Synthesis and biological evaluation of 1-substituted-3(5)-(6-methylpyridin- 2-yl)-4-(quinolin-6-yl)pyrazoles as transforming growth factor-β type 1 receptor kinase inhibitors

Article abstract of DOI:10.1016/j.bmc.2011.03.008

A series of 1-substituted-3(5)-(6-methylpyridin-2-yl)-4-(quinolin-6-yl) pyrazoles 14a-e, 15a-e, 17a-c, and 18a-d have been synthesized and evaluated for their ALK5 inhibitory activity in an enzyme assay and in a cell-based luciferase reporter assay. The 6

Full text of DOI:10.1016/j.bmc.2011.03.008

Bioorganic & Medicinal Chemistry 19 (2011) 2633–2640
Contents lists available at ScienceDirect
Bioorganic & Medicinal Chemistry
journal homepage: www.elsevier.com/locate/bmc
Synthesis and biological evaluation of 1-substituted-3(5)-(6-methylpyridin-
2-yl)-4-(quinolin-6-yl)pyrazoles as transforming growth factor-b type 1
receptor kinase inhibitors
Cheng Hua Jin, Maddeboina Krishnaiah, Domalapally Sreenu, Kota Sudhakar Rao, Vura Bala Subrahmanyam,
⇑
Chul-Yong Park, Jee-Yeon Son, Yhun Yhong Sheen, Dae-Kee Kim
College of Pharmacy, Ewha Womans University, 11-1 Daehyun-dong, Seodaemun-gu, Seoul 120-750, Republic of Korea
a r t i c l e i n f o
a b s t r a c t
Article history:
A series of 1-substituted-3(5)-(6-methylpyridin-2-yl)-4-(quinolin-6-yl)pyrazoles 14a–e, 15a–e, 17a–c,
and 18a–d have been synthesized and evaluated for their ALK5 inhibitory activity in an enzyme assay
and in a cell-based luciferase reporter assay. The 6-quinolinyl pyrazole analogue 14b inhibited ALK5
Received 13 January 2011
Revised 3 March 2011
Accepted 4 March 2011
Available online 10 March 2011
phosphorylation with IC50 value of 0.022
assay using HaCaT cells permanently transfected with p3TP-luc reporter construct.
Ó 2011 Elsevier Ltd. All rights reserved.
lM and showed 84% inhibition at 0.1 lM in a luciferase reporter
Keywords:
TGF-b
ALK5 inhibitor
Fibrosis
Cancer
Kinase assay
Cell-based luciferase reporter assay
1. Introduction
hundred genes involved in cell differentiation, proliferation,
apoptosis, migration, and extracellular matrix production
(Fig. 1).4 TGF-b plays a critical role in the initiation and progression
of fibrosis in various organ systems such as kidney,5 heart,6 lung,7
and liver.8 Deregulation of TGF-b signaling has been implicated in
various human diseases including cancer,9 pancreatic diseases,10
and hematological malignancies.11
The transforming growth factor-b (TGF-b) family members,
which include TGF-bs, activins, and bone morphogenetic proteins
(BMPs) are structurally related secreted cytokines found in species
ranging from worms and insects to mammals. A wide spectrum of
cellular functions such as proliferation, differentiation, adhesion,
migration, and apoptosis are regulated by TGF-b family members.
The three major TGF-b isoforms, TGF-b1, TGF-b2, and TGF-b3, are
expressed in mammals, and each is encoded by unique gene and
expressed in a tissue-specific manner. TGF-b1 is the prototype
and major isoform of this family of cytokines. TGF-b transduces
signals through two distinct serine/threonine kinase receptors,
termed type I and type II.1–3 The signaling cascade is promoted
by the binding of ligand to the constitutively active type II receptor.
Subsequently, the type I receptor, also called as activin receptor-
like kinase 5 (ALK5), is phosphorylated in the juxtamembrane GS
domain stimulating its kinase activity. The activated ALK5 propa-
gates the signals through phosphorylation of receptor-regulated
Smads such as Smad2 and Smad3 that in turn form complexes with
the common-mediator Smad, Smad4. These Smad complexes,
when delivered to the nucleus regulate the expression of several
The extensive comprehension regarding TGF-b-mediated
ALK5-dependent signaling pathway has suggested the therapeutic
potential of TGF-b signaling antagonist. One of the strategies used
to inhibit TGF-b signaling is to block the catalytic activity of ALK5.
Small molecule ALK5 inhibitors bind to the ATP binding pocket
located next to the Smad2 and Smad3 binding site in a competitive
manner, thus, preventing phosphorylation of these proteins.
Several small molecule ALK5 inhibitors such as 1 (SB-431542),12
2
(SB-505124),13
3
(GW6604),14
4
(SD-208),15,16 and
5
(LY-2157299)17 are in various stages of clinical development
(Fig. 2).
We have prepared a number of the 2-pyridyl-substituted
five-membered heterocycles as ALK5 inhibitors and found that
insertion of a methylene, a methyleneamino, or an aminomethyl-
ene linkage between a central five-membered heterocyclic ring
and a phenyl ring significantly increased ALK5 inhibitory activity
and selectivity.18–26 IN-1130 (6), one of our preclinical candidates,
demonstrated its remarkable activity as a suppressor of fibrogenic
process of unilateral ureteral obstruction in rats underscoring the
⇑
Corresponding author. Tel.: +82 2 3277 3025; fax: +82 2 3277 2467.
E-mail addresses: dkkim@ewha.ac.kr, dkkim@in2gen.com (D.-K. Kim).
0968-0896/$ - see front matter Ó 2011 Elsevier Ltd. All rights reserved.
doi:10.1016/j.bmc.2011.03.008

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C. H. Jin et al. / Bioorg. Med. Chem. 19 (2011) 2633–2640
Among them, A-83-01 (8) exhibited significant inhibition of the
transcriptional activity induced by ALK5. We recently reported a
new class of 2-pyridyl-substituted pyrazoles possessing
a
thioamide linkage, and one of the compounds in this series, 3-(3-
(6-methylpyridin-2-yl)-4-(quinolin-6-yl)-1H-pyrazole-1-carbo-
thioamido)benzamide (9), showed more than 90% inhibition at
0.1 lM in luciferase reporter assay using HaCaT cells transiently
transfected with p3TP-luc reporter construct and ARE-luc reporter
construct.23 Although insertion of a thioamide linkage between a
pyrazole ring and a phenyl ring markedly increased ALK5 inhibi-
tory activity as shown in previous reports,23,33 it was found that
this thioamide linkage was rather unstable and slowly cleaved to
generate a pyrazole ring on long-term storage.
On the basis of this observation, we attempted to replace the
thioamide linkage with a chemically stable thioamidomethylene
or thioamidoethylene linkage, thus, prepared the compounds
18a–d as target molecules. To compare the influence of the
thioamidomethylene or thioamidoethylene linkage of 18a–d, their
counterpart derivatives 14a–e and 17a–c possessing the amidom-
ethylene or amidoethylene linkage were also prepared. All target
molecules in this report have
a 6-quinolinyl moiety at the
4-position of the pyrazole ring rather than a 4-quinolinyl moiety
of 8 since the former has been proved to be a better moiety in
ALK5 inhibition than the latter in our previous work.23 A docking
model of ALK5:7 complex showed that the nitrogen atom of the
6-quinolinyl moiety formed a H-bond with backbone amide NH
of His283 in the hinge region of the kinase, originally a binding
pocket for the adenine ring of ATP.24 To examine whether the capa-
bility of the nitrogen atom of the 6-quinolinyl moiety as a H-bond
acceptor could be increased by aromatic substitution, we intro-
duced an electron-donating methoxy group at the 4-position of
the 6-quinolinyl moiety (compounds 14c, 14d, and 17c).
