 (11.91), S: 5.46 (5.45).
6. Experimental
6.1.1.3. N-(benzylcarbamoyl)-4-(3-(4-(dimethylamino)phenyl)-5-
(methoxyphenyl)-4,5-dihydro-1H-pyrazol-1-yl)benzenesulfonamide
(2c). Light yellow crystals; yield ¼ 51%; m.p. 197e198 ꢁC; Rf ¼ 0.70
(toluene:ethyl acetate:formic acid, 5:4:1); IRymax (KBr, in cmꢂ1):
3348, 3030 and 2934 (NHeCOeNH), 1692 and 1507 (C]O of urea),
1592 (C]N), 1336 and 1151 (SO2N); 1H NMR (400 MHz, DMSO-d6,
6.1. Chemistry
Melting points were determined by open capillary tubes and are
uncorrected. Purity of the compounds was checked on TLC plates
(silica gel G) which were visualized by exposing to iodine vapours.
Infrared (IR) spectra were recorded (in KBr) on a BIO-RAD FTS-135
spectrophotometer and 1HNMR spectra were recorded on a Bruker
Spectrospin DPX 200e400 MHz spectrometer using deuterated
DMSO as solvent and tetramethyl silane (TMS) as an internal
d
): 2.97 [6H, s, N(CH3)2], 3.09 [1H, dd, J ¼ 4.4 Hz, J ¼ 17.6 Hz H-trans
(pyrazoline)], 3.71 (3H, s, OCH3), 3.89 [1H, dd, J ¼ 9.0 Hz, J ¼ 17.6 Hz,
H-4 cis (pyrazoline)], 4.14 (2H, d, J ¼ 5.6 Hz-CH2-Phenyl), 5.47 [1H,
dd, J ¼ 4.4 Hz, J ¼ 11.6 Hz, H-5 (pyrazoline)], 6.76 (2H, d, J ¼ 8.4 Hz,
H-30, H-50), 6.85 (1H, brs, CONH), 6.90 (2H, d, J ¼ 8.0 Hz, H-3, H-5),
7.00 (2H, d, J ¼ 8.0 Hz, H-2, H-6), 7.11 (2H, d, J ¼ 6.8 Hz, H-3ʺ, H-5ʺ),
7.18e7.22 (5H, m, for benzyl protons), 7.59e7.63 (4H, m, H-20, H-60,
standard. Chemical shifts are given in
d (ppm) scale and coupling
constants (J values) are expressed in Hz. Mass spectra (MS) were
recorded on MALDI-TOF. Elemental analysis was carried out on
CHNS Elementar (Vario EL III).
H-2ʺ, H-6ʺ), 10.44 (1H, brs, SO2NH); 13C NMR (75 MHz, DMSO-d6,
d):
42.69 (CH2NH), 55.57 (OCH3 at C-4), 66.39 (C-5 pyrazoline), 151.78
(C-3 pyrazoline), 155.80 (C]O); MALDI (m/z): 583 [Mþ], 584
[Mþ1], 585 [Mþ2], 582 [Mꢂ1]; CHNS Analysis for C32H33N5O4S
Found (Calculated) C: 65.88 (65.85), H: 5.71 (5.70), N: 11.98 (12.00),
S: 5.51 (5.49).
6.1.1. General procedure for synthesis of sulfonylureas (2aeq)
A solution of appropriate pyrazoline (1 mmol) in dry acetone
was refluxed over anhydrous K2CO3 (2 mmol) for 1e1.5 h. At this
temperature, a solution of the appropriate isocyanate or iso-
thiocynate (1.2 mmol) in dry acetone 5 ml was added in a drop wise
manner. It was refluxed for 24e72 h. Acetone was removed under
reduced pressure. The solid residue thus obtained was suspended
in water and acidified with acetic acid. It was stirred for 30 min and
filtered. The residue was washed with plenty of distilled water in
order to make the residue free from potassium acetate. It was dried
and crystallized from methanol.
6.1.1.4. N-(benzylcarbamoyl)-4-(3-(4-(dimethylamino)phenyl)-
5-p-tolyl-4,5-dihydro-1H-pyrazol-1-yl)benzenesulfonamide
(2d).
Yellow crystals; yield ¼ 42%; m.p. 217e218 ꢁC; Rf ¼ 0.88 (chlor-
oform:acetone, 8:2); IRymax (KBr, in cmꢂ1): 3321, 3040 and 2968
(NHeCOeNH), 1711 and 1507 (C]O of urea), 1595 (C]N), 1332 and
1159 (SO2N); 1H NMR (300 MHz, DMSO-d6, d): 2.24 (3H, s, CH3),
2.95 [6H, s, N(CH3)2], 3.07 [1H, dd, J ¼ 5.8 Hz, J ¼ 14.1 Hz, H-trans
(pyrazoline)], 3.88 [1H, dd, J ¼ 6.9, J ¼ 17.1 Hz, H-4 cis (pyrazoline)],
4.05e4.07 (2H, m, eCH2ePhenyl), 5.40 [1H, dd, J ¼ 4.2 Hz,
J ¼ 11.6 Hz, H-5 (pyrazoline)], 6.29 (1H, brs, CONH), 6.75 (2H, d,
J ¼ 8.4 Hz, H-30, H-50), 6.87 (2H, d, J ¼ 8.7 Hz, H-3ʺ, H-5ʺ), 7.00e7.60
(13H, m, H-20, H-60, H-2, H-3, H-4, H-5, H-6, H-2ʺ, H-6ʺ H-30’’, H-40’’,
6.1.1.1. N-(bezylcarbamoyl)-4-(3-(4-(dimethylamino)phenyl)-5-
phenyl-4,5-dihydro-1H-pyrazol-1-yl)benzenesulfonamide
(2a).
