Design, synthesis and biological evaluation of 4-(1- (4(sulphanilamide) phenyl)-3-(methyl)-1H-pyrazol-5-yl)dine urea and N-acyl derivatives as a soluble epoxide hydrolase inhibitors

Article abstract of DOI:10.1007/s00044-013-0817-8

A series of novel sEH inhibitors containing a N-substituted piperidine ring [N-urea (8a-i ) (9a-l) and amide derivatives (6a-l) (7a-l )] with pyrazole (a five-membered polar heterocycle) as a pharmacophore lead for sEH inhibition have been designed, synth

Full text of DOI:10.1007/s00044-013-0817-8

MEDICINAL
CHEMISTRY
RESEARCH
Med Chem Res (2014) 23:2178–2197
DOI 10.1007/s00044-013-0817-8
ORIGINAL RESEARCH
Design, synthesis and biological evaluation of 4-(1-
(4(sulphanilamide)phenyl)-3-(methyl)-1H-pyrazol-5-yl)dine urea
and N-acyl derivatives as a soluble epoxide hydrolase inhibitors
•
Vijaykumar D. Nimbarte Hadianawala Murtuza Sahishna Phaniraj
•
•
•
Shweta Shrivastava V. G. M. Naidu N. Satheesh Kumar Krishnam Raju Atcha
•
•
Received: 7 August 2013 / Accepted: 21 September 2013 / Published online: 10 October 2013
Ó Springer Science+Business Media New York 2013
Abstract A series of novel sEH inhibitors containing a
N-substituted piperidine ring [N-urea (8a–i) (9a–l) and
amide derivatives (6a–l) (7a–l)] with pyrazole (a five-
membered polar heterocycle) as a pharmacophore lead for
sEH inhibition have been designed, synthesized and eval-
uated as novel analogues to reduce blood pressure eleva-
tion and inflammatory roles by acting as sEH inhibitors.
The synthesized compound shows varying degree of
selectivity towards the sEH enzymes. Particularly com-
pounds 9g and 8h emerged as the most potent sEH inhib-
itor displaying IC50 values of 0.224 0.014 and
0.220 0.03 lM for in vitro sEH inhibition. Molecular
docking studies of the designed sEH dual inhibitors are
performed using 1ZD5 for sEH as the targeted proteins and
which revealed H-bond interactions similar to AUDA.
Structure–activity relationships provided useful insights in
these classes of compounds and paved the way to design
novel analogues with increased potency.
Keywords AUDA ꢀ (1,5)-Diarylpyrazole derivatives ꢀ
Hypertension ꢀ N-Acyl ꢀ sEH inhibition ꢀ Urea
Introduction
Soluble epoxide hydrolases are a group of enzymes that
facilitate the addition of water to an epoxide, resulting in
the formation of a vicinal diol. The sEH belongs to a/b
hydrolase family, specifically acting on ether bonds (ether
hydrolase) (Newman et al., 2005). Due to the structure
resemblance it shows that the sEH evolved from bacterial
haloalkane dehalogenase. Several types of epoxide hydro-
lases have been identified, including sEH, mammalian
epoxide hydrolase (mEH), cholesterol epoxide hydrolase
(Morisseau and Hammock, 2005), Leukotrienes A4
hydrolase and hepoxilin hydrolase.
These epoxide hydrolases differ in their substrate spec-
ificity. For example, sEH shows selectivity for aliphatic
epoxides such as fatty acid epoxides similarly mEH is more
selective for cyclic and arene epoxides. The four regio-
isomeric epoxides of arachidonic acid are, namely, 5, 6-, 8,
9-, 11, 12-, and 14, 15 epoxyeicosatrienoic acids (also
known as epoxyeicosatrienoic acids, i.e. EETs) and epox-
ides of linoleic acid (Fretland and Omiecinski, 2000). The
diol products of sEH mediated hydrolysis of EETs are
referred to as dihydroxyeicosatrienoic acids (DHETs). The
microsomal epoxide hydrolase (mEH) and soluble epoxide
hydrolase (sEH) are well known EHs in mammals. These
enzymes are very distantly related, have different sub
cellular localisation, and have different but partially over-
lapping substrate selectivity’s (Falck et al., 2003).
V. D. Nimbarte ꢀ H. Murtuza ꢀ S. Phaniraj ꢀ K. R. Atcha (&)
Department of Medicinal Chemistry, National Institute of
Pharmaceutical Education and Research (NIPER) Hyderabad,
Balanagar, Hyderabad 500037, India
e-mail: raju@niperhyd.ac.in
V. D. Nimbarte
e-mail: vnimbarte@gmail.com
S. Shrivastava ꢀ V. G. M. Naidu
Department of Pharmacology and Toxicology, National Institute
of Pharmaceutical Education and Research (NIPER) Hyderabad,
Balanagar, Hyderabad 500037, India
e-mail: vgmnaidu@niperhyd.ac.in
N. Satheesh Kumar
The cytochrome P450-mediated polyunsaturated fatty
acid epoxide is an important biochemical pathway medi-
ates of inflammation and blood pressure regulation (Node
Department of Pharmaceutical Analysis, National Institute of
Pharmaceutical Education and Research (NIPER) Hyderabad,
Balanagar, Hyderabad 500037, India
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Med Chem Res (2014) 23:2178–2197
2179
Fig. 1 Structures of reference
sEH inhibitor
O
S
R
O
N
N
O
H
OR
N
N
N
H
N
H
R1
O
O
1
AUDA (Standard)
CH3
Boc
CH3
H
Boc
N
N
N
N
N
N
N
NHNH2
f
b,c
d.e
a
+
O
RO2S
RO2S
RO2S
R=NH ,CH
3
H3C
O
2
N
H
O
OH
O
OH
N
Boc
5
3
4
R=NH ,CH
2
3
isonipecotic acid
2
Scheme 1 Reagents and conditions: synthesis of amide/acyl deriv-
atives of substituted pyrazoles. a NaOH, (Boc)2O, THF, 0 °C to rt,
24 h, 97 %; b CDI, DMF, 0 °C, 1 h; c (i) NaH (60 % oil dispersion),
DMF, 0 °C, (ii) acetone, °C to rt, 24 h, 70 %;
e EtOH, reflux, 6 h, 83 %; f HCl, EtOH, rt, 4 h, 97 %
d
NaNO2;
CH3
N
7a
7b
6a:
: R = NH2 , R1= Ph
: R = NH2,R1= p-ClPh
R = Me,R1 = Ph
N
6b
6c
6d
6e
: R = Me,R1= p-ClPh
: R = Me, R1 = p-MePh
: R = Me, R = p-OMePh
: R = Me, R1 = p-NO2 Ph
7c: R = NH2 , R1= p-MePh
7d: R = NH2,R1= p-OMePh
7e: R = NH2,R1= p-NO2Ph
7f: R = NH2,R1= Pr
RO2S
h, i
N
6f: R = Me, R1= Pr
CH3
R1COCl
O
N
N
R1
6a - 6f, 7a - 7f
RO2
S
CH3
8a: R = NH2, R2 = Et
8b: R = NH2 ,R2 = Pr
8c: R = NH2, R2 = i-Pr
9a: R = Me, R2 = Et
: R = Me, R2 = Pr
N
H
9b
N
N
5
9c: R = Me, R2 -Pr
=
i
h, i
8d
: R = NH2, R2 = Bu
9d: R = Me, R2 = Bu
9e: R = Me, R2 = Cy
9f
: R = Me, R2 = Ph
9g: R = Me, R2 = Bz
9h: R = Me, R2 = p-CH3 Ph
8e: R = NH2, R3 = Cy
8f: R = NH2, R2 = Ph
8g: R = NH2, R2 = Bz
R = NH2, CH3
RO2
S
R2NCO
N
8h
: R = NH2, R2 = p-CH3 Ph
8i: R = NH2, R2
=
-Cl Ph
o
9i
9j
:
:
R = Me, R2 =o-Cl Ph
R2
O
N
R = Me, R2 p-Cl Ph
=
H
9k: R = Me, R2 = 2-Et Ph
9l : R = Me, R2 = Ph Et
8a - 8l, 9a - 9i
Scheme 2 Reagents and conditions: h THF; i Et3N, 0 °C to rt, 3 h (85–90 %)
Fig. 2 Structure–activity
relationship representation of
synthesised sEH Inhibitors
analogues
CH
3
N
N
R = NH2, Me
RO2S
N
Alliphatic side chain substitution
shows improved activity
R2
O
N
H
Urea linked side chain essential for
potential sEH Inhibition
because of of th ehydrogen donor
ability of the pharmacophore
Para substituted aryl side chain
shows improved sEH Inhibition
activity (Rose et al. JMC 2010, 33,
7067)
et al., 2001). Once formed these compounds are used into
phospholipids membrane, and released by action of phos-
pholipase A2. EETs elicit a wide range of biological effects
they are putative endothelial derived hyperpolarisation
factors (EDHF) which increases open state frequency of
Ca?? ion channels which leads to vasodilatation of
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Med Chem Res (2014) 23:2178–2197
coronary arterioles and renal microvessels via the activa-
tion of BK channels (big potassium, i.e. BK) EETs elicit a
wide range of biological effects (Node et al., 2001).
Notably, potent function in vasodilatation as EDHF is
mediated through 11, 12EET is, EDHF a long-sought
endogenous metabolite with robust vascular smooth muscle
relaxing activity (Node et al., 1999). Antiinflammatory
activities exhibited mainly due to EETs, and especially
because 11, 12-EET, apparently by decreasing the
expression of cytokine induced endothelial cell adhesion
molecules, such as vascular cell adhesion molecule 1, i.e.
VCAM-1 (Fitzpatrick et al., 1986). In addition, EETs
prevented leucocyte adhesion to the vascular wall by
inhibiting NFjB (nuclear factor kappa-light-chain-enhan-
cer of activated B cells) and IKB (inhibitor of kappa B)
kinases (Iber et al., 2000). Hence, it is conceivable that
EET elevation resulting from sEH inhibition could inhibit
the NFjB pathway, and thus ameliorate vascular inflam-
mation. These properties suggest a potential application of
sEH inhibitors to the mitigation of endothelial dysfunction.
The sEH played important role in the arachidonic acid
metabolism, 4 linoleic acid (Kessler et al., 1999) and other
lipid epoxides, some which are endogenous chemical
mediators. The sEH-mediated hydrolysis of the epoxides
diminishes this activity (Samuelsson et al., 2007). Epoxides
arachidonic acid (epoxyeicosatrienoic acids or EETs) are
known effectors of blood pressure (Wallace et al., 2002) and
modulators vascular permeability (Dailey and Imming,
1999; Zalewski et al., 2006). It is already reported in that
treatment with selective sEH inhibitors significantly reduces
the blood pressure of spontaneous hypertensive rats (SHRs)
or angiotensin II induced hypertension in rats (Friesen and
Mancini, 2008; Wells and McClendon, 2007); in addition,
male knockout sEH mice have significantly lower blood
pressure than wild-type mice, further supporting the role of
sEH in blood pressure regulation. The sEH hydrolysis of
EETs also regulates their incorporation into coronary
endothelial phospholipids, suggesting a regulation of endo-
thelial function by sEH (Taylor, 2007; Chan et al., 2010).
The EETs have also demonstrated anti-inflammatory prop-
erties in endothelial cells (Smith et al., 2005; Hwang et al.,
2011).
Table 1 Inhibition of human recombinant sEH by compound 8a–8i,
9a–9l, 6a–6f and 7a–7f
Compound
code
R
R1
% sEH
IC50
inhibition value (lM)b
(100 lM)a
8a
8b
8c
8d
8e
8f
NH2 Ethyl
23.31
68.61
104.86
81.95
98.95
92.70
69.15
105.28
NA
–
NH2 Propyl
–
NH2 Isopropyl
NH2 Butyl
22.256 1.32
10.082 0.84
NH2 Cyclohexyl
NH2 Phenyl
0.275 0.027
16.699 2.11
8g
8h
8i
NH2 Benzyl
–
NH2 p-Methyl phenyl
NH2 o-Chloro phenyl
Me Ethyl
0.224 0.014
–
9a
9b
9c
9d
9e
9f
–
–
Me Propyl
–
–
Me Isopropyl
Me Butyl
45.40
99.53
113.97
89.89
94.22
NA
13.607 0.68
0.269 0.04
Me Cyclohexyl
Me Phenyl
3.471 0.52
0.220 0.03
9g
9h
9i
Me Benzyl
–
Me p-Methyl phenyl
Me o-Chloro phenyl
Me p-Chloro phenyl
Me 2-Ethyl phenyl
Me Phenyl ethyl
Me Phenyl
–
NA
–
9j
NA
–
9k
9l
NA
–
NA
–
6a
6b
6c
6d
6e
6f
NA
–
Me p-Chloro phenyl
Me p-Methyl phenyl
NA
–
42.08
–
Me p-Methoxy henyl 15.15
–
Me p-Nitro phenyl
Me Propyl
NA
–
–
–
7a
7b
7c
7d
7e
7f
NH2 Phenyl
57.2
32.5
0
–
NH2 p-Chloro phenyl
NH2 p-Methyl phenyl
–
–
NH2 p-Methoxy phenyl 32.89
–
NH2 p-Nitro phenyl
0
–
NH2 Propyl
68.7
–
AUDA
0.0065 0.002
Values are the means (SD of three independent experiments) with
sEH Fluorescent Inhibitor Screening Assay Kit (catalogue no.