Figure 1. TGF-b signaling pathway.
potential clinical benefits in the treatment of renal fibrosis27 and
ameliorated experimental autoimmune encephalomyelitis,
a
mouse model for multiple sclerosis, by inhibition of TGF-b signal-
ing.28 It also lessened tunical fibrosis and corrected penile
curvature in rats,29 inhibited cancer metastasis in MMTV/c-Neu
breast cancer mice, and enhanced CTL response in cancer mice.30
IN-1233 (7), another preclinical candidate, effectively prevented
development and progression of pulmonary arterial hypertension
in monocrotaline rat model through inhibition of TGF-b signaling31
and prevented granulation tissue formation after bare metallic
stent placement in a rat urethral model.32
2. Results and discussion
2.1. Chemistry
The 3-(6-methylpyridin-2-yl)-1-(phenylcarboxamidomethyl)-
4-(quinolin-6-yl)pyrazoles 14a–e were synthesized as shown in
Scheme 1. The 6-chloroquinoline (10a) and 6-chloro-4-methoxy-
quinoline (10b) were coupled with 2-acetyl-6-methylpyridine in
Tojo et al. reported a novel class of ALK5 inhibitors that possess
a thioamide linkage between a pyrazole ring and a phenyl ring.33
O
N
F
NH2
N
O
O
HN
N
N
N
N
O
O
N
O
N
N
N
N
NH
N
H
NH2
N
H
N
N
N
N
N
Cl
5
(LY-2157299)
1 (SB-431542)
3
2
(GW6604)
4 (SD-208)
(SB-505124)
N
N
N
N
O
O
S
S
N
NH2
NH2
N
N
N
N
N
HN
N
HN
N
N
H
N
H
N
N
N
NH2
O
8 (A-83-01)
9
6 (IN-1130)
7 (IN-1233)
Figure 2. ALK5 inhibitors under development.

C. H. Jin et al. / Bioorg. Med. Chem. 19 (2011) 2633–2640
2635
N
N
N
N
O
b
NH
R1
Cl
R1
a
N
O
R1
N
N
10a: R1 = H
11a : R1 = H (75%)
12a: R1 = H (84%)
10b: R1 = OMe
11b: R1 = OMe(54%)
12b : R1 = OMe (73%)
H
R2
N
N
N
Cl
H
O
N
N
N
R1
+
c
R1
N
O
N
O
13a : R2= H
N
N
R2
HN
13b : R2 = CN
13c: R2 = CONH2
R2
15a: R1 = H, R2= H ( 9%)
15b : R1 = H, R2= CN (11%)
15c: R1 = OMe, R2= H (14%)
14a: R1 = H, R2 = H (73%)
14b: R1 = H, R2= CN (61%)
14c: R1 = OMe, R2 = H (80%)
14d : R1 = OMe, R2 = CN(76%)
15d : R1 = OMe, R2 = CN (14%)
15e : R1 = H, R2= CONH2 (16%)
14e: R1 = H, R2= CONH (49%)
2
Scheme 1. Reagents and conditions: (a) palladium(II) acetate, 2-dicyclohexylphosphino-20-(N,N-dimethylamino)biphenyl, potassium tert-butoxide, anhydrous THF, 75 °C,
14 h; (b) (i) DMFꢀDMA, 90 °C, 4 h; (ii) N2H4ꢀH2O, EtOH, reflux, 4 h; (c) NaH, NaI (cat.), DMF, rt, 30 min (for 13a and 13b) or Cs2CO3, DMF, 120 °C, 1 h (for 13c).
the presence of potassium tert-butoxide, palladium(II) acetate, and
2-dicyclohexylphosphino-20-(N,N-dimethylamino)biphenyl
in
N
anhydrous THF to afford the ketones 11a23 and 11b34 in 75% and
54% yields, respectively. Treatment of 11a and 11b with
N,N-dimethylformamide dimethyl acetal and followed by reaction
with hydrazine monohydrate in absolute EtOH gave the pyrazoles
12a23 and 12b34 in 84% and 73% yields, respectively. The pyrazoles
12a and 12b were alkylated with 2-chloro-N-phenylacetamide
(13a)35 or 2-chloro-N-(3-cyanophenyl)acetamide (13b)36 in the
presence of NaH in anhydrous DMF to yield the target compounds
14a–d and their positional isomers 15a–d in 61–80% and 9–14%
yields, respectively. The positional isomers were separated by
MPLC, and their structures were confirmed by NOE experiments.
In NOE experiments, irradiation of the methylene protons of the
14a at d 5.14 gave an enhancement of the proton H-5 in pyrazole
ring at d 7.81, while irradiation of the methylene protons of the
15a at d 5.06 gave no enhancement of the proton H-5 in pyrazole
ring at d 7.90, confirming the respective positions of alkylation.
Alkylation of 12a with 3-(2-chloroacetamido)benzamide (13c)37
in the presence of Cs2CO3 in DMF at 120 °C gave the positional
isomers 14e and 15e in 49% and 16% yields, respectively.
a
H
N
R2
12a, 12b
N
R1
N
O
N
1
2
17a
17b
: R = H, R = H (55%)
1
2
: R = H, R = CN (51%)
1
2
17c
: R = OMe, R = CN (39%)
Scheme 3. Reagents and conditions: (a) 16a or 16b, Cs2CO3, DMF, 120 °C, 1–3 h.
targetcompounds17a–cin39–55%yields. In thiscase, thepositional
isomers of the 17a–c were not isolated after column
chromatography.
Thionation of the 14a, 14b, 17a, and 17b with Lawesson’s
reagent in anhydrous DME at 85 °C produced the thioamides
18a–d in 37–67% yields (Scheme 4). As expected, all prepared
target compounds were quite stable at room temperature on
long-term storage.
Reaction of aniline and 3-aminobenzonitrile with 3-bromoprop-
anoyl chloride in the presence of K2CO3 in CH2Cl2 gave 3-bromo-
2.2. Biological evaluation
N-phenylpropanamide
(16a)38
and
3-bromo-N-(3-cyano-
phenyl)propanamide (16b) in 58% and 70% yields, respectively
(Scheme 2). The 3-(6-methylpyridin-2-yl)-1-(phenylcarboxamido-
ethyl)-4-(quinolin-6-yl)pyrazoles17a–cweresynthesizedasshown
in Scheme3. Alkylationof the pyrazoles 12a and 12b with 16a or 16b
in the presence of Cs2CO3 in anhydrous DMF at 120 °C afforded the
To investigate whether these compounds 14a–e, 17a–c, and
18a–d could inhibit ALK5, a kinase assay was performed using
the purified human ALK5 kinase domain produced in Sf9 insect
cells. The compounds 15a–e, the positional isomers of 14a–e, dis-
played no significant ALK5 inhibitory activity up to a concentration
of 1 lM (Table 1). It has been also observed that all the compounds
having a methoxy substituent at the 4-position of the 6-quinolinyl
moiety (14c, 14d, 15c, 15d, and 17c) displayed no significant ALK5
a
O
inhibitory activity up to a concentration of 1 lM. We envisioned
O
H2N
R2
R2
Br
N
H
that introduction of an electron-donating group in the 6-quinolinyl
moiety may increase the capability of the nitrogen atom in that
moiety as a H-bond acceptor, thus, potentiating ALK5 inhibitory
activity. But, the result showed that a 4-methoxy group in the 6-
quinolinyl moiety seemed to be not accommodated favorably into
Br
Cl
16a: R2 = H
(58%)
(70%)
16b: R2 = CN
Scheme 2. Reagents and conditions: (a) K2CO3, CH2Cl2, reflux, 4 h.

2636
C. H. Jin et al. / Bioorg. Med. Chem. 19 (2011) 2633–2640
N
S
a
N
14a, 14b, 17a, 17b
R2
( )n
N
H
N
N
18a: n = 1, R2 = H (67%)
2
18b
: n = 1, R = CN (73%)
2
18c
: n = 2, R = H (37%)
2
18d
: n = 2, R = CN (46%)
Scheme 4. Reagents and conditions: (a) Lawesson’s reagent, DME, 85 °C, 12 h.