Orange crystals; yield ¼ 41%; m.p. 209e210 ꢁC; Rf ¼ 0.85 (tolue-
ne:ethyl acetate:formic acid, 5:4:1); IRymax (KBr, in cmꢂ1): 3337,
3034 and 2909 (NHeCOeNH), 1712 and 1530 (C]O of urea), 1593
H-50’’, H-60’’ and SO2NH); 13C NMR (75 MHz, DMSO-d6,
d): 21.18
(C]N), 1329 and 1160 (SO2N); 1H NMR (400 MHz, DMSO-d6,
d
):
(CH3 at C-4), 43.86 (CH2NH), 66.79 (C-5 pyrazoline), 152.09 (C-3
pyrazoline), 154.58 (C]O); MALDI (m/z): 567 [Mþ], 568 [Mþ1], 566
[Mꢂ1], 565 [Mꢂ2]; CHNS Analysis for C32H33N5O3S Found (Calcu-
lated) C: 67.72 (67.70), H: 5.88 (5.86), N: 12.33 (12.34), S: 5.64
(5.65).
2.96 [6H, s, N(CH3)2], 3.09 [1H, dd, J ¼ 4.2 Hz, J ¼ 11.7 Hz H-trans
(pyrazoline)], 3.91 [1H, dd, J ¼ 8.7 Hz, J ¼ 12.6 Hz, H-4 cis (pyr-
azoline)], 4.10 (2H, m, -CH2-Phenyl), 4.38 [1H, dd, J ¼ 3.9 Hz,
J ¼ 8.7 Hz, H-5 (pyrazoline)], 6.58 (1H, brs, CONH), 6.75 (2H, d,
J ¼ 6.6 Hz, H-30, H-50), 6.93 (2H, d, J ¼ 5.7 Hz, H-3ʺ, H-5ʺ), 7.13e7.36
(11H, m, phenyl, benzyl protons and SO2NH), 7.54 (2H, d, J ¼ 5.7 Hz,
H-2ʺ, H-6ʺ), 7.61 (2H, d, J ¼ 6.3 Hz, H-20, H-60); 13C NMR (75 MHz,
6.1.1.5. N-(benzylcarbamoyl)-4-(5-(2-chlorophenyl)-3-(4-(dimethy-
lamino)phenyl)-4,5-dihydro-1H-pyrazol-1-yl)benzenesulfonamide
(2e). Light yellow crystals; yield ¼ 51%; m.p. 209e210 ꢁC; Rf ¼ 0.79
(toluene:ethyl acetate:formic acid, 5:4:1); IRymax (KBr, in cmꢂ1):
3346, 3067 and 2984 (NHeCOeNH), 1710 and 1507 (C]O of urea),
1604 (C]N), 1337 and 1161 (SO2N); 1H NMR (400 MHz, DMSO-d6,
DMSO-d6, d): 43.42 (CH2NH), 66.94 (C-5 pyrazoline), 151.4 (C-3
pyrazoline), 156.40 (C]O); MALDI (m/z): 553 [Mþ], 552 [Mꢂ1];
CHNS Analysis for C31H31N5O3S Found (Calculated): C: 67.21
(67.25), H: 5.66 (5.64), N: 12.66 (12.65), S: 5.81 (5.79).