10011671, Cayman Chemicals Inc., Ann Arbor, MI)
In contrast, diols derived from epoxylinoleate (leuko-
toxin) changes membrane permeability and calcium
homeostasis, (Penning et al., 1997) which is responsible for
results in inflammation that is controlled by nitric oxide
synthase and endothelin-1 (Hwang et al., 2007). Inflamma-
tion and hypoxia are reported with micro molar concentra-
tions of leukotoxin (Huang et al., 2010) depresses in vitro
mitochondrial respiration in (Shen et al., 2009a) and cause
* Enzymes (5 ll human sEH) were incubated with (2 ll) inhibitors
for 15 min in Assay buffer at 25 °C before substrate introduction ([S])
5 ll). Results are means (SD of three separate experiments)
a
Determined via a kinetic fluorescent assay, results are means (SD of
three separate experiments). Percent inhibition at 100 lM concen-
tration
b
Data points are triplicate average. We observed coefficient variation
between 5 and 10 %
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Table 2 Inhibition of human recombinant sEH by compound 8c, 8d,
8e, 8f, 8h, 9c, 9d, 9e and 9f
Compound. R and R2
code
% sEH
IC50 value
inhibition (lM)b
(100 lM)a
8c
8d
8e
R = NH2, R2 = i-Pr
104.86
81.95
98.95
22.256 1.32
R = NH2, R2 = butyl
10.082 0.84
0.275 0.027
R = NH2,
R2 = cyclohexyl
8f
R = NH2, R2 = Ph
92.70
16.699 2.11
0.224 0.014
8h
R = NH2,
R2 = p-Me–Ph
105.28
9c
9d
9e
R = Me, R2 = i-Pr
R = Me, R2 = butyl
99.53
113.97
89.89
13.607 0.68
0.269 0.04
3.471 0.52
R = Me,
R2 = cyclohexyl
Fig. 4 IC 50 value (lM)b of synthesized sEH inhibitors 8c, 8d, 8e,
8f, 8h, 9c, 9d, 9e and 9f, respectively
9f
R = Me, R2 = Ph
94.22
–
0.220 0.03
AUDA
–
0.0065 0.002
All analogues were screened by using In vitro Cayman’s
fluorescence-based sEH inhibitor screening assay kit
(Hwang et al., 2007) containing mammalian recombinant
sEH enzyme and analogues which showed greater than
80 % inhibition were taken and drug response curve (DRC)
was constructed, IC50 values were determined for them.
The obtained results were showing that the synthesized
compounds show promising sEH inhibition.
Results and discussion
Design and molecular modelling studies
1,3-disubstituted ureas have been developed as a potent sEH
inhibitor. The most common inhibitors are DCU (N,N0-
dicyclohexyl urea), ACU (N,N0-adamantylcyclohexyl urea).
Although these compound are very potent their use has been
restricted because of poor physical property, mainly water
solubility. Thus, second generation sEH inhibitors like
12-(3-adamantan-1-yl-ureido)-dodecanoic acid (AUDA)
and 1-adamantan-3-(5-(2-(2-ethylethoxy) ethoxy) pentyl)
urea (AEPU) have been developed (Fig. 1).
Fig. 3 Dose–response curve at 1, 10 and 100 lM concentration,
respectively. Results are means (SD of three separate experiments)
mammalian cardiopulmonary toxicity in vivo (Morisseau
et al., 2001; Kim et al., 2005; Campbell et al., 1996).
Epoxyeicosatrienoic acids (EETs) are formed in mam-
malian tissues by epoxygenases of the cytochrome P450
(CYP) superfamily that use arachidonic acid as their sub-
strates. Various EET regioisomers (including the 5,6-, 8,9-,
11,12-, and 14,15-EETs generated by CYP) are known to
have biological activities that render them potentially
beneficial for human health (Fang et al., 2001), although
their mechanism of action is poorly understood. Increasing
the biological concentration of EETs is emerging as a
strategy for the treatment of cardiovascular disease and
inflammatory disorders (Arand et al., 1996).
The poor oral bioavailability of AUDA and other sEH
inhibitor lead to the need for a new drug with good water
solubility and oral bioavailability. To increase the physical
and pharmacokinetic parameter, heterocyclic group is
incorporated as polar functionality and as a secondary
pharmacophore but this resulted in decreased potency
(Anton et al., 2002).
Shen et al. show that 4-substituted piperidine-derived
trisubstituted ureas are highly potent and selective inhibi-
tors for sEH. The 4-position of piperidine is found to
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Med Chem Res (2014) 23:2178–2197
Fig. 5 Dose–response curve at 1, 10 and 100 lM concentration of 8c, 8d, 8e and 8f, respectively. Results are means (SD of three separate
experiments)
crucial and use of five-membered polar heterocycle,
proved, improved sEH inhibitory activity.
protected acid 2 in 97 % yield. The acid 2 was coupled with
1,1-carbonyldi-1H-imidazole (CDI) in DMF solvent to give
imidazole coupled intermediate which was in situ further
treated with acetone under Claisen reaction conditions
(Hwanget al., 2006) using NaH as base and DMF as solvent at
room temperature to afford the requisite intermediate 1,3
diketone 3 in 70 % yield. Condensation of the diketone 3 with
methylsulphonyl phenyl hydrazine/sulphonamide phenyl
hydrazineinthepresenceofethanol gavecompounds4a/4b in
85 and 83 % yield, respectively. The compounds 4a/4b upon
Boc deprotection (Sonda et al., 2003) using HCl gave key
pyrazole intermediates 5a/5b in 85 and 90 % yield, respec-
tively (Scheme 1). The pyrazole intermediates 5a/5b was
treated with various acid chlorides and isocyanate in the pre-
sence of triethylamine as base and solvent THF afforded
corresponding novel piperidine amide and urea derivatives of
substituted pyrazoles (6a–6f), (7a–7f), (8a–8i) and (9a–9l),
respectively in approximately 85–90 % yield (Scheme 2).
Hammock and his group reported the first inhibitor
with urea and acyl pharmacophore for sEH activity
(Spector et al., 2004). We propose to prepare the
compounds that have piperidine ring and N-substituted
urea/acyl derivative of piperidine as a sEH inhibitor.
The best docking result was found with Compounds of
(9a–9l) and (8a–8i) series having hydrogen bond interaction
with sEH. The docking results match with that of the refer-
ence ligands (Atcha et al., 2012).
Chemistry
The novel piperidine amide derivatives of substituted pyra-
zoles were synthesized starting from isonipecotic acid 1. The
NH group of the isonipecotic acid1 was protected (Shen et al.,
2009b) using (Boc)2O and NaOH as base to give Boc
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Med Chem Res (2014) 23:2178–2197
2183
Fig. 6 Dose–response curve at 1, 10 and 100 lM concentration of 9c, 9d, 9e and 9f, respectively. Results are means (SD of three separate
experiments)
Structure–activity relationship
aryl side chain (8h, 8j, 6c, 6e) with electron donating group
shows potentially improved activity as compared to ortho
substituted urea pharmacophore linked compounds (8i and
9i) (Fig. 2) (Rose et al., 2010). The above observation on
the effect of urea pharmacophore and para substituted side
chain on the urea linked pharmacophore on inhibition of
sEH.
Comparison of sEH inhibitors having variable-length
spacer and effect of ortho and para substitution
on the aryl side chain
These results suggested that 1; 5-diarylpyrazole group is
sterically hindered, which has been proven to decrease sEH
inhibition. Subsequently, attempts to improve sEH inhibi-
tory activity were initiated by increasing the length of the
linker between the 1,5-diarylpyrazole linked piperidine
group and the urea group to increase hydrogen donor
ability of the pharmacophore. Acid chloride compound of
6a–f and 7a–f in which a biarylpyrazole-mediated piperi-
dine ring and an acyl group are directly connected, showed
poor sEH inhibitory activity as compared with compound
of 8a–i and 9a–l series which is linked with biarylpyrazole-
mediated piperidine ring with urea pharmacophore. A
compound with urea linked alkyl side chain of 8a–f and
9a–f series were reported to show improved the sEH
inhibition and the compound with para substitution of
methyl, methoxy, chloro and nitro group on the urea linked
Biology
The ability of the synthesized compounds to inhibit sEH
enzyme was evaluated by in vitro biological evaluation of all
compoundsforsEHactivityisplannedtobedoneusingSoluble
Epoxide Hydrolase Inhibitor Screening Assay kit (10011671).
The assay utilises (3-phenyl-oxiranyl)-acetic acid cyano-(6-
methoxy-naphtalen-2-yl)-methyl ester (PHOME) as substrate.
When the epoxide moiety of PHOME is hydrolysed by epoxide
hydrolase, an intramolecularcyclisation occurs which results in
the release of cyanohydrins under basic conditions. The cya-
nohydrin quickly decomposes into cyanide ion and highly
fluorescent 6-methoxy-2-methoxy-2-naphthaldehyde which
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Table 3 Molecular docking
study data for of human
recombinant sEH by the
designed compound
Compound
code
Docking
score
H-
bonding
Amino acid involved
in interactions
8a
8b
8c
8d
8e
8f
-7.7
-5.1
-8.4
-9.6
-9.4
-10.1
-10.0
-10.0
-10.5
-9.3
-9.5
-9.6
-9.1
-10.7
-10.0
-10.0
-10.9
-11.4
-9.3
-10.5
-10.3
-7.2
-5.3
-3.8
-2.5
-9.6
-5.5
-7.8
-6.2
-5.3
-5.4
-9.7
-7.5
2
3
3
2
3
2
2
2
2
5
4
5
3
4
5
5
4
4
4
4
4
0
1
0
2
2
2
1
2
1
2
3
4
ASP 333, TYR 381
ASP 333,TYR 381, TYR 465
ASP 333, TYR 381
ASP 333, TYR 381
ASP 333,TYR 381, TYR 465
ASP 333, TYR 381
8g
8h
8i
ASP 333, TYR 381
TYR 381
ASP 333, TYR 381
9a
9b
9c
9d
9e
9f
ARG 408, ASP 333, HIS 523
ASP 333,TYR 381, TYR 465, ARG 408
ASP 333,TYR 381, TYR 465, ARG 408
ARG 408, ASP 333, TYR 381
ASP 333,TYR 381, TYR 465, ARG 408
ASP 333,TYR 381, TYR 465, ARG 408, HIS 523
ASP 333,TYR 381, TYR 465, PHE 496, HIS 523
ARG 408, ASP 333, TYR 381, HIS 523
ASP 333,TYR 381, TYR 465, ARG 408
ASP 333,TYR 381, TYR 465, ARG 408
ASP 333,TYR 381, TYR 465, ARG 408
ARG 408, ASP 333, TYR 381, TYR 465
ASN 364
9g
9h
9i
9j
9k
9l
6a
6b
6c
6d
6e
6f
PRO 362, ASN 364
ASN 364
TYR 381, TYR 465
ASP 333,TYR 381, TYR 465
ASP 333, TYR 381, TYR 465, ASN 471
–
7a
7b
7c
7d
7e
7f
ASN 364
–
TYR 381, TYR 465
ASP 333,TYR 381
TYR 381, TYR 465
Molecular modelling
can be analysed using an excitation wavelength of 330 nm and
an emission wavelength of 465 nm (Sonda et al., 2003).The
preliminary in vitro findings of sEH enzyme inhibition studies
showed that, all the compounds (6a–6f, 7a–7f, 8a–8i, 9a–9l)
series were shown 54–100 % inhibition of the sEH enzyme at
100 lM concentration and compounds 8h and 9f emerged as
the most potent sEH inhibitors, displaying IC50 values of
0.224 0.014 and 0.220 0.03 lM for in vitro sEH inhibi-
tion, respectively which as compared to that of standard AUDA
0.0065 0.002 lM (Tables 1, 2).
Molecular docking studies were performed to get an insight
from molecular perspective about the observed sEH inhibi-
tory activity. Urea (8a–i and 9a–l) and N-acyl derivatives
(6a–f and 7a–f) subjected to docking studies. All these
compounds were built on maestro molecular builder of
¨
Schrodinger and geometry optimisation was performed
¨
using OPLS-2005 force field in Schrodinger Macro Model
(Fang et al., 2001). These compounds were docked into sEH
target (PDB ID: 1ZD5) (Arand et al., 1996) using Glide
docking tool of Schrodinger suite. NC7 was considered as
reference compound and results are presented in (Table 3;
Fig. 7). All the docked compounds have shown the similar
These results clearly indicate that all the compounds are
showing potent sEH inhibition. This activity may be due to
the additional interactions of urea linked functionalities
(Figs. 3, 4, 5, 6).
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2185
Fig. 7 Top view of 2D image
showing interactions of
compound 9f with sEH (PDB
ID: 1ZD5)
type of docking pose to that of the co-crystal ligand, NC7.
These compounds exhibited hydrogen bonding interactions
of urea linked side-chain with Asn364, Pro362, Asn471 and
Tyr381. The H-bond distances are in the range of
urea (sEH pharmacophore) side chain can improve the
inhibitory activity, and 8h and 9f displays improved in vitro
inhibition in fluorescence based sEH assay.
On the basis of molecular docking studies it was con-
cluded that the compound of Urea (8a–i and 9a–l) showed
the significant H-bonding interactions in the region of side-
chain and in back bone region of the scaffold. All designed
compound are found to have similar interactions and same
range of docking scores which resembles to the NC7
(ligand for the sEH 1ZD5).
˚
1.776–2.158 A. The bond distances between Asp333,
Tyr381, Tyr465 and side-chain alkyl chain and carbonyl
group of selected molecules and NC7 are in the range of
˚
1.88–2.56 A. Besides the above interactions, all molecules
of the present work exhibit additional hydrogen bonding
interaction of the aliphatic alkyl side chain with Asn364. In
case of molecules 6c, 7c, 8h, 9h and 9l the hydrophobic
spacer [alkyl side chain-(CH2)n] between piperidine and
urea/N-Acyl was noticed in the hydrophobic region and aryl
Experimental
´
˚
side chain was oriented towards the Tyr465, 1.852 A with
´
´
˚
˚
Tyr 381, 1.921 A, Asp333 and 2.429 A with His523. Higher
binding affinity of new compounds is a consequence of
incorporation of piperidine linked substituted aryl nucleus to
the 1,5 heterocyclic chain which mainly composed of phar-
macophore of urea linked side-chain.
General materials and methods
Reagents and solvents were purchased from commercial
suppliers (Across, Sigma-Aldrich, Avra) and used as pro-
vided, unless indicated otherwise. All the solvents used for
reactions were analytical grade and used as provided.
Reactions were carried out in oven-dried glassware under
nitrogen atmosphere and stirred at room temperature, unless
indicated otherwise. AUDA was purchased from Prolab.
1H NMR was recorded on either a Varian Unity 500 or
Bruker Avance 300 MHz’s. The samples were made in
CDCl3 and/or DMSO-d6 using TMS (tetramethylsilane) as
the internal standard. The chemical shifts are expressed as
d values in parts per million (d), using the residual solvent
Conclusions
In conclusion, a series of novel sEH inhibitors were designed
and synthesized to provide the basis for a structure–activity
relationship (SAR) studies. The synthesized compounds
show significant inhibition of sEH. This study has suggested
that a grouping of diaryl pyrazole and piperidine mediated
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Med Chem Res (2014) 23:2178–2197
1
1
peaks (chloroform: H, 7.26 d; DMSO: H, 2.50 d) as a
reference. Coupling constants are given in Hertz (Hz). The
peak patterns are indicated by the following abbreviations:
brs = broad singlet, s = singlet, d = doublet, t = triplet,
q = quartet and m = multiple.
