Design, synthesis, and antiproliferative activity of 3,4-diarylpyrazole-1- carboxamide derivatives against melanoma cell line

Article abstract of DOI:10.1002/ardp.201000375

Synthesis of a new series of 3,4-diarylpyrazole-1-carboxamide derivatives is described. Their antiproliferative activity against A375P human melanoma cell line was tested and the effect of substituents on the diarylpyrazole scaffold was investigated. The

Full text of DOI:10.1002/ardp.201000375

Arch. Pharm. Chem. Life Sci. 2011, 344, 745–754
745
Full Paper
Design, Synthesis, and Antiproliferative Activity of 3,4-
Diarylpyrazole-1-carboxamide Derivatives Against Melanoma
Cell Line
Mohammed I. El-Gamal1,2, Hong Seok Choi3, Hae-Guk Cho3, Jun Hee Hong3, Kyung Ho Yoo2, and
Chang-Hyun Oh1,2
1 Department of Biomolecular Science, University of Science and Technology, Daejeon, Republic of Korea
2 Biomaterials Center, Korea Institute of Science and Technology, Seoul, Republic of Korea
3 College of Pharmacy, Chosun University, Gwangju, Republic of Korea
Synthesis of a new series of 3,4-diarylpyrazole-1-carboxamide derivatives is described. Their
antiproliferative activity against A375P human melanoma cell line was tested and the effect of
substituents on the diarylpyrazole scaffold was investigated. The biological results indicated that
five synthesized compounds (Ig, Ii, IIc, IIg, and IIh) exhibited similar activity to Sorafenib. In addition,
three compounds (IIa, IIb, and IIi) were more potent than Sorafenib. Among all of these derivatives,
compound IIa which has dimethylamino and phenolic moieties showed the most potent
antiproliferative activity against A375P human melanoma cell line. Virtual screening was carried
out through docking of the most potent compound IIa into the domain of V600E-b-Raf and the
binding mode was studied.
Keywords: A375P / Antiproliferative activity / 3,4-Diarylpyrazole / 1H-Pyrazole-1-carboxamide / Melanoma
Received: December 19, 2010; Revised: January 12, 2011; Accepted: January 19, 2011
DOI 10.1002/ardp.201000375
Introduction
trials. As for immunotherapy, interferon alfa-2b (Intron-A) [7]
has been approved by both the FDA and EMEA for adjuvant
treatment of melanoma patients, and aldesleukin (Proleukin)
[8, 9] has been also approved for the treatment of metastatic
melanoma in the USA.
Melanoma is the most aggressive form of skin cancer and is
the fastest growing cancer in the United States [1, 2]. Early
stage melanoma can be cured surgically. However, mela-
noma metastasizing to major organs (stage IV) is virtually
incurable [1]. Patients with advanced melanoma have a
median survival time of less than one year, and the estimated
5-year survival time is less than 15% [1, 3]. With the incidence
of melanoma rapidly rising in the United States and other
developed countries, there is an urgent need to develop more
effective drugs [4–6].
There are many promising, potent, and selective antipro-
liferative agents for treatment of melanoma. Sorafenib [10–
15] is an oral multikinase inhibitor that targets 2 classes of
kinases which are known to be involved in both tumor
proliferation and angiogenesis [16]. It inhibits Raf kinases
(Raf-1 and b-Raf), as well as proangiogenic receptor tyrosine
kinases of the PDGFR and VEGFR family [12]. The antiproli-
ferative activity of Sorafenib against melanoma is assumed to
be due to b-Raf inhibition and induction of apoptosis in a
caspase-independent manner [17]. Sorafenib demonstrated
high antiproliferative activity against different melanoma
xenografts and cell lines [17], but not in case of advanced
metastatic melanoma (stage IV) [16]. In addition, sorafenib
has been implicated in the development of reversible
posterior leukoencephalopathy syndrome and secondary
erythrocytosis [18]. These side effects together with the poor
The current treatments involve surgical removal of the
tumor, immunotherapy, radiotherapy, chemotherapy, vari-
ous combinations, or the use of new treatments in clinical
Correspondence: Chang-Hyun Oh, Biomaterials Center, Korea Institute
of Science and Technology, PO Box 131, Cheongryang, Seoul 130-650,
Republic of Korea.
E-mail: choh@kist.re.kr
Fax: þ82-2-958-5189
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M. I. El-Gamal et al.
Arch. Pharm. Chem. Life Sci. 2011, 344, 745–754
ment of melanoma have been identified [19, 20]. In the
present study, compounds A [19] and B [21] (Fig. 1) were
considered as the parent compounds for design of our target
compounds. In our efforts in order to develop new antipro-
liferative agents for treatment of melanoma, we designed and
synthesized new 3,4-diarylpyrazole derivatives possessing an
amide moiety at position 1 of the pyrazole ring. The synthes-
ized compounds Ia–i and IIa–i were designed by introduction
of derivatives of the carboxamide side chain of compound B
into position 1 of the pyrazole ring of compound A. The
phenolic hydroxy group of A was retained in compounds
IIa–i and modified into methoxy group in compounds Ia–i
in order to examine its effect on the activity (Fig. 1). Herein, we
report the synthesis and antiproliferative activity against
A375P human melanoma cell line of these compounds.
In-silico and molecular docking studies are also reported.
OH
N
Cl
H
N
O
N
N
HN
NH
N
O
N
N
O
HO
A
B
OR1
Cl
N
N
HN
R
N
R = dialkylamino, heterocycloalkyls
R1 = H, CH3
Figure 1. Structures of the parent compounds A and B, and target
compounds.
Results and discussion
efficiency of sorafenib in case of advanced metastatic mela-
noma encourage the search for new antiproliferative agents
for treatment of melanoma.
Chemistry
3,4-Diarylpyrazole derivatives Ia–i and IIa–i with amide
moiety at position 1 of the pyrazole ring were prepared
according to the sequence of reactions, illustrated in
Scheme 1. Methylation of the phenolic hydroxyl group of
Moreover, antiproliferative agents with 3,4-diarylpyrazole
scaffold targeting b-Raf kinase that can be efficient for treat-
OH
OCH3
OCH3
OCH3
Cl
Cl
Cl
Cl
a
c
d
b
OH
Cl
O
CH3
CH3
CH3
O
O
1
2
3
4
OCH3
OCH3
OCH3
Cl
Cl
OCH3
COOPh
Cl
N
N
N
e
f
N
COOPh
N
NH
+
O
N
N
N
N
5
8
6
7
R
OCH3
OCH3
OH
O
Cl
Cl
Cl
NH
R
h
R
HN
N
HN
N
N
g
N
N
N
+
O
O
N
N
N
Ia-i
9
IIa-i
Reagents and conditions: (a) (CH3)2SO4, K2CO3, acetone; (b) KMnO4, C5H5N, H2O; (c) acetyl chloride, MeOH;
(d) 4-picoline, LHMDS, THF; (e) (i) DMF-DMA, (ii) hydrazine monohydrate, EtOH; (f) phenyl chloroformate, TEA, THF;
.