Table 1
Inhibitory activity of 1-substituted-3(5)-(6-methylpyridin-2-yl)-4-(quinolin-6-yl)pyrazoles 14a–e, 15a–e, 17a–c, and 18a–d on ALK5
N
N
N
N
H
N
H
N
H
N
N
N
N
N
R1
R1
R1
N
R1
N
N
N
O
O
S
X
N
N
N
N
R2
R2
HN
R2
R2
14a-e
R1
18a, 18b
15a-e
17a-c, 18c, 18d
p3TP-luciferase activityd,e (% control)
Compd
R2
X
IC50
(lM)
Selectivity indexc
ALK5a
p38ab
Mock
TGF-b
14a
14b
14c
14d
14e
15a
15b
15c
15d
15e
17a
17b
17c
18a
18b
18c
18d
2
9
100
51
1
4
3
1
2
9
4
8
2
7
7
2
5
5
H
H
OMe
OMe
H
H
H
OMe
OMe
H
H
H
OMe
H
H
H
CN
H
CN
CONH2
H
CN
H
CN
CONH2
H
CN
CN
H
CN
H
0.207
0.022
>1.0
>1.0
0.075
>1.0
>1.0
>1.0
>1.0
>1.0
0.025
0.101
>1.0
0.094
0.051
0.088
0.232
0.054
0.017
>1.0
>1.0
>1.0
>1.0
>1.0
>1.0
>1.0
>1.0
>1.0
>1.0
>1.0
>1.0
>1.0
>1.0
>1.0
>1.0
0.63
0.594
0.480
>5
>45
16
108
108
58
102
110
104
107
104
34
>13
O
O
O
>40
>10
61
119 13
>11
>20
>11
>3
11
28
44
31
64
77
34
20
4
5
6
3
0
3
H
H
S
S
CN
6
a
ALK5 was expressed in Sf9 insect cells as human recombinant GST-fusion protein by means of the vaculovirus expression system. A Proprietary radioisotopic protein
kinase assay (33PanQinaseÒ Activity Assay) was performed at ProQinase GmbH (Freiburg, Germany) using casein as a substrate.
b
p38a MAP kinase was expressed as untagged human recombinant protein in E. coli. The enzyme was purified by Ni-NTH-agarose (Qiagen). A Proprietary radioisotopic
protein kinase assay (33PanQinaseÒ Activity Assay) was performed at ProQinase GmbH (Freiburg, Germany) using ATF2 as a substrate.
c
IC50 of p38
a
/IC50 of ALK5.
Luciferase activity was determined at a concentration of 0.1
Activity is given as the mean SD of three independent experiments run in triplicate relative to control incubations with DMSO vehicle.
d
e
l
M of inhibitor.
the ATP binding pocket of ALK5. As we expected, among the pyra-
zoles possessing an amidomethylene or a thioamidomethylene
linkage, introduction of a carbonitrile- or a carboxamide-substitu-
ent at the meta-position on the phenyl ring increased ALK5
18c (IC50 = 0.088 lM), respectively, suggesting that the combina-
tion of a longer linkage and an aromatic substituent in the phenyl
ring makes the inhibitors difficult to bind into the ATP binding
pocket of ALK5. Although it was previously demonstrated by Tojo
et al.33 and us (unpublished work) that the pyrazoles possessing
a thioamido linkage between a pyrazole ring and a phenyl ring
were much more potent in ALK5 inhibition than those possessing
a respective carboxamido linkage, it is not the case in this series
of compounds. The pyrazole 18a possessing a thioamidomethylene
linkage was 2.2-fold more potent than the corresponding 14a pos-
sessing an amidomethylene linkage, whereas 18b, 18c, and 18d
possessing a thioamidomethylene or a thioamidoethylene linkage
were 2.3-fold, 3.5-fold, and 2.3-fold less potent than the corre-
sponding 14b, 17a, and 17b possessing an amidomethylene or an
inhibitory activity, thus, 14b (IC50 = 0.022
0.075 M) were 9.4-fold and 2.8-fold more inhibitory than the
unsubstituted 14a (IC50 = 0.207 M), respectively, and 18b
(IC50 = 0.051 M) was 1.8-fold more inhibitory than the unsubsti-
tuted 18a (IC50 = 0.094 M). However, in the pyrazoles possessing
lM) and 14e (IC50 =
l
l
l
l
an amidoethylene or a thioamidoethylene linkage, introduction of
a carbonitrile-substituent at the meta-position on the phenyl ring
decreased ALK5 inhibitory activity. The pyrazoles 17b (IC50
0.101 M) and 18d (IC50 = 0.232 M) were 4.0-fold and 2.6-fold
less inhibitory than the unsubstituted 17a (IC50 = 0.025 M) and
=
l
l
l

C. H. Jin et al. / Bioorg. Med. Chem. 19 (2011) 2633–2640
2637
Figure 3. Effect of 14b on the activity of TGF-b-induced ALK5. HaCaT cells were permanently transfected with p3TP-luciferase reporter gene. Luciferase activity was
determined in the presence of different concentrations of each compound and is given as the mean SD of three independent experiments run in triplicate relative to control.
amidoethylene linkage, respectively. In this series, the most potent
compound 14b was equipotent to 6 (IC50 = 0.017 M) and 2.5-fold
more potent than 2 (IC50 = 0.054 M).
compounds didn’t inhibit p38
a MAP kinase up to the maximum
l
concentration of 1 M. The selectivity index of 14b against p38a
l
l
MAP kinase is >45, that is, higher than those of 2 (11) and 6 (28).
To evaluate TGF-b-induced downstream transcriptional activa-
tion to ALK5 signaling, cell-based luciferase activity of all target
molecules was measured using HaCaT cells permanently transfec-
ted with p3TP-luciferase reporter gene at a concentration of
4. Experimental
4.1. General methods
0.1 lM (Table 1). The p3TP-luciferase reporter construct contains
1H NMR spectra were recorded on a varian Unity 400 spectro-
photometer. Chemical shifts are reported in parts per million
(ppm) relative to internal tetramethylsilane in CDCl3, CDCl3/
CD3OD, or DMSO-d6. Infrared spectra were recorded on a FT-infra-
red spectrometer (Bio-Rad). High resolution mass spectra electro
spray ionization (HRMS-ESI) was obtained on an Agilent technolo-
gies 6220 TOF LC/MS spectrometer. All melting points were taken
in Pyrex capillaries using an electrothermal digital melting point
apparatus (Buchi) and were not corrected. Analytical thin-layer
chromatography (TLC) was performed on Merck Silica Gel 60F-
254 glass plates. Medium pressure liquid chromatography (MPLC)
was performed using Merck Silica Gel 60 (230–400 mesh) with an
YFLC-540 ceramic pump (Yamagen). All chemicals and solvents
were purchased from Aldrich or TCI Laboratory Chemicals.
three AP-1 binding elements and the plasminogen-activator inhib-
itor-1 (PAI-1) promoter.39 Similar to kinase assay, the compounds
15a–e, 14c, 14d, and 17c showed no ALK5 inhibitory activity, and
inhibition of the luciferase activity by most compounds consisted
with that of kinase assay. The pyrazole 14b was the most inhibi-
tory, showing 84% inhibition that is comparable to that of 6
(80%) and higher than that of 2 (66%).
The ALK5 inhibitory activity of 14b was compared with those of
2 and 6 at five different concentrations (0.003, 0.01, 0.03, 0.05, and
0.1 lM) using HaCaT cells permanently transfected with p3TP-
luciferase reporter gene. As shown in Figure 3, 14b inhibited
ALK5 in a dose-dependent manner and was equipotent to 6 and
more potent than 2.
The kinase domain of p38
a MAP kinase is known to be one of
the most homologous to that of ALK5,40 therefore, it was chosen
to examine the selectivity profile of this series of compounds. All
4.2. General procedures
the target molecules we prepared were devoid of p38
a MAP kinase
inhibitory activity up to the maximum concentration of 1
l
M
4.2.1. Synthesis of 1-(6-methylpyridin-2-yl)-2-(quinolin-6-yl)-
ethanone (11a)
tested. The 14b was found to be the most selective in this series,
showing the selectivity index of >45, that is, higher than those of
6 (28) and 2(11).
