t-Butyl pyridine and phenyl C-region analogues of 2-(3-fluoro-4-methylsulfonylaminophenyl)propanamides as potent TRPV1 antagonists

Article abstract of DOI:10.1016/j.bmc.2017.03.004

A series of 2-substituted 6-t-butylpyridine and 4-t-butylphenyl C-region analogues of 2-(3-fluoro-4-methylsulfonamidophenyl)propanamides were investigated for hTRPV1 antagonism. The analysis of structure activity relationships indicated that the pyridine

Full text of DOI:10.1016/j.bmc.2017.03.004

Bioorganic & Medicinal Chemistry xxx (2017) xxx–xxx
Contents lists available at ScienceDirect
Bioorganic & Medicinal Chemistry
journal homepage: www.elsevier.com/locate/bmc
t-Butyl pyridine and phenyl C-region analogues of 2-(3-fluoro-4-
methylsulfonylaminophenyl)propanamides as potent TRPV1 antagonists
Sunho Lee a, Dong Wook Kang b, HyungChul Ryu c, Changhoon Kim a, Jihyae Ann a, Hobin Lee a, Eunhye Kim d,
Sunhye Hong d, Sun Choi d, Peter M. Blumberg e, Robert Frank-Foltyn f, Gregor Bahrenberg f,
Hannelore Stockhausen f, Thomas Christoph f, Jeewoo Lee a,
⇑
a Laboratory of Medicinal Chemistry, Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea
b Department of Pharmaceutical Science and Technology, College of Health and Medical Science, Catholic University of Deagu, Gyeongsan-si, Gyeongsangbuk-do 38430,
Republic of Korea
c J2H Biotech, Ansan-si, Gyeonggi-do 15426, Republic of Korea
d National Leading Research Laboratory of Molecular Modeling & Drug Design, College of Pharmacy, Graduate School of Pharmaceutical Sciences, Ewha Womans University,
Seoul 03760, Republic of Korea
e Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
f Grünenthal Innovation, Grünenthal GmbH, D-52078 Aachen, Germany
a r t i c l e i n f o
a b s t r a c t
Article history:
A series of 2-substituted 6-t-butylpyridine and 4-t-butylphenyl C-region analogues of 2-(3-fluoro-4-
methylsulfonamidophenyl)propanamides were investigated for hTRPV1 antagonism. The analysis of
structure activity relationships indicated that the pyridine derivatives generally exhibited a little better
antagonism than did the corresponding phenyl surrogates for most of the series. Among the compounds,
compound 7 showed excellent antagonism toward capsaicin activation with Ki = 0.1 nM and compound
60S demonstrated a strong antiallodynic effect with 83% MPE at 10 mg/kg in the neuropathic pain model.
The docking study of 7S in our hTRPV1 homology model indicated that the interactions between the
A/B-regions of 7S with Tyr511 and the interactions between the t-butyl and ethyl groups in the C-region
of 7S with the two hydrophobic binding pockets of hTRPV1 contributed to the high potency.
Ó 2017 Elsevier Ltd. All rights reserved.
Received 14 February 2017
Revised 2 March 2017
Accepted 2 March 2017
Available online xxxx
Keywords:
Vanilloid receptor 1
TRPV1 antagonists
Analgesic
1. Introduction
Recently, we demonstrated that
a series of N-((6-trifluo-
romethyl-pyridin-3-yl)methyl) 2-(3-fluoro-4-methylsulfonami-
TRP family members represent critical nociceptors, responding
both directly to chemical and thermal insults as well as indirectly
in response to signaling pathways activated in response to inflam-
mation and cellular injury.1–3 Among TRP family members, TRPV1,
the receptor for capsaicin, has become a target of particular
therapeutic interest for a broad range of conditions including
inflammatory and neuropathic pain. While complementary thera-
peutic strategies are directed at TRPV1 agonists and antagonists,
antagonists have received the greatest attention. Intense medicinal
chemical efforts, coupled with insights from structural analysis of
TRPV1 and computer modeling,4–7 are yielding potent lead
compounds.8 The current paper describes our on-going efforts to
refine our understanding of the structure–activity relations of
antagonists targeting human TRPV1.
dophenyl)propanamides (Template I) were potent and
stereoselective hTRPV1 antagonists for multiple activators
(Fig. 1).9–18 Like capsaicin, our antagonistic template can be
divided into three pharmacophoric parts, designated the A, B and
C-regions as shown in Fig. 1. The structure activity relationships
of the template have been investigated for the B-region, including
the evaluation of
a
-substituted acetamide15 and urea18 groups.
Likewise, the structure activity relationships have been investi-
gated for the C-region, in which a variety of functional groups
including the amino,9 oxy,10 thio,11 alkyl12, aryl13 and sulfon-
amido17 groups were incorporated at the 2-position of pyridine
and the pyridine core was modified by its isomers14 or by a phenyl
group.16 In these series, numerous compounds exhibited highly
potent antagonism toward TRPV1 activators including capsaicin
(CAP), N-arachidonoyl dopamine (NADA), low pH, and heat
(45 °C) and antagonism was stereospecific to the S-configuation.
Additionally, in vivo studies of selected antagonists demonstrated
⇑
Corresponding author.
E-mail address: jeewoo@snu.ac.kr (J. Lee).
http://dx.doi.org/10.1016/j.bmc.2017.03.004
0968-0896/Ó 2017 Elsevier Ltd. All rights reserved.
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2
S. Lee et al. / Bioorganic & Medicinal Chemistry xxx (2017) xxx–xxx
Leu547/Thr550
C
B
A
F3C
H
N
H
N
X
F
*
N
F
*
O
S
O
O
S
O
R
O
R
O
N
H
N
H
X = N, CH
Met514/Leu515
Template I
R
N
O
S
C
=
R2, R, R, R3
Template II
Fig. 1. Design of t-butylpyridine and phenyl C-region TRPV1 antagonists.
that these compounds blocked capsaicin-induced hypothermia,
consistent with their in vitro mechanism of action as hTRPV1
antagonists, and that they produced strong antiallodynic effects
in neuropathic pain models.