d
): 2.96 [6H, s, N(CH3)2], 3.07 [1H, dd, J ¼ 4.8 Hz, J ¼ 17.2 Hz, H-trans
6.1.1.2. N-(benzylcarbamoyl)-4-(5-(4-(chlorophenyl)-3-(4-(dimethy-
lamino)phenyl)-4,5-dihydro-1H-pyrazol-1-yl)benzenesulfonamide
(2b). Light yellow crystals; yield ¼ 38%; m.p. 196e197 ꢁC; Rf ¼ 0.78
(toluene:ethyl acetate:formic acid, 5:4:1); IRymax (KBr, in cmꢂ1):
3365, 3026 and 2913 (NHeCOeNH), 1692 and 1505 (C]O of urea),
1593 (C]N), 1337 and 1151 (SO2N); 1H NMR (400 MHz, DMSO-d6,
(pyrazoline)], 3.70e3.72 (1H, m, CONH), 4.01 [1H, dd, J ¼ 12.4 Hz,
17.6 Hz, H-4 cis (pyrazoline)], 4.11 (2H, d, J ¼ 4.4 Hz, eCH2ePhenyl),
5.68 [1H, dd, J ¼ 4.8 Hz, J ¼ 11.6 Hz, H-5 (pyrazoline)], 6.68 (1H, brs,
SO2NH), 6.74 (2H, d, J ¼ 8.4 Hz, H-30, H-50), 6.84 (2H, d, J ¼ 8.0 Hz, H-
2ʺ, H-6ʺ), 7.04e7.62 (13H, m, H-20, H-60, H-3ʺ, H-5ʺ, H-3, H-4, H-5, H-
6, H-20’’, H-30’’, H-40’’, H-50’’, H-60’’); 13C NMR (75 MHz, DMSO-d6,
d):
d
): 2.96 [6H, s, N(CH3)2], 3.09 [1H, dd, J ¼ 5.2 Hz, J ¼ 17.2 Hz, H-trans
43.78 (CH2NH), 68.14 (C-5 pyrazoline), 152.66 (C-3 pyrazoline),
(pyrazoline)], 3.42 (1H, brs, CONH), 3.89 [1H, dd, J ¼ 12.4 Hz,
155.86 (C]O). MALDI (m/z): 588 [Mþ], 589 [Mþ1], 590 [Mþ2], 587

S. Ovais et al. / European Journal of Medicinal Chemistry 80 (2014) 209e217
215
[Mꢂ1]; CHNS Analysis for C31H30ClN5O3S Found (Calculated) C:
DMSO-d6, d): 2.96 [6H, s, N(CH3)2], 3.44e3.47 [1H, m, H-trans
63.33 (63.31), H: 5.17 (5.14), N: 11.93 (11.91), S: 5.48 (5.45).
(pyrazoline)], 4.04 [1H, dd, J ¼ 5.1 Hz, J ¼ 15.2 Hz, H-cis (pyrazo-
line)], 4.07e4.09 (2H, m, eCH2ePhenyl), 5.51 [1H, dd, J ¼ 4.6 Hz,
J ¼ 12.0 Hz, H-5 (pyrazoline)], 6.74 (2H, d, J ¼ 8.1 Hz, H-3ʺ, H-5ʺ),
6.99e7.62 (13H, H-20, H-60, H-2, H-3, H-5, H-6, H-2ʺ, H-6ʺ, H-20’’, H-
30’’, H-40’’, H-50’’, H-60’’), 8.10 (1H, brs, SO2NH); 13C NMR (75 MHz,
6.1.1.6. N-(benzylcarbamoyl)-4-(3-(4-(dimethylamino)phenyl)-5-
(3,4,-dimethoxyphenyl)-4,5-dihydro-1H-pyrazol-1-yl)benzenesulfo-
namide (2f). Reddish brown crystals; yield ¼ 31%; m.p.189e190 ꢁC;
Rf ¼ 0.56 (toluene:ethyl acetate:formic acid, 5:4:1); IRymax (KBr, in
cmꢂ1): 3334, 3034 and 2999 (NHeCOeNH), 1692 and 1519 (C]O of
urea), 1592 (C]N), 1330 and 1152 (SO2N); 1H NMR (400 MHz,
DMSO-d6, d): 52.33 (CH2NH), 66.83 (C-5 pyrazoline), 151.47 (C-3
pyrazoline), 176.69 (C]S); MALDI (m/z): 604 [Mþ], 605 [Mþ1].
CHNS Analysis for C31H30ClN5O2S2 Found (Calculated) C: 61.65
(61.63), H: 5.03 (5.00), N: 11.60 (11.59), S: 10.62 (10.61).
DMSO-d6,
d
): 2.95 [6H, s, N(CH3)2], 3.12 [1H, dd, J ¼ 12.4 Hz,
J ¼ 17.6 Hz, H-trans (pyrazoline)], 3.15e3.20 (1H, m, CONH), 3.69
(3H, s, OCH3), 3.71 (3H, s, OCH3), 3.88 [1H, dd, J ¼ 8.7 Hz, 13.2 Hz, H-
4 cis (pyrazoline)], 4.13e4.15 (1H, m, -CH2-phenyl), 5.43 [1H, dd,
J ¼ 3.9 Hz, 8.7 Hz, H-5 (pyrazoline)], 5.75 (1H, brs, SO2NH), 6.69e
7.23 (12H, m, H-30, H-50, H-2, H-5, H-6, H-3ʺ, H-5ʺ, H-20’’, H-30’’, H-
40’’, H-50’’, H-60’’), 7.60e7.63 (4H, m,, H-20, H-60, H-2ʺ, H-6ʺ); 13C
6.1.1.10. N-(benzylcarbamothioyl)-4-(3-(4-(dimethylamino)phenyl)-
5-(4-methoxyphenyl-4,5-dihydro-1H-pyrazol-1-yl)benzenesulfona-
mide (2j). Light yellow; yield ¼ 51%; m.p. 226e227 ꢁC; Rf ¼ 0.65
(toluene:ethyl acetate:formic acid, 5:4:1); IRymax (KBr, in cmꢂ1):
3323, 3061 and 2975 (NHeCSeNH), 1539 and 1505 (C]S of thio-
urea), 1594 (C]N), 1329 and 1125 (SO2N); 1H NMR (400 MHz,
NMR (75 MHz, DMSO-d6, d
): 43.36 (CH2NH), 55.72 (OCH3 at C-30
and C-40), 68.85 (C-5 pyrazoline), 152.69 (C-3 pyrazoline), 155.72
(C]O); MALDI (m/z): 613 [Mþ], 614 [Mþ1], 612 [Mꢂ1]; CHNS
Analysis for C33H35N5O5S Found (Calculated) C: 64.54 (64.58), H:
5.73 (5.75), N: 11.44 (11.41), S: 5.25 (5.22).