8.35; N, 6.11; O, 27.91; found C, 57.61; H, 8.34; N, 6.10;
O, 27.90.
Tert-butyl 4-(3-oxobutanoyl)piperidine-1-carboxylate (3)
Highresolution massspectra were recorded onMicro Mass
VG-7070H Mass spectrometer for ESI. Infrared spectra were
recorded on Perkin-Elmer Infrared spectrophotometer with
NaCl optics. Spectra were calibrated against the polystyrene
absorption at 1,610 cm-1. Samples were scanned in neat KBr
pellets. Melting points were determined on an SMP3 Stuart
melting point apparatus and are uncorrected.
This compound was prepared by addition of 1,10-carbonyl-
diimidazole (1.7 g, 10.5 mmol) to a solution of 1-(tert-
butoxycarbonyl)piperidine-4-carboxylic acid (2) (2 g,
8.8 mmol) in dimethyl formamide (5 mL) was added at 0 °C
and the mixture was stirred vigorously for 1 h. Further, to a
solution of NaH (60 % oil dispersion) (0.5 g, 13 mmol) in
dimethylformamide (10 mL) was added acetone (1 mL,
13 mmol) at 0 °C and stirred for about 1 h. Subsequently,
1,10-carbonyldiimidazole coupled boc-protected isonipe-
cotic acid was added to the mixture and stirred for 30 min.
The reaction mixture was allowed to warm to room tem-
perature and stirred for overnight. The resulting mixture was
quenched with cool water and acidified to pH 5–6 with 5 M
citric acid. It was extracted with EtoAc/hexanes (1:1)
(2 9 100 mL, then 2 9 50 mL) and the combined organic
extracts were washed with brine and dried over anhydrous
NaSO4. Solvent was evaporated under reduced pressure
which was then purified by silica gel column chromatogra-
phy using EtoAc/hexanes (1:9) as an eluent to get compound
the diketone 3 (1.04 g, 70 %) and it was obtained as a white
For TLC, precoated aluminium sheets were used
(Merck, Silica Gel 60 F254). The spots were visualised by
UV light. Column chromatography was performed using
silica gel (60–120, 100–200 mesh) and the column was
usually eluted with EtOAc/hexanes. All evaporation of
solvents was carried out under reduced pressure on Hei-
dolph Laborota-4000 rotary evaporator below 45 °C. All
compounds were characterised by NMR and MS.
Purity of the compounds were detected by HPLC system
[Waterse2695 (alliance)] consisting of low pressure gradient
pump plus auto sampler and Photo Diode Array (PDA)
detector. The column used was GRACE-C18 (250 9 4.6 9
5 mm). The mobile phase was 1 % TFA (pH 3.25) and ACN
(gradient elution) with a flow rate of 1 mL/min.
solid; mp 53–55 °C; IR (KBr): m 3,358, 1,686, 1,605 cm-1
;
1
TLC: EtoAc/hexanes (3:7), Rf * 0.5; H NMR (CDCl3,
300 MHz): d 5.50 (1H, s), 4.18–4.11 (2H, m), 2.79–2.62 (2H,
m), 2.34–2.27 (1H, m), 2.07 (3H, s), 1.58–1.52 (2H, m), 1.45
(s, 9H); 13C NMR (75 MHz, DMSO-d6): d 186.1 (C1), 168.5
(C2), 149.5 (C3), 82.7 (C4), 74.2 (C5), 49.2 (C6, C7), 45.3
(C8), 41.5 (C9, C10), 30.1 (C11), 27.5 (C12), 27.2 (C13),
26.2 (C14); MS (ESI): m/z [M?23]? 292; Anal. Calcd. for
C14H23NO4: C, 62.43; H, 8.61; N, 5.20; O, 23.76; Found C,
62.41; H, 8.60; N, 5.21; O, 23.75.
Starting material
The isonipecotic acid 1 was commercially obtained from
Avra lab and used as provided.
1-(Tert-butoxycarbonyl)piperidine-4-carboxylic acid (2)
This compound was prepared by addition of drop wise 1 N
NaOH (20 mL) to a solution of acid 1 (1 g, 7.75 mmol) in
THF (5 mL) at 0 °C. To this was added di-tert-butyl
dicarbonate (4 mL, 16.7 mmol) drop-wise over a period of
5 min with vigorous stirring. After 30 min, the mixture was
brought to room temperature and allowed to stir overnight.
The resulting mixture was concentrated to half of the ori-
ginal volume and then neutralised with dilute HCl (pH
5–6). The precipitated compound was filtered, washed with
water and air-dried to give the titled compound 2 (1.73 g,
97 %) and it was obtained as a white colour solid; mp
144–147 °C; IR (KBr): m 3,214, 1,734, 1,662 cm-1. TLC:
General procedure for the synthesis of boc protected
(methylsulphonyl/sulphonamide) phenyl pyrazoles (4a)
and (4b)
This compounds were prepared by addition (4-(methyl-
sulphonyl)phenyl)hydrazine (1.0 g, 5.3 mmol)/4-hydrazi-
nylbenzenesulphonamide (1.0 g, 5.3 mmol) a solution of
tert-butyl 4-(3-oxobutanoyl)piperidine-1-carboxylate
3
(2.0 g, 7.4 mmol) in ethanol (75 mL) was and refluxed for
about 20 h. The resulting mixture was allowed to cool to
room temperature and solvent was evaporated under
reduced pressure. The residue was extracted with EtoAc
(2 9 50 ml) followed by brine wash (2 9 30 ml). The
combined organic layer was then dried over anhydrous
NaSO4 and the solvent was evaporated under reduced
pressure which was then purified by silica gel column
1
Methanol, Rf * 0.7; H NMR (CDCl3, 300 MHz): d 4.02
(d, 2H, J = 12.0 Hz), 2.85 (t, 2H, J = 12.0 Hz), 2.54–2.43
(m, 1H), 1.9 (d, 2H, J = 13.2 Hz), 1.71–1.56 (m, 2H), 1.45
(s, 9H); 13C NMR (75 MHz, DMSO-d6) d 161.5 (C1),
149.5 (C2), 149.0, 82.7 (C3), 49.2 (C4, C5), 45.3 (C6), 41.5
(C7, C8), 27.5 (C9), 27.2 (C10), 26.2 (C11); MS (ESI): m/z
[M ? 23]? 252; Anal. Calcd. for C11H19NO4 C, 57.62; H,
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Med Chem Res (2014) 23:2178–2197
2187
chromatography using EtoAc/Hexanes (3:7) as an eluent to
(methylsulphonyl)phenyl)-1H-pyrazol-5-yl)piperidine-1-car-
boxylate (4a)/tert-butyl 4-(3-methyl-1-(4-sulphamoylphe-
nyl)-1H-pyrazol-5-yl)piperidine-1-carboxylate (4b) (2.7 g,
6.4 mmol) in ethanol (10 ml) was and stirred vigorously
for about 4 h at room temperature. The solvent was
evaporated under reduced pressure and the obtained resi-
due was washed with Methanol: EtoAc (1:9) (2 9 30 ml)
to give compounds 5a and 5b, respectively.
give compounds 4a and 4b, respectively.
Tert-butyl 4-(3-methyl-1-(4-(methylsulphonyl)phenyl)-1H-
pyrazol-5-yl)piperidine-1-carboxylate (4a)
This compound was prepared from compound 3 (2.0 g,
7.4 mmol) by the general procedure detailed above and it
was obtained as a yellow solid (2.7 g, 83 % yield); mp
160–163 °C; TLC: EtoAc/Hexanes (6:4), Rf * 0.5. IR
4-(3-Methyl-1-(4-(methylsulphonyl)phenyl)-1H-pyrazol-5-
yl)piperidine (5a)
(KBr): m 1,703, 1,415, 1,315, 1,151 cm-1 1H NMR
;
(CDCl3, 300 MHz): d 8.06 (d, 2H, J = 9.1 Hz), 7.63
(d, 2H, J = 9.1 Hz), 6.07 (s, 1H), 4.22–4.14 (m, 2H), 3.11
(s, 3H), 2.84–2.78 (m, 1H), 2.67 (t, 2H, J = 12.8 Hz), 2.31
(s, 3H),1.80 (d, 2H, J = 12.1 Hz), 1.67–1.53 (m, 2H), 1.47
(s, 9H); 13C NMR (75 MHz, DMSO-d6) d 161.5 (C1),
149.5 (C2), 149.0 (C3), 143.9 (C4), 133.4 (C5), 130.3 (C6),
127.1 (C11), 110.2 (C12), 82.7 (C13), 49.2 (C14), 48.7
(C15), 45.3 (C16), 44.5 (C17), 37.2 (C18), 27.5 (C19), 27.2
(C20), 26.2 (C21); MS (ESI): m/z [M?1]? 420; Anal.
Calcd. for C21H29N3O4S: C, 60.12; H, 6.97; N, 10.02; O,
15.25; S, 7.64, Found C, 60.11; H, 6.98; N, 10.02; O,
15.24; S, 7.63.
This compound was prepared from compound 4a (2.0 g,
7.4 mmol) by the general procedure detailed above and it
was obtained as a white solid (2.0 g, 97 % yield); mp
183–187 °C. TLC: methanol, Rf * 0.2; IR (KBr): m 3,401,
1
1,433, 1,289, 1,150 cm-1; H NMR (CDCl3, 300 MHz): d
9.68–9.55 (m, 3H), 8.05 (d, 2H, J = 8.3 Hz), 7.67 (d, 2H,
J = 6.3 Hz), 6.19 (s, 1H), 3.38 (d, 2H, J = 12.1 Hz), 3.13
(s, 3H), 3.09–3.06 (m, 1H), 3.00–2.92 (m, 2H), 2.28 (s,
3H), 2.19–1.97 (m, 4H); 13C NMR (75 MHz, DMSO-d6) d
161.5 (C1), 149.5 (C2), 149.0 (C3), 143.9 (C4), 133.4 (C5),
130.3 (C6), 127.1 (C11), 110.2 (C12), 82.7 (C13), 49.2
(C14), 44.5 (C15), 37.2 (C16); MS (ESI): m/z [M?1]? 320;
Anal. Calcd for C16H21N3O2S C, 60.16; H, 6.63; N, 13.16;
O, 10.02; S, 10.04; Found C, 60.15; H, 6.62; N, 13.15; O,
10.01; S, 10.03.
Tert-butyl 4-(3-methyl-1-(4-sulphamoylphenyl)-1H-
pyrazol-5-yl)piperidine-1-carboxylate (4b)
This compound was prepared from compound 3 (2.0 g,
7.4 mmol) by the general procedure detailed above and it
was obtained as a yellow solid (2.7 g, 83 % yield); mp
201–203 °C; TLC: EtoAc/Hexanes (7:3), Rf * 0.4. IR
4-(3-Methyl-5-(piperidin-4-yl)-1H-pyrazol-1-
yl)benzenesulphonamide (5b)
This compound was prepared from compound 4b (2.0 g,
7.4 mmol) by the general procedure detailed above and it
was obtained as white solid (2.0 g, 97 % yield); mp
244–246 °C; IR (KBr): m 3,326, 1,326, 1,156 cm-1; TLC:
methanol/DCM (1:1), Rf * 0.4. 1H NMR (CDCl3,
300 MHz): d 8.01 (d, 2H, J = 8.3 Hz), 7.81–7.74 (m, 1H),
7.53 (d, 2H, J = 8.4 Hz), 6.08 (s, 1H), 3.07 (d, 2H,
J = 12.4 Hz), 2.85–2.74 (m, 1H), 2.63–2.50 (m, 4H), 2.27
(s, 3H), 1.82–1.71 (m, 2H), 1.63–1.48(m, 2H); 13C NMR
(75 MHz, DMSO-d6) d 161.5 (C1), 149.5 (C2), 149.0 (C3),
143.9 (C4), 133.4 (C5), 130.3 (C6), 127.1 (C11), 110.2
(C12), 82.7 (C13), 44.5 (C14), 37.2 (C15); MS (ESI): m/z
[M?1]? 321; Anal. Calcd for C15H20N4O2S, C, 56.23; H,
6.29; N, 17.49; O, 9.99; S, 10.01; Found C, 56.22; H, 6.27;
N, 17.48; O, 9.98; S, 10.02.
(KBr): m 3,284, 1,673, 1,343, 1,166 cm-1 1H NMR
;
(CDCl3, 300 MHz): d 8.06 (d, 2H, J = 8.5 Hz), 7.52 (d,
2H, J = 4.0 Hz), 6.95–6.80 (m, 2H), 6.06 (s, 1H),
4.16–4.11 (m, 2H), 2.75–2.57 (m, 3H), 2.28 (s, 3H), 1.80
(d, 1H, J = 12.6 Hz), 1.61–1.49 (m, 2H), 1.45 (s, 9H).; 13
C
NMR (75 MHz, DMSO-d6) d 161.5 (C1), 149.5 (C2),
149.0 (C3), 143.9 (C4), 133.4 (C5), 130.3 (C6), 127.1
(C11), 110.2 (C12), 82.7 (C13), 49.2 (C14), 48.7 (C15),
45.3 (C16), 44.5 (C17), 37.2 (C18), 27.5 (C19), 27.2 (C20);
MS (ESI): m/z [M?1]? 421; Anal. Calcd. for
C20H28N4O4S C, 57.12; H, 6.71; N, 13.32; O, 15.22; S,
7.62; Found: C, 57.11; H, 6.70; N, 13.32; O, 15.22; S, 7.62.
General procedure for the synthesis of 4-(3-methyl-1-(4-
(methylsulphonyl)phenyl)-1H-pyrazol-5-yl)piperidine (5a)/
4-(3-methyl-5-(piperidin-4-yl)-1H-pyrazol-1-
General procedure for piperidine amide disubstituted
pyrazole (6a–6f and 7a–7f) synthesis
yl)benzenesulphonamide pyrazoles (5b)
To a solution of compound 4a/4b (0.4 g, 1.2 mmol) in
THF (15 mL) was added Et3N (2 mL) and stirred for about
This compound was prepared by the addition of HCl
(0.5 ml) to a solution of tert-butyl 4-(3-methyl-1-(4-
123

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Med Chem Res (2014) 23:2178–2197
(4-(3-Methyl-1-(4-(methylsulphonyl)phenyl)-1H-pyrazol-5-
yl)piperidin-1-yl)(p-tolyl)methanone (6c)
20 min. To the resulting mixture, the corresponding acid
chloride was added at 0 °C and allowed to come to room
temperature and stirred for 3 h. The solvent was evaporated
under vacuum to give respective amide derivative which
was further purified by column chromatography using
EtoAc/hexanes as an eluent.