(g) substituted ethanamines, K2CO3, CH2Cl2; (h) BF3 Me2S,CH2Cl2.
Scheme 1. Synthesis of the target compounds Ia–i and IIa–i.
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3,4-Diarylpyrazole-1-Carboxamides: Docking Study
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Table 1. Antiproliferative activity of methoxy compounds Ia–i
against A375P cell line.
2-chloro-5-methylphenol (1) using dimethyl sulfate gave
1-chloro-2-methoxy-4-methylbenzene (2) [22]. Oxidation of
the methyl group of 2 using KMnO4 produced 4-chloro-3-
methoxybenzoic acid (3) [23], which upon esterification with
methanol in the presence of acetyl chloride afforded the
corresponding methyl ester 4. The pyridyl derivative 5 was
obtained by treatment of 4 with 4-picoline in the presence of
lithium bis(trimethylsilyl)amide (LHMDS). Cyclization to the
pyrazole compound 6 was carried out by treatment of 5 with
dimethylformamide dimethyl acetal (DMF-DMA), and sub-
Structure
Comp. No.
Ia
R
IC50 (mM)
14.8
CH3
N
CH3
Ib
>20
CH3
N
CH3
sequent
treatment
with
hydrazine
monohydrate.
Interaction of 6 with phenyl chloroformate in the presence
of triethylamine gave a mixture of pyrazole-2-carboxylate
derivative 7 and pyrazole-1-carboxylate derivative 8 in an
approximate ratio of 1:4ꢀ1:5. The mixture was then reacted
with the appropriate ethanamines to produce the target
methoxy compounds Ia–i in combination with their
regioisomers 9. Compounds Ia–i with lower Rf values on
TLC were obtained in the pure form after purification by flash
column chromatography. Demethylation of the methoxy
group of Ia–i using boron trifluoride–methyl sulfide complex
afforded the corresponding hydroxy derivatives IIa–i.
Ic
>20
>20
N
O
Id
CH3
O
N
OCH3
Cl
CH3
R
HN
O
N
N
Ie
If
15.1
18.8
N
N CH3
N
Antiproliferative activity and discussion
The antiproliferative activity of the synthesized compounds
against A375P human melanoma cell line was tested. The
ability of the 1H-pyrazole-1-carboxamide derivatives to
inhibit the growth of A375P cell line is summarized in
Tables 1 and 2. The results are expressed as IC50 values.
Sorafenib was selected as a reference standard.
O
N
N
CH3
Ig
Ih
12.7
N
N
As listed in Tables 1 and 2, some of the compounds showed
moderate activity, while compounds Ig, Ii, IIc, IIg, and IIh
having IC50 values ranging from 11.8 to 12.7 mM exhibited
similar activity to that of sorafenib (IC50 ¼ 12.5 mM). In
addition, compounds IIa, IIb, and IIi with IC50 values of
4.5, 8.1, and 8.3 mM, respectively, showed more potent anti-
proliferative activity than that of sorafenib. Compounds Ig
and Ii possess a meta-methoxy group on the benzene ring
while the other six potent compounds possess a hydroxy
group. And the R moiety of compounds Ig and IIg is piper-
idinyl moiety and that of compounds Ii and IIi is pyrrolidinyl.
The R moieties of compounds IIa, IIb, IIc, and IIh are dime-
thylamino, diethylamino, morpholino, and 2-methylpiper-
idinyl, respectively.
>20
H3C
Ii
12.5
12.5
N
Sorafenib
phenolic moiety may induce additional DNA damage effect
in the presence of copper and oxygen.
Most of hydroxyl compounds were generally more potent
than the corresponding methoxy derivatives, which suggests
that the m-hydroxy group on the benzene ring is optimal for
the activity. This may be attributed to hydrogen bond for-
mation at the receptor site. Docking of IIa structure into the
domain of V600E-b-Raf kinase crystal structure revealed the
formation of two hydrogen bonds by the hydroxyl group at
the binding site (molecular docking part). Or the o-chloro-
The effect of the terminal substituents of the tail at po-
sition
1 of the pyrazole ring was also investigated.
Compounds Id and IId having a 2,6-dimethylmorpholine
ring showed diminished activity. We can conclude that this
moiety is unfavorable for antiproliferative activity against
melanoma of this series. This may be due to the steric and/or
electronic effect(s) of this moiety at the receptor site. In
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M. I. El-Gamal et al.
Arch. Pharm. Chem. Life Sci. 2011, 344, 745–754
Table 2. Antiproliferative activity of hydroxy compounds IIa–i
against A375P cell line.
was more potent than that of N-acetyl derivatives If. These
results may be rationalized by the steric and/or electronic
effect(s) of the acetyl group, compared with the methyl
group. Introduction of a methyl group on the piperidine
ring (compound Ih) diminished the activity compared with
unsubstituted piperidine ring (compound Ig). Similarly,
introduction of two methyl groups on the morpholine ring
(compound IId) diminished the activity, compared with
unsubstituted morpholine derivative (compound IIc).
In conclusion, a new series of 3,4-diaryl-1H-pyrazole-1-car-
boxamide derivatives was synthesized based on our previous
literature studies. Among all of these derivatives, compound
IIa with substituted m-hydroxyphenyl and dimethylamino
moieties showed the most potent antiproliferative activity
against A375P human melanoma cell line. We can conclude
that these moieties are optimal for antiproliferative activity
of this series of compounds. Further modification of these
compounds in order to improve their potency is currently in
progress.
Structure
Comp. No.
IIa
R
IC50 (mM)
4.5
CH3
N
CH3
IIb
8.1
CH3
N
CH3
IIc
12.5
N
O
IId
>20
CH3
O
N
OH
Cl
CH3
R
HN
O
N
Lipinski’s rule of five and drug-likeness profile
N
IIe
IIf
>20
>20
In this work, the bioavailability of the most active com-
pounds Ig, Ii, IIa–c, and IIg–i was assessed using ADME
(absorption, distribution, metabolism, elimination) predic-
tion methods. In particular, we calculated the compliance
of compounds to the Lipinski’s rule of five [24]. This approach
has been widely used as a filter for substances that would
likely be further developed in drug design programs. In
addition, we calculated the total polar surface area (TPSA)
since it is another key property that has been linked to drug
bioavailability. Thus, passively absorbed molecules with a
TPSA > 140 are thought to have low oral bioavailability [25].
Molecules violating more than one of these rules may have
problems with bioavailability. Predictions of ADME proper-
ties for the studied compounds are given in Table 3. The
results showed that all the potent compounds comply with
these rules and even sorafenib showed no violation.