DMSO-d6, d): 2.96 [6H, s, N(CH3)2], 3.06e3.08 [1H, m, H-trans
(pyrazoline)], 3.71 (3H, s, OCH3), 3.88 [1H, dd, J ¼ 11.2 Hz,
J ¼ 17.8 Hz, H-4 cis (pyrazoline)], 4.41e4.44 (2H, m, eCH2ePhenyl),
5.41e5.44 [1H, m, H-5 (pyrazoline)], 6.75 (2H, d, J ¼ 8.4 Hz, H-30, H-
50), 6.83e7.61 (15H, m, for aromatic protons), 8.01e8.04 (1H, m,
6.1.1.7. N-(benzylcarbamoyl)-4-(3-(4-(dimethylamino)phenyl)-5-
(3,4,5-trimethoxyphenyl)-4,5-dihydro-1H-pyrazol-1-yl)benzene-
sulfonamide (2g). Brown crystals; yield ¼ 42%; m.p. 130e131 ꢁC;
Rf ¼ 0.83 (chloroform: acetone, 9: 1); IRymax (KBr, in cmꢂ1): 3339,
3061 and 2930 (NHeCOeNH), 1693 and 1504 (C]O of urea), 1592
SO2NH); 13C NMR (75 MHz, DMSO-d6,
d): 53.30 (CH2NH), 55.38
(OCH3 at C-4), 66.89 (C-5 pyrazoline), 151.64 (C-3 pyrazoline),
176.71 (C]S). MALDI (m/z): 599 [Mþ], 600 [Mþ1], 598 [Mꢂ1].
CHNS Analysis for C32H33N5O2S2 Found (Calculated) C: 64.10
(64.08), H: 5.56 (5.55), N: 11.66 (11.68), S: 10.71 (10.69).
(C]N), 1331 and 1151 (SO2N); 1H NMR (200 MHz, DMSO-d6, d):
2.96 [6H, s, N(CH3)2], 3.43e3.48 [1H, m, H-trans (pyrazoline)], 3.63
(3H, s, OCH3 at C-4), 3.71 (6H, s, OCH3 X 2 at C-3 and C-5), 4.41 [1H,
dd, J ¼ 12.4 Hz, 17.6 Hz, H-4 cis (pyrazoline)], 4.60e4.64 (1H, m, e
CH2ephenyl), 5.01e5.04 [1H, m, H-5 (pyrazoline)], 6.24 (1H, brs, e
CONHe), 6.62 (2H, s, H-2, H-6), 6.76 (2H, d, J ¼ 8.0 Hz, H-30, H-50),
6.92e7.50 (7H, m, H-3ʺ, H-5ʺ, H-20’’, H-30’’, H-40’’, H-50’’, H-60’’), 7.91
6.1.1.11. N-(bezylcarbamothioyl)-4-(3-(4-(dimethylamino)phenyl)-
5-p-tolyl-4,5-dihydro-1H-pyrazol-1-yl)benzenesulfonamide
(2k).
Light orange crystals; yield ¼ 31%; m.p. 191e193 ꢁC; Rf ¼ 0.90
(chloroform:acetone, 9:1); IRymax (KBr, in cmꢂ1): 3344, 3048 and
2985 (NHeCSeNH), 1528 and 1502 (C]S), 1592 (C]N), 1331 and
1125 (SO2N); 1H NMR (500 MHz, DMSO-d6, d): 2.25 (3H, s, CH3),
(1H, broad singlet, SO2NH); 13C NMR (75 MHz, DMSO-d6,
d): 43.44
2.95 [6H, s, N(CH3)2], 3.02e3.04 [1H, m, H-trans (pyrazoline)],
3.30e3.32 (1H, m, CSNH), 3.84e3.86 [1H, m, H-4 cis (pyrazoline)],
4.27e4.28 (2H, m, eCH2ePhenyl), 5.34e5.39 [1H, m, H-5 (pyrazo-
line)], 6.74 (2H, d, J ¼ 9.0 Hz, H-30, H-50), 6.38 (2H, d, J ¼ 8.0 Hz, H-3ʺ,
H-5ʺ), 7.13e7.20 (9H, m, for tolyl and benzyl aromatic protons), 7.43
(2H, d, J ¼ 8.0 Hz, H-2ʺ, H-6ʺ), 7.58 (2H, d, J ¼ 9.0 Hz, H-20, H-60), 7.59
(CH2NH), 56.17 (OCH3 at C-30 and C-50), 60.69 (OCH3 at C-40), 64.52
(C-5 pyrazoline), 154.62 (C-3 pyrazoline), 157.55 (C]O); MALDI (m/
z): 643 [Mþ], 644 [Mþ1], 645 [Mþ2], 642 [Mꢂ1]. CHNS Analysis for
C
34H37N5O6S Found (Calculated) C: 63.40 (63.43), H: 5.77 (5.79), N:
10.90 (10.88), S: 4.99 (4.98).