To a solution of 6-chloroquinoline (12.24 mmol) in tetrahydrofu-
ran (50 mL), 1-(6-methylpyridin-2-yl)ethanone (12.24 mmol),
palladium(II) acetate (0.24 mmol), 2-dicyclohexylphosphino-
20-(N,N-dimethylamino)biphenyl (0.49 mmol), and potassium
tert-butoxide (26.92 mmol) were added. The resulting mixture was
heated to 75 °C for 14 h. After cooled to room temperature, the
reaction mixture was slowly quenched with acetic acid (3 mL). The
mixture was filtered through a celite pad and washed with EtOAc
(50 mL). The filtrate was evaporated to dryness under reduced pres-
sure, and the residue was purified by MPLC on silica gel using and
EtOAc/hexane (1:1) as eluent to give the titled compound as an
off-white solid. Yield 75%; 1H NMR (CDCl3) d 2.68 (s, 3H), 4.75 (s,
2H), 7.34 (dd, 1H, J = 7.6, 0.4 Hz), 7.40 (dd, 1H, J = 8.2, 4.2 Hz), 7.71
3. Conclusion
In this report, a series of 1-substituted-3(5)-(6-methylpyridin-
2-yl)-4-(quinolin-6-yl)pyrazoles have been synthesized and evalu-
ated for their ALK5 inhibitory activity in an enzyme assay and in a
cell-based luciferase reporter assay. The structure–activity rela-
tionships in this series of compounds have been established and
discussed. The pyrazole analogue 14b showed the most significant
ALK5 inhibitory activity in the series of compounds that is much
higher than that of 2 and is equipotent to 6. This series of

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C. H. Jin et al. / Bioorg. Med. Chem. 19 (2011) 2633–2640
(t, 1H, J = 7.6 Hz), 7.76 (dd, 1H, J = 8.8, 2.0 Hz), 7.80 (d, 1H, J = 2.0 Hz),
7.87 (br d, 1H, J = 7.6 Hz), 8.11 (d, 1H, J = 8.8 Hz), 8.15 (br d, 1H,
J = 8.2 Hz), 8.88 (dd, 1H, J = 4.2, 1.8 Hz).
Compound 14a: yield 73%; mp 198.9 °C; IR (KBr) 3274, 2930,
1688, 1554 cmꢂ1 1H NMR (CDCl3) d 2.53 (s, 3H), 5.14 (s, 2H),
;
7.08 (t, 1H, J = 7.6 Hz), 7.12 (d, 1H, J = 7.6 Hz), 7.27 (t, 2H,
J = 7.6 Hz), 7.30 (d, 1H, J = 7.6 Hz), 7.40 (dd, 1H, J = 8.2, 4.2 Hz),
7.48 (d, 2H, J = 8.0 Hz), 7.53 (t, 1H, J = 7.6 Hz), 7.65 (dd, 1H,
J = 8.8, 1.6 Hz), 7.81 (s, 1H), 7.85 (d, 1H, J = 1.6 Hz), 8.03 (d, 1H,
J = 8.8 Hz), 8.08 (d, 1H, J = 8.2 Hz), 8.90 (dd, 1H, J = 4.2, 1.6 Hz),
8.98 (br s, 1H); HRMS-ESI m/z [M+H]+ calcd for C26H22N5O:
420.1819, found 420.1834. Compound 15a: yield 9%; mp
4.2.2. 2-(4-Methoxyquinolin-6-yl)-(6-methylpyridin-2-
yl)ethanone (11b)
This compound was prepared according to the same procedure
for 11a using 10b as the starting material. Yield 54%; 1H NMR
(CDCl3) d 2.65 (s, 3H), 3.70 (s, 3H), 4.67 (s, 2H), 6.14 (d, 1H,
J = 7.6 Hz) 7.31 (br d, 1H, J = 7.6 Hz), 7.32 (d, 1H, J = 8.8 Hz), 7.39
(d, 1H, J = 7.6 Hz), 7.63 (dd, 1H, J = 8.8, 2.2 Hz), 7.67 (t, 1H,
J = 7.8 Hz), 7.81 (br d, 1H, J = 8.0 Hz), 8.37 (dd, 1H, J = 2.2, 0.4 Hz).
189.2 °C; IR (KBr) 3278, 2924, 1686, 1553 cmꢂ1 1H NMR (CDCl3)
;
d 2.69 (s, 3H), 5.06 (s, 2H), 7.04 (d, 1H, J = 7.6 Hz), 7.11 (tt, 1H,
J = 7.4, 1.2 Hz), 7.23 (dd, 1H, J = 8.0, 0.4 Hz), 7.30–7.35 (m, 2H),
7.40 (br d, 1H, overlapped, J = 8.4, 4.4 Hz), 7.51 (d, 1H, overlapped,
J = 8.8 Hz), 7.53 (t, 1H, overlapped, J = 7.8 Hz), 7.61 (dd, 2H, J = 8.4,
0.8 Hz), 7.76 (d, 1H, J = 2.4 Hz), 7.90 (s, 1H), 8.01 (d, 1H, J = 8.8 Hz),
8.08 (br d, 1H, overlapped, J = 8.4 Hz), 8.89 (dd, 1H, J = 4.4, 1.8 Hz),
9.76 (br s, 1H); HRMS-ESI m/z [M+H]+ calcd for C26H22N5O:
420.1819, found 420.1832.
4.2.3. 6-(3-(6-Methylpyridin-2-yl)-1H-pyrazol-4-yl)quinoline
(12a)
A mixture of 11a (4.58 mmol) and N,N-dimethylformamide di-
methyl acetal (10 mL) was heated at 90 °C for 4 h. After cooled to
room temperature, the reaction mixture was evaporated to dryness
under reduced pressure. The residue was dissolved in EtOH (10 mL),
and to it, hydrazine monohydrate (22.9 mmol) was added. The
mixture was heated at reflux temperature for 4 h, then cooled to
room temperature, and evaporated to dryness under reduced pres-
sure. The residue was diluted with CHCl3 (200 mL) and washed with
water (50 mL) and brine (50 mL). The CHCl3 solution was dried over
anhydrous Na2SO4, filtered, and evaporated to dryness under
reduced pressure. The residue was purified by MPLC on silica gel
using MeOH/CHCl3 (1:30) as eluent to give the titled compound as
a white foam. Yield 84%; 1H NMR (CDCl3) d 2.60 (s, 3H), 7.08 (dd,
1H, J = 7.6, 0.4 Hz), 7.14 (d, 1H, J = 8.0 Hz), 7.42 (t, 1H, J = 7.8 Hz),
7.47 (dd, 1H, J = 8.2, 4.2 Hz), 7.76 (s, 1H), 7.80 (dd, 1H, J = 8.8,
2.0 Hz), 7.92 (d, 1H, J = 2.0 Hz), 8.20 (d, 1H, overlapped, J = 8.8 Hz),
8.21 (dd, 1H, overlapped, J = 8.2, 1.8 Hz), 8.95 (dd, 1H, J = 4.2, 1.8 Hz).