2. Result and discussion
2.1. Chemistry
Docking studies using our established hTRPV1 homology
model indicated that the 2-substituent and the 6-trifluoromethyl
groups in the pyridine C-region made hydrophobic interactions
with the pockets composed of Met514/Leu515 and Leu547/
Thr550, respectively, that were critical for their potent antago-
nism.9–13
The general synthesis of target compounds was described in
Scheme 1. Starting from 6-t-butyl-2-hydroxynicotinonitrile19,20
and 4-t-butyl-2-hydroxybenzonitrile21, the 2-hydroxy groups were
converted to the corresponding chloride (Y = Cl, Method A) or tri-
flate (Y = OTf, Method B), respectively. The 2-hydroxy, chloride,
or triflate groups in the t-butylpyridine and phenyl C-region were
transformed to a variety of substituents including amino, oxy, thio
and alkyl/aryl groups employing 3 different methods (Methods
C-E) as appropriate. The nitrile group was reduced into the corre-
sponding amine by catalytic hydrogenation or with borane/LiAlH4.
Finally, the synthesized C-region amines were coupled with the
propionic acid A-region14 previously reported to afford the final
compounds 1–62.
As part of our continuing effort to advance TRPV1 antagonists
as clinical candidates for neuropathic pain, we have investigated
the t-butylpyridine and phenyl surrogates of the 6-trifluo-
romethylpyridine C-region derivatives previously reported as
potent antagonists. The motivation was that our modeling sug-
gested that the t-butyl group in this series might provide a fit
superior to that of the trifluoromethyl group for the hydrophobic
pocket composed of Leu547/Thr550 (Fig. 1). In this paper, we
synthesized a series of 2-substituted 6-t-butylpyridin-3-ylmethyl
and 4-t-butylbenzyl C-region derivatives (Template II) and
evaluated their antagonism toward activation of hTRPV1 by
capsaicin. With selected potent antagonists in the series, we
characterized their analgesic activities in a neuropathic pain
model. Finally, we carried out a docking study using our hTRPV1
homology model to identify their mode of binding to the
receptor.
2.2. In vitro TRPV1 antagonism
The synthesized compounds were evaluated in vitro for TRPV1
antagonism as measured by inhibition of activation by capsaicin
(100 nM). The assays were conducted using a fluorometric imaging
plate reader (FLIPR) with hTRPV1 heterologously expressed in
Chinese hamster ovary (CHO) cells.9 The results are summarized
in Tables 1–4.
ꢀ
b
a
X
X
X
CN
CN
CN
Y
R
OH
X = N, CH
X = N Y = Cl, OTf
X = CH Y = OTf
R = NR2, OR, SR, CR3
d
c
H
X
NH2
X
N
*
F
HO
*
F
O
R
O
R
O
S
O
N S
O
N
H
H
O
Scheme 1. The synthesis of t-butylpyridine and phenyl C-region antagonists. Reaction and conditions: (a) [Method A] phenylphosphonic dichloride, sealed tube, 170 °C, 10 h
(Y = Cl); [Method B] trifluoromethanesulfonic anhydride, TEA, MC, 0 °C, 1 h (Y = OTf); (b) [Method C] neat R-X (X = NH, OH, SH), r.t, 12 h, for 1–8, 12⁄, 18⁄, 19⁄, 27⁄, 28⁄, 33⁄, 34⁄
(Y = Cl), 42–47, 59–62 (Y = OTf) (⁄ added DBU as a base and reflux); [Method D] R-X (X = I, Br, SH, OH), K2CO3, 18-crown-6 ether, CH3CN (or DMF), reflux, 14 h for 9–11, 13–17,
20–24, 48–58 (Y = OH), 25, 26, 29–32, 35–38 (Y = Cl); [Method E] Pd(PPh3)4, 2 M Na2CO3, RB(OH)2, toluene/1,4-dioxane (2:1 v/v), reflux, 12 h, for 39, 40, 41, 63, 64 (Y = OTf);
[Method F] R1NH, EDC, HOBt, TEA, DMF or 1,4-dioxane, r.t, 12 h for 30–32 (for the conversion of R = S(CH2)2CO2H to R = S(CH2)2CONR1); (c) [Method G] 2 M BH3ÁSMe2 in THF,
reflux, 16 h for 1–38, 41–48, 51, 54, 57–62; [Method H] LiAlH4, ether, reflux, 12 h for 49, 50, 52, 53, 55, 56; [Method I] H2, Pd/C, MeOH/AcOH (10:3 v/v), 40 °C, 12 h for 39, 40,
63, 64; (d) EDC, HOBt, TEA, DMF (or CH3CN, 1,4-dioxane, CH2Cl2), r.t, 12 h.
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S. Lee et al. / Bioorganic & Medicinal Chemistry xxx (2017) xxx–xxx
3
Table 1
In vitro hTRPV1 antagonistic activities for 2-amino derivatives.
H
N
X
F
O
O
R
N S
H
O
R
X = N
Ki [CAP] (nM)
1.2
X = CH
Ki [CAP] (nM)
1.0
1
42
*
N
N
2
2.5
*
3
4
5
1.2
1.1
0.9
43
44
45
8.1
1.9
6.2
* N
* N
*
N
6
7
8
1.9
0.1
0.3
46
0.7
* N
* N
* N
47
0.8
*
N
N
First, we investigated the SAR for 2-amino derivatives of the 6-t-
(e.g. 12 vs. 16, 13 vs. 17). However, in the comparison between
straight and cyclic alkoxy derivatives (e.g. 13 vs. 18, 14 vs. 19)
the straight alkoxy derivatives were more potent. The insertion
of an oxygen into the pentyl chain of compound 13, providing 20
and 21, led to a clear reduction in potency. The 2-benzyloxy deriva-
tives were also investigated and the 4-fluorobenzyloxy derivative
(23) showed good antagonism.