(1H, brs, SO2NH); 13C NMR (75 MHz, DMSO-d6,
d): 20.93 (CH3 at C-
6.1.1.8. N-(benzylcarbamothioyl)-4-(3-(4-(dimethylamino)phenyl)-
4), 51.92 (CH2NH), 55.20 (OCH3 at C-4), 66.04 (C-5 pyrazoline),
5-phenyl-4,5-dihydro-1H-pyrazol-1-yl)benzenesulfonamide
(2h).
151.31 (C-3 pyrazoline), 175.95 (C]S); MALDI (m/z): 583 [Mþ], 584
Yellow crystals; yield ¼ 56%; m.p. 204e205 ꢁC; Rf ¼ 0.88 (tolue-
ne:ethyl acetate:formic acid, 5:4:1); IRymax (KBr, in cmꢂ1): 3323,
3076 and 2948 (NHeCSeNH), 1528 and 1455 (C]S of thiourea),
1592 (C]N), 1328 and 1125 (SO2N); 1H NMR (400 MHz, DMSO-d6,
[Mþ1], 582 [Mꢂ1]; CHNS Analysis for
C32H33N5O2S2 Found
(Calculated) C: 65.80 (65.84), H: 5.71 (5.70), N: 12.01 (12.00), S:
10.97 (10.99).
d
): 2.96 [6H, s, N(CH3)2], 3.06 [1H, dd, J ¼ 9.9 Hz, J ¼ 13.2 Hz H-trans
6.1.1.12. N-(benzylcarbamothioyl)-4-(5-(2-chlorophenyl)-3-(4-
(dimethylamino)phenyl)-4,5-dihydro-1H-pyrazol-1-yl)benzenesulfo-
namide (2l). Yellow crystals; yield ¼ 41%; m.p. 194e195 ꢁC;
Rf ¼ 0.75 (toluene:ethyl acetate:formic acid, 5:4:1); IRymax (KBr, in
cmꢂ1): 3342, 3034 and 2982 (NHeCSeNH), 1551 and 1507 (C]S of
thiourea), 1591 (C]N), 1334 and 1136 (SO2N); 1H NMR (400 MHz,
(pyrazoline)], 3.89 [1H, dd, J ¼ 9.6 Hz, J ¼ 12.6 Hz, H-4 cis (pyr-
azoline)], 4.26e4.28 (1H, m, CSNH), 4.62e4.67 (m, eCH2ePhenyl),
5.45 [1H, dd, J ¼ 3.9 Hz, J ¼ 7.8 Hz, H-5 (pyrazoline)], 6.75 (2H, d,
J ¼ 6.6 Hz, H-30, H-50), 6.83e6.90 (2H, m, H-3ʺ, H-5ʺ), 7.16e7.48
(10H, m, for phenyl and benzyl protons), 7.60 (2H, d, J ¼ 6.3 Hz, H-20,
H-60), 7.90e7.91 (1H, m, SO2NH); 13C NMR (75 MHz, DMSO-d6,
d
):
DMSO-d6,
d
): 2.97 [6H, s, N(CH3)2], 3.15 [1H, dd, J ¼ 4.4 Hz,
52.41 (CH2NH), 66.94 (C-5 pyrazoline), 151.40 (C-3 pyrazoline),
176.25 (C]S); MALDI (m/z): 569 [Mþ], 570 [Mþ1], 568 [Mꢂ1].
CHNS Analysis for C31H31N5O2S2 Found (Calculated) C: 65.39
(65.35), H: 5.45 (5.48), N: 12.31 (12.29), S: 11.22 (11.26).
J ¼ 17.6 Hz, H-trans (pyrazoline)], 3.94 [1H, dd, J ¼ 12.4 Hz, 18.0 Hz,
H-4 cis (pyrazoline)], 4.66e4.71 (2H, m, eCH2ePhenyl), 5.59 [1H,
dd, J ¼ 4.8 Hz, J ¼ 11.6 Hz, H-5 (pyrazoline)], 6.67 (2H, d, J ¼ 8.8 Hz,
H-30, H-50), 7.01 (2H, d, J ¼ 8.4 Hz, H-2ʺ, H-6ʺ), 7.09e7.65 (13H, m, H-
40, H-60, H-3ʺ, H-5ʺ, H-3, H-4, H-5, H-6, H-20’’, H-30’’, H-40’’, H-50’’, H-
60’’), 8.76e8.78 (1H, m, CSNH), 11.43e11.44 (1H, m, SO2NH); 13C
6.1.1.9. N-(Benzylcarbamothioyl)-4-(5-(4-chlorophenyl)-3-(4-(dime-
thylamino)phenyl)-4,5-dihydro-1H-pyrazol-1-yl)benzenesulfona-
mide (2i). Yellow crystals; yield ¼ 44%; m.p. 229e230 ꢁC; Rf ¼ 0.87
(toluene:ethyl acetate:formic acid, 5:4:1); IRymax (KBr, in cmꢂ1):
3339, 3064 and 2974 (NHeCSeNH), 1551 and 1495 (C]S of thio-
urea), 1591 (C]N), 1344 and 1165 (SO2N); 1H NMR (400 MHz,
NMR (75 MHz, DMSO-d6, d): 52.85 (CH2NH), 66.58 (C-5 pyrazoline),
151.71 (C-3 pyrazoline), 175.98 (C]S); MALDI (m/z): 603 [Mþ], 604
[Mþ1], 605 [Mþ2]; CHNS Analysis for C31H30ClN5O2S2 Found
(Calculated) C: 61.65 (61.63), H: 5.04 (5.00), N: 11.63 (11.59), S:
10.58 (10.61).