4.2.7. N-(3-Cyanophenyl)-2-(3-(6-methylpyridin-2-yl)-4-(quin-
olin-6-yl)-1H-pyrazol-1-yl)acetamide (14b) and N-(3-cyanophe-
nyl)-2-(5-(6-methylpyridin-2-yl)-4-(quinolin-6-yl)-1H-pyrazol-
1-yl)acetamide (15b)
These compounds were prepared according to the same proce-
dure for 14a and 15a using 12a and 13b, and the residue was puri-
fied by MPLC on silica gel using MeOH/CHCl3 (1:40) as eluent to
give the titled compounds as white solids. 14b: yield 61%; mp
222.1 °C; IR (KBr) 3263, 2927, 2228, 1702, 1558 cmꢂ1 1H NMR
;
(CDCl3) d 2.56 (s, 3H), 5.23 (s, 2H), 7.17 (d, 1H, J = 7.6 Hz), 7.24
(d, 1H, J = 8.0 Hz), 7.31–7.36 (m, 2H), 7.43 (dd, 1H, J = 8.4, 4.4 Hz),
7.55 (t, 1H, J = 7.8 Hz), 7.63–7.67 (m, 2H), 7.82 (s, 1H), 7.85 (d,
1H, J = 2.0 Hz), 7.92 (br s, 1H), 8.07 (d, 1H, J = 8.8 Hz), 8.11 (br d,
1H, overlapped, J = 8.4 Hz), 8.93 (dd, 1H, J = 4.4, 1.6 Hz), 9.94 (br
s, 1H); HRMS-ESI m/z [M+H]+ calcd for C27H21N6O: 445.1771, found
445.1790. Compound 15b: yield 11%; mp 136.8 °C; IR (KBr) 3281,
4.2.4. 4-Methoxy-6-(3-(6-methylpyridin-2-yl)-1H-pyrazol-4-yl)-
quinoline (12b)
This compound was prepared according to the same procedure
for 12a using 11b as the starting material. Yield 73%; 1H NMR
(CDCl3) d 2.58 (s, 3H), 3.84 (s, 3H), 6.30 (d, 1H, J = 8.0 Hz) 7.05 (d,
1H, J = 7.6, Hz), 7.11 (d, 1H, J = 8.0 Hz), 7.40 (t, 1H, overlapped,
J = 7.6 Hz), 7.42 (d, 1H, overlapped, J = 8.8 Hz), 7.53 (d, 1H,
J = 7.6 Hz), 7.71 (s, 1H), 7.72 (dd, 1H, J = 8.8, 2.0 Hz), 8.57 (d, 1H,
J = 2.0 Hz), 11.20 (br s, 1H).
2928, 2231, 1696, 1586 cmꢂ1 1H NMR (CDCl3) d 2.69 (s, 3H),
;
5.05 (s, 2H), 7.06 (d, 1H, J = 7.6 Hz), 7.27 (d, 1H, J = 7.6 Hz), 7.39
(dt, 1H, J = 7.6, 1.4 Hz), 7.41–7.47 (m, 2H), 7.54 (dd, 1H, overlapped,
J = 8.8, 1.6 Hz), 7.57 (t, 1H, overlapped, J = 7.8 Hz), 7.78 (d, 1H,
J = 2.0 Hz), 7.89 (ddd, 1H, J = 8.0, 2.4, 1.6 Hz), 7.91 (s, 1H), 7.99 (t,
1H, J = 1.6 Hz), 8.10 (br d, 1H, J = 8.8 Hz), 8.16 (br d, 1H, overlapped,
J = 8.0 Hz), 8.91 (dd, 1H, J = 4.4, 2.0 Hz), 10.41 (br s, 1H); HRMS-ESI
m/z [M+H]+ calcd for C27H21N6O: 445.1771, found 445.1791.
4.2.5. 3-(2-Chloroacetamido)benzamide (13c)
To a stirred solution of 3-aminobenzamide (2.20 mmol) in
CHCl3 (22 mL), a saturated NaHCO3 solution (22 mL) and chloro-
acetyl chloride (4.41 mmol) were added. The mixture was stirred
at room temperature for 2 h and diluted with H2O (40 mL). The
mixture was extracted with CHCl3 (2 ꢁ 50 mL), and the CHCl3 solu-
tion was dried over anhydrous NaSO4, filtered, and evaporated to
dryness under reduced pressure. The residue was crystallized from
Et2O/hexane to give the titled compound as a white solid. Yield
91%; 1H NMR (DMSO-d6) d 4.28 (s, 2H), 7.36 (br s, 1H), 7.40 (t,
1H, J = 7.6 Hz), 7.58 (dt, 1H, J = 7.6, 0.8 Hz), 7.76 (ddd, 1H, J = 8.0,
2.0, 0.8 Hz), 7.96 (br s, 1H), 8.05 (t, 1H, J = 1.8 Hz), 10.49 (br s, 1 H).
4.2.8. 2-(4-(4-Methoxyquinolin-6-yl)-3-(6-methylpyridin-2-yl)-
1H-pyrazol-1-yl)-N-phenylacetamide (14c) and 2-(4-(4-methoxy-
quinolin-6-yl-)-5-(6-methylpyridin-2-yl-)-1H-pyrazol-1-yl)-N-
phenylacetamide (15c)
These compounds were prepared according to the same proce-
dure for 14a and 15a using 12b and 13a, and the residue was puri-
fied by MPLC on silica gel using MeOH/CHCl3 (1/30) as eluent to
give the titled compounds as white solids. Compound 14c: yield
80%; mp 268.9 °C; IR (KBr) 3409, 2925, 1691, 1563 cmꢂ1 1H
;
NMR (CDCl3) d 2.55 (s, 3H), 3.80 (s, 3H), 5.05 (s, 2H), 6.27 (d, 1H,
J = 7.6 Hz), 7.08–7.13 (m, 2H), 7.27–7.33 (m, 4H), 7.47–7.50 (m,
3H), 7.54 (t, 1H, J = 7.6 Hz), 7.69 (dd, 1H, J = 8.8, 2.0 Hz), 7.79 (s,
1H), 8.53 (d, 1H, J = 2.0 Hz), 8.59 (br s, 1H); HRMS-ESI m/z
[M+H]+ calcd for C27H24N5O2: 450.1925, found 450.1943. Com-
pound 15c: yield 14%; mp 193.2 °C; IR (KBr) 3264, 2931, 1692,
4.2.6. 2-(3-(6-Methylpyridin-2-yl)-4-(quinolin-6-yl)-1H-pyrazol-
1-yl)-N-phenylacetamide (14a) and 2-(5-(6-methylpyridin-2-yl)-
4-(quinolin-6-yl)-1H-pyrazol-1-yl)-N-phenylacetamide (15a)
To a solution of pyrazole 12a (0.47 mmol) in anhydrous DMF
(4 mL), a catalytic amount of sodium iodide, 2-chloro-N-phenyl-
acetamide (13a) (0.56 mmol), and NaH (0.56 mmol) were added.
The mixture was stirred at room temperature for 30 min and then
evaporated to dryness under reduced pressure. The residue was
purified by MPLC on silica gel using MeOH/CHCl3 (1:40) as eluent
to give the two positional isomers 14a and 15a as white solids.
1591 cmꢂ1 1H NMR (CDCl3) d 2.66 (s, 3H), 3.81 (s, 3H), 5.04 (s,
;
2H), 6.34 (d, 1H, J = 7.6 Hz), 7.03 (d, 1H, J = 7.6 Hz), 7.09 (tt, 1H,
J = 7.4, 1.2 Hz), 7.21 (d, 1H, J = 7.6 Hz), 7.29–7.36 (m, 3H),
7.49–7.53 (m, 2H), 7.55 (dd, 1H, J = 7.6, 2.0 Hz), 7.61 (dd, 2H,
J = 8.4, 1.2 Hz), 7.87 (s, 1H), 8.42 (d, 1H, J = 1.6 Hz), 9.76 (br s,
1H); HRMS-ESI m/z [M+H]+ calcd for C27H24N5O2: 450.1925, found
450.1921.

C. H. Jin et al. / Bioorg. Med. Chem. 19 (2011) 2633–2640
2639
4.2.9. N-(3-Cyanophenyl)-2-(4-(4-methoxyquinolin-6-yl)-3-(6-
methylpyridin-2-yl)-1H-pyrazol-1-yl)acetamide (14d) and N-(3-
cyanophenyl)-2-(4-(4-methoxyquinolin-6-yl)-5-(6-methylpyri-
din-2-yl)-1H-pyrazol-1-yl)acetamide (15d)
solid which was purified by crystallization from Et2O/hexane to
give the titled compound. Yield 70%; mp 98.4 °C; IR (KBr) 3222,
2233, 1676 cmꢂ1 1H NMR (CDCl3) d 2.99 (t, 2H, J = 6.4 Hz), 3.70
;
(t, 2H, J = 6.4 Hz), 7.39–7.45 (m, 2H), 7.75 (dt, 1H, J = 7.6, 2.0 Hz),
These compounds were prepared according to the same proce-
dure for 14a and 15a using 12b and 13b, and the residue was puri-
fied by MPLC on silica gel using MeOH/CHCl3 (1:25) as eluent to
give the titled compounds as white solids. Compound 14d: yield
7.94 (br s, 1H), 7.97 (br s, 1H); HRMS-ESI m/z [M+H]+ calcd for
C10H10BrN2O: 252.9971, found 252.9980.