This compound was prepared by treating compound 4a
with p-methyl phenyl isocyanate using the procedure
detailed above and it was obtained as a white solid in 96 %
as yield; mp 197–199 °C; TLC: EtoAc/hexanes (9:1),
Rf * 0.3; IR (KBr): m 1,615, 1,300, 1,149 cm-1; 1H NMR
(DMSO-d6, 300 MHz): d 8.29 (d, 2H, J = 8.7 Hz), 8.07
(d, 2H, J = 8.7 Hz), 7.68–7.56 (m, 4H), 6.14 (s, 1H),
4.84–4.69 (m, 1H), 3.716–3.580 (m, 1H), 3.13 (s, 3H),
3.08–2.98 (m, 3H), 2.37 (s, 3H), 2.26(s, 3H), 1.87–1.70 (m,
2H), 1.64–1.51 (m, 2H); 13C NMR (CDCl3, 75 MHz): d
164.5 (C1), 152.5 (C2), 149.0 (C3), 145.9 (C4), 135.6 (C5),
134.3 (C6), 128.0 (C11), 110.2 (C12), 82.7 (C13), 49.2
(C14), 48.7 (C15), 45.3 (C16), 44.5 (C17), 37.2 (C18), 28.2
(C19), 27.6 (C20), 27.3 (C21), 26.4 (C22), 24.5 (C23), 18.5
(C24); MS (ESI): m/z [M?1]? 438; HRMS (ESI m/z)
Calcd for C24H27N3O3S: 438.1841 and found: 438.1840;
Anal. Calcd. for C24H27N3O3S C, 65.88; H, 6.22; N, 9.60;
O, 10.97; S, 7.33, Found, C, 65.87; H, 6.21; N, 9.62; O,
10.96; S, 7.33; Purity: 99.22 % (Rt = 12.60 min).
(4-(3-Methyl-1-(4-(methylsulphonyl)phenyl)-1H-pyrazol-5-
yl)piperidin-1-yl) (Phenyl)methanone (6a)
This compound was prepared by treating compound 4a
with phenyl isocyanate using the procedure detailed above
and it was obtained as a white solid in 95 % as yield; mp
82–84 °C; TLC: EtoAc/hexanes (9:1), Rf * 0.4. IR (KBr):
1
m 3,438, 1,625, 1,299, 1,151 cm-1; H NMR (DMSO-d6,
300 MHz): d 8.27 (d, 2H, J = 8.7 Hz), 8.07 (d, 2H,
J = 8.7 Hz), 7.68–7.56 (m, 6H), 6.14 (s, 1H), 4.84–4.69
(m, 1H), 3.71–3.58 (m,1H), 3.13 (s, 3H), 3.08–2.98 (m,
2H), 2.30 (s, 3H), 1.87–1.70 (m, 2H), 1.64–1.51 (m, 2H).;
13C NMR (75 MHz, DMSO-d6) d 161.5 (C1), 149.5 (C2),
149.0 (C3), 143.9 (C4), 133.4 (C5), 130.3 (C6), 127.1
(C11), 110.2 (C12), 82.7 (C13), 49.2 (C14), 48.7 (C15),
45.3 (C16), 44.5 (C17), 37.2 (C18), 27.5 (C19), 27.2 (C20),
26.2 (C21), 24.3 (C22), 18.3 (C23); MS (ESI): m/z [M?1]?
424; HRMS (ESI m/z) Calcd for C23H25N3O3S: 424.1687
and found: 424.1689; Anal. Calcd. for C23H25N3O3S: C,
65.23; H, 5.95; N, 9.92; O, 11.33; S, 7.57. Found C, 65.22;
H, 5.96; N, 9.91; O, 11.32; S, 7.56; purity: 96.47 %
(Rt = 11.665 min).
(4-Methoxyphenyl)(4-(3-methyl-1-((methylsulphonyl)
phenyl)-1H-pyrazol-5-yl)piperidin-1-yl)methanone (6d)
This compound was prepared by treating compound 4a
with p-methoxyphenyl isocyanate using the procedure
detailed above and it was obtained as a white solid in 96 %
as yield; mp 96–98 °C; TLC: EtoAc/hexanes (9:1),
Rf * 0.3; IR (KBr): m 2,924, 2,855, 1,624, 1,244,
(4-Chlorophenyl)(4-(3-methyl-1-(4(methylsulphonyl)
phenyl)-1H-pyrazol-5-yl) piperidin-1-yl)methanone (6b)
1
1,150 cm-1; H NMR (DMSO-d6, 300 MHz): d 8.23 (d,
2H, J = 8.7 Hz), 8.07 (d, 2H, J = 8.7 Hz), 7.68–7.56 (m,
4H), 6.14 (s, 1H), 4.84–4.69 (m, 1H), 3.716–3.580 (m, 1H),
3.13 (s, 3H), 3.08–2.98 (m, 3H), 2.31(s, 3H), 2.26(s, 3H),
1.87–1.70 (m, 2H), 1.64–1.51 (m, 2H), 13C NMR (CDCl3,
75 MHz): d 162.5 (C1), 152.5 (C2), 149.2 (C3), 145.9
(C4), 135.6 (C5), 134.5 (C6), 128.4 (C11), 110.2 (C12),
82.7 (C13), 49.3 (C14), 48.6 (C15), 45.2 (C16), 44.5 (C17),
37.2 (C18), 36.5 (C19), 27.5 (C20), 27.3 (C21), 27.3 (C22),
24.5 (C23), 18.5 (C24); MS (ESI): m/z [M?1]? 438;
This compound was prepared by treating compound 4a
with 4-chlorophenyl isocyanate using the procedure
detailed above and it was obtained as a white solid in 93 %
as yield; mp 196–198 °C; TLC: EtoAc/hexanes (9:1),
1
Rf * 0.4; IR (KBr): m 1,615, 1,299, 1,150, 840 cm-1; H
NMR (DMSO-d6, 300 MHz): d 8.24 (d, 2H, J = 8.7 Hz),
8.17 (d, 2H, J = 8.7 Hz), 7.64–7.53 (m, 4H), 6.14 (s, 1H),
4.82–4.66 (m, 1H), 3.71–3.58 (m, 1H), 3.13 (s, 3H),
3.08–2.98 (m, 2H), 2.30 (s, 3H), 1.87–1.70 (m, 2H),
1.64–1.51 (m, 2H); 13C NMR (CDCl3, 75 MHz): d 165.5
(C1), 151.5 (C2), 149.0 (C3), 145.9 (C4), 135.3 (C5), 134.3
(C6), 128.1 (C11), 110.2 (C12), 82.7 (C13), 49.2 (C14),
48.7 (C15), 45.3 (C16), 44.5 (C17), 37.2 (C18), 27.6 (C19),
27.3 (C20), 26.4 (C21), 24.5 (C22), 18.5 (C23); MS (ESI):
m/z [M?1]? 458; HRMS (ESI m/z) Calcd for
C23H24ClN3O3S: 458.1256 and found: 458.1258; Anal.
Calcd. for C23H24ClN3O3S C, 60.32; H, 5.28; Cl, 7.74; N,
9.18; O, 10.48, S, 7.00; Found C, 60.31; H, 5.29; Cl, 7.73;
N, 9.17; O, 10.47; S, 7.00; Purity: 99.62 %
(Rt = 12.863 min).
HRMS
(ESI
m/z)
Calcd
for
C24H27N3O4S
(M?1) = 454.1843, Found (M?1) = m/z 454.1842; Anal.
Calcd. for C24H27N3O4S C, 63.56; H, 6.00; N, 9.26; O,
14.11; S, 7.07, Found, C, 63.55; H, 6.01; N, 9.27; O, 14.10;
S, 7.06; Purity: 96.53 % (Rt = 11.752 min).
(4-(3-Methyl-1-(4-(methylsulphonyl)phenyl)-1H-pyrazol-5-
yl)piperidin-1-yl)(4-nitrophenyl)methanone (6e)
This compound was prepared in 95 % yield as a white solid
by treating compound 4a with 4-nitrophenyl isocyanate
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Med Chem Res (2014) 23:2178–2197
2189
using the procedure detailed above; mp 191–193 °C; TLC:
EtoAc/hexanes (9:1), Rf * 0.4; IR (KBr): m 2,921, 1,636,
3.72–3.46 (m, 1H), 3.02–2.90 (m, 2H), 2.42–2.36 (m, 2H),
2.26 (s, 3H), 1.80–1.64 (m, 2H),1.57–1.48 (m, 2H), 13C
NMR (CDCl3, 75 MHz): d 8.07 (d, 2H, J = 8.5 Hz), 7.65
(d, 2H, J = 8.5 Hz), 6.07 (s, 1H), 4.69 (d, 1H,
J = 11.8 Hz), 3.91 (d, 1H, J = 13.7 Hz), 3.13 (s, 3H),
3.07–2.90 (m, 2H), 2.56–2.44 (m, 1H), 2.41–2.31 (m, 2H),
2.29 (s, 3H), 1.88 (d, 2H, J = 12.4 Hz), 1.62–1.50 (m, 2H),
1.14 (t, 3H, J = 7.36 Hz), 13C NMR (CDCl3, 75 MHz): d
161.5 (C1), 151.2 (C2), 149.8 (C3), 145.8 (C4), 139.8 (C5),
134.5 (C6), 128.4 (C11), 110.2 (C12), 82.7 (C13), 45.2
(C14), 44.5 (C15), 37.2 (C16), 36.5 (C17), 27.5 (C18), 27.3
(C19), 27.3 (C20), 26.4 (C21), 18.5 (C22); MS (ESI): m/
z [M?1]? 425; HRMS (ESI m/z) Calcd for C22H24N4O3S:
425.1644 and found: 425.1645; Anal. Calcd for
C22H24N4O3S C, 62.24; H, 5.70; N, 13.20; O, 11.31; S,
7.55, Found C, 62.23; H, 5.71; N, 13.21; O, 11.30; S, 7.55;
Purity: 96.30 % (Rt = 5.413 min).
1,596, 1,277, 1,149 cm-1
;
1H NMR (DMSO-d6,
300 MHz): d 8.29 (d, 2H, J = 8.7 Hz), 8.07 (d, 2H,
J = 8.7 Hz), 7.68–7.56 (m, 4H), 6.14 (s, 1H), 4.84–4.69
(m, 1H), 3.716–3.580 (m, 1H), 3.13 (s, 3H), 3.08–2.98 (m,
3H), 2.30 (s, 3H), 1.87–1.70 (m, 2H), 1.64–1.51 (m, 2H);
13C NMR (CDCl3, 75 MHz): d 161.5 (C1), 151.5 (C2),
149.2 (C3), 145.5 (C4), 138.6 (C5), 134.5 (C6), 128.4
(C11), 110.2 (C12), 82.7 (C13), 49.3 (C14), 48.6 (C15),
45.2 (C16), 44.5 (C17), 37.2 (C18), 36.5 (C19), 27.3 (C20),
27.3 (C21), 26.4 (C22), 18.5 (C23); MS (ESI): m/z [M?1]?
469; HRMS (ESI m/z) Calcd for C23H24N4O5S: 469.1535
and found: 469.1536; Anal. Calcd. for C23H24N4O5S C,
58.96; H, 5.16; N, 11.96; O, 17.07; S, 6.84, Found C,
58.95; H, 5.15; N, 11.96; O, 17.06; S, 6.83; Purity: 97.44 %
(Rt = 11.204 min).
1-(4-(3-Methyl-1-(4-(methylsulphonyl)phenyl)-1H-pyrazol-
4-(5-(1-(4-Chlorobenzoyl)piperidin-4-yl)-3-methyl-1H-
5-yl)piperidin-1-yl)propan-1-one (6f)
pyrazol-1-yl)benzene-sulphonamide (7b)
This compound was prepared by treating compound 4a
with ethyl isocyanate using the procedure detailed above
and it was obtained as a white solid in 96 % as yield; mp
157–159 °C; TLC: EtoAc/hexanes (9:1), Rf * 0.4; IR
This compound was prepared by treating compound 4b
with 4-chlorophenyl isocyanate using the procedure
detailed above and it was obtained as a white solid in 96 %
as yield; mp 250–251 °C; TLC: EtoAc/hexanes (9:1),
Rf * 0.5; IR (KBr): m 3,203, 3,070, 1,616, 1,268,
(KBr): m 2,920, 1,645, 1,298, 1,151 cm-1 1H NMR
;
1
(DMSO-d6, 300 MHz): d 8.07 (d, 2H, J = 8.5 Hz), 7.65
(d, 2H, J = 8.5 Hz), 6.07 (s, 1H), 4.69 (d, 1H,
J = 11.8 Hz), 3.91 (d, 1H, J = 13.7 Hz), 3.13 (s, 3H),
3.07–2.90 (m, 2H), 2.56–2.44 (m, 1H), 2.41–2.31 (m, 2H),
2.29 (s, 3H), 1.88 (d, 2H, J = 12.4 Hz), 1.62–1.50 (m, 2H),
1.14 (t, 3H, J = 7.36 Hz); 13C NMR (CDCl3, 75 MHz): d
161.5 (C1), 151.2 (C2), 149.8 (C3), 145.8 (C4), 139.6 (C5),
134.3 (C6), 128.4 (C7), 110.2 (C8), 82.7 (C9), 45.2 (C10),
44.5 (C11), 37.2 (C12), 36.5 (C13), 27.5 (C14), 27.3 (C15),
27.3 (C16), 26.4 (C17), 18.9 (C18), 18.5 (C19); MS (ESI):
m/z [M?1]? 376; HRMS (ESI m/z) Calcd for
C19H25N3O3S: 376.1693 and found: 376.1694; Anal.
Calcd. for C19H25N3O3S C, 60.78; H, 6.71; N, 11.19; O,
12.78; S, 8.54, Found C, 60.79; H, 6.72; N, 11.18; O,
12.77; S, 8.53; Purity: 97.44 % (Rt = 10.043 min).