216
S. Ovais et al. / European Journal of Medicinal Chemistry 80 (2014) 209e217
6.1.1.13. N-(benzylcarbamothioyl)-4-(3-(4-(dimethylamino)phenyl)-
5-(3,4,5-trimethoxyphenyl)-4,5-dihydro-1H-pyrazol-1-yl)benzene-
sulfonamide (2m). Yellow crystals; yield ¼ 44%; m.p. 204e205 ꢁC;
Rf ¼ 0.92 (toluene:ethyl acetate:formic acid, 5:4:1); IRymax (KBr, in
cmꢂ1): 3362, 3052 and 2940 (NHeCSeNH), 1548 and 1502 (C]S of
thiourea), 1581 (C]N), 1338 and 1120 (SO2N); 1H NMR (300 MHz,
benzenesulfonamide (2p). Light yellow crystals; yield ¼ 42%; m.p.
224e225 ꢁC; Rf ¼ 0.90 (toluene:ethyl acetate:formic acid, 5:4:1);
IRymax (KBr, in cmꢂ1): 3349, 3038 and 2945 (NHeCSeNH),1554 and
1502 (C]S of thiourea), 1591 (C]N), 1338 and 1144 (SO2N); 1H
NMR (400 MHz, DMSO-d6, d): 0.81e0.83 (3H, m, eCH2eCH2eCH2e
CH3), 1.17e1.20 (2H, m, eCH2eCH2eCH2eCH3), 1.35e1.38 (2H, m, e
CH2eCH2eCH2eCH3), 2.95e2.97 [8H, m, eCH2eCH2eCH2eCH3,
N(CH3)2], 3.01e3.04 [1H, m, H-trans (pyrazoline)], 3.71 (3H, s,
OCH3), 3.86 [1H, dd, J ¼ 9.6 Hz, J ¼ 17.6 Hz, H-4 cis (pyrazoline)],
5.42e5.44 [1H, m, H-5 (pyrazoline)], 6.51e6.54 (1H, m, CSNH), 6.75
(2H, d, J ¼ 7.2 Hz, H-30, H-50), 6.89 (2H, d, J ¼ 7.2 Hz,, H-3, H-5), 6.93
(2H, d, J ¼ 9.2 Hz, H-2, H-6), 7.17 (2H, d, J ¼ 7.6 Hz, H-3ʺ, H-5ʺ), 7.51
(2H, d, J ¼ 8.4 Hz, H-2ʺ, H-6ʺ), 7.60 (2H, d, J ¼ 6.7 Hz, H-20, H-60),
DMSO-d6,
d): 2.96 [6H, s, N(CH3)2], 3.43e3.48 [1H, m, H-trans
(pyrazoline)], 3.62 (3H, s, OCH3 at C-4), 3.69 (6H, s, OCH3 X 2 at C-3
and C-5), 3.85 [1H, dd, J ¼ 7.8 Hz, 17.1 Hz, H-4 cis (pyrazoline)],
4.24e4.27 (1H, m, eCH2ephenyl), 5.29 [1H, dd, J ¼ 4.6 Hz, 11.6 Hz,
H-5 (pyrazoline)], 6.59 (2H, s, H-2, H-6), 6.75 (2H, d, J ¼ 8.1 Hz, H-3,
H-5), 6.84e7.60 (11H, m, H-20, H-60, H-2ʺ, H-3ʺ, H-5ʺ, H-6ʺ, H-20’’, H-
30’’, H-40’’, H-50’’, H-60’’), 7.85e7.87 (1H,m, CSNH), 8.31 (1H, s,
SO2NH); 13C NMR (75 MHz, DMSO-d6,
d): 53.53 (CH2NH), 56.65
7.83e7.85 (1H, m, SO2NH). 13C NMR (75 MHz, DMSO-d6,
d): 14.62 (e
(OCH3 at C-30 and C-50), 60.64 (OCH3 at C-40), 66.90 (C-5 pyrazo-
line),151.29 (C-3 pyrazoline), 174.64 (C]S); MALDI (m/z): 659 [Mþ],
660 [Mþ1], 659 [Mꢂ1]; CHNS Analysis for C34H37N5O5S Found
(Calculated) C: 61.91 (61.89), H: 5.63 (5.65), N: 10.62 (10.61), S: 9.74
(9.72).
CH2e CH2eCH2eCH3), 20.83 (eCH2e CH2eCH2eCH3), 31.75 (e
CH2e CH2eCH2eCH3), 46.21 (eCH2eCH2eCH2eCH3), 52.83
(CH2NH), 55.38 (OCH3 at C-4), 67.61 (C-5 pyrazoline), 151.69 (C-3
pyrazoline), 174.74 (C]S); MALDI (m/z): 565 [Mþ], 564 [Mꢂ1];
CHNS Analysis for C29H35N5O3S2 Found (Calculated) C: 61.55
(61.57), H: 6.24 (6.24), N: 12.60 (12.38), S: 11.36 (11.34).