4.2.12. 3-(3-(6-Methylpyridin-2-yl)-4-(quinolin-6-yl)-1H-pyrazol-
1-yl)-N-phenylpropanamide (17a)
76%; mp 149.5 °C; IR (KBr) 3254, 2942, 2229, 1700, 1572 cmꢂ1
;
1H NMR (CDCl3) d 2.46 (s, 3H), 3.79 (s, 3H), 5.21 (s, 2H), 6.26 (d,
1H, J = 7.6 Hz), 7.05 (d, 1H, J = 7.6 Hz), 7.15 (d, 1H, J = 7.6 Hz),
This compound was prepared according to the same procedure
for 14e using 12a and 3-bromo-N-phenylpropanamide (16a), and
the residue was purified by MPLC on silica gel using MeOH/CHCl3
(1:30) as eluent to give the titled compound as a white solid. Yield
55%; mp 191.4 °C; IR (KBr) 3266, 2927, 1677, 1596, 1548 cmꢂ1; 1H
NMR (CDCl3) d 2.59 (s, 3H), 3.07 (t, 2H, J = 6.0 Hz), 4.65 (t, 2H,
J = 6.0 Hz), 7.07 (t, 1H, J = 7.4 Hz), 7.11 (d, 1H, J = 7.6 Hz), 7.15 (d,
1H, J = 8.0 Hz), 7.24–7.29 (m, 2H), 7.37 (dd, 1H, J = 8.4, 4.4 Hz),
7.46 (t, 1H, J = 7.8 Hz), 7.49 (d, 2H, J = 7.6 Hz), 7.56 (dd, 1H,
J = 8.8, 2.0 Hz), 7.71 (br s, 2H), 7.97 (d, 1H, J = 8.8 Hz), 8.03 (d, 1H,
J = 7.6 Hz), 8.28 (br s, 1H), 8.87 (dd, 1H, J = 4.4, 1.8 Hz); HRMS-ESI
m/z [M+H]+ calcd for C27H24N5O: 434.1975, found 434.1978.
7.24–7.29 (m, 2H), 7.33 (d,
, 1H, J = 8.8 Hz), 7.45 (t, 1H,
J = 7.6 Hz), 7.53 (d, 1H, J = 7.6 Hz), 7.62 (dd, 1H, J = 8.8, 2.0 HZ),
7.64–767 (m, 1H), 7.76 (s, 1H), 7.84 (br d, 1H, J = 1.2 Hz), 8.46 (d,
1H, J = 2.4 Hz), 10.65 (br s, 1H); HRMS-ESI m/z [M+H]+ calcd for
C
28H23N6O2: 475.1877, found 475.1880. Compound 15d: yield
14%; mp 245.9 °C; IR (KBr) 2955, 2231, 1700, 1587 cmꢂ1 1H
;
NMR (CDCl3) d 2.65 (s, 3H), 3.80 (s, 3H), 5.03 (s, 2H), 6.26 (d, 1H,
J = 7.6 Hz), 7.05 (d, 1H, J = 7.6 Hz), 7.23 (d, 1H, J = 8.0 Hz), 7.34 (d,
1H, J = 8.8 Hz), 7.38 (dt, 1H, J = 7.6, 1.2 Hz), 7.42 (t, 1H, J = 8.0 Hz),
7.50 (dd, 1H, overlapped, J = 8.8, 2.4 Hz), 7.51 (d, 1H, overlapped,
J = 7.6 Hz), 7.55 (t, 1H, J = 7.8 Hz), 7.83 (ddd, 1H, J = 8.4, 2.4,
1.6 Hz), 7.86 (s, 1H), 8.04 (t, 1H, J = 1.4 Hz), 8.41 (d, 1H,
J = 2.4 Hz), 10.40 (br s, 1H); HRMS-ESI m/z [M+H]+ calcd for
4.2.13. N-(3-Cyanophenyl)-3-(3-(6-methylpyridin-2-yl)-4-
(quinolin-6-yl)-1H-pyrazol-1-yl)propanamide (17b)
C
28H23N6O2: 475.1877, found 475.1878.
This compound was prepared according to the same procedure
for 14e using 12a and 16b, and the residue was purified by MPLC
on silica gel using MeOH/CHCl3 (1:30) as eluent to give the titled
compound as a white solid. Yield 51%; mp 74.9 °C; IR (KBr) 3258,
4.2.10. 3-(2-(3-(6-Methylpyridin-2-yl)-4-(quinolin-6-yl)-1H-
pyrazol-yl)-1H-pyrazol-acetamido)benzamide (14e) and 3-(2-
(5-(6-methylpyridin-2-yl)-4-(quinolin-6-yl)-1H-pyrazol-1-yl)-
acetamido)benzamide (15e)
2934, 2230, 1688 cmꢂ1 1H NMR (CDCl3) d 2.63 (s, 3H), 3.11 (t,
;
2H, J = 5.8 Hz), 4.62 (t, 2H, J = 5.8 Hz), 7.11 (d, 1H, J = 7.6 Hz), 7.15
(d, 1H, J = 7.6 Hz), 7.28–7.34 (m, 2H), 7.39 (dd, 1H, J = 8.2, 4.4 Hz),
7.48 (t, 1H, J = 7.6 Hz), 7.54 (dd, 1H, J = 8.8, 2.0 Hz), 7.68 (s, 1H),
7.70 (d, 1H , J = 2.0 Hz), 7.77–7.80 (m, 1H), 7.91 (br s, 1H), 7.98
(d, 1H, J = 8.8 Hz), 8.05 (br d, 1H, overlapped, J = 8.0 Hz), 8.88 (dd,
1H, J = 4.4, 1.8 Hz), 9.52 (br s, 1H); HRMS-ESI m/z [M+H]+ calcd
for C28H23N6O: 459.1928, found 459.1931.
To a stirred solution of 12a (0.17 mmol) in anhydrous DMF
(1.5 mL), 13c (0.21 mmol) and Cs2CO3 (0.26 mmol) were added.