We also investigated the 2-oxy derivatives of the 4-t-butylphe-
nyl C-region. As in the 2-amino series, they exhibited similar or
less potent antagonism compared to the corresponding 6-t-butyl-
pyridine surrogates. Among them, the 2-hexyloxy (51) and
2-isopentyloxy (54) derivatives displayed potent antagonism with
Ki = 0.5 and 0.6 nM, respectively.
We next explored the SAR for 2-thio derivatives of the
6-t-butylpyridine C-region (Table 3). Generally, the antagonistic
activities of the 2-thio derivatives were slightly less potent than
those of the corresponding 2-oxy derivatives. Moreover, the
incorporation of a polar group at the terminus of the 2-alkylthio
group (30–32) led to a dramatic reduction in antagonism. For the
cyclohexylthio derivative (34), the two stereoisomers in the
propanamide B-region revealed a marked stereospecific preference
for the S-isomer (34S), consistent with our previous findings.9
The 4-t-butylphenyl C-region surrogates (60, 60S, 60R)
exhibited similar stereospecific antagonism. The 2-benzylthio
derivatives (35–38) exhibited moderate antagonism regardless of
substituent.
butylpyridine C-region (Table 1). The acyclic and cyclic amine
derivatives with 4–6 carbons (1–5) in this study exhibited similar
and potent antagonism with a range of Ki = 0.9–2.5 nM. It was
previously reported that 4-substituted piperidinyl derivatives of
the 6-trifluoromethylpyridine C-region demonstrated excellent
antagonism.14 This was in line with 6-t-butylpyridine surrogates
(6–8), which also proved to be very potent antagonists. In particu-
lar, the 4-ethyl (7) and 4-benzyl piperidinyl (8) derivatives
displayed exceptional antagonism with Ki = 0.1 and 0.3 nM,
respectively.
We also examined the 2-amino derivatives of the 4-t-butylphe-
nyl C-region. They showed similar or less potent antagonism com-
pared to the corresponding 6-t-butylpyridine surrogates. Among
them, 4-methyl (46) and 4-phenyl (47) piperidinyl derivatives dis-
played potent antagonism with Ki = 0.7 and 0.8 nM, respectively.
We next explored the SAR for 2-oxy derivatives of the 6-t-butyl-
pyridine C-region (Table 2). In the straight 2-alkyloxy derivatives
(9–14), the antagonism was enhanced as the number of carbons
in the chain increased up to 4–5 carbons. The butyloxy (12) and
pentyloxy (13) derivatives showed similar and potent antagonism
with a range of Ki = 0.8–0.9 nM. The SAR of branched 2-alkoxy and
2-cycloalkoxy derivatives was also studied. The comparison of
activity between straight and branched alkoxy derivatives
indicated that the branched derivatives exhibited slightly better
antagonism than did the corresponding straight alkoxy derivatives
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S. Lee et al. / Bioorganic & Medicinal Chemistry xxx (2017) xxx–xxx
Table 2
In vitro hTRPV1 antagonistic activities for 2-oxy derivatives.
R
X = N
Ki [CAP] (nM)
14.3
X = CH
Ki [CAP] (nM)
9
*
O
O
10
11
14.8
1.7
*
48
49
4.4
1.4
* O
12
13
0.9
0.8
*
O
50
51
2.2
0.5
* O
* O
14
2.7
15
16
2.3
0.6
* O
* O
52
53
54
2.1
3.8
0.6
*
*
O
O
17
0.8
18
19
20
1.5
55
56
1.8
8.1
* O
* O
* O
2.5
23.9
O
21
5.6
* O
O
22
23
24
4.4
0.8
6.0
57
58
2.9
3.8
* O
* O
* O
v
F
OCH3
Finally, we investigated representative 2-alkyl, 2-cycloalkyl and
aryl derivatives of the 6-t-butylpyridine and 4-t-butylphenyl
C-regions (Table 4). As was the case with other substituents, the
6-t-butylpyridine C-region derivatives displayed more potent
antagonism than did those of the 4-t-butylphenyl C-region. In par-
ticular, the 4-fluorophenyl derivative (41) displayed excellent
antagonism with Ki = 0.3 nM.
and anti-allodynic activity with high potency and efficacy in a neu-
ropathic pain model and proved to be superior to previous leads.11
Thus, we evaluated the in vivo analgesic activities of its t-butylpyr-
idine and phenyl surrogates, 34S and 60S, upon oral administration
in the Bennett mouse model22 (CCI: Chronic Constriction Injury
model) of neuropathic pain (Fig. 2). Compound 60S demonstrated
a dose-dependent antiallodynic effect on cold allodynia with max
83% MPE at 10 mg/kg. The pattern for compound 34S was more
complicated, with it affording greater than 50% MPE at 3 mg/kg
but then yielding decreased antiallodynic activity as the dose
was increased from 3 mg/kg to 10 mg/kg. Analysis of capsaicin-
induced hypothermia by 34S revealed the same pattern (46% and
2.3. Analgesic activity
Previously, we reported that the 2-cyclohexylthio-6-trifluo-
romethylpyridine C-region derivative exhibited dose-dependent
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S. Lee et al. / Bioorganic & Medicinal Chemistry xxx (2017) xxx–xxx
5
Table 3
In vitro hTRPV1 antagonistic activities for 2-thio derivatives.
R
X = N
Ki [CAP] (nM)
3.2
X = CH
Ki [CAP] (nM)
6.7
25
59
*
S
S
26
27
28
3.1
1.5
5.9
*
*
*
S
S
29
30
4.1
*
*
S
S
CF3
51.8
N
N
N
31
32
17.1
112
*
*
S
S
O
33
2.5
8.5
3.4
*
*
*
S
S
S
34
60
7.4
6.0
34S
60S
S
34R
36.4
60R
89.2
*
S
35
36
4.0
3.4
*
*
*
S
S
S
Cl
37
38
3.8
3.5
Cl
*
S
OMe
Table 4
In vitro hTRPV1 antagonistic activities for 2-alkyl/aryl derivatives.