6.1.1.14. N-(butylcarbamothioyl)-4-(3-(4-(dimethylamino)phenyl)-5-
phenyl-4,5-dihydro-1H-pyrazol-1-yl)benzenesulfonamide
(2n).
6.1.1.17. N-(cyclohexylcarbamothioyl)-4-(3-(4-(dimethylamino)
phenyl)-5-phenyl-4,5-dihydro-1H-pyrazol-1-yl)benzenesulfonamide
(2q). Yellow crystals; yield ¼ 56%; m.p. 142e143 ꢁC; Rf ¼ 0.97
(toluene:ethyl acetate:formic acid, 5:4:1); IRymax (KBr, in cmꢂ1):
3327, 3071 and 2931 (NHeCSeNH), 1533 and 1504 (C]S of thio-
urea), 1590 (C]N), 1364 and 1149 (SO2N); 1H NMR (400 MHz,
Yellow crystals; yield ¼ 46%; m.p. 205e207 ꢁC; Rf ¼ 0.88 (tolue-
ne:ethyl acetate:formic acid, 5:4:1); IRymax (KBr, in cmꢂ1): 3348,
3030 and 2934 (NHeCSeNH), 1553 and 1502 (C]S), 1591 (C]N),
1341 and 1146 (SO2N); 1H NMR (400 MHz, DMSO-d6, d): 0.74e0.82
(3H, m, -CH2- CH2eCH2eCH3), 1.23e1.40 (2H, m, eCH2eCH2eCH2e
CH3), 1.41e1.44 (2H, m, eCH2eCH2eCH2eCH3), 2.34e2.36 (2H, m,
eCH2eCH2eCH2eCH3), 2.97 [6H, s, N(CH3)2], 3.14 [1H, dd,
J ¼ 3.6 Hz, J ¼ 13.5 Hz H-trans (pyrazoline)], 3.93 [1H, dd, J ¼ 9.3 Hz,
J ¼ 13.5 Hz, H-4 cis (pyrazoline)], 5.58 [1H, dd, J ¼ 4.8 Hz,
J ¼ 12.0 Hz, H-5 (pyrazoline)], 6.76 (2H, d, J ¼ 8.0 Hz, H-30, H-50),
7.03 (2H, d, J ¼ 8.0 Hz,, H-3ʺ, H-5ʺ), 7.23e7.36 (5H, m,, H-20, H-40, H-
60, H-2ʺ, H-6ʺ), 7.93e8.00 (1H, m, CSNH), 8.36e8.39 (1H, m,
DMSO-d6, d): 1.23e1.76 (10H, m, cyclohexyl ring), 2.94 (1H, s, axial-
H at C-1 of cyclohexyl ring), 2.97 [6H, s, N(CH3)2], 3.14 [1H, dd,
J ¼ 3.6 Hz, J ¼ 13.8 Hz H-trans (pyrazoline)], 3.96 [1H, dd, J ¼ 9.3 Hz,
J ¼ 13.2 Hz, H-4 cis (pyrazoline)], 5.58 [1H, dd, J ¼ 3.3 Hz, J ¼ 9.0 Hz,
H-5 (pyrazoline)], 6.76 (2H, d, J ¼ 6.9 Hz, H-30, H-50), 7.03 (2H, d,
J ¼ 6.6 Hz,, H-3ʺ, H-5ʺ), 7.23e7.36 (5H, m,, H-2, H-3, H-4, H-5, H-6),
7.60e7.64 (4H, m, H-20, H-60, H-2ʺ, H-6ʺ), 8.05e8.13 (1H, m,
SO2NH); 13C NMR (75 MHz, DMSO-d6,
d): 14.58 (eCH2eCH2eCH2e
SO2NH); 13C NMR (75 MHz, DMSO-d6,
d): 52.33 (CH2NH), 66.90 (C-5
CH3), 20.90 (eCH2eCH2eCH2eCH3), 31.68 (eCH2eCH2eCH2eCH3),
47.56 (eCH2eCH2eCH2eCH3), 52.53 (CH2NH), 66.95 (C-5 pyrazo-
line),152.43 (C-3 pyrazoline), 175.74 (C]S). MALDI (m/z): 535 [Mþ],
536 [Mþ1]. CHNS Analysis for C28H33N5O2S2 Found (Calculated) C:
62.79 (62.77), H: 6.24 (6.21), N: 13.09 (13.07), S: 11.96 (11.97).
pyrazoline), 151.40 (C-3 pyrazoline), 176.05 (C]S); MALDI (m/z):
561 [Mþ], 562 [Mþ1], 560 [Mꢂ1], 559 [Mꢂ2]; CHNS Analysis for
C30H35N5O2S2 Found (Calculated) C: 64.16 (64.14), H: 6.30 (6.28), N:
12.49 (12.47), S: 11.44 (11.42).