1,164 cm-1; H NMR (DMSO-d6, 300 MHz): d 8.21 (s,
2H), 7.91 (d, 2H, J = 7.7 Hz), 7.60 (d, 2H, J = 7.7 Hz),
7.53–7.39 (m, 1H), 7.21 (d, 2H, J = 7.8 Hz), 6.23 (s, 1H),
4.54–4.39 (m, 1H), 3.72–3.43 (m, 1H), 3.02–2.90 (m, 2H),
2.42–2.36 (m, 2H), 2.26 (s, 3H), 1.80–1.64 (m, 2H),
1.57–1.48 (m, 2H), 13C NMR (CDCl3, 75 MHz): d 161.5
(C1), 151.2 (C2), 149.8 (C3), 145.8 (C4), 139.8 (C5), 134.5
(C6), 128.4 (C11), 110.2 (C12), 82.7 (C13), 45.2 (C14),
44.5 (C15), 37.2 (C16), 36.5 (C17), 27.5 (C18), 27.3 (C19),
27.3 (C20), 26.4 (C21), 18.5 (C22); MS (ESI): m/z [M?1]?
459; HRMS (ESI m/z) Calcd for C22H23ClN4O3S:
459.1253 and found: 459.1252; Anal. Calcd for
C22H23ClN4O3S C, 57.57; H, 5.05; Cl, 7.72; N, 12.21; O,
10.46; S, 6.99, Found C, 57.56; H, 5.04; Cl, 7.71; N, 12.20;
O, 10.43; S, 6.89; Purity: 96.41 % (Rt = 6.624 min).
4-(5-(1-Benzoylpiperidin-4-yl)-3-methyl-1H-pyrazol-1-yl)
4-(3-Methyl-5-(1-(4-methylbenzoyl)piperidin-4-yl)-1H-
benzenesulphonamide (7a)
pyrazol-1-yl)benzenesulphonamide (7c)
This compound was prepared by treating compound 4b
with phenyl isocyanate using the procedure detailed above
and it was obtained as a white solid in 95 % as yield; mp
138–139 °C; TLC: EtoAc/hexanes (9:1), Rf * 0.5; IR
(KBr): m 3,206, 3,064, 1,613, 1,279, 1,163 cm-1; 1H NMR
(DMSO-d6, 300 MHz): d 8.21 (s, 2H), 7.91 (d, 2H,
J = 7.7 Hz), 7.63 (d, 2H, J = 7.7 Hz), 7.43–7.36 (m, 2H),
7.22 (d, 2H, J = 7.8 Hz), 6.20 (s, 1H), 4.56–4.38 (m, 1H),
This compound was prepared by treating compound 4b
with 4-methylphenyl isocyanate using the procedure
detailed above and it was obtained as a white solid in 96 %
as yield; mp 253–254 °C; TLC: EtoAc/hexanes (9:1),
Rf * 0.4; IR (KBr): m 3,204, 2,939, 1,614, 1,214,
1
1,163 cm-1; H NMR (DMSO-d6, 300 MHz): d 7.92 (d,
2H, J = 8.7 Hz), 7.65 (d, 2H, J = 8.7 Hz), 7.46 (s, 2H),
7.27 (d, 2H, J = 6.8 Hz), 7.22 (d, 2H, J = 7.8 Hz), 6.26 (s,
123

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1H), 4.56–4.38 (m, 1H), 3.72–3.46 (m, 1H), 3.02 (t, 2H,
J = 11.68 Hz), 2.82–2.66 (m, 1H), 2.31 (s, 3H), 2.18 (s,
3H), 1.90–1.64 (m, 2H), 1.57–1.48 (m, 2H); 13C NMR
(CDCl3, 75 MHz): d 162.5 (C1), 151.2 (C2), 149.5 (C3),
145.8 (C4), 139.8 (C5), 137.5 (C6), 128.4 (C11), 110.2
(C12), 82.7 (C13), 47.2 (C14), 45.2 (C15), 44.5 (C16), 37.2
(C17), 36.5 (C18), 27.5 (C19), 27.3 (C20), 27.3 (C21), 26.4
(C22), 18.5 (C23); MS (ESI): m/z [M?1]? 439; HRMS
(ESI m/z) Calcd for C23H26N4O3S: 439.1842 and found:
439.1844; Anal. Calcd for C23H26N4O3S: C, 62.99; H,
5.98; N, 12.78; O, 10.94; S, 7.31, Found C, 62.99; H, 5.98;
N, 12.78; O, 10.94; S, 7.31; Purity: 97.10 %
(Rt = 6.642 min).
82.7 (C13), 45.2 (C14), 44.5 (C15), 37.2 (C16), 36.5 (C17),
27.5 (C18), 27.3 (C19), 27.3 (C20), 26.4 (C21), 18.5 (C22);
MS (ESI): m/z [M?1]? 470; HRMS (ESI m/z) Calcd for
C22H23N5O5S: 470.1490 and found: 470.1490; Anal. Calcd
for C22H23N5O5S C, 56.28; H, 4.94; N, 14.92; O, 17.04; S,
6.83, Found C, 56.27; H, 4.93; N, 14.91; O, 17.04; S, 6.83;
Purity: 97.44 % (Rt = 10.94 min).
4-(3-Methyl-5-(1-propionylpiperidin-4-yl)-1H-pyrazol-1-
yl)benzenesulphonamide (7f)
This compound was prepared by treating compound 4b with
ethyl isocyanate using the procedure detailed above and it
was obtained as a white solid in 96 % as yield; mp 96–98 °C;
TLC: EtoAc/hexanes (9:1), Rf * 0.5; IR (KBr): m 3,205,
4-(5-(1-(4-Methoxybenzoyl)piperidin-4-yl)-3-methyl-1H-
pyrazol-1-yl)benzenesulphonamide (7d)
3,073, 1,619, 1,214, 1,162 cm-1 1H NMR (DMSO-d6,
;
300 MHz): d 7.93 (d, 2H, J = 8.7 Hz), 7.65–7.56 (m, 2H),
7.43–7.35 (m, 2H), 6.13 (s, 1H), 4.44 (d, 1H, J = 12.6 Hz),
3.83 (d, 1H, J = 12.6 Hz), 3.03–2.93 (m, 2H), 2.37–2.22 (m,
3H), 2.17 (s, 3H), 1.78 (d, 2H, J = 12.6 Hz, 2H), 1.50–1.29
(m, 2H), 0.98 (t, 3H, J = 7.7 Hz); 13C NMR (CDCl3,
75 MHz): d 160.5 (C1), 145.2 (C2), 139.8 (C3), 137.5 (C4),
128.4 (C5), 110.5 (C6), 82.7 (C7), 48.2 (C8), 45.2 (C9), 44.5
(C10), 37.2 (C11), 36.5 (C12), 27.5 (C13), 27.3 (C14), 27.3
(C15), 26.4 (C16), 18.5 (C17), 18.2 (C18); MS (ESI): m/
z [M?1]? 377; HRMS (ESI m/z) Calcd for C18H24N4O3S:
377.1650 and found: 377.1649; Anal. Calcd for
C18H24N4O3S C, 57.43; H, 6.43; N, 14.88; O, 12.75; S, 8.52,
Found C, 57.42; H, 6.42; N, 14.87; O, 12.75; S, 8.52; Purity:
99.29 % (Rt = 9.356 min).
This compound was prepared by treating compound 4b with
4-methoxy phenyl isocyanate using the procedure detailed
above and it was obtained as a white solid in 96 % as yield;
mp 218–219 °C. TLC: EtoAc/hexanes (9:1), Rf * 0.4; IR
(KBr): m 3,202, 1,606, 1,253, 1,164, 1,251 cm-1; 1H NMR
(DMSO-d6, 300 MHz): d 7.92 (d, 2H, J = 8.7 Hz), 7.65 (d,
2H, J = 8.7 Hz), 7.46 (s, 2H), 7.37 (d, 2H, J = 6.8 Hz), 6.92
(d, 2H, J = 7.8 Hz), 6.26 (s, 1H), 4.56–4.38 (m, 1H),
3.72–3.46 (m, 1H), 3.02 (t, 2H, J = 11.68 Hz), 2.82–2.66
(m, 1H), 2.31 (s, 3H), 2.18 (s, 3H), 1.90–1.64 (m,
2H),1.57–1.48 (m, 2H); 13C NMR (CDCl3, 75 MHz): d
161.5 (C1), 152.2 (C2), 149.5 (C3), 145.2 (C4), 139.8 (C5),
137.5 (C6), 128.4 (C11), 110.2 (C12), 82.7 (C13), 47.2
(C14), 45.2 (C15), 44.5 (C16), 37.2 (C17), 36.5 (C18), 27.5
(C19), 27.3 (C20), 27.3 (C21), 26.4 (C22), 18.5 (C23); MS
(ESI): m/z [M?1]? 455; HRMS (ESI m/z) Calcd for
C23H26N4O4S: 455.1747 and found: 455.1747; Anal. Calcd
for C23H26N4O4S C, 60.77; H, 5.77; N, 12.33; O, 14.08; S,
7.05, Found C, 60.78; H, 5.76; N, 12.31; O, 14.08; S, 7.0;
Purity: 96.88 % (Rt = 10.943 min).
General procedure for synthesis of the piperidine urea
disubstituted pyrazole (8a–8i, 9a–9l)
To a solution of compound 4a/4b (0.4 g, 1.2 mmol) in
THF (15 mL) was added Et3N (2 mL) and stirred for about
20 min. To the resulting mixture, the corresponding iso-
cyanate was added at 0 °C and allowed to come to room
temperature and stirred for 3 h. The solvent was evaporated
under vacuum to give respective urea derivatives which
was further purified by column chromatography using
EtoAc/hexanes as an eluent.
4-(3-Methyl-5-(1-(4-nitrobenzoyl)piperidin-4-yl)-1H-
pyrazol-1-yl)benzenesulphonamide (7e)
This compound was prepared by treating compound 4b
with 4-nitrophenyl isocyanate using the procedure detailed
above and it was obtained as a white solid in 96 % as yield;
mp 268–270 °C; TLC: EtoAc/hexanes (9:1), Rf * 0.5. IR
(KBr): m 3,201, 1,623, 1,343, 1,265, 1,164 cm-1; 1H NMR
(DMSO-d6, 300 MHz): d 8.29 (d, 2H, J = 8.5 Hz), 8.03
(d, 2H, J = 8.5 Hz), 7.61 (d, 2H, J = 7.9 Hz), 7.53 (d, 2H,
J = 8.3 Hz), 7.07 (s, 2H), 6.12 (s, 1H), 4.80–4.68 (m, 1H),
3.69–3.55 (m, 1H), 2.89–2.75 (m, 1H), 2.29 (s, 3H),
2.07–1.94 (m, 2H), 1.86–1.50 (m, 4H); 13C NMR (CDCl3,
75 MHz): d 160.5 (C1), 151.2 (C2), 148.5 (C3), 145.2
(C4), 139.8 (C5), 137.5 (C6), 128.4 (C11), 110.5 (C12),
N-Ethyl-4-(3-methyl-1-(4-sulphamoylphenyl)-1H-pyrazol-
5-yl)piperidine-1-carboxamide (8a)
This compound was prepared by treating compound 4b
with ethyl isocyanate using the procedure detailed above
and it was obtained as a white solid in 93 % as yield; mp
245–246 °C; IR (KBr): m 3,414, 3,189, 1,627, 1,333,
1,162 cm-1; TLC: EtoAc/hexanes (9:1), Rf * 0.2; 1H
NMR (DMSO-d6, 300 MHz): d 8.03 (d, 2H, J = 8.5 Hz),
7.52 (d, 2H, J = 8.5 Hz), 7.09 (brs, 2H), 6.05 (s, 1H), 5.66
123

Med Chem Res (2014) 23:2178–2197
2191
(brs, 1H), 4.11–4.04 (m, 2H), 3.25–3.16 (m, 2H), 2.91–2.81
(m, 1H), 2.67 (t, 2H, J = 12.3 Hz), 2.27 (s, 3H), 1.80 (d,
2H, J = 12.1 Hz), 1.62–1.48 (m, 2H), 1.11 (t, 3H,
J = 7.2 Hz), 13C NMR (CDCl3, 75 MHz): d 160.7 (C1),
149.0 (C2), 148.3 (C3), 147.2 (C4), 142.5 (C5), 142.2 (C6),
126.7 (C7), 124.7 (C8), 104.6 (C9), 45.4 (C10), 43.5 (C11),
40.1 (C12), 40.0 (C13), 32.4 (C14), 31.2 (C15), 31.1 (C16),
18.9 (C17), 18.0 (C18); MS (ESI): m/z [M?1]? 392.
HRMS (ESI m/z) Calcd for C18H25N5O3S: 392.1748 and
found: 392.1749; Anal. Calcd for C18H25N5O3S C, 55.22;
H, 6.44; N, 17.89; O, 12.26; S, 8.19, Found C, 55.21; H,
6.43; N, 17.88; O, 12.27; S, 8.20; Purity: 98.83 %
(Rt = 8.56 min).
142.0 (C6), 138.9 (C7), 128.7 (C8), 126.7 (C9), 107.6
(C10), 45.4 (C11), 44.5 (C12), 42.1 (C13), 42.0 (C14), 35.4
(C15), 35.2 (C16), 34.1 (C17), 18.5 (C18), 18.2 (C19); MS
(ESI): m/z [M?1]? 406; HRMS (ESI m/z) Calcd for
C19H27N5O3S: 406.1899 and found: 406.1899; Anal. Calcd
for C19H27N5O3S C, 56.28; H, 6.71; N, 17.27; O, 11.84; S,
7.91; Found C, 56.27; H, 6.72; N, 17.28; O, 11.84; S, 7.91;
Purity: 99.01 % (Rt = 9.49 min).
N-Butyl-4-(3-methyl-1-(4-sulphamoylphenyl)-1H-pyrazol-
5-yl)piperidine-1-carboxamide (8d)
This compound was prepared by treating compound 4b
with butyl isocyanate using the procedure detailed above
and it was obtained as a white solid in 95 % as yield; mp
180–182 °C; TLC: EtoAc/hexanes (9:1), Rf * 0.3. IR
(KBr): m 3,430, 3,413, 1,615, 1,322, 1,161 cm-1; 1H NMR
(DMSO-d6, 300 MHz): d 8.07 (d, 2H, J = 8.5 Hz),
7.55–7.51 (m, 2H), 7.39–7.33 (m, 2H), 6.18–6.14 (brs, 1H),
6.1 (s, 1H), 4.16 (d, 2H, J = 12.8 Hz), 2.65 (t, 2H,
J = 12.1 Hz), 2.59–2.54 (m, 2H), 2.26 (s, 3H), 2.12 (s,
1H), 1.83–1.78 (m, 2H), 1.59–1.51 (m, 2H), 1.48–1.42 (m,
2H), 1.29–1.26 (m, 2H), 0.90 (t, 3H, J = 7.1 Hz); 13C
NMR (75 MHz, DMSO-d6) d 160.7 (C1), 149.0 (C2),
148.3 (C3), 147.2 (C4), 142.5 (C5), 142.2 (C6), 126.7 (C7),
124.7 (C8), 104.6 (C9), 45.4 (C10), 43.5 (C11), 40.1 (C12),
40.0 (C13), 32.4 (C14), 31.2 (C15), 31.1 (C16), 18.9 (C17),
18.7 (C18), 18.1 (C19); MS (ESI): m/z [M?1]? 420;
HRMS (ESI m/z) Calcd for C20H29N5O3S: 420.2031 and
found: 420.2030; Anal. Calcd for C20H29N5O3S C, 57.26;
H, 6.97; N, 16.69; O, 11.44; S, 7.64, Found C, 57.25; H,
6.95; N, 16.67; O, 11.44; S, 7.64; Purity: 90.62 %
(Rt = 10.57 min).