The mixture was heated at 120 °C for 1 h and then cooled to room
temperature. The mixture was diluted with water (10 mL) and ex-
tracted with CHCl3 (2 ꢁ 50 mL). The CHCl3 solution was dried over
anhydrous Na2SO4, filtered, and evaporated to dryness under
reduced pressure. The residue was purified by MPLC on silica gel
using MeOH/CH2Cl2 (1:20) as eluent to give the titled compounds
as yellow solids. Compound 14e: yield 49%; mp 245.0 °C; IR
4.2.14. N-(3-Cyanophenyl)-3-(4-(4-methoxyquionolin-6-yl)-3-
(6-methylpyridin-2-yl)-1H-pyrazol-1-yl)propanamide (17c)
This compound was prepared according to the same procedure
for 14e using 12b and 16b, and the residue was purified by MPLC
on silica gel using MeOH/CH2Cl2 (1:20) as eluent to give the titled
compound as a white solid. Yield 39%; mp 140 °C; IR (KBr) 3066,
(KBr) 3401, 3317, 3218, 1699, 1646, 1585 cmꢂ1 1H NMR (CDCl3/
;
CD3OD) d 2.50 (s, 3H), 5.11 (s, 2H), 7.17 (d, 1H, J = 7.6 Hz), 7.25
(d, 1H, J = 7.6 Hz), 7.39 (t, 1H, J = 8.0 Hz), 7.44 (dd, 1H, J = 8.4,
4.4 Hz), 7.57 (t, 1H, J = 7.6 Hz), 7.58–7.61 (m, 1H, J = 8.0 Hz), 7.64
(dd, 1H, J = 8.8, 2.0 Hz), 7.76 (ddd, 1H, J = 8.0, 2.0, 1.2 Hz), 7.85 (d,
1H, J = 2.0 Hz), 7.93 (d, 1H, J = 8.8 Hz), 7.98 (s, 1H), 7.99 (t, 1H,
J = 2.0 Hz), 8.15 (dd, 1H, J = 8.4, 1.2 Hz), 8.77 (dd, 1H, J = 4.4,
1.2 Hz); HRMS-ESI m/z [M+H]+ calcd for C27H23N6O2: 463.1877,
found 463.1891. Compound 15e: yield 16%; mp 207.8 °C; IR (KBr)
2230, 1689, 1579 cmꢂ1 1H NMR (CDCl3) d 2.55 (s, 3H), 3.03 (t,
;
2H, J = 6.2 Hz), 3.78 (s, 3H), 4.56 (t, 2H, J = 6.2 Hz), 6.24 (d, 1H,
J = 7.6 Hz), 7.09 (br d, 1H, J = 8.0 Hz), 7.14 (br d, 1H, J = 7.6 Hz),
7.26–7.35 (m, 3H), 7.46 (t, 1H, J = 7.8 Hz), 7.52 (d, 1H, J = 7.6 Hz),
7.54 (dd, 1H, J = 8.8, 1.6 Hz), 7.66 (s, 1H), 7.87 (d, 1H, overlapped,
J = 1.6 Hz), 7.88 (d, 1H, overlapped, J = 8.0 Hz), 8.41 (d, 1H,
J = 2.4 Hz), 9.98 (br s, 1H); HRMS-ESI m/z [M+H]+ calcd for
3286, 3202, 1669, 1588 cmꢂ1 1H NMR (CDCl3) d 2.69 (s, 3H),
;
5.08 (s, 2H), 5.87 (br s, 1H), 6.31 (br s, 1H), 7.05 (d, 1H,
J = 7.6 Hz), 7.24 (d, 1H, J = 8.0 Hz), 7.38–7.42 (m, 2H), 7.51–7.55
(m, 3H), 7.76 (d, 1H, J = 2.0 Hz), 7.88 (s, 1H), 7.90 (dd, 1H, J = 8.0,
1.2 Hz), 8.03 (d, 1H, J = 8.8 Hz), 8.06 (t, 1H, J = 1.8 Hz), 8.10 (br d,
1H, J = 8.0 Hz), 8.89 (dd, 1H, J = 4.4, 1.6 Hz), 10.32 (br s, 1H);
HRMS-ESI m/z [M+H]+ calcd for C27H23N6O2: 463.1877, found
463.1897.
C29H25N6O2: 489.2034, found 489.2051.
4.2.15. 2-(3-(6-Methylpyridin-2-yl)-4-(quinolin-6-yl)-1H-
pyrazol-1-yl)-N-phenylethanethioamide (18a)
A stirred mixture of 14a (0.96 mmol), Lawesson’s reagent
(0.96 mmol), and anhydrous DME (3 mL) in a dry sealed tube
was heated at 85 °C for 12 h. After cooled to room temperature,
the solvent was evaporated to dryness under reduced pressure,
and the residue was purified by MPLC on silica gel using MeOH/
CHCl3 (1:30) as eluent to give the titled compound as a light yellow
solid. Yield 67%; mp 214.6 °C; IR (KBr) 3265, 2934, 1594,
4.2.11. 3-Bromo-N-(3-cyanophenyl)propanamide (16b)
3-Bromopropanoyl chloride (40.63 mmol) was added dropwise
to a mixture of 3-aminobenzonitrile (33.86 mmol) and anhydrous
K2CO3 (40.63 mmol) in CH2Cl2 at room temperature. The resulting
mixture was heated at reflux temperature for 4 h, then cooled to
room temperature, and slowly poured into cold water (120 mL).
The aqueous solution was extracted with CH2Cl2 (2 ꢁ 100 mL),
and the CH2Cl2 solution was dried over anhydrous Na2SO4, filtered,
and evaporated to dryness under reduced pressure to give a white
1136 cmꢂ1 1H NMR (CDCl3) d 2.54 (s, 3H), 5.47 (s, 2H), 7.15 (d,
;
1H, J = 8.0 Hz), 7.23–7.27 (m, 1H), 7.32 (d, 1H, J = 7.6 Hz),
7.36–7.42 (m, 3H), 7.55 (t, 1H, J = 7.8 Hz), 7.66 (dd, 1H, J = 8.8,
2.0 Hz), 7.75 (dd, 2H, J = 7.6, 1.2 Hz), 7.83 (s, 1H), 7.86 (d, 1H,
J = 2.0 Hz), 8.03 (d, 1H, J = 8.8 Hz), 8.10 (dd, 1H, J = 8.4, 0.8 Hz),

2640
C. H. Jin et al. / Bioorg. Med. Chem. 19 (2011) 2633–2640
8.91 (dd, 1H, J = 4.4, 1.6 Hz), 10.53 (br s, 1H); HRMS-ESI m/z [M+H]+
calcd for C26H22N5S: 436.1590, found 436.1611.
2. Shi, J.; Massague, J. Cell 2003, 113, 685.
3. Massague, J. Nat. Rev. Mol. Cell Biol. 2000, 1, 169.
4. Derynck, R.; Zhang, Y. E. Nature 2003, 425, 577.
5. Wang, W.; Koka, V.; Lan, H. Y. Nephrology 2005, 10, 48.
6. Lim, H.; Zhu, Y. Z. Cell. Mol. Life Sci. 2006, 63, 2584.
7. Gu, L.; Zhu, Y.-J.; Yang, X.; Guo, Z.-J.; Xu, W.-B.; Tian, X.-L. Acta Pharmacol. Sin.
2007, 28, 382.
8. Shek, F. W.; Benyon, R. C. Eur. J. Gastroenterol. Hepatol. 2004, 16, 123.
9. Bierie, B.; Moses, H. L. Nat. Rev. Cancer 2006, 6, 506.
10. Rane, S. G.; Lee, J.-H.; Lin, H.-M. Cytokine Growth Factor Rev. 2006, 17, 107.
11. Dong, M.; Blobe, G. C. Blood 2006, 107, 4589.
4.2.16. N-(3-Cyanophenyl)-2-(3-(6-methylpyridin-2-yl)-4-(quin-
olin-6-yl)-1H-pyrazol-1-yl)ethanethioamide (18b)
This compound was prepared according to the same procedure
for 18a using 14b as the starting material. Yield 73%; mp 230.8 °C;
IR (KBr) 3282, 2926, 2233, 1583 cmꢂ1 1H NMR (CDCl3) d 2.52 (s,
;
3H), 5.54 (s, 2H), 7.14 (d, 1H, J = 7.6 Hz), 7.21 (d, 1H, J = 8.0 Hz),
7.37–7.43 (m, 2H), 7.46–7.52 (m, 2H), 7.66 (d, 1H, J = 8.4 Hz),
7.85 (br s, 2H), 7.95 (d, 1H, J = 8.0 Hz), 8.06 (d, 1H, J = 8.8 Hz),
8.11 (d, 1H, J = 8.0 Hz), 8.23 (s, 1H), 8.92 (d, 1H, J = 4.0 Hz), 11.57
(br s, 1H); HRMS-ESI m/z [M+H]+ calcd for C27H21N6S: 461.1543,
found 461.1566.
12. Halder, S. K.; Beauchamp, R. D.; Datta, P. K. Neoplasia 2005, 7, 509.
13. Byfield, S. D.; Major, C.; Laping, N. J.; Roberts, A. B. Mol. Pharmacol. 2004, 65,
744.
14. De Gouville, A. C.; Boullay, V.; Krysa, G.; Pilot, J.; Brusq, J. M.; Loriolle, F.;
Gauthier, J. M.; Papworth, S. A.; Laroze, A.; Gellibert, F.; Huet, S. Br. J. Pharmacol.
2005, 145, 166.
15. Ge, R.; Rajeev, V.; Ray, P.; Lattime, E.; Rittling, S.; Medicherla, S.; Protter, A.;
Murphy, A.; Chakravarty, J.; Dugar, S.; Schreiner, G.; Barnard, N.; Reiss, M. Clin.
Cancer Res. 2006, 12, 4315.