Theoretically, these compounds should present good passive
oral absorption and differences in their bioactivity cannot be
attributed to this property.
N
N CH3
N
O
N
N
CH3
IIg
IIh
12.2
11.8
N
N
H3C
IIi
8.3
N
Sorafenib
12.5
Currently, there are many approaches to assess a com-
pound drug-likeness based on topological descriptors, finger-
prints of molecular drug-likeness structure keys or other
properties such as clogP and molecular weight [26]. In this
work, we used the Osiris program [27] for calculating the
fragment-based drug likeness of the most potent compounds
and comparing them with sorafenib. Interestingly, all the
potent compounds Ig, Ii, IIa–c, and IIg–I demonstrated better
drug-likeness values (from 7.72 to 2.69) than sorafenib (–4.2).
The drug-scores of the potent compounds have also been
determined in the present study. The results showed that
the eight potent compounds demonstrated higher drug-score
general, it was found that dialkylamino and pyrrolidinyl
derivatives were more potent than other derivatives with
6-membered rings. This may be attributed to steric effect
of the bulkier substituents at the receptor site. By comparing
the activities of compounds Ia,b with those of IIa,b, we find
that smaller alkyl groups, two methyl groups, are more
optimal for activity than the slightly longer groups, ethyl
groups. Upon comparing the activity of the piperazinyl
derivatives, it was found that the N-methyl derivative Ie
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Arch. Pharm. Chem. Life Sci. 2011, 344, 745–754
3,4-Diarylpyrazole-1-Carboxamides: Docking Study
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Table 3. Solubility and calculated Lipinski’s rule of five for the most active compounds over human melanoma (A375P) cell line.
logSb
Parameter
a
Compd. No. IC50
clogPc
TPSAd
MWe
n ONf
n OHNHg
n violations
Ig
Ii
IIa
IIb
IIc
IIg
IIh
12.7
12.5
4.5
ꢂ5.22
ꢂ4.95
ꢂ3.95
ꢂ4.55
ꢂ4.02
ꢂ4.91
ꢂ5.28
ꢂ4.64
ꢂ6.69
3.81
3.49
2.49
3.36
2.41
3.61
3.90
3.30
4.27
72.29
72.29
83.28
83.28
92.52
83.28
83.28
83.28
92.35
439.95
425.92
385.86
413.91
427.89
425.92
439.95
411.89
464.82
7
7
7
7
8
7
7
7
7
1
1
2
2
2
2
2
2
3
0
0
0
0
0
0
0
0
0
8.1
12.5
12.2
11.8
8.3
IIi
Sorafenib
12.5
a
2
e
Data taken from Tables 1 and 2. b Solubility parameter. c Calculated lipophilicity. d Total polar surface area (A ). Molecular weight.
˚
f
g
Number of hydrogen bond acceptor. Number of hydrogen bond donor.
values than sorafenib (Fig. 2). Moreover, we used the Osiris
docking into the domain of b-Raf kinase. Compound IIa
which is the most potent derivative of this series was used
for docking study as a representative example. All calcu-
lations were performed using MOE 2008.10 software [28]
installed on 2.0G Core 2 Duo. The crystal structure of
V600E-b-Raf Kinase in complex with PLX4032 (PDB code:
3OG7) was obtained from protein data bank (PDB) [29]. The
automated docking program of MOE 2008.10 was used for
docking of IIa into the domain of V600E-b-Raf kinase. The
complex was energy-minimized with a MMFF94ꢁ force-field
[30] till the gradient convergence 0.01 kcal/mol was reached.
The docking study has revealed that the ligand has bound in
the active site of one of the protomers in the protein dimer
through the formation of four strong hydrogen bonds
between the binding site and the ligand. These hydrogen
program for prediction of the overall toxicity of the most
active derivatives as it may point to the presence of some
fragments generally responsible for the irritant, mutagenic,
tumorigenic, or reproductive effects in these molecules.
Interestingly, most of the active compounds presented a
low in-silico toxicity risk profile, similar to sorafenib (Fig. 2).
These theoretical data reinforced the cytotoxicity experimen-
tal data described in this work pointing these compounds as
lead compounds with low toxicity risk profile.
Molecular docking
The level of antiproliferative activity of the synthesized com-
pounds over melanoma cells, in which b-Raf kinase is over-
expressed and mutated, promoted us to perform molecular
Figure 2. In-silico toxicity risks (left panel) and drug-score (right panel) of sorafenib and the potent antiproliferative pyrazole derivatives over
melanoma cancer (M, mutagenic; T, tumorigenic; I, irritant; R, reproductive).
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750
M. I. El-Gamal et al.
Arch. Pharm. Chem. Life Sci. 2011, 344, 745–754
Figure 3. Interaction between compound IIa and V600E-b-Raf, hydrogen bonds are shown as black lines (left panel). The ligand IIa (space
filling) is embedded into the kinase domain (right panel).
bonds have been formed between the phenolic hydroxyl Experimental
˚
hydrogen atom and Val-B590 (1.43 A); phenolic hydroxyl
˚
oxygen atom and Asn-B512 (1.80 A); pyrazole N2 atom and
Chemistry
˚
Lys-B591 (1.81 A); and carbonyl oxygen atom and Leu-B515
˚
(2.02 A). Figures 3 and 4 demonstrate the binding model of
All melting points were obtained on a Walden Precision
Apparatus Electrothermal 9300 apparatus and are uncorrected.
Mass spectra (MS) were taken in ESI mode on a Waters 3100 Mass
Detecter (Waters, Milford, MA, USA). Nuclear magnetic reso-
nance (NMR) spectroscopy was performed using a Bruker ARX-
400, 400 MHz spectrometers (Bruker Bioscience, Billerica, MA,
USA) with TMS as an internal standard. IR spectra (KBr disks) were
recorded with a Bruker FT-IR instrument (Bruker Bioscience,
Billerica, MA, USA). %Purity of the target compounds (>95%)
were determined by LC-MS analysis. All reagents and solvents
were purchased from Aldrich chemical Co. and Tokyo Chemical
Industry (TCI) Co., and used without further purification.
the most potent compound IIa with the binding site of
V600E-b-Raf. The results of this molecular docking study
can support the postulation that our active compounds
may act on the same enzyme target, b-Raf, whose inhibition
can lead to antiproliferative effect against melanoma cells.
1-Chloro-2-methoxy-4-methylbenzene 2
A mixture of 2-chloro-5-methylphenol (1, 21.5 g, 150 mmol),
dimethyl sulfate (20.8 g, 165 mmol), and anhydrous K2CO3
(51.8 g, 375 mmol) in acetone (250 mL) was heated under reflux
for 1 h. The mixture was filtered, and the filtrate was evaporated
under reduced pressure. Water (150 mL) was added to the resi-
due and the resulting mixture was carefully extracted with
Et2O. The organic layer was separated and the aqueous layer
was extracted with Et2O (3 ꢁ 50 mL). The combined
Et2O extracts were washed with brine, dried over anhydrous
Na2SO4, and filtered. The organic solvent was evaporated under
reduced pressure, and the residue was used in the next step
without further purification. MS m/z: 159.5 (Mþ þ 3), 158.5
(Mþ þ 2), 157.5 (Mþ þ 1).