R
X = N
Ki [CAP] (nM)
X = CH
Ki [CAP] (nM)
2.8
39
1.9
61
*
40
41
3.1
0.3
62
9.8
*
*
F
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6
S. Lee et al. / Bioorganic & Medicinal Chemistry xxx (2017) xxx–xxx
2.4. Molecular modeling
100
75
50
25
0
34S
*
To analyse the binding interactions of t-butylpyridine C-region
*
*
60S
antagonists, we performed a flexible docking study of the S-isomer
of compound 7 (7S), the most potent antagonist in this series, with
our hTRPV1 model9 constructed on the basis of our rat TRPV1
model.4 Structurally, compare to the previously reported
GRT123609, 7S has t-butyl and ethyl groups in the C-region pyri-
dine and piperidine rings, repectively.
As shown in Fig. 3, the binding modes of 7S and GRT12360
appeared to be similar. The 4-methylsulfonaminophenyl group in
the A-region occupied the deep bottom hole and was involved in
the hydrophobic interactions with Tyr511, Ile564, and Ile569. The
fluorine atom in the A-region showed a hydrogen bonding interac-
tion with Ser512 and hydrophobic interactions with Val508,
Tyr555, and Tyr565. The amide group in the B-region was able to
form hydrogen bonding with Tyr511 and contributed to the proper
positioning of the C-region. The t-butyl group in the C-region ori-
ented toward the hydrophobic pocket composed of Leu547 and
Thr550, along with Phe587 from the adjacent monomer. Moreover,
the 4-ethylpiperidine ring in the C-region participated in the
hydrophobic interactions with Tyr511, Leu515 and Met514. It
*
*
*
0.001 0.01
0.1
1
10
100
Dose (mg/kg)
Fig. 2. Analgesic activity of compounds 34S, 60S on CCI-induced cold allodynia
(Bennett model) after oral administration in the mouse. Data, n = 10, mean SEM,
*p < 0.05 vs vehicle. MPE, maximal possible effect.
15% MPE at 3 and 10 mg/kg po, respectively, data not shown), sug-
gesting that 34S might be a partial agonist at 10 mg/kg under these
conditions.
Fig. 3. Docking results of 7S and GRT12360 in the hTRPV1 model. (A) 2-D representation of the binding interactions of 7S (left) and GRT12360 (right) in hTRPV1. Hydrogen
bonding interactions are illustrated with in blue dashed line arrows, and hydrophobic interactions are displayed with curved patches. (B) The Fast Connolly surface of hTRPV1
and the van der Waals surface of docked ligands. MOLCAD was used to create the molecular surface of hTRPV1 and the surface is displayed with the lipophilic potential
property. For clarity, the surface of hTRPV1 is Z-clipped and that of ligands are colored in magenta and purple, repectively.
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S. Lee et al. / Bioorganic & Medicinal Chemistry xxx (2017) xxx–xxx
7
was noted that Tyr511 was involved in interactions with all three
of the A, B and C-regions of 7S.
purified by flash column chromatography on silica gel using
EtOAc/hexanes (1:4) as eluant.
4.2.3. Method C
3. Conclusion
A mixture of t-butyl starting material (1.00 mmol) and amine
(or alcohol, thiol) (1.20 mmol) was stirred for 12 h at room temper-
ature. The reaction mixture was extracted with EtOAc (10 mL). The
aqueous phase was saturated with aq. NaCl and extracted again
with EtOAc (15 mL). The combined organic extracts were washed
with 1 N HCl (5 mL) and brine (5 mL), dried over MgSO4, filtered,
and concentrated in vacuo. The residue was purified by flash col-
umn chromatography on silica gel using EtOAc/hexanes (1:10) as
eluant.
The structure activity relationship of 2-substituted 6-t-butyl-
pyridine and 4-t-butylphenyl C-region derivatives of 2-(3-fluoro-
4-methylsulfonamidophenyl)propanamides for antagonism of
hTRPV1 was investigated. The analysis indicated that the pyridine
C-region derivatives generally exhibited a little better antagonism
than did the corresponding phenyl surrogates for most of the ser-
ies. A number of compounds showed excellent antagonism toward
capsaicin activation with subnanomolar potencies. Among them,
the analgesic activity of the two chiral 2-cyclohexylthiopyridine
(34S) and phenyl (60S) analogues were evaluated orally in the
CCI neuropathic mouse model. Compound 60S demonstrated
strong anti-allodynia activity with 83% MPE at 10 mg/kg in the
neuropathic pain model whereas 34S displayed partial agonism
at 10 mg/kg. The docking study of S-isomer of compound 7 (7S),
an exceptionally potent antagonist with Ki = 0.1 nM, in our hTRPV1
homology model indicated that Tyr511 engaged in hydrogen
bonding with the carbonyl of the B-region and a charge-transfer
interaction with the phenyl in the A-region, while the t-butyl and
ethyl groups in the C-region interacted with the hydrophobic pock-
ets of the binding site.
4.2.4. Method D
A mixture of t-butyl starting material (1.00 mmol), alkyl halide
(or alcohol, thiol) (2.00 mmol), K2CO3 (2.00 mmol), and 18-crown-
6 ether (1.50 mmol) in DMF (or CH3CN) was refluxed for 14 h. The
reaction mixture was cooled to ambient temperature and extracted
with EtOAc (10 mL). The aqueous phase was saturated with aq
NaCl and extracted again with EtOAc (15 mL). The combined
organic extracts were washed with 1 N HCl (5 mL) and brine
(5 mL), dried over MgSO4, filtered, and concentrated in vacuo. The
residue was purified by flash column chromatography on silica
gel using EtOAc/hexanes (1:10) as eluant.
4. Experimental
4.2.5. Method E
A mixture of t-butyl starting material (1.00 mmol), Pd(PPh3)4
(0.10 mmol), and 2 M Na2CO3 (7.30 mmol) in toluene was refluxed
for 30 min. After 30 min, to the reaction mixture was added boro-
nic acid (2.00 mmol) in 1,4-dioxane. The reaction mixture was
refluxed for 14 h. The reaction mixture was cooled to ambient tem-
perature and extracted with EtOAc (10 mL). The aqueous phase
was saturated with aq NaCl and extracted again with EtOAc
(15 mL). The combined organic extracts were washed with 1 N
HCl (5 mL) and brine (5 mL), dried over MgSO4, filtered, and
concentrated in vacuo. The residue was purified by flash column
chromatography on silica gel using EtOAc/hexanes (1:30) as
eluant.