4-(3-Methyl-1-(4-sulphamoylphenyl)-1H-pyrazol-5-yl)-N-
propylpiperidine-1-carboxamide (8b)
This compound was prepared by treating compound 4b
with propyl isocyanate using the procedure detailed above
and it was obtained as a white solid in 95 % as yield; mp
251–253 °C; IR (KBr): m 3,435, 3,187, 1,623, 1,331,
1,164 cm-1; TLC: EtoAc/hexanes (9:1), Rf * 0.2; 1H
NMR (DMSO-d6, 300 MHz): d 8.04 (d, 2H, J = 8.3 Hz),
7.51 (d, 2H, J = 8.5 Hz), 6.70 (s, 2H), 6.05 (s, 1H), 5.12
(brs, 1H), 4.03 (d, 2H, J = 13.4 Hz), 3.16 (q, 2H,
J = 7.0 Hz), 2.89–2.80 (m, 1H), 2.77–2.71 (m, 2H), 2.29
(s, 3H), 1.80 (d, 2H, J = 11.0 Hz), 1.65–1.55 (m, 2H),
1.53–1.46 (m, 2H), 0.9 (t, 3H, J = 7.3 Hz); 13C NMR
(CDCl3, 75 MHz): d 160.7 (C1), 149.2 (C2), 148.5 (C3),
147.1 (C4), 142.8 (C5), 142.2 (C6), 138.6 (C7), 126.7 (C8),
124.7 (C9), 104.6 (C10), 45.4 (C11), 43.5 (C12), 40.1
(C13), 40.0 (C14), 35.4 (C15), 35.2 (C16), 34.1 (C17), 18.3
(C18), 18.2 (C19); MS (ESI): m/z [M?1]? 406; HRMS
(ESI m/z) Calcd for C19H27N5O3S: 406.1899 and found:
406.1899; Anal. Calcd for C19H27N5O3S C, 56.28; H, 6.71;
N, 17.27; O, 11.84; S, 7.91, Found C, 56.28; H, 6.71; N,
17.27; O, 11.84; S, 7.91; Purity: 97.61 % (Rt = 9.52 min).
N-Cyclohexyl-4-(3-methyl-1-(4-sulphamoylphenyl)-1H-
pyrazol-5-yl)piperidine-1-carboxamide (8e)
This compound was prepared by treating compound 4b
with cyclohexyl isocyanate using the procedure detailed
above and it was obtained as a white solid in 94 % as yield;
mp 259–260 °C; TLC: EtoAc/hexanes (9:1), Rf * 0.2; IR
(KBr): m 3,407, 3,187, 1,620, 1,327, 1,161 cm-1; 1H NMR
(DMSO-d6, 300 MHz): d 7.99 (d, 2H, J = 8.3 Hz), 7.57
(d, 2H, J = 8.5 Hz), 7.35 (s, 2H), 6.07 (s, 1H), 5.82 (d, 1H,
J = 7.7 Hz), 4.05 (d, 2H, J = 13.2 Hz), 3.50–3.42 (m,
1H), 2.93–2.85 (m, 1H), 2.63 (t, 2H, J = 12.5 Hz), 2.23 (s,
3H), 1.83–1.67 (m, 5H), 1.61–1.43 (m, 4H), 1.29–1.12 (m,
5H); 13C NMR (75 MHz, DMSO-d6) d 160.7 (C1), 148.5
(C2), 144.9 (C3), 144.2 (C4), 139.2 (C5), 127.9 (C6), 123.0
(C7), 110.5 (C8), 83.4 (C9), 46.7 (C10), 44.2 (C11), 38.2
(C12), 37.1 (C13), 31.8 (C14), 29.0 (C15), 27.1 (C16), 27.0
(C17), 25.7 (C18), 24.4 (C19), 18.9 (C20), 18.7 (C21), 18.5
(C22); MS (ESI): m/z [M?1]? 446; HRMS (ESI m/z)
N-Isopropyl-4-(3-methyl-1-(4-sulphamoylphenyl)-1H-
pyrazol-5-yl)piperidine-1-carboxamide (8c)
This compound was prepared by treating compound 4b
with isopropyl isocyanate using the procedure detailed
above and it was obtained as a white solid in 96 % as yield;
mp 257–259 °C; TLC: EtoAc/hexanes (9:1), Rf * 0.2. IR
1
(KBr): m 3,421, 3,188, 1,627, 1,330, 1,164 cm-1. H NMR
(DMSO-d6, 300 MHz): d 8.04 (d, 2H, J = 8.5 Hz), 7.51
(d, 2H, J = 8.5 Hz), 6.85 (s, 2H), 6.05 (s, 1H), 4.90 (d, 1H,
J = 7.5 Hz), 4.02 (d, 2H, J = 12.8 Hz), 3.12 (q, 1H,
J = 7.3 Hz), 2.91–2.81 (m, 1H), 2.70 (t, 2H, J = 12.3 Hz),
2.28 (s, 3H), 1.80 (d, 2H, J = 13.2 Hz), 1.64–1.51 (m, 2H),
1.14 (d, 6H, J = 6.4 Hz), 13C NMR (CDCl3, 75 MHz): d
161.2 (C1), 149.8 (C2), 148.3 (C3), 147.3 (C4), 142.8 (C5),
123

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N-Benzyl-4-(3-methyl-1-(4-sulphamoylphenyl)-1H-
Calcd for C22H31N5O3S: 446.2205 and found: 446.2204;
Anal. Calcd for C22H31N5O3S C, 59.30; H, 7.01; N, 15.72;
O, 10.77; S, 7.20; Found C, 59.31; H, 7.00; N, 15.73; O,
10.78; S, 7.21; Purity: 93.75 % (Rt = 11.59 min).
pyrazol-5-yl)piperidine-1-carboxamide (8h)
This compound was prepared by treating compound 4b
with benzyl isocyanate using the procedure detailed above
and it was obtained as a white solid in 96 % as yield; mp
222–224 °C; TLC: EtoAc/hexanes (9:1), Rf * 0.3. IR
N-Benzyl-4-(3-methyl-1-(4-sulphamoylphenyl)-1H-
pyrazol-5-yl)piperidine-1-carboxamide (8f)
(KBr): m 3,337, 1,618, 1,256, 1,159 cm-1 1H NMR
.
(DMSO-d6, 300 MHz): d 8.07 (d, 2H, J = 8.5 Hz),
7.88–7.80 (m, 1H), 7.60–7.53 (m, 2H), 7.47–7.43 (m, 1H),
7.28 (s, 1H), 7.21 (t, 2H, J = 7.5 Hz), 6.1 (s, 1H), 4.26 (d,
2H, J = 12.86 Hz), 3.16–3.10 (m, 4H), 2.80 (t, 2H,
J = 12.86 Hz), 2.26 (s, 3H), 1.89–1.83 (m, 1H), 1.42 (s,
2H), 1.38–1.32 (m, 3H); 13C NMR (75 MHz, DMSO-d6) d
162.2 (C1), 149.3 (C2), 145.5 (C3), 144.0 (C4), 139.2 (C5),
129.2 (C6), 127.0 (C7), 108.5 (C8), 83.4 (C9), 46.7 (C10),
45.6 (C11), 44.2 (C12), 38.2 (C13), 37.1 (C14), 31.8 (C15),
29.6 (C16), 29.0 (C17), 27.1 (C18), 27.0 (C19), 25.7 (C20),
24.4 (C21), 18.9 (C22), 18.7 (C23); MS (ESI): m/z [M?1]?
454. HRMS (ESI m/z) Calcd for C23H27N5O3S: 454.1945
and found: 454.1946; Anal. Calcd for C23H27N5O3S C,
60.91; H, 6.00; N, 15.44; O, 10.58; S, 7.07; Found C,
60.91; H, 6.00; N, 15.44; O, 10.58; S, 7.07; Purity: 96.56 %
(Rt = 10.91 min).
This compound was prepared by treating compound 4b
with phenyl isocyanate using the procedure detailed above
and it was obtained as a white solid in 95 % as yield; mp
231–233 °C; TLC: EtoAc/hexanes (9:1), Rf * 0.3. IR
(KBr): m 3,294, 1,633, 1,340, 1,165 cm-1 1H NMR
;
(DMSO-d6, 300 MHz): d 8.07 (d, 2H, J = 8.5 Hz),
7.88–7.80 (m, 2H), 7.55–7.51 (m, 2H), 7.29–7.26 (m, 2H),
7.22–7.20 (m, 2H), 6.78–6.73 (brs, 1H), 6.1 (s, 1H), 4.36
(d, 2H, J = 12.86 Hz), 4.18–4.13 (m, 2H), 2.89–2.83 (m,
2H), 2.78–2.69 (m, 2H), 2.26 (s, 3H), 1.83–1.78 (m, 2H),
1.59–1.51 (m, 2H); 13C NMR (75 MHz, DMSO-d6) d
160.2 (C1), 148.3 (C2), 144.5 (C3), 144.2 (C4), 139.2 (C5),
127.2 (C6), 123.0 (C7), 110.5 (C8), 83.4 (C9), 46.7 (C10),
44.2 (C11), 38.2 (C12), 37.1 (C13), 31.8 (C14), 29.6 (C15)
29.0 (C16), 27.1 (C17), 27.0 (C18), 25.7 (C19), 24.4 (C20),
18.9 (C21), 18.7 (C22); MS (ESI): m/z 454 [M?1]?.
HRMS (ESI m/z) Calcd for C23H27N5O3S: 453.1791 and
found: 453.1792; Anal. Calcd for C23H27N5O3S; C, 60.91;
H, 6.00; N, 15.44; O, 10.58; S, 7.07; Found C; C, 60.91; H,
6.00; N, 15.44; O, 10.58; S, 7.07; Purity: 96.24 %
(Rt = 11.03 min).
N-(4-Chlorophenyl)-4-(3-methyl-1-(4-sulphamoylphenyl)-
1H-pyrazol-5-yl)piperidine-1-carboxamide (8i)
This compound was prepared by treating compound 4b with
p-chlorophenyl isocyanate using the procedure detailed
above and it was obtained as a white solid in 94 % as yield;
mp 234–236 °C; TLC: EtoAc/hexanes (9:1), Rf * 0.2. IR
(KBr): m 3,295, 1,633, 1,300, 1,151 cm-1; 1H NMR (DMSO-
d6, 300 MHz): d 8.07 (d, 2H, J = 8.5 Hz), 7.69–7.64 (m,
2H), 7.55–7.51 (m, 2H), 7.47–7.43 (m, 2H), 7.18–7.06 (m,
2H), 7.08–7.04 (m, 2H), 6.1 (s, 1H), 4.26 (d, 2H,
J = 12.8 Hz), 3.15–3.12 (m, 2H), 3.09–3.06 (m, 1H), 2.26
(s, 3H), 1.89–1.83 (m, 1H), 1.66–1.61 (m, 2H); 13C NMR
(75 MHz, DMSO-d6) d 161.2 (C1), 149.8 (C2), 146.5 (C3),
145.2 (C4), 139.8 (C5), 129.0 (C6), 108.5 (C7), 84.4 (C8),
46.7 (C9), 45.6 (C10), 44.2 (C11), 38.2 (C12), 37.1 (C13),
31.8 (C14), 29.6 (C15), 29.0 (C16), 27.8 (C17), 27.0 (C18),
25.5 (C19), 24.4 (C20), 18.9 (C21), 18.7 (C22); MS (ESI): m/
z [M?1] ?475; HRMS (ESI m/z) Calcd for C22H24ClN5O3S:
475.1413 and found: 475.1412; Anal. Calcd for
C22H24ClN5O3S C, 55.75; H, 5.10; Cl, 7.48; N, 14.78; O,
10.13; S, 6.77; Purity: 97.50 % (Rt = 10.98 min).
4-(3-Methyl-1-(4-sulphamoylphenyl)-1H-pyrazol-5-yl)-N-
p-tolylpiperidine-1-carboxamide (8g)
This compound was prepared by treating compound 4b
with p-tolyl isocyanate using the procedure detailed above
and it was obtained as a white solid in 93 % as yield; mp
223–225 °C; TLC: EtoAc/hexanes (9:1), Rf * 0.2. IR
(KBr): m 3,300, 1,635, 1,341, 1,165 cm-1 1H NMR
;
(DMSO-d6, 300 MHz): d 8.07 (d, 2H, J = 8.5 Hz),
7.55–7.51 (m, 2H), 7.47–7.43 (m, 2H), 7.28–7.24 (m, 2H),
7.08–7.04 (m, 2H), 6.89–6.82 (m, 1H), 6.1 (s, 1H), 4.26 (d,
2H, J = 12.86 Hz), 2.38–2.36 (m, 1H), 2.26 (s, 6H),
1.89–1.83 (m, 2H), 1.66–1.61 (m, 2H), 1.38–1.32 (m, 2H);
13C NMR (75 MHz, DMSO-d6) d 161.2 (C1), 148.3 (C2),
144.5 (C3), 144.2 (C4), 139.2 (C5), 127.2 (C6), 123.0 (C7),
110.5 (C8), 83.4 (C9), 46.7 (C10), 45.6 (C11), 44.2 (C12),
38.2 (C13), 37.1 (C14), 31.8 (C15), 29.6 (C16), 29.0 (C17),
27.1 (C18), 27.0 (C19), 25.7 (C20), 24.4 (C21), 18.9 (C22),
18.7 (C23); MS (ESI): m/z [M?1]? 454; HRMS (ESI m/z)
Calcd for C23H27N5O3S: 454.1951 and found: 454.1952;
Anal. Calcd for C23H27N5O3S C, 60.91; H, 6.00; N, 15.44;
O, 10.58; S, 7.07; Found C, 60.92; H, 6.01; N, 15.44; O,
10.59; S, 7.07; Purity: 96.62 % (Rt = 11.77 min).