4-Chloro-3-methoxybenzoic acid 3
A stirred mixture of compound 2 (11.17 g, 71 mmol), potassium
permanganate (35.0 g, 221 mmol), pyridine (36 mL), and water
(107 mL) was heated at 508C for 24 h. The mixture was then stirred
at room temperature for 13 h. The mixture was filtered and MnO2
was suspended in hot water and again filtered off. The combined
aqueous filtrates were washed with ethyl acetate (3 ꢁ 75 mL) and
Figure 4. 2D-presentation for the binding interactions of compound
IIa with V600E-b-Raf kinase domain.
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Arch. Pharm. Chem. Life Sci. 2011, 344, 745–754
3,4-Diarylpyrazole-1-Carboxamides: Docking Study
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then acidified with 2 N H2SO4. The precipitate was filtered off,
washed with water, and dried to give the title compound (11.98 g,
90%). M.p.: 215–2168C (lit. m.p.: 217–2198C [23]).
added to the above solution at 08C. The reaction mixture was
stirred at the same temperature for 2 h. The mixture was diluted
with H2O (10 mL) and CH2Cl2 (15 mL). The organic layer was
separated, and the aqueous layer was extracted again with
CH2Cl2 (2 ꢁ 15 mL). The combined organic layer extracts were
washed with brine and dried over anhydrous MgSO4. The organic
solvent was evaporated under reduced pressure and the residue
(a mixture of compounds 7 and 8) was used in the next step
without further purification.
Methyl 4-chloro-3-methoxybenzoate 4
Acetyl chloride (1.9 mL, 28.1 mmol) was added dropwise to a
solution of 3 (1.0 g, 5.4 mmol) in MeOH (40 mL) at 08C and the
reaction mixture was then stirred at room temperature for 15 h.
After evaporation of the organic solvent, the residue was purified
by flash column chromatography (silica gel, hexane/ethyl acetate
5:1 v/v) to give 4 (0.91 g, 85%) as a crystalline solid. M.p.: 49–508C;
1H-NMR (DMSO-d6) d 3.88 (s, 3H), 3.94 (s, 3H), 7.55–7.62 (m, 3H); MS
m/z: 204.0 (Mþ þ 3), 203.0 (Mþ þ 2), 202.0 (Mþ þ 1).
General procedure for preparation of compounds Ia–i
To a solution of the crude product of the previous step (0.1 g,
0.246 mmol) in dry CH2Cl2 (3 mL), a solution of the appropriate
ethanamine derivative (0.738 mmol) in dry CH2Cl2 (2 mL) and
anhydrous K2CO3 (68 mg, 0.492 mmol) were added. The reaction
mixture was stirred at room temperature for 1 h. Water (5 mL) was
added to the reaction mixture and the organic layer was separated.
The aqueous layer was extracted with CH2Cl2 (2 ꢁ 3 mL) and the
combined organic layer extracts were washed with brine and dried
over anhydrous MgSO4. The organic solvent was evaporated under
reduced pressure and the residue was obtained.
1-(4-Chloro-3-methoxyphenyl)-2-(pyridin-4-yl)ethanone 5
To a solution of compound 4 (1.0 g, 5.0 mmol) and 4-picoline
(0.5 mL, 5.6 mmol) in THF (5 mL) in a cooled bath at ꢂ258C,
LHMDS (3.7 mL, 1.0 M solution in THF, 19.9 mmol) was slowly
added to maintain the temperature at ꢂ258C. The resulting
mixture was stirred overnight at room temperature. The mixture
was quenched with saturated aqueous NH4Cl. Ethyl acetate was
added and the organic layer was separated. The aqueous layer
was extracted with ethyl acetate (3 ꢁ 10 mL). The combined
organic layer extracts were washed with brine and dried over
anhydrous Na2SO4. The organic solvent was evaporated under
reduced pressure and the residue was purified by flash column
chromatography (silica gel, hexane/ethyl acetate 1:1 v/v then
switching to hexane/ethyl acetate 1:5 v/v) to yield compound 5
(0.58 g, 45%). M.p.: 85–888C; 1H-NMR (DMSO-d6) d 3.96 (s, 3H), 4.53
(s, 2H), 7.30 (d, 2H, J ¼ 4.1 Hz), 7.64–7.69 (m, 3H), 8.53 (d, 2H,
J ¼ 4.5 Hz); MS m/z: 265.0 (Mþ þ 3), 264.0 (Mþ þ 2), 263.0
(Mþ þ 1).
3-(4-Chloro-3-methoxyphenyl)-N-(2-(dimethylamino)-
ethyl)-4-(pyridin-4-yl)-1H-pyrazole-1-carboxamide Ia
It was purified by flash column chromatography (silica gel, ethyl
acetate then switching to ethyl acetate/methanol 4:1 v/v). Yield
72%; mp: 247–2488C; IR (KBr) [cmꢂ1]: 3436, 3093, 3000, 1729,
1603, 1543, 1522, 1478, 1410, 1262, 1245, 1140, 1059, 1035; 1H-
NMR (CD3OD) d 2.36 (s, 6H), 2.65 (t, 2H, J ¼ 6.5 Hz), 3.57 (t, 2H,
J ¼ 6.5 Hz), 3.75 (s, 3H), 7.02 (d, 1H, J ¼ 2.0 Hz), 7.22 (dd, 1H,
J ¼ 2.0 Hz, J ¼ 8.1 Hz), 7.33 (d, 1H, J ¼ 8.1 Hz), 7.38 (d, 2H,
J ¼ 6.0 Hz), 8.52 (d, 2H, J ¼ 6.1 Hz), 8.61 (s, 1H); 13C-NMR
(CD3OD) d 154.9, 150.3, 149.7, 141.8, 141.1, 134.8, 134.2, 130.5,
122.8, 121.6, 113.0, 111.8, 112.7, 56.4, 53.5, 43.4, 37.3; MS m/z:
402.93 (Mþ þ 3), 401.96 (Mþ þ 2), 400.95 (Mþ þ 1).