4.1. General
All chemical reagents were commercially available. Silica gel
column chromatography was performed on silica gel 60,
230–400 mesh, Merck. Nuclear magnetic resonance (1H NMR and
13C NMR) spectra were recorded on JEOL JNM-LA 300 [300 MHz
(1H), 75 MHz
(
13C)] and Bruker Avance 400 MHz FT-NMR
[400 MHz (1H), 100 MHz (13C)] spectrometers. Chemical shifts are
reported in ppm units with Me4Si as a reference standard. Mass
spectra were recorded on a VG Trio-2 GC–MS and 6460 Triple Quad
LC/MS. All final compounds were purified to >95% purity, as deter-
mined by high-performance liquid chromatography (HPLC). HPLC
was performed on an Agilent 1120 Compact LC (G4288A) instru-
ment using an Agilent Eclipse Plus C18 column (4.6 Â 250 mm,
4.2.6. Method F
A mixture of carboxylic acid compound (1.00 mmol), amine
5
l
m) and a Daicel Chiralcel OD-H column (4.6 Â 250 mm, 5
lm).
(1.00 mmol),
1-(3-dimethylaminopropyl)-3-ethyl-carbodiimide
hydrochloride (1.00 mmol) and 1-hydroxybenzotriazole hydrate
(1.00 mmol) in DMF (5 mL) was stirred for 12 h at room tempera-
ture. The reaction mixture was extracted with EtOAc (10 mL). The
aqueous phase was saturated with aq NaCl and extracted again
with EtOAc (15 mL). The combined organic extracts were washed
with 1 N HCl (5 mL) and brine (5 mL), dried over MgSO4, filtered,
and concentrated in vacuo. The residue was purified by flash
column chromatography on silica gel using EtOAc/hexanes (1:4
to 1:1) as eluant.
4.2. General procedure
4.2.1. Method A
A
mixture of t-butyl starting material (1.00 mmol) and
phenylphosphonic dichloride (1.3 mL) was refluxed for 10 h in a
sealed tube. The reaction mixture was cooled to ambient tempera-
ture and filtered through a silica gel pad. Water (15 mL) was added
to the filtrate, after which the filtrate was extracted with EtOAc
(15 mL Â 2). The combined organic extracts were dried over
MgSO4, filtered, and concentrated in vacuo. The residue was puri-
fied by flash column chromatography on silica gel using EtOAc/
hexanes (1:10) as eluant.
4.2.7. Method G
To a stirred solution of nitrile (1.00 mmol) in anhydrous THF
(10 mL) was added 2 M BH3ÁSMe2 in THF (1.10 mmol) at room tem-
perature. After being refluxed for 16 h, the mixture was cooled to
ambient temperature, 2 N HCl was added dropwise, and the
solution was then refluxed for 30 min. After cooling to ambient
temperature, the mixture was neutralized with 1 N NaOH and
extracted with EtOAc several times. The combined organic layers
were washed with brine, dried over MgSO4, and concentrated in
vacuo. The residue was purified by flash column chromatography
on silica gel using MeOH/CH2Cl2 (1:10) as eluant.
4.2.2. Method B
To a mixture of t-butyl starting material (1.00 mmol) in CH2Cl2
was added triethylamine (3.00 mmol), trifluoromethanesulfonic
anhydride (1.10 mmol) at 0 °C. The reaction mixture was stirred
at 0 °C for 1.5 h. The reaction mixture was extracted with EtOAc
(15 mL Â 2). The combined organic extracts were dried over
MgSO4, filtered, and concentrated in vacuo. The residue was
Please cite this article in press as: Lee S., et al. Bioorg. Med. Chem. (2017), http://dx.doi.org/10.1016/j.bmc.2017.03.004

8
S. Lee et al. / Bioorganic & Medicinal Chemistry xxx (2017) xxx–xxx
4.2.8. Method H
4.40 (m, 2H), 3.50 (q, J = 7.1 Hz, 1H), 3.00 (m, 7H), 1.60 (m, 6H),
1.50 (d, J = 7.1 Hz, 3H), 1.30 (s, 9H), MS (FAB) m/z 491 (MH+).
To a stirred solution of nitrile (1.00 mmol) in anhydrous ether
(10 mL) was added LiAlH4 (2.00 mmol) at 0 °C. After being refluxed
for 12 h, the mixture was cooled to 0 °C, H2O (10 mL) was slowly
added dropwise, followed by 15% aqueous NaOH solution
(10 mL) and H2O (30 mL). After addition, the mixture was allowed
to warm to ambient temperature with stirring for 30 min. The mix-
ture was then filtered over Celite and concentrated in vacuo. The
residue was purified by flash column chromatography on silica
gel using MeOH/CH2Cl2 (1:10) as eluant.
4.3.5. N-((2-(Azepan-1-yl)-6-(tert-butyl)pyridin-3-yl)methyl)-2-
(3-fluoro-4-(methylsulfonamido)phenyl)propanamide (5)
Yield 63%, white solid, 1H NMR (300 MHz, CDCl3) d 7.52 (t,
J = 8.4 Hz, 1H), 7.24 (d, J = 7.7 Hz, 1H), 7.16 (dd, J = 11.3, 2.0 Hz,
1H), 7.08 (d, J = 8.7 Hz, 1H), 6.74 (d, J = 7.7 Hz, 1H), 6.16 (bs, 1H),
4.37 (m, 2H), 3.51 (q, J = 7.1 Hz, 1H), 3.34–3.30 (m, 4H), 3.02 (s,
3H), 1.73 (m, 4H), 1.58–1.49 (m, 4H), 1.51 (d, J = 7.1 Hz, 3H), 1.29
(s, 9H), MS (FAB) m/z 505 (MH+).