N-Ethyl-4-(3-methyl-1-(4-(methylsulphonyl)phenyl)-1H-
pyrazol-5-yl)piperidine-1-carboxamide (9a)
This compound was prepared by treating compound 4a
with ethyl isocyanate using the procedure detailed above
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2193
and it was obtained as a white solid in 96 % as yield; mp
73–75 °C; IR (KBr): m 3,349, 1,623, 1,544, 1,297,
1,150 cm-1; TLC: EtoAc/hexanes (9:1), Rf * 0.3; 1H
NMR (DMSO-d6, 500 MHz): d 8.05 (d, 2H, J = 8.5 Hz),
7.66 (d, 2H, J = 8.5 Hz), 6.08 (s, 1H), 5.81 (brs, 1H),
4.09–4.06 (m, 2H), 3.21–3.17 (m, 2H), 3.15 (s, 3H),
2.92–2.87 (m, 1H), 2.70 (t, 2H, J = 12.3 Hz), 2.27 (s, 3H),
1.80 (d, 2H, J = 12.3 Hz), 7.99–7.59 (m, 2H), 1.10 (t, 3H,
J = 7.5 Hz); 13C NMR (75 MHz, DMSO-d6) d 161.7 (C1),
149.2 (C2), 146.5 (C3), 129.0 (C4), 108.5 (C5), 84.4 (C6),
46.7 (C7), 45.6 (C8), 38.2 (C9), 37.1 (C10), 31.5 (C11),
29.7 (C12), 29.0 (C13), 27.8 (C14), 27.0 (C15), 25.5 (C16),
24.4 (C17), 18.9 (C18), 18.7 (C19); MS (ESI): m/z [M?1]?
391; HRMS (ESI m/z) Calcd for C19H26N4O3S: 391.1793
and found: 391.1794; Anal. Calcd for C19H26N4O3S C,
58.44; H, 6.71; N, 14.35; O, 12.29; S, 8.21; Found C,
58.44; H, 6.71; N, 14.35; O, 12.29; S, 8.21; Purity: 96.3 %
(Rt = 5.4 min).
J = 6.6 Hz), 4.04 (d, 2H, J = 14.2 Hz), 3.94–3.88 (m,
1H), 3.12 (s, 3H), 2.79–2.74 (m, 1H), 2.70 (t, 2H,
J = 12.3 Hz), 2.28 (s, 3H), 1.81 (d, 2H, J = 12.3 Hz),
1.57 (m, 2H), 1.13 (d, 6H, J = 6.6 Hz), 13C NMR
(75 MHz, DMSO-d6) d 162.5 (C1), 155.0 (C2), 149.5 (C3),
143.9 (C4), 133.4 (C5), 130.3 (C6), 127.1 (C7), 110.2 (C8),
82.7 (C9), 82.5 (C10), 82.3 (C11), 81.9 (C12), 49.2 (C13),
48.7 (C14), 45.3 (C15), 37.2 (C16), 37.0 (C17), 27.0 (C18),
18.6 (C19), 18.3 (C20); MS (ESI): m/z 405 [M?1]?;
HRMS (ESI m/z) Calcd for C20H28N4O3S: 405.19513 and
found: 405.19212; Anal. Calcd for C20H28N4O3S C, 59.38;
H, 6.98; N, 13.85; O, 11.87; S, 7.93; Found C, 59.37; H,
6.99; N, 13.84; O, 11.86; S, 7.93; Purity: 96.4 %
(Rt = 6.6 min).
N-Butyl-4-(3-methyl-1-(4-(methylsulphonyl)phenyl)-1H-
pyrazol-5-yl)piperidine-1-carboxamide (9d)
This compound was prepared by treating compound 4b
with butyl isocyanate using the procedure detailed above
and it was obtained as a white solid in 95 % as yield; mp
86–89 °C; TLC: EtoAc/hexanes (9:1), Rf * 0.3. IR (KBr):
4-(3-Methyl-1-(4-(methylsulphonyl)phenyl)-1H-pyrazol-5-
yl)-N-propylpiperidine-1-carboxamide (9b)
1
This compound was prepared by treating compound 4a
with propyl isocyanate using the procedure detailed above
and it was obtained as a white solid in 96 % as yield; mp
86–89 °C; IR (KBr): m 3,340, 1,620, 1,548, 1,293,
1,148 cm-1; TLC: EtoAc/hexanes (9:1), Rf * 0.3; 1H
NMR (DMSO-d6, 500 MHz): d 8.05 (d, 2H, J = 8.5 Hz),
7.66 (d, 2H, J = 8.5 Hz), 6.08 (s, 1H), 5.81(brs, 1H),
4.09–4.06 (m, 2H), 3.21–3.17 (m, 2H), 3.15 (s, 3H),
2.92–2.87 (m, 1H), 2.70 (t, 2H, J = 12.3 Hz), 2.27 (s, 3H),
1.80 (d, 2H, J = 12.3 Hz), 1.64–1.55 (m, 2H), 1.55–1.48
(m, 2H) 1.10 (t, 3H, J = 7.5 Hz); 13C NMR (75 MHz,
DMSO-d6) d 161.9 (C1), 149.2 (C2), 146.0 (C3), 129.0
(C4), 108.5 (C5), 84.4 (C6), 46.7 (C7), 45.5 (C8), 44.2 (C9)
38.2 (C10), 37.1 (C11), 31.5 (C12), 29.7 (C13), 29.0 (C14),
27.8 (C15), 27.0 (C16), 25.5 (C17), 24.4 (C18), 18.9 (C19),
18.7 (C20); MS (ESI): m/z 405 [M?1]?; HRMS (ESI m/z)
Calcd for C20H28N4O3S: 405.1951 and found: 405.1950;
Anal. Calcd for C20H28N4O3S C, 59.38; H, 6.98; N, 13.85;
O, 11.87; S, 7.93; Found C, 59.37; H, 6.97; N, 13.84; O,
11.86; S, 7.92; Purity: 97.1 % (Rt = 6.6 min).
m 3,352, 1,628, 1,595, 1,537, 1,298, 1,151 cm-1; H NMR
(DMSO-d6, 500 MHz): d 8.06 (d, 2H, J = 8.3 Hz), 7.69
(d, 2H, J = 8.3 Hz), 6.16 (brs, 1H), 6.09 (s, 1H), 4.07 (d,
2H, J = 13.0 Hz), 3.18 (s, 3H), 3.14–3.03 (m, 2H),
2.99–2.85 (m, 1H), 2.68 (t, 2H, J = 12.3 Hz), 2.26 (s, 3H),
1.80 (d, 2H, J = 12.1 Hz), 1.59–1.37 (m, 4H), 1.38–1.22
(m, 2H), 0.903 (t, 3H, J = 6.8 Hz); 13C NMR (75 MHz,
DMSO-d6) d 161.2 (C1), 149.3 (C2), 144.5 (C3), 144.0
(C4), 134.4 (C5), 133.3 (C6), 130.8 (C7), 126.1 (C8), 125.2
(C9), 110.4 (C10), 83.2 (C11), 82.7 (C12), 49.1 (C13), 45.7
(C14), 45.4 (C15), 45.1 (C16), 44.9 (C17), 37.4 (C18),
27.37 (C19), 18.6 (C20), 18.3 (C21); MS (ESI): m/z 419
[M?1]?; HRMS (ESI m/z) Calcd for C21H30N4O3S:
419.2156 and found: 419.2155; Anal. Calcd for
C21H30N4O3S C, 60.26; H, 7.22; N, 13.39; O, 11.47; S,
7.66 Found C, 60.27; H, 7.23; N, 13.38; O, 11.47; S, 7.66;
Purity: 98.8 % (Rt = 8.1 min).
N-Cyclohexyl-4-(3-methyl-1-(4-(methylsulphonyl)phenyl)-
1H-pyrazol-5-yl)piperidine-1-carboxamide (9e)
N-Isopropyl-4-(3-methyl-1-(4-(methylsulphonyl)phenyl)-
This compound was prepared treating compound 4a with
cyclohexyl isocyanate using the procedure detailed above
and it was obtained as a white solid in 96 % as yield; mp
209–211 °C. TLC: EtoAc/hexanes (9:1), Rf * 0.3. IR
1H-pyrazol-5-yl)piperidine-1-carboxamide (9c)
This compound was prepared by treating compound 4a
with isopropyl isocyanate using the procedure detailed
above and it was obtained as a white solid in 96 % as yield;
mp 171–173 °C; TLC: EtoAc/hexanes (9:1), Rf * 0.3. IR
(KBr): m 3,277, 1,619, 1,544, 1,294, 1,153 cm-1; 1H NMR
(DMSO-d6, 500 MHz): d 8.05 (d, 2H, J = 8.5 Hz), 7.65
(d, 2H, J = 8.5 Hz), 6.07 (s, 1H), 5.03 (d, 1H,
1
(KBr): m 3,333, 1,612, 1,542, 1,293, 1,152 cm-1. H NMR
(DMSO-d6, 500 MHz): d 8.06 (d, 2H, J = 8.5 Hz), 7.69
(d, 2H, J = 8.5 Hz), 6.10 (s, 1H), 5.78 (brs, 1H), 4.07 (d,
2H, J = 12.7 Hz), 3.55–3.42 (m, 1H), 3.18 (s, 3H),
2.98–2.87 (m, 1H), 2.67 (t, 2H, J = 12.3 Hz), 2.25 (s, 3H),
1.87–1.68 (m, 5H), 1.62–1.44 (m, 4H), 1.32–1.06 (m, 5H);
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13C NMR (75 MHz, DMSO-d6): d 160.2 (C1), 155.0 (C2),
149.5 (C3), 144.9 (C4), 133.4 (C5), 130.3 (C5), 129.2 (C6),
127.1 (C7), 110.2 (C8), 83.0 (C9), 49.12 (C10), 45.7 (C11),
44.5 (C12), 44.3 (C13), 38.5(C14), 37.2 (C15), 36.5 (C16),
34.3 (C17), 34.02 (C18),29.2 (C19), 27.3 (C20), 27.0
(C21), 18.9 (C22), 18.3 (C23); MS (ESI): m/z 445 [M?1]?;
HRMS (ESI m/z) Calcd for C23H32N4O3S: 445.2219 and
found: 445.2217; Anal. Calcd for C23H32N4O3S C, 62.13;
H, 7.25; N, 12.60; O, 10.80; S, 7.21; Found C, 62.14; H,
7.24; N, 12.61; O, 10.81; S, 7.21; Purity: 99.3 %
(Rt = 9.3 min).
(C9), 127.0 (C10), 110.2 (C11), 83.0 (C12), 82.7 (C13),
49.12 (C14), 45.7 (C15), 44.5 (C16), 44.3 (C17), 44.0
(C18), 36.5 (C19), 34.3 (C20), 34.02 (C21), 27.37 (C22),
?
18.9 (C23), 18.3 (C24); MS (ESI): m/z 453 [M?1]
;
HRMS (ESI m/z) Calcd for C24H28N4O3S: 453.1915 and
found: 453.1915; Anal. Calcd for C24H28N4O3S: C, 63.69;
H, 6.24; N, 12.38; O, 10.61; S, 7.09; Found C, 63.69; H,
6.24; N, 12.38; O, 10.61; S, 7.09; Purity: 97.7 %
(Rt = 9.7 min).
N-Benzyl-4-(3-methyl-1-(4-(methylsulphonyl) phenyl)-1H-
pyrazol-5-yl)piperidine-1-carboxamide (9h)
4-(3-Methyl-1-(4-(methylsulphonyl)phenyl)-1H-pyrazol-5-
yl)-N-phenylpiperidine-1-carboxamide (9f)
This compound was prepared by treating compound 4a
with benzyl isocyanate using the procedure detailed above
and it was obtained as a white solid in 96 % as yield; mp
172–174 °C. TLC: EtoAc/hexanes (9:1), Rf * 0.5. IR
(KBr): m 3,316, 1,615, 1,530, 1,290, 1,149 cm-1; 1H NMR
(DMSO-d6, 500 MHz): d 8.06 (d, 2H, J = 7.0 Hz), 7.70
(d, 2H, J = 7.0 Hz), 7.29–7.25 (m, 4H), 7.20–7.16 (m,
1H), 6.92 (brs, 1H), 6.11 (s, 1H), 4.31 (d, 2H, J = 5.5 Hz),
4.13 (d, 2H, J = 13.2 Hz), 3.19 (s, 3H), 3.02–2.90 (m, 1H),
2.73 (t, 2H, J = 12.3 Hz), 2.25 (s, 3H), 1.82 (d, 2H,
J = 12.3 Hz), 1.62–1.45 (m, 2H); 13C NMR (75 MHz,
DMSO-d6): d 161.2 (C1), 149.4 (C2), 144.7 (C3), 144.2
(C4), 137.7 (C5), 134.6 (C6), 133.2 (C7), 130.3 (C8), 129.1
(C9), 127.2 (C10), 110.2 (C11), 83.0 (C12), 82.7 (C13),
49.12 (C14), 45.6 (C15), 44.0 (C16), 44.0 (C17), 43.6
(C18), 36.5 (C19), 34.3 (C20), 34.02 (C21), 27.37 (C22),
18.9 (C23), 18.3 (C24); MS (ESI): m/z 453 [M?1]?;
HRMS (ESI m/z) Calcd for C24H28N4O3S: 453.1945 and
found: 453.1954; Anal. Calcd for C24H28N4O3S: C, 63.69;
H, 6.24; N, 12.38; O, 10.61; S, 7.09; Found C, 63.69; H,
6.24; N, 12.38; O, 10.61; S, 7.09 Purity: 98.9 %
(Rt = 8.5 min).