4-(3-(4-Chloro-3-methoxyphenyl)-1H-pyrazol-4-yl)
pyridine 6
Compound 5 (1.0 g, 3.8 mmol) was added to DMF-DMA (5.14 mL,
38.2 mmol) and the mixture was stirred at room temperature for
18 h. The resulting solution was concentrated to dryness to
furnish an oil which was used in the next step without purifi-
cation. To a portion of the oil from the previous step (0.137 g,
0.457 mmol) in EtOH (3 mL) was added hydrazine monohydrate
(0.04 mL, 0.76 mmol) and the reaction mixture was stirred over-
night at room temperature. Water (5 mL) was added to the
reaction mixture and the organics were extracted with ethyl
acetate (3 ꢁ 5 mL). The combined organic layer extracts were
washed with brine and dried over anhydrous Na2SO4. After
evaporation of the organic solvent, the residue was purified
by column chromatography (silica gel, hexane/ethyl acetate
1:1 v/v then switching to hexane/ethyl acetate 1:5 v/v) to yield
compound 6 (0.11 g, 81%). M.p.: 248–2518C; 1H-NMR (DMSO-d6) d
3.77 (s, 3H), 6.97 (dd, 1H, J ¼ 1.5 Hz, J ¼ 1.6 Hz), 7.18 (s, 1H), 7.28
(d, 2H, J ¼ 5.9 Hz), 7.45 (d, 1H, J ¼ 8.0 Hz), 8.14 (brs, 1H), 8.48 (d,
2H, J ¼ 6.0 Hz), 13.39 (brs, 1H); MS m/z: 289.0 (Mþ þ 3), 288.0
(Mþ þ 2), 287.0 (Mþ þ 1).
3-(4-Chloro-3-methoxyphenyl)-N-(2-(diethylamino)ethyl)-
4-(pyridin-4-yl)-1H-pyrazole-1-carboxamide Ib
It was purified by flash column chromatography (silica gel, ethyl
acetate then switching to ethyl acetate/methanol 6:1 v/v). Yield
58%; mp: 115–1168C; IR (KBr) [cmꢂ1]: 3439, 3093, 3000, 1729, 1603,
1522, 1497, 1410, 1245, 1140, 1059, 1035; 1H-NMR (DMSO-d6) d 0.99
(t, 6H, J ¼ 6.4 Hz), 2.49 (q, 4H, J ¼ 6.3 Hz), 2.63 (t, 2H, J ¼ 5.9 Hz),
3.16 (t, 2H, J ¼ 5.1 Hz), 3.73 (s, 3H), 7.02 (d, 1H, J ¼ 2.0 Hz), 7.22 (dd,
1H, J ¼ 2.1 Hz, J ¼ 7.9 Hz), 7.33 (d, 1H, J ¼ 8.1 Hz), 7.35 (d, 2H,
J ¼ 5.9 Hz), 8.48 (brs, 1H), 8.53 (d, 2H, J ¼ 6.1 Hz), 8.74 (s, 1H); MS
m/z: 431.1 (Mþ þ 3), 430.1 (Mþ þ 2), 429.1 (Mþ þ 1).
3-(4-Chloro-3-methoxyphenyl)-N-(2-morpholinoethyl)-4-
(pyridin-4-yl)-1H-pyrazole-1-carboxamide Ic
It was purified by flash column chromatography (silica gel, ethyl
acetate then switching to ethyl acetate/methanol 4:1 v/v). Yield
80%; mp: 140–1418C; IR (KBr) [cmꢂ1]: 3350, 3129, 2965, 1734,
1605, 1582, 1512, 1464, 1411, 1339, 1279, 1145, 1119, 1057; 1H-
NMR (DMSO-d6) d 2.43–2.53 (m, 6H), 3.43 (t, 2H, J ¼ 6.1 Hz), 3.56
(t, 4H, J ¼ 4.0 Hz), 3.77 (s, 3H), 7.03 (d, 1H, J ¼ 2.1 Hz), 7.23 (dd,
1H, J ¼ 2.0 Hz, J ¼ 7.9 Hz), 7.34 (d, 2H, J ¼ 5.9 Hz), 7.50 (d, 1H,
J ¼ 6.1 Hz), 8.53 (d, 2H, J ¼ 6.0 Hz), 8.57 (brs, 1H), 8.79 (s, 1H); MS
m/z: 445.0 (Mþ þ3), 444.0 (Mþ þ 2), 443.0 (Mþ þ 1).
Phenyl 3-(4-chloro-3-methoxyphenyl)-4-(pyridin-4-yl)-
1H-pyrazole-1-carboxylate 8
To a solution of compound 6 (0.1 g, 0.35 mmol) in anhydrous
THF (10 mL), triethylamine (0.112 g, 1.1 mmol) was slowly added
at 08C. Phenyl chloroformate (0.165 g, 1.05 mmol) was slowly
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M. I. El-Gamal et al.
Arch. Pharm. Chem. Life Sci. 2011, 344, 745–754
3-(4-Chloro-3-methoxyphenyl)-N-(2-(2,6-
dimethylmorpholino)ethyl)-4-(pyridin-4-yl)-1H-pyrazole-
1-carboxamide Id
3-(4-Chloro-3-methoxyphenyl)-4-(pyridin-4-yl)-N-(2-
(pyrrolidin-1-yl)ethyl)-1H-pyrazole-1-carboxamide Ii
It was purified by flash column chromatography (silica gel, ethyl
acetate). Yield 67%; mp: 244–2478C; IR (KBr) [cmꢂ1]: 3439, 3093,
1729, 1603, 1543, 1522, 1497, 1459, 1245, 1140, 1059, 1035; 1H-
NMR (CDCl3) d 1.84 (t, 4H, J ¼ 5.4 Hz), 2.62 (t, 4H, J ¼ 5.3 Hz), 2.78
(t, 2H, J ¼ 6.1 Hz), 3.31 (t, 2H, J ¼ 6.0 Hz), 3.74 (s, 3H), 7.03 (d, 1H,
J ¼ 1.9 Hz), 7.11 (dd, 1H, J ¼ 1.9 Hz, J ¼ 8.1 Hz), 7.24 (d, 1H,
J ¼ 8.0 Hz), 7.37 (d, 2H, J ¼ 5.9 Hz), 7.89 (brs, 1H), 8.44 (s, 1H),
8.57 (d, 2H, J ¼ 6.0 Hz); MS m/z: 428.9 (Mþ þ 3), 427.9 (Mþ þ 2),
426.9 (Mþ þ 1).
It was purified by flash column chromatography (silica gel, ethyl
acetate). Yield 79%; mp: 87–898C; IR (KBr) [cmꢂ1]: 3208, 3098,
2975, 1733, 1600, 1583, 1524, 1465, 1408, 1338, 1252, 1148,
1092, 1074; 1H-NMR (CDCl3) d 1.18 (d, 6H, J ¼ 6.3 Hz), 1.85 (t,
2H, J ¼ 10.1 Hz), 2.62 (t, 2H, J ¼ 6.1 Hz), 2.78 (d, 2H, J ¼ 11.4 Hz),
3.58 (q, 2H, J ¼ 5.8 Hz), 3.68 (t, 2H, J ¼ 5.9 Hz), 3.78 (s, 3H), 7.00
(d, 1H, J ¼ 1.8 Hz), 7.06 (brs, 1H), 7.22 (dd, 1H,
J ¼ 1.9 Hz, J ¼ 8.0 Hz), 7.37 (d, 2H, J ¼ 4.5 Hz), 7.68 (d, 1H,
J ¼ 7.9 Hz), 8.44 (s, 1H), 8.57 (d, 2H, J ¼ 4.4 Hz); 13C-NMR
(CDCl3) d 158.7, 153.8, 152.9, 143.4, 134.9, 134.0, 132.5, 127.1,
126.7, 125.0, 124.5, 115.8, 75.4, 62.8, 60.0, 59.6, 55.4, 40.6, 22.7;
MS m/z: 473.0 (Mþ þ 3), 472.0 (Mþ þ 2), 471.0 (Mþ þ 1).