4.2.9. Method I
The mixture of nitrile (1.00 mmol) and Pd/C in MeOH/AcOH
(10:3 v/v) was stirred at 40 °C under H2 (1 atm). After stirring,
the mixture was filtered over Celite and concentrated in vacuo.
The residue was purified by flash column chromatography on silica
gel using MeOH/ CH2Cl2 (1:10) as eluant.
4.3.6. N-((6-(tert-Butyl)-2-(4-methylpiperidin-1-yl)pyridin-3-yl)
methyl)-2-(3-fluoro-4-(methylsulfonamido)phenyl)propanamide (6)
Yield 63%, white solid, 1H NMR (300 MHz, CDCl3) d 7.51 (t,
J = 8.2 Hz, 1H), 7.30 (d, J = 7.7 Hz, 1H), 7.19–7.05 (m, 2H), 6.89 (d,
J = 7.7 Hz, 1H), 4.45–4.39 (m, 2H), 3.52 (q, J = 7.0, 1H), 3.25 (m,
2H), 3.02 (s, 3H), 2.78 (m, 2H), 1.71–1.50 (m, 5H), 1.51 (d,
J = 7.1 Hz, 3H), 1.30 (s, 9H), 0.97 (d, J = 6.6 Hz, 3H), MS (FAB) m/z
505 (MH+).
4.2.10. General procedure for amide coupling
A mixture of 2-(3-fluoro-4-(methylsulfonamido)phenyl) propa-
noic acid (1.00 mmol), amine (1.00 mmol), 1-(3-dimethylamino-
propyl)-3-ethyl-carbodiimide hydrochloride (1.50 mmol) and
1-hydroxybenzotriazole hydrate (1.50 mmol) in DMF (5 mL) was
stirred for 12 h at room temperature. The reaction mixture was
extracted with EtOAc (10 mL). The aqueous phase was saturated
with aq NaCl and extracted again with EtOAc (15 mL). The com-
bined organic extracts were washed with 1 N HCl (5 mL) and brine
(5 mL), dried over MgSO4, filtered, and concentrated in vacuo. The
residue was purified by flash column chromatography on silica
gel using EtOAc/hexanes (1:2 to 1:1) as eluant.
4.3.7. N-((6-(tert-Butyl)-2-(4-ethylpiperidin-1-yl)pyridin-3-yl)
methyl)-2-(3-fluoro-4-(methylsulfonamido)phenyl)propanamide (7)
Yield 60%, white solid, 1H NMR (300 MHz, CDCl3) d 7.51 (t,
J = 8.4 Hz, 1H), 7.30 (d, J = 7.9 Hz, 1H), 7.16 (d, J = 11.3 Hz, 1H),
7.09 (d, J = 7.7 Hz, 2H), 6.89 (d, J = 7.7 Hz, 1H), 6.45 (s, 1H), 4.50–
4.36 (m, 2H), 3.51 (q, J = 7,1 Hz, 1H), 3.31–3.23 (m, 2H), 3.01 (s,
3H), 2.83–2.71 (m, 2H), 1.81–1.73 (m, 2H), 1.51 (d, J = 6.9 Hz,
3H), 1.29–1.02 (m, 14H), 0.92 (t, J = 7.1 Hz, 3H), MS (FAB) m/z
519 (MH+).
4.3. Chemical spectra
4.3.8. N-((2-(4-Benzylpiperidin-1-yl)-6-(tert-butyl)pyridin-3-yl)
methyl)-2-(3-fluoro-4-(methylsulfonamido)phenyl)propanamide (8)
Yield 75%, white solid, 1H NMR (300 MHz, CDCl3) d 7.51 (m, 1H),
7.32–7.07 (m, 8H), 6.89 (d, J = 7.7 Hz, 1H), 6.80 (bt, 1H), 6.56 (bs,
1H), 4.41 (m, 2H), 3.50 (q, J = 7.1 Hz, 1H), 3.25 (m, 2H), 3.00 (s,
3H), 2.75 (m, 2H), 2.58 (d, J = 6.6 Hz, 3H), 1.75–1.65 (m, 3H), 1.50
(d, J = 7.1 Hz, 3H), 1.28 (m, 11H), MS (FAB) m/z 581 (MH+).
4.3.1. N-((6-(tert-Butyl)-2-(butyl(methyl)amino)pyridin-3-yl)
methyl)-2-(3-fluoro-4-(methylsulfonamido)phenyl)propanamide (1)
Yield 55%, white solid, 1H NMR (300 MHz, CDCl3) d 7.53 (dd,
J = 8.3, 8.3 Hz, 1H), 7.45 (d, J = 7.9 Hz, 1H), 7.19–7.05 (m, 3H),
6.52 (bs, 1H), 6.13 (bt, 1H), 4.46 (d, J = 5.9 Hz, 2H), 3.50 (q,
J = 7.1 Hz, 1H), 3.12–3.05 (m, 2H), 3.04 (s, 3H), 2.80 (s, 3H),
1.42–1.58 (m, 5H), 1.38–1.20 (m, 11H), 0.90 (t, J = 7.3 Hz, 3H), MS
(FAB) m/z 493 (MH+).