This compound was prepared by treating compound 4a
with phenyl isocyanate using the procedure detailed above
and it was obtained as a white solid in 95 % as yield; mp
186–188 °C; TLC: EtoAc/hexanes (9:1), Rf * 0.4; IR
(KBr): m 3,299, 1,634, 1,592, 1,545, 1,299, 1,150 cm-1; 1H
NMR (DMSO-d6, 500 MHz): d 8.06 (d, 2H, J = 8.7 Hz),
7.65 (d, 2H, J = 8.7 Hz), 7.60–7.56 (m, 1H), 7.31–7.28
(m, 3H), 6.25 (brs, 1H), 6.08 (s, 1H), 4.13 (d, 2H,
J = 13.1 Hz), 3.13 (s, 3H), 2.89–2.84 (m, 1H), 2.75 (t, 2H,
J = 12.3 Hz), 2.28 (s, 3H), 1.82 (d, 2H, J = 1 Hz),
1.62–1.55 (m, 2H); 13C NMR (75 MHz, DMSO-d6) d
160.2 (C1), 149.5 (C2), 144.9 (C3), 144.0 (C4), 133.4 (C5),
133.2 (C6), 130.3 (C7), 127.1 (C8), 125.0 (C9), 110.2
(C10), 83.0 (C11), 82.7 (C12), 49.12 (C13), 45.7 (C14),
44.5 (C15), 44.3 (C16), 44.0 (C17), 36.5 (C18), 34.3 (C19),
34.02 (C20), 27.37 (C21), 18.9 (C22), 18.3 (C23); MS
(ESI): m/z 439 [M?1]?; HRMS (ESI m/z) Calcd for
C23H26N4O3S: 439.1791 and found: 439.1792; Anal. Calcd
for C23H32N4O3S C, 62.13; H, 7.25; N, 12.60; O, 10.80; S,
7.21; Found C, 62.14; H, 7.24; N, 12.61; O, 10.81; S, 7.21;
Purity: 98.8 % (Rt = 8.6 min).
N-(2-Chlorophenyl)-4-(3-methyl-1-(4(methylsulphonyl)
4-(3-Methyl-1-(4-(methylsulphonyl)phenyl)-1H-pyrazol-5-
phenyl)-1H-pyrazol-5-yl) piperidine-1-carboxamide (9i)
yl)-N-(p-tolyl)piperidine-1-carboxamide (9g)
This compound was prepared by treating compound 4a
with p-chlorophenyl isocyanate using the procedure
detailed in above and it was obtained as a white solid in
96 % as yield; mp 179–181 °C; TLC: EtoAc/hexanes (9:1),
Rf * 0.3, IR (KBr): m 3,319, 1,630, 1,593, 1,530, 1,299,
This compound was prepared by treating compound 4a
with p-tolyl isocyanate using the procedure detailed above
and it was obtained as a white solid in 95 % as yield; mp
213–215 °C. TLC: EtoAc/hexanes (9:1), Rf * 0.3; IR
(KBr): m 3,302, 1,633, 1,594, 1,513, 1,247, 1,151 cm-1; 1H
NMR (DMSO-d6, 500 MHz): d 8.12 (brs, 1H), 8.06 (d, 2H,
J = 8.5 Hz), 7.69 (d, 2H, J = 8.5 Hz), 7.30 (d, 2H,
J = 8.3 Hz), 7.02 (d, 2H, J = 8.1 Hz), 6.12 (s,1H), 4.27
(d, 2H, J = 13.6 Hz), 3.17 (s, 3H), 3.03–2.91 (m, 1H), 2.79
(t, 2H, J = 12.5 Hz), 2.27 (s, 6H), 1.87 (d, 2H,
J = 12.5 Hz), 1.72–1.55 (m, 2H); 13C NMR (75 MHz,
DMSO-d6) d 161.2 (C1), 149.4 (C2), 144.7 (C3), 144.0
(C4), 137.7 (C5), 133.6 (C6), 133.2 (C7), 130.3 (C8), 129.1
1
1,149 cm-1; H NMR (DMSO-d6, 500 MHz): d 8.07 (d,
2H, J = 8.5 Hz), 8.01 (brs, 1H), 7.67 (d, 2H, J = 8.5 Hz),
7.34 (d, 1H, J = 7.5 Hz), 7.23 (t, 2H, J = 7.5 Hz), 6.99 (t,
1H, J = 7.5 Hz), 6.12 (s, 1H), 4.19 (d, 2H, J = 13.2 Hz),
3.14 (s, 3H), 3.01–2.90 (m, 3H), 2.29 (s, 3H), 1.93 (d, 2H,
J = 12.3 Hz), 1.74–1.65 (m, 2H); 13C NMR (75 MHz,
DMSO-d6): d 161.5 (C1), 149.5 (C2), 144.7 (C3), 144.0
(C4), 137.7 (C5), 134.6 (C6), 133.0 (C7), 130.3 (C8), 129.2
(C9), 127.2 (C10), 110.2 (C11), 83.0 (C12), 82.7 (C13),
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Med Chem Res (2014) 23:2178–2197
2195
49.12 (C14), 45.6 (C15), 44.0 (C16), 43.6 (C17), 36.5
(C18), 34.3 (C19), 34.02 (C20), 27.37 (C21), 18.9 (C22),
18.3 (C23); MS (ESI): m/z 474 [M?1]?; HRMS (ESI m/z)
Calcd for C23H25ClN4O3S: 474.1413 and found: 474.1414;
Anal. Calcd for C23H25ClN4O3S: C, 58.40; H, 5.33; Cl,
7.50; N, 11.85; O, 10.15; S, 6.78; Found: C, 58.40; H, 5.33;
Cl, 7.50; N, 11.85; O, 10.15; S, 6.78; Purity: 98.5 %
(Rt = 10.0 min).
(C15), 44.0 (C16), 43.6 (C17), 36.5 (C18), 34.3 (C19),
34.02 (C20), 29.2 (C21), 27.3 (C22), 27.1 (C23), 18.9
(C24), 18.3 (C25); MS (ESI): m/z 467 [M?1]?; HRMS
(ESI m/z) Calcd for C25H30N4O3S: 467.2100 and found:
467.2104; Anal. Calcd for C25H30N4O3S: C, 58.40; H,
5.33; Cl, 7.50; N, 11.85; O, 10.15; S, 6.78; Found: C,
58.40; H, 5.33; Cl, 7.50; N, 11.85; O, 10.15; S, 6.78;
Purity: 99.3 % (Rt = 9.2 min).
N-(4-Chlorophenyl)-4-(3-methyl-1-(4(methylsulphonyl)-
4-(3-Methyl-1-(4-(methylsulphonyl)phenyl)-1H-pyrazol-5-
phenyl)-1H-pyrazol-5-yl)piperidine-1-carboxamide (9j)
yl)-N-phenethylpiperidine-1-carboxamide (9l)
This compound was prepared by treating compound 4b with
4-chloro isocyanate using the procedure detailed above and it
was obtained as a white solid in 93 % as yield; mp
245–246 °C. IR (KBr): m 3,414, 3,189, 1,627, 1,333,
1,162 cm-1. TLC: EtoAc/hexanes (9:1), Rf * 0.3; 1H NMR
(DMSO-d6, 500 MHz): d 8.57 (brs, 1H), 7.99 (d, 2H,
J = 7.9 Hz), 7.69–7.59 (m, 2H), 7.52–7.41 (m, 2H),
7.24–7.15 (m, 2H), 6.20–6.11 (m, 1H), 4.20 (d, 2H,
J = 12.8 Hz), 3.14 (s, 3H), 3.05–2.94 (m, 1H), 2.79 (t, 2H,
J = 13.8 Hz), 2.22 (s, 3H), 1.84 (d, 2H, J = 12.1 Hz),
1.62–1.47 (m, 2H); 13C NMR (75 MHz, DMSO-d6) d 161.5
(C1), 149.5 (C2), 144.7 (C3), 144.5 (C4), 137.7 (C5), 134.6
(C6), 133.6 (C7), 130.3 (C8), 129.2 (C9), 127.2 (C10), 110.2
(C11), 83.0 (C12), 82.7 (C13), 49.12 (C14), 45.6 (C15), 44.0
(C16), 43.6 (C17), 36.5 (C18), 34.3 (C19), 34.02 (C20),
27.37 (C21), 18.9 (C22), 18.3 (C23); MS (ESI): m/z 474
[M?1]?; HRMS (ESI m/z) Calcd for C23H25ClN4O3S:
474.1413 and found: 474.1413; Anal. Calcd for
C23H25ClN4O3S: C, 58.40; H, 5.33; Cl, 7.50; N, 11.85; O,
10.15; S, 6.78; Found: C, 58.40; H, 5.33; Cl, 7.50; N, 11.85;
O, 10.15; S, 6.78; Purity: 98.1 % (Rt = 9.5 min).
This compound was prepared by treating compound 4a
with N-phenyl ethyl isocyanate using the procedure
detailed above and it was obtained as a white solid in 93 %
as yield; mp 72–74 °C; IR (KBr): m 3,349, 1,629, 1,594,
1,534, 1,298, 1,150 cm-1; TLC: EtoAc/hexanes (9:1),
1
Rf * 0.5. H NMR (DMSO-d6, 500 MHz): d 8.07 (d, 2H,
J = 8.5 Hz), 7.67 (d, 2H, J = 8.5 Hz), 7.31–7.17 (m, 5H),
6.08 (s, 1H), 5.98 (brs, 1H), 4.05 (d, 2H, J = 13.2 Hz),
3.42–3.33 (m, 2H), 3.16 (s, 3H), 2.95–2.86 (m, 1H), 2.81 (t,
2H, J = 7.2 Hz), 2.69 (t, 2H, J = 12.1 Hz), 2.28 (s, 3H),
1.80 (d, 2H, J = 12.3 Hz), 1.61–1.47 (m, 2H); 13C NMR
(75 MHz, DMSO-d6) : d 161.7 (C1), 149.2 (C2), 144.4
(C3), 144.0 (C4), 137.7 (C5), 134.6 (C6), 133.6 (C7), 130.5
(C8), 129.0 (C9), 127.2 (C10), 110.2 (C11), 83.0 (C12),
82.7 (C13), 49.12 (C14), 45.6 (C15), 44.0 (C16), 43.6
(C17), 36.5 (C18), 34.3 (C19), 34.02 (C20), 29.2 (C21),
27.3 (C22), 27.1 (C23), 18.9 (C24), 18.3 (C25); MS (ESI):
m/z 467 [M?1]?; HRMS (ESI m/z) Calcd for
C25H30N4O3S: 467.2114 and found: 467.2114; Anal. Calcd
for C25H30N4O3S: C, 64.35; H, 6.48; N, 12.01; O, 10.29; S,
6.87; Found: CC, 64.35; H, 6.48; N, 12.01; O, 10.29; S,
6.87; Purity: 94.3 % (Rt = 9.2 min).
N-(2-Ethylphenyl)-4-(3-methyl-1-(4-
3(methylsulphonyl)phenyl)-1H-pyrazol-5-yl)piperidine-1-
carboxamide (9k)
Molecular modelling experimental procedure
Protein structure is downloaded from Protein Data Bank
(PDB ID 1ZD5) (Arand et al., 1996). Protein preparation
wizard is used to do the necessary corrections in the crystal
structure. Grid is prepared by taking co-crystal ligands as a
centroid of the grid. Docking is performed using Glide
docking tool in Schrodinger suite.
This compound was prepared by treating compound 4a
with 2-ethylphenyl isocyanate using the procedure detailed
above and it was obtained as a white solid in 94 % as yield;
mp 222–224 °C. IR (KBr): m 3,343, 1,620, 1,595, 1,532,
1,296, 1,150 cm-1. TLC: EtoAc/hexanes (9:1), Rf * 0.4.
1H NMR (DMSO-d6, 500 MHz):
d 8.06 (d, 2H,
J = 8.5 Hz), 7.64 (d, 2H, J = 8.5 Hz), 7.33–7.24 (m, 2H),
7.22–7.16 (m, 2H), 6.07 (s,1H), 5.26 (brs, 1H), 4.00 (d, 2H,
J = 13.0 Hz), 3.49–3.39 (m, 2H), 3.12 (s, 3H), 2.89–2.78
(m, 1H), 2.69 (t, 2H, J = 10.0 Hz), 2.30 (s, 3H), 1.81 (d,
2H, J = 12.5 Hz), 1.63–1.48 (m, 2H), 1.25 (t, 3H,
J = 7.2 Hz); 13C NMR (75 MHz, DMSO-d6) : d 161.2
(C1), 149.7 (C2), 144.5 (C3), 144.0 (C4), 137.7 (C5), 134.6
(C6), 133.6 (C7), 130.5 (C8), 129.0 (C9), 127.2 (C10),
110.2 (C11), 83.0 (C12), 82.7 (C13), 49.12 (C14), 45.6
sEH IC50 assay procedure
The ability of the test compounds listed in the Table 1 to
inhibit sEHs (IC50 and %inhibition at 100 lMconcentration)
was determined using Soluble Epoxide Hydrolase Inhibitor
Screening Assay kit (Catalogue no.10011671, Cayman
Chemical, Ann Arbor, MI, USA). Enzymes (5 ll human
sEH) were incubated with 2 ll inhibitors for 15 min in
25 mM Bis–Tris/HCl buffer (188 ll; pH 7.0) at 25 °C before
123

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Med Chem Res (2014) 23:2178–2197
Friesen RW, Mancini JA (2008) Microsomal prostaglandin
E
5 ll of substrate (cyano(2-methoxynaphthalen-6-yl)methyl
trans-(3-phenyl-oxyran-2-yl)methyl carbonate (CMNPC)
was added. Activity was assessed by measuring the appear-
ance of the fluorescent 6-methoxynaphthaldehyde product
(kem = 330 nm, kex = 465 nm) at 25 °C during a 15-min
incubation (Spectramax M2; Molecular Device, Inc., Sun-
nyvale, CA). The IC50s were calculated from at least three
separate runs, each in triplicate, to obtain the standard
deviation given in the ‘‘Results and discussion’’ section. The
IC50 was determined from at least four points in the linear
region of the inhibition curve with at least one point above
and one below the IC50.
synthase-1 (mPGES-1): a novel antiinflammatory therapeutic
target. J Med Chem 51:4059–4067
Huang SX, Li HY, Liu JY, Morisseau C, Hammock BD (2010)
Incorporation of piperazino functionality into 1,3-disubstituted
urea as the tertiary pharmacophore affording potent inhibitors of
soluble epoxide hydrolase with improved pharmacokinetic
properties. J Med Chem 53:8376–8386
Hwang SH, Morisseau C, Do Z, Hammock BD (2006) Solid-phase
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Hwang SH, Tsai HJ, Liu JY, Morisseau C, Hammock BD (2007)
Orally bioavailable potent soluble epoxide hydrolase inhibitors.
J Med Chem 50:3540–3825
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Acknowledgments Author thank National Institute of Pharmaceu-
tical Education and Research (NIPER)-Hyderabad; and Indian Insti-
tute of Chemical Technology (IICT)-Hyderabad for providing
facilities and Department of Pharmaceuticals (DoP); Government of
India (GoI) for financial support.
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