General procedure for preparation of compounds IIa–i
To a solution of compound Ia–i (0.1 mmol) in methylene
chloride (3 mL), BF3 ꢃ Me2S (0.13 g, 1 mmol) was added dropwise
at room temperature under N2 and the reaction mixture was
stirred at the same temperature for 48 h. The mixture was
quenched with saturated aqueous NaHCO3. Ethyl acetate
(3 mL) was added and the organic layer was separated. The
aqueous layer was extracted with ethyl acetate (3 ꢁ 2 mL). The
combined organic layer extracts were washed with brine and
dried over anhydrous Na2SO4. The organic solvent was evapo-
rated under reduced pressure and the residue was obtained.
3-(4-Chloro-3-methoxyphenyl)-N-(2-(4-methylpiperazin-
1-yl)ethyl)-4-(pyridin-4-yl)-1H-pyrazole-1-carboxamide Ie
It was purified by flash column chromatography (silica gel, ethyl
acetate). Yield 44%; mp: 247–2498C; 1H-NMR (DMSO-d6) d 2.28 (s,
3H), 2.36–2.51 (m, 8H), 2.63 (t, 2H, J ¼ 5.9 Hz), 3.17 (t, 2H,
J ¼ 6.0 Hz), 3.77 (s, 3H), 6.97 (d, 1H, J ¼ 2.0 Hz), 7.17 (dd, 1H,
J ¼ 1.9 Hz, J ¼ 7.9 Hz), 7.29 (d, 1H, J ¼ 8.0 Hz), 7.46 (d, 2H,
J ¼ 5.4 Hz), 7.95 (brs, 1H), 8.25 (s, 1H), 8.49 (d, 2H, J ¼ 5.2 Hz);
MS m/z: 457.9 (Mþ þ 3), 456.9 (Mþ þ 2), 455.9 (Mþ þ 1).
3-(4-Chloro-3-hydroxyphenyl)-N-(2-(dimethylamino)ethyl)-
4-(pyridin-4-yl)-1H-pyrazole-1-carboxamide IIa
It was purified by flash column chromatography (silica gel, ethyl
acetate then switching to ethyl acetate/methanol 4:1 v/v). Yield
43%; m.p.: 276–2778C; IR (KBr) [cmꢂ1]: 3392, 3128, 2970, 2925,
1730, 1612, 1593, 1514, 1418, 1346, 1293, 1207, 1155, 1004; 1H-
NMR (DMSO-d6) d 2.37 (s, 6H), 2.68 (t, 2H, J ¼ 6.9 Hz), 3.60 (t, 2H,
J ¼ 6.7 Hz), 6.88 (d, 1H, J ¼ 2.0 Hz), 6.91 (dd, 1H,
J ¼ 8.1 Hz, J ¼ 2.1 Hz), 7.08 (d, 1H, J ¼ 8.0 Hz), 7.36 (d, 2H,
J ¼ 5.9 Hz), 8.04 (brs, 1H), 8.42 (d, 2H, J ¼ 6.1 Hz), 8.61 (s, 1H);
13C-NMR (DMSO-d6) d 153.1, 149.8, 147.7, 141.6, 140.8, 138.3,
134.6, 134.2, 122.1, 120.3, 119.8, 116.2, 113.4, 56.5, 46.3, 37.1;
MS m/z: 388.97 (Mþ þ 3), 387.96 (Mþ þ 2), 386.96 (Mþ þ 1).
N-(2-(4-Acetylpiperazin-1-yl)ethyl)-3-(4-chloro-
3-methoxyphenyl)-4-(pyridin-4-yl)-1H-pyrazole-
1-carboxamide If
It was purified by flash column chromatography (silica gel, ethyl
acetate then switching to ethyl acetate/methanol 4:1 v/v). Yield
66%; mp: 247–2488C; IR (KBr) [cmꢂ1]: 3454, 3094, 3000, 1722,
1703, 1603, 1543, 1522, 1497, 1410, 1262, 1245, 1140, 1099,
1059, 1035; 1H-NMR (CD3OD) d 2.10 (s, 3H), 2.48–2.60 (m, 6H),
3.32 (t, 2H, J ¼ 5.0 Hz), 3.52 (t, 4H, J ¼ 4.1 Hz), 3.77 (s, 3H), 7.08 (d,
1H, J ¼ 2.0 Hz), 7.24 (dd, 1H, J ¼ 2.0 Hz, J ¼ 7.9 Hz), 7.36 (d, 1H,
J ¼ 8.0 Hz), 7.55 (d, 2H, J ¼ 6.0 Hz), 8.54 (d, 2H, J ¼ 6.1 Hz), 8.60
(s, 1H); MS m/z: 486.0 (Mþ þ 3), 485.0 (Mþ þ 2), 484.0 (Mþ þ 1).
3-(4-Chloro-3-hydroxyphenyl)-N-(2-(diethylamino)ethyl)-
4-(pyridin-4-yl)-1H-pyrazole-1-carboxamide IIb
It was purified by flash column chromatography (silica gel, ethyl
acetate then switching to ethyl acetate/methanol 6:1 v/v). Yield
55%; mp: 220–2228C; IR (KBr) [cmꢂ1]: 3393, 3126, 2970, 1730,
1610, 1593, 1513, 1417, 1344, 1293, 1206, 1155, 1003; 1H-NMR
(CD3OD) d 1.14 (t, 6H, J ¼ 7.0 Hz), 2.76 (q, 4H, J ¼ 7.1 Hz), 2.84 (t,
2H, J ¼ 6.6 Hz), 3.45 (t, 2H, J ¼ 6.5 Hz), 6.87 (d, 1H, J ¼ 1.9 Hz),
6.90 (dd, 1H, J ¼ 8.0 Hz, J ¼ 1.9 Hz), 7.05 (d, 1H, J ¼ 8.1 Hz), 7.38
(d, 2H, J ¼ 5.8 Hz), 8.49 (d, 2H, J ¼ 5.9 Hz), 8.64 (s, 1H); MS m/z:
416.97 (Mþ þ 3), 415.97 (Mþ þ 2), 414.97 (Mþ þ 1).