4.3.9. N-((6-(tert-Butyl)-2-methoxypyridin-3-yl)methyl)-2-(3-fluoro-
4-(methylsulfonamido)phenyl)propanamide (9)
4.3.2. N-((6-(tert-Butyl)-2-(dipropylamino)pyridin-3-yl)methyl)-2-
(3-fluoro-4-(methylsulfonamido)phenyl)propanamide (2)
Yield 52%, white solid, 1H NMR (300 MHz, CDCl3) d 7.51 (t,
J = 8.2 Hz, 1H), 7.29 (d, J = 7.7 Hz, 1H), 7.17 (dd, J = 11.3, 1.8 Hz,
1H), 7.08 (d, J = 8.4 Hz, 1H), 6.85 (d, J = 7.7 Hz, 1H), 6.74 (bs, 1H),
6.47 (bt, 1H), 4.47–4.33 (m, 2H), 3.49 (q, J = 7.0 Hz, 1H), 3.07–
2.96 (m, 7H), 1.52–1.34 (m, 7H), 1.29 (s, 9H), 0.82 (t, J = 7.3 Hz,
6H), MS (FAB) m/z 507 (MH+)
Yield 58%, pale yellow solid, 1H NMR (300 MHz, CDCl3) d 7.51
(dd, J = 8.1, 8.1 Hz, 1H), 7.37 (d, J = 7.5 Hz, 1H), 7.15–7.06 (m, 2H),
6.80 (d, J = 7.2 Hz, 1H), 6.01 (bt, 1H), 4.30 (m, 2H), 3.89 (s, 3H),
3.49 (q, J = 6.9 Hz, 1H), 3.02 (s, 3H), 1.48 (d, J = 6.9 Hz, 2H), 1.30
(s, 9H), MS (FAB) m/z 438 (MH+).
4.3.10. N-((6-(tert-Butyl)-2-ethoxypyridin-3-yl)methyl)-2-(3-fluoro-
4-(methylsulfonamido)phenyl)propanamide (10)
Yield 55%, pale yellow solid, 1H NMR (300 MHz, CDCl3) d 7.50
(dd, J = 8.1, 8.1 Hz, 1H), 7.36 (d, J = 7.8 Hz, 1H), 7.17–7.05 (m, 2H),
6.78 (d, J = 7.5 Hz, 1H), 6.54 (bs, 1H), 6.05 (bt, 1H), 4.40–4.28 (m,
4H), 3.48 (q, J = 6.9 Hz, 1H), 3.03 (s, 3H), 1.33 (d, J = 6.9 Hz, 1H),
1.32–1.25 (m, 12H), MS (FAB) m/z 452 (MH+).
4.3.3. N-((6-(tert-Butyl)-2-(pyrrolidin-1-yl)pyridin-3-yl)methyl)-2-
(3-fluoro-4-(methylsulfonamido)phenyl)propanamide (3)
Yield 55%, white solid, 1H NMR (300 MHz, CDCl3) d 7.51 (t,
J = 8.2 Hz, 1H), 7.24 (d, J = 7.7 Hz, 1H), 7.20 (dd, J = 11.0, 2.0 Hz,
1H), 7.08 (d, J = 8.8 Hz, 1H), 6.50 (bs, 1H), 5.90 (bs, 1H), 4.40 (d,
J = 4.6 Hz, 2H), 3.50 (q, J = 7.0 Hz, 1H), 3.39 (m, 4H), 3.02 (s, 3H),
1.83 (m, 4H), 1.50 (d, J = 7.1 Hz, 3H), 1.29 (s, 9H), MS (FAB) m/z
477 (MH+).
4.3.11. N-((6-(tert-Butyl)-2-propoxypyridin-3-yl)methyl)-2-(3-fluoro-
4-(methylsulfonamido)phenyl)propanamide (11)
Yield 48%, white solid, 1H NMR (300 MHz, CDCl3) d 7.50 (dd,
J = 8.4, 8.4 Hz, 1H), 7.37 (d, J = 7.2 Hz, 1H), 7.13 (dd, J = 11.1,
2.0 Hz, 1H), 7.06 (d, J = 8.2 Hz, 1H), 6.79 (d, J = 7.5 Hz, 1H), 6.03
(bt, 1H), 4.40–4.21 (m, 4H), 3.48 (q, J = 7.1 Hz, 1H), 3.02 (s, 3H),
1.78–1.65 (m, 2H), 1.48 (d, J = 7.1 Hz, 3H), 1.29 (s, 9H), 0.98 (t,
J = 7.5 Hz, 3H), MS (FAB) m/z 466 (MH+).
4.3.4. N-((6-(tert-Butyl)-2-(piperidin-1-yl)pyridin-3-yl)methyl)-2-(3-
fluoro-4-(methylsulfonamido)phenyl)propanamide (4)
Yield 43%, white solid, 1H NMR (300 MHz, CDCl3) d 7.51 (t,
J = 8.2 Hz, 1H), 7.30 (d, J = 7.9 Hz, 1H), 7.20 (dd, J = 11.2, 2.0 Hz,
1H), 7.09 (d, J = 8.2 Hz, 1H), 6.90 (m, 1H), 6.89 (d, J = 7.8 Hz, 1H),
Please cite this article in press as: Lee S., et al. Bioorg. Med. Chem. (2017), http://dx.doi.org/10.1016/j.bmc.2017.03.004

S. Lee et al. / Bioorganic & Medicinal Chemistry xxx (2017) xxx–xxx
9
4.3.12. N-((2-Butoxy-6-(tert-butyl)pyridin-3-yl)methyl)-2-(3-fluoro-
4-(methylsulfonamido)phenyl)propanamide (12)
(bs, 1H), 6.28 (bt, 1H), 4.45–4.34 (m, 2H), 4.34–4.20 (m, 2H),
3.57–3.42 (m, 3H), 3.35 (s, 3H), 3.02 (s, 3H), 2.00–1.87 (m, 2H),
1.48 (d, J = 7.1 Hz, 3H), 1.29 (s, 9H), MS (FAB) m/z 496 (MH+).
Yield 77%, white solid, 1H NMR (300 MHz, CDCl3) d 7.50 (dd,
J = 8.4, 8.4 Hz, 1H), 7.36 (d, J = 7.5 Hz, 1H), 7.15–7.05 (m, 2H),
6.79 (d, J = 7.5 Hz, 1H), 6.59 (bs, 1H), 6.06 (bt, 1H), 4.39–4.23 (m,
4H), 3.48 (q, J = 7.3 Hz, 1H), 3.02 (s, 3H), 1.69 (m, 2H), 1.48 (d,
J = 7.1 Hz, 3H), 1.43 (m, 2H), 1.29 (s, 9H), 0.97 (t, J = 7.3 Hz, 3H),
MS (FAB) m/z 480 (MH+).