16. Kapoun, A. M.; Gaspar, N. J.; Wang, Y.; Damm, D.; Liu, Y.-W.; O’Young, G.; Quon,
D.; Lam, A.; Munson, K.; Tran, T.-T.; Ma, J. Y.; Murphy, A.; Dugar, S.;
Chakravarty, S.; Protter, A. A.; Wen, F.-Q.; Liu, X.; Rennard, S. I.; Higgins, L. S.
Mol. Pharmacol. 2006, 70, 518.
17. Mundla, S. R. PCT Int. Appl. WO 2007018818 A1, 2007.
18. Kim, D.-K.; Kim, J.; Park, H.-J. Bioorg. Med. Chem. Lett. 2004, 14, 2401.
19. Kim, D.-K.; Kim, J.; Park, H.-J. Bioorg. Med. Chem. 2004, 12, 2013.
20. Kim, D.-K.; Jang, Y.; Lee, H. S.; Park, H.-J.; Yoo, J. J. Med. Chem. 2007, 50, 3143.
21. Kim, D.-K.; Choi, J. H.; An, Y. J.; Lee, H. S. Bioorg. Med. Chem. Lett. 2008, 18, 2122.
22. Kim, D.-K.; Jung, S. H.; Lee, H. S.; Dewang, P. M. Eur. J. Med. Chem. 2009, 44, 568.
23. Dewang, P. M.; Kim, D.-K. Bioorg. Med. Chem. Lett. 2010, 20, 4228.
24. Kim, D.-K.; Lee, Y.-I.; Lee, Y. W.; Dewang, P. M.; Sheen, Y. Y.; Kim, Y. W.; Park,
H.-J.; Yoo, J.; Lee, H. S.; Kim, Y.-K. Bioorg. Med. Chem. 2010, 18, 4459.
25. Kim, Y. W.; Kim, Y. K.; Lee, J. Y.; Chang, K. T.; Lee, H. J.; Kim, D.-K.; Sheen, Y. Y.
Xenobiotica 2008, 38, 325.
26. Kim, Y. W.; Kim, Y. K.; Kim, D.-K.; Sheen, Y. Y. Xenobiotica 2008, 38, 451. 23.
27. Moon, J.-A.; Kim, H.-T.; Cho, I.-S.; Sheen, Y. Y.; Kim, D.-K. Kidney Int. 2006, 70,
1234.
28. Luo, J.; Ho, P. P.; Buckwalter, M. S.; Hsu, T.; Lee, L. Y.; Zhang, H.; Kim, D.-K.; Kim,
S.-J.; Gambhir, S. S.; Steinman, L.; Wyss-Coray, T. J. Clin. Invest. 2007, 117, 3306.
29. Ryu, J.-K.; Piao, S.; Shin, H.-Y.; Choi, M. J.; Zhang, L. W.; Jin, H.-R.; Kim, W. J.;
Han, J.-Y.; Hong, S. S.; Park, S. H.; Lee, S.-J.; Kim, I.-H.; Lee, C. R.; Kim, D.-K.;
Mamura, M.; Kim, S.-J.; Suh, J.-K. J. Sex. Med. 2009, 6, 1284.
30. Lee, G. T.; Hong, J. H.; Mueller, T. J.; Watson, J. A.; Kwak, C.; Sheen, Y. Y.; Kim, D.-
K.; Kim, S. J.; Kim, I. Y. J. Urol. 2008, 180, 2660.
31. Long, L.; Crosby, A.; Yang, X.; Southwood, M.; Upton, P. D.; Kim, D.-K.; Morrell,
N. W. Circulation 2009, 119, 566.
32. Kim, J. H.; Song, H.-Y.; Park, J.-H.; Yoon, H.-J.; Park, H. G.; Kim, D.-K. Radiology
2010, 255, 75.
33. Tojo, M.; Hamashima, Y.; Hanyu, A.; Kajimoto, T.; Saitoh, M.; Miyazono, K.;
Node, M.; Imamura, T. Cancer Sci. 2005, 96, 791.
34. Munchhof, M. J.; Blumberg, L. C. PCT Int. Appl. WO 2004/026306 A2, 2004.
35. Pier, G. B.; Delia, P.; Mojgan, A. T.; Francesca, F.; Giulia, S.; Stefania, B.; Romeo,
R.; Allan, R. M.; Stefania, G.; Katia, V.; Pier, A. B. Bioorg. Med. Chem. 2007, 15,
2514.
36. Zhang, L.; Li, H.; Zhu, Q.; Liu, J.; Chen, L.; Leng, Y.; Jiang, H.; Liu, H. Bioorg. Med.
Chem. 2009, 17, 7301.
37. Jacobs, W. A.; Heidelberger, M. J. Am. Chem. Soc. 1917, 39, 1439.
38. Rajavel, R.; Mahesh, U.; Shao, Q. Y. Org. Lett. 2006, 8, 713.
39. Wrana, J. L.; Attisano, L.; Carcamo, J.; Zentella, A.; Doody, J.; Laiho, M.; Wang, X.
F.; Massague, J. Cell 1992, 71, 1003.
4.2.17. 3-(3-(6-Methylpyridin-2-yl)-4-(quinolin-6-yl)-1H-pyrazol-
1-yl)-N-phenylpropanethioamide (18c)
This compound was prepared according to the same procedure
for 18a using 17a as the starting material. Yield 37%; mp 87.4 °C; IR
(KBr) 3197, 2926, 1590, 1129 cmꢂ1; 1H NMR (CDCl3) d 2.61 (s, 3H),
3.54 (t, 2H, J = 6.0 Hz), 4.77 (t, 2H, J = 6.0 Hz), 7.08 (d, 1H,
J = 7.6 Hz), 7.11–7.16 (m, 2H), 7.23 (td, 2H, J = 7.6, 1.6 Hz), 7.39
(dd, 1H, J = 8.2, 4.2 Hz), 7.47 (t, 1H, J = 7.8 Hz), 7.49–7.55 (m, 2H),
7.67 (d, 1H, J = 2.0 Hz), 7.70 (s, 1H), 7.98 (d, 1H, J = 8.8 Hz), 8.03
(dd, 1H, J = 8.2, 1.2 Hz), 8.88 (dd, 1H, J = 4.2, 1.8 Hz), 10.64 (br s,
1H); HRMS-ESI m/z [M+H]+ calcd for C27H24N5S: 450.1747, found
450.1767.
4.2.18. N-(3-Cyanophenyl)-3-(3-(6-methylpyridin-2-yl)-4-(quin-
olin-6-yl)-1H-pyrazol-1-yl)propanethioamide (18d)
This compound was prepared according to the same procedure
for 18a using 17b as the starting material. Yield 46%; mp 94.6 °C; IR
(KBr) 3200, 2927, 2232, 1586, 1171 cmꢂ1 1H NMR (CDCl3) d 2.63
;
(s, 3H), 3.58 (t, 2H, J = 5.8 Hz), 4.74 (t, 2H, J = 5.8 Hz), 7.04 (d, 1H,
J = 7.6 Hz), 7.16 (d, 1H, J = 8.0 Hz), 7.31 (t, 1H, J = 8.0 Hz),
7.37–7.40 (m, 2H), 7.47 (t, 1H, J = 7.6 Hz), 7.50 (dd, 1H, J = 8.8,
2.0 Hz), 7.66 (s, 1H), 7.67 (d, 1H, J = 2.0 Hz), 7.90 (br s, 1H), 8.00
(d, 2H, J = 8.4 Hz), 8.06 (br d, 1H, J = 8.4 Hz), 8.88 (dd, 1H, J = 4.4,
1.6 Hz), 11.27 (br s, 1H); HRMS-ESI m/z [M+Na]+ calcd for
C28H22N6NaS: 497.1519, found 497.1537.
Acknowledgment
This work was supported by RP-Grant 2009 of Ewha Womans
University.
References and notes
40. Eyers, P. A.; Craxton, M.; Morrice, N.; Cohen, P.; Goedert, M. Chem. Biol. 1998, 5,
321.
1. Heldin, C. H.; Miyazono, K.; Ten Dijke, P. Nature 1997, 390, 465.