6.2. Pharmacology
6.1.1.15. N-(butylcarbamothioyl)-4-(5-(4-chlorophenyl)-3-(4-(dime-
thylamino)phenyl)-4,5-dihydro-1H-pyrazol-1-yl)benzenesulfona-
mide (2o). Yellow crystals; yield ¼ 46%; m.p. 221e223 ꢁC; Rf ¼ 0.66
(toluene:ethyl acetate:formic acid, 5:4:1); IRymax (KBr, in cmꢂ1):
3349, 3048 and 2929 (NHeCSeNH), 1558 and 1503 (C]S of thio-
urea), 1593 (C]N), 1331 and 1128 (SO2N); 1H NMR (400 MHz,
6.2.1. Anti-hyperglycaemic activity
All the experiments were carried out in albino rats of Wistar
strain (either sex) were procured from Central Animal House of
Jamia Hamdard, New Delhi (Registration no. 173/CPCSEA). The ex-
periments were performed in accordance with the guidelines for
the care and use of laboratory animals, laid down by the Committee
for the Purpose of Control and Supervision of Experiments in Ani-
mals (CPCSEA), Ministry of Social Justice and Empowerment, Govt.
of India, Jan. 2000. Animals described as fasted were deprived of
food for at least 16 h but allowed free access to water. Carbox-
ymethyl cellulose CMC (1%w/v) in distilled water was used as
vehicle for dosing in all the experiments. All treatments were given
orally using gauge.
Fasted rats were divided into groups of six animals each. Ani-
mals of group-I were fed with the vehicle (CMC 1% w/v in distilled
water) in a volume of 10 ml/kg, while animals of group II were given
gliclazide 0.05 mM/kg suspended in the vehicle. Animals of the
experimental group (III - XIX) were administered the suspension of
the test compounds at a dosage of 0.05 mM/kg b.w. A glucose load
(3 g/kg) was given to each animal exactly after 30 min post
administration of the respective treatments. Blood samples were
collected from retro-orbital plexus (under mild condition) just
prior to and 60 min after the glucose loading and blood glucose
DMSO-d6, d): 0.75 (3H, t, eCH2eCH2eCH2eCH3), 1.21e1.23 (2H, m,
eCH2eCH2eCH2eCH3), 1.35e1.38 (2H, m, eCH2eCH2eCH2eCH3),
2.95e2.97 [8H, m, eCH2eCH2eCH2eCH3, N(CH3)2], 3.21e3.23 [1H,
m, H-trans (pyrazoline)], 3.86 [1H, dd, J ¼ 9.6 Hz, J ¼ 17.3 Hz, H-4 cis
(pyrazoline)], 5.48 [1H, dd, J ¼ 4.8 Hz J ¼ 12.1 Hz, H-5 (pyrazoline)],
6.51e6.53 (1H, m, CSNH), 6.74 (2H, d, J ¼ 6.0 Hz, H-30, H-50), 6.87
(2H, d, J ¼ 6.6 Hz,, H-3ʺ, H-5ʺ), 7.27 (2H, d, J ¼ 5.1 Hz, H-3, H-5), 7.39
(2H, d, J ¼ 5.1 Hz, H-2, H-6), 7.45e7.51 (3H, m, H-20, H-60, SO2NH),
7.58 (2H, d, J ¼ 6.3 Hz, H-2ʺ, H-6ʺ); 13C NMR (75 MHz, DMSO-d6,
d
):
14.98 (eCH2eCH2eCH2eCH3), 21.76 (eCH2eCH2eCH2eCH3), 31.72
(eCH2eCH2eCH2eCH3), 47.93 (eCH2eCH2eCH2eCH3), 52.55
(CH2NH), 67.04 (C-5 pyrazoline), 151.75 (C-3 pyrazoline), 174.75
(C]S); MALDI (m/z): 570 [Mþ], 571 [Mþ1], 572 [Mþ2], 569 [Mꢂ1],
568 [Mꢂ2]; CHNS Analysis for C28H32ClN5O2S2 Found (Calculated)
C: 58.99 (58.98), H: 5.67 (5.66), N: 12.29 (12.28), S: 11.27 (11.25).
6.1.1.16. N-(butylcarbamothioyl)-4-(3-(4-(dimethylamino)phenyl)-5-
( 4 - m e t h o x y p h e n y l ) - 4 , 5 - d i h y d r o - 1 H - p y r a z o l - 1 - y l )

S. Ovais et al. / European Journal of Medicinal Chemistry 80 (2014) 209e217
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10 mM DL-glyceraldehyde, 0.1 mM NADPH and enzyme prepara-
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stock of pyrazoline substituted benzenesulfonylurea/thiourea de-
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working solution were added to the enzyme assay mixture and
incubated for 5 min before initiating the reaction by NADPH as
described above. The percent inhibition with test compound was
calculated considering the enzyme activity in the absence of in-
hibitor as 100%. The concentration of each test sample giving 50%
inhibition (IC50) was determined by non-linear regression analysis
of log concentration of compound versus percentage inhibition.
Acknowledgement
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The authors are grateful to the bioinformatics infrastructure
facility (BIF) of Jamia Hamdard, for providing the facility for in silico
studies. One of the authors, Syed Ovais is thankful to the Hamdard
National Foundation (HNF) for awarding a fellowship.
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