4.3.20. N-((6-(tert-Butyl)-2-(cyclopentyloxy)pyridin-3-yl)methyl)-2-
(3-fluoro-4-(methylsulfonamido)phenyl)propanamide (20)
Yield 76%, white solid, 1H NMR (300 MHz, CDCl3) d 7.50 (dd,
J = 8.3, 8.3 Hz, 1H), 7.35 (d, J = 7.7 Hz, 1H), 7.14–7.05 (m, 2H),
6.77 (d, J = 7.5 Hz, 1H), 6.59 (bs, 1H), 6.03 (bt, 1H), 5.44 (m, 1H),
4.36–4.21 (m, 1H), 3.48 (q, J = 6.8 Hz, 1H), 3.02 (s, 3H), 1.96 (m,
2H), 1.75–1.60 (m, 6H), 1.48 (d, J = 7.1 Hz, 3H), 1.29 (s, 9H), MS
(FAB) m/z 492 (MH+).
4.3.13. N-((6-(tert-Butyl)-2-(pentyloxy)pyridin-3-yl)methyl)-2-(3-
fluoro-4-(methylsulfonamido)phenyl)propanamide (13)
Yield 54%, white solid, 1H NMR (300 MHz, CDCl3) d 7.47 (dd,
J = 8.1, 8.1 Hz, 1H), 7.33 (d, J = 7.5 Hz, 1H), 7.11 (dd, J = 11.4,
1.8 Hz, 1H), 7.03 (d, J = 8.4 Hz, 1H), 6.76 (d, J = 7.5 Hz, 1H), 6.51
(bs, 1H), 6.03 (bt, 1H), 4.38 (m, 4 H), 3.48 (q, J = 6.9 Hz, 1H), 3.01
(s, 3H), 1.70 (m, 2 H), 1.47 (d, J = 6.9 Hz, 3H), 1.40–1.36 (m, 4H),
1.39 (s, 9H), 0.92 (t, J = 6.9 Hz, 3H), MS (FAB) m/z 494 (MH+).
4.3.21. N-((6-(tert-Butyl)-2-(cyclohexyloxy)pyridin-3-yl)methyl)-2-
(3-fluoro-4-(methylsulfonamido)phenyl)propanamide (21)
Yield 74%, white solid, 1H NMR (300 MHz, CDCl3) d 7.50 (dd,
J = 8.3, 8.3 Hz, 1H), 7.36 (d, J = 7.3 Hz, 1H), 7.14–7.05 (m, 2H),
6.77 (d, J = 7.5 Hz, 1H), 6.70 (bs, 1H), 6.14 (bt, 1H), 5.10 (m, 1H),
4.39–4.23 (m, 2H), 3.49 (q, J = 7.1 Hz, 1H), 3.02 (s, 3H), 1.92 (m,
2H), 1.71 (m, 2H), 1.60–1.25 (m, 6H), 1.48 (d, J = 7.1 Hz, 1H), 1.28
(s, 9H), MS (FAB) m/z 506 (MH+).
4.3.14. N-((6-(tert-Butyl)-2-(hexyloxy)pyridin-3-yl)methyl)-
2-(3-fluoro-4-(methylsulfonamido)phenyl)propanamide (14)
Yield 83%, white solid, 1H NMR (300 MHz, CDCl3) d 7.50 (dd,
J = 8.4, 8.4 Hz, 1H), 7.36 (d, J = 7.5 Hz, 1H), 7.15–7.05 (m, 2H),
6.79 (d, J = 7.5 Hz, 1H), 6.58 (bs, 1H), 6.07 (bt, 1H), 4.39–4.24 (m,
4H), 3.48 (q, J = 7.0 Hz, 1H), 3.02 (s, 3H), 1.71 (m, 2H), 1.48 (d,
J = 7.1 Hz, 3H), 1.45–1.25 (m, 6H), 1.29 (s, 9H), 0.91 (m, 3H), MS
(FAB) m/z 508 (MH+).
4.3.22. N-((2-(Benzyloxy)-6-(tert-butyl)pyridin-3-yl)methyl)-
2-(3-fluoro-4-(methylsulfonamido)phenyl)propanamide (22)
Yield 86%, white solid, 1H NMR (300 MHz, CDCl3) d 7.46–7.30
(m, 7H), 7.06 (dd, J = 11.2, 1.8 Hz, 1H), 6.95 (d, J = 8.4 Hz, 1H),
6.84 (d, J = 7.5 Hz, 1H), 6.53 (bs, 1H), 6.06 (bt, 1H), 5.42 (m, 2H),
4.42–4.26 (m, 2H), 3.38 (q, J = 7.1 Hz, 1H), 2.98 (s, 3H), 1.41 (d,
J = 7.1 Hz, 3H), 1.30 (s, 9H), MS (FAB) m/z 514 (MH+).
4.3.15. N-((6-(tert-Butyl)-2-isopropoxypyridin-3-yl)methyl)-
2-(3-fluoro-4-(methylsulfonamido)phenyl)propanamide (15)
Yield 80%, pale yellow solid, 1H NMR (300 MHz, CDCl3) d 7.51
(dd, J = 8.1, 8.1 Hz, 1H), 7.36 (d, J = 7.8 Hz, 1H), 7.14–7.05 (m, 2H),
6.77 (d, 7.8 Hz, 1H), 6.05 (bt, 1H), 5.33 (m, 1H), 4.28 (m, 2H),
3.48 (q, J = 6.9 Hz, 1H), 3.02 (s, 3H), 1.49 (d, J = 6.9 Hz, 3H), 1.29–
1.25 (m, 15H), MS (FAB) m/z 466 (MH+).
4.3.23. N-((6-(tert-Butyl)-2-((4-fluorobenzyl)oxy)pyridin-3-yl)
methyl)-2-(3-fluoro-4-(methylsulfonamido)phenyl)propanamide (23)
Yield 63%, white solid, 1H NMR (300 MHz, CDCl3) d 7.48–7.35
(m, 4H), 7.09–6.97 (m, 4H), 6.84