3-(4-Chloro-3-methoxyphenyl)-N-(2-(piperidin-1-yl)ethyl)-
4-(pyridin-4-yl)-1H-pyrazole-1-carboxamide Ig
It was purified by flash column chromatography (silica gel, ethyl
acetate). Yield 80%; mp: 150–1528C; IR (KBr) [cmꢂ1]: 3326, 2937,
1722, 1603, 1522, 1497, 1458, 1245, 1140, 1098, 1058, 1034; 1H-
NMR (DMSO-d6) d 1.35–1.46 (m, 6H), 2.29 (t, 4H, J ¼ 6.9 Hz), 2.64 (t,
2H, J ¼ 6.0 Hz), 3.08 (t, 2H, J ¼ 5.8 Hz), 3.76 (s, 3H), 6.96 (d, 1H,
J ¼ 2.1 Hz), 7.11 (dd, 1H, J ¼ 2.0 Hz, J ¼ 8.1 Hz), 7.28 (d, 1H,
J ¼ 8.0 Hz), 7.36 (d, 2H, J ¼ 4.9 Hz), 8.22 (s, 1H), 8.48 (d, 2H,
J ¼ 4.6 Hz); MS m/z: 443.0 (Mþ þ 3), 442.0 (Mþ þ 2), 441.0 (Mþ þ 1).
3-(4-Chloro-3-hydroxyphenyl)-N-(2-morpholinoethyl)-4-
(pyridin-4-yl)-1H-pyrazole-1-carboxamide IIc
3-(4-Chloro-3-methoxyphenyl)-N-(2-(2-methylpiperidin-
It was purified by flash column chromatography (silica gel, ethyl
acetate then switching to ethyl acetate/methanol 6:1 v/v). Yield
42%; mp: 220–2228C; IR (KBr) [cmꢂ1]: 3382, 3129, 2920, 1732,
1611, 1562, 1497, 1437, 1352, 1295, 1193, 1148, 1116; 1H-NMR
(DMSO-d6) d 2.42–2.51 (m, 6H), 3.44 (t, 2H, J ¼ 6.2 Hz), 3.56 (t, 4H,
J ¼ 4.1 Hz), 7.00 (d, 1H, J ¼ 2.0 Hz), 7.31-7.38 (m, 3H), 7.48 (d, 1H,
J ¼ 8.0 Hz), 8.52 (d, 2H, J ¼ 6.0 Hz), 8.75 (s, 1H); MS m/z: 430.91
(Mþ þ 3), 429.91 (Mþ þ 2), 428.91 (Mþ þ 1).
1-yl)ethyl)-4-(pyridin-4-yl)-1H-pyrazole-1-carboxamide Ih
It was purified by flash column chromatography (silica gel, ethyl
acetate). Yield 68%; mp: 219–2218C; 1H-NMR (CDCl3) d 1.07 (d, 3H,
J ¼ 6.2 Hz), 1.54–1.63 (m, 6H), 2.33–2.61 (m, 5H), 3.30 (t, 2H,
J ¼ 5.1 Hz), 3.79 (s, 3H), 6.98 (d, 1H, J ¼ 2.1 Hz), 7.10 (dd, 1H,
J ¼ 2.0 Hz, J ¼ 8.0 Hz), 7.23 (d, 1H, J ¼ 7.9 Hz), 7.38 (d, 2H,
J ¼ 6.0 Hz), 8.23 (s, 1H), 8.54 (d, 2H, J ¼ 5.8 Hz); MS m/z:
457.01 (Mþ þ 3), 456.08 (Mþ þ 2), 455.07 (Mþ þ 1).
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Arch. Pharm. Chem. Life Sci. 2011, 344, 745–754
3,4-Diarylpyrazole-1-Carboxamides: Docking Study
753
3-(4-Chloro-3-hydroxyphenyl)-N-
(2-(2,6-dimethylmorpholino)ethyl)-4-(pyridin-4-yl)-
1H-pyrazole-1-carboxamide IId
3-(4-Chloro-3-hydroxyphenyl)-4-(pyridin-4-yl)-N-
(2-(pyrrolidin-1-yl)ethyl)-1H-pyrazole-1-carboxamide IIi
It was purified by flash column chromatography (silica gel, ethyl
acetate). Yield 40%; mp: >3008C; IR (KBr) [cmꢂ1]: 3376, 2974,
2802, 1733, 1610, 1500, 1424, 1368, 1153, 1089, 1003; 1H-NMR
(CD3OD) d 1.78 (t, 4H, J ¼ 5.2 Hz), 2.31 (t, 4H, J ¼ 5.3 Hz), 2.62 (t,
2H, J ¼ 6.3 Hz), 3.01 (t, 2H, J ¼ 6.1 Hz), 7.01 (d, 1H, J ¼ 2.0 Hz),
7.09 (dd, 1H, J ¼ 1.8 Hz, J ¼ 7.8 Hz), 7.22 (d, 1H, J ¼ 8.0 Hz), 7.36
(d, 2H, J ¼ 5.8 Hz), 8.53 (d, 2H, J ¼ 6.0 Hz), 8.62 (s, 1H); MS m/z:
414.98 (Mþ þ 3), 413.96 (Mþ þ 2), 412.97 (Mþ þ 1).
It was purified by flash column chromatography (silica gel, ethyl
acetate then switching to ethyl acetate/methanol 10:1 v/v). Yield
56%; mp: 188–1898C; IR (KBr) [cmꢂ1]: 3398, 3128, 2925, 1728,
1611, 1563, 1495, 1434, 1326, 1295, 1144, 1087, 1053, 1H-NMR
(CD3OD) d 1.15 (d, 6H, J ¼ 8.3 Hz), 2.59–2.94 (m, 6H), 3.36 (t, 2H,
J ¼ 4.9 Hz), 3.58–3.69 (m, 2H), 6.91 (d, 1H, J ¼ 2.0 Hz), 6.99 (dd,
1H, J ¼ 7.9 Hz, J ¼ 2.1 Hz), 7.25 (d, 1H, J ¼ 8.0 Hz), 7.38 (d, 2H,
J ¼ 6.0 Hz), 8.49 (d, 2H, J ¼ 6.0 Hz), 8.62 (s, 1H); MS m/z: 458.74
(Mþ þ 3), 457.87 (Mþ þ 2), 456.83 (Mþ þ 1).
Evaluation of the biological activity
A375P cells were purchased from American Type Culture
Collection (ATCC, Rockville, MD, USA) and maintained in
Dulbecco’s modified eagle medium (DMEM, Welgene, Daegu,
Korea) supplemented with 10% foetal bovine serum (FBS,
Welgene, Daegu, Korea) and 1% penicillin/streptomycin
(Welgene, Daegu, Korea) in a humidified atmosphere with 5%
CO2 at 378C. A375P cells were taken from culture substrate
with 0.05% trypsin-0.02% EDTA and plated at a density of
5 ꢁ 103 cells/well in 96 well plates and then incubated at
378C for 24 h in a humidified atmosphere with 5% CO2 prior
to treatment with various concentrations (3-fold serial dilution,
12 points) of test compounds. The cells were incubated for 48 h
after treatment with the test compounds. The A357P cell viability
was assessed by the conventional 3-(4,5-dimethylthiazol-2-yl)-2,5-
diphenyltetrazolium bromide (MTT) reduction assay. MTT assays
were carried out with CellTiter 961 (Promega) according to the
manufacturer’s instructions. The absorbance at 590 nm was
recorded using EnVision 2103 (Perkin Elmer; Boston, MA,
USA). The IC50 was calculated using GraphPad Prism 4.0 software.
3-(4-Chloro-3-hydroxyphenyl)-N-(2-(4-methylpiperazin-
1-yl)ethyl)-4-(pyridin-4-yl)-1H-pyrazole-1-carboxamide IIe
It was purified by flash column chromatography (silica gel, ethyl
acetate). Yield 49%; mp: 257–2598C; IR (KBr) [cmꢂ1]: 3400, 3126,
2973, 1733, 1610, 1592, 1512, 1404, 1357, 1293, 1155, 1094,
1003; 1H-NMR (DMSO-d6) d 2.26 (s, 3H), 2.46–2.58 (m, 8H), 2.64
(t, 2H, J ¼ 6.1 Hz), 3.12 (t, 2H, J ¼ 5.9 Hz), 6.98 (d, 1H, J ¼ 1.9 Hz),
7.14 (dd, 1H, J ¼ 2.0 Hz, J ¼ 8.1 Hz), 7.27 (d, 1H, J ¼ 7.9 Hz), 7.52
(d, 2H, J ¼ 6.0 Hz), 8.12 (brs, 1H), 8.44 (d, 2H, J ¼ 6.1 Hz), 8.53 (s,
1H); MS m/z: 443.95 (Mþ þ 3), 442.95 (Mþ þ 2), 441.95 (Mþ þ 1).
N-(2-(4-Acetylpiperazin-1-yl)ethyl)-3-(4-chloro-3-
hydroxyphenyl)-4-(pyridin-4-yl)-1H-pyrazole-1-
carboxamide IIf
It was purified by flash column chromatography (silica gel, ethyl
acetate then switching to ethyl acetate/methanol 4:1 v/v). Yield
61%; mp: 259–2608C; IR (KBr) [cmꢂ1]: 3347, 3126, 2932, 1731,
1611, 1510, 1433, 1346, 1155, 1003; 1H-NMR (CD3OD) d 2.08 (s,
3H), 2.47–2.59 (m, 6H), 2.95 (t, 2H, J ¼ 5.0 Hz), 3.46 (t, 4H,
J ¼ 5.1 Hz), 6.99 (d, 1H, J ¼ 1.9 Hz), 7.16 (dd, 1H,
J ¼ 1.9 Hz, J ¼ 8.0 Hz), 7.30 (d, 1H, J ¼ 7.7 Hz), 7.48 (d, 2H,
J ¼ 5.9 Hz), 8.12 (s, 1H), 8.56 (d, 2H, J ¼ 5.7 Hz); MS m/z: 472.0
(Mþ þ 3), 471.0 (Mþ þ 2), 470.0 (Mþ þ 1).
Molecular docking methodology
Docking studies were performed using MOE 2008.10. With this
purpose, the crystal structure of V600E-b-Raf Kinase oncogenic
mutant was obtained from Protein Data Bank [29] (PDB ID: 3OG7)
in order to prepare the protein for docking study. Docking
procedure was followed using the standard protocol imple-
mented in MOE 2008.10 and the geometry of resulting complex
was studied using the MOE’s pose viewer utility.
3-(4-Chloro-3-hydroxyphenyl)-N-(2-(piperidin-1-yl)ethyl)-
4-(pyridin-4-yl)-1H-pyrazole-1-carboxamide IIg
It was purified by flash column chromatography (silica gel, ethyl
acetate). Yield 44%; mp: 273–2768C; IR (KBr) [cmꢂ1]: 3416, 2932,
1730, 1612, 1510, 1433, 1347, 1154, 1002; 1H-NMR (CD3OD) d
1.38–1.56 (m, 6H), 2.24 (t, 4H, J ¼ 7.1 Hz), 2.66 (t, 2H, J ¼ 6.2 Hz),
3.22 (t, 2H, J ¼ 6.0 Hz), 6.97 (d, 1H, J ¼ 2.0 Hz), 7.09 (dd, 1H,
J ¼ 1.9 Hz, J ¼ 8.1 Hz), 7.26 (d, 1H, J ¼ 7.8 Hz), 7.39 (d, 2H,
J ¼ 5.7 Hz), 8.04 (s, 1H), 8.49 (d, 2H, J ¼ 5.6 Hz); MS m/z:
428.94 (Mþ þ 3), 427.94 (Mþ þ 2), 426.95 (Mþ þ 1).
We’d like to thank the Chemical Computing Group Inc, 1010 Sherbrooke
Street West, Suite 910, Montreal, H3A 2R7, Canada, for its valuable
agreement to use the package of MOE 2008.10 software. We are also
grateful to Korea Institute of Science and Technology (KIST) for
financial support.
The authors have declared no conflict of interest.
3-(4-Chloro-3-hydroxyphenyl)-N-(2-(2-methylpiperidin-
References
1-yl)ethyl)-4-(pyridin-4-yl)-1H-pyrazole-1-carboxamide IIh
It was purified by flash column chromatography (silica gel, ethyl
acetate then switching to ethyl acetate/methanol 10:1 v/v). Yield
50%; mp: 273–2768C; IR (KBr) [cmꢂ1]: 3408, 2932, 1728, 1611,
1509, 1435, 1345, 1156, 1002; 1H-NMR (CD3OD) d 1.06 (d, 3H,
J ¼ 5.9 Hz), 1.36–1.48 (m, 6H), 2.30–2.59 (m, 5H), 3.08 (t, 2H,
J ¼ 5.4 Hz), 6.92 (d, 1H, J ¼ 1.8 Hz), 7.07 (dd, 1H,
J ¼ 1.9 Hz, J ¼ 7.9 Hz), 7.21 (d, 1H, J ¼ 7.7 Hz), 7.37 (d, 2H,
J ¼ 5.8 Hz), 8.50 (d, 2H, J ¼ 5.8 Hz), 8.59 (s, 1H); MS m/z: 443.0
(Mþ þ 3), 442.0 (Mþ þ 2), 441.0 (Mþ þ 1).
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M. I. El-Gamal et al.
Arch. Pharm. Chem. Life Sci. 2011, 344, 745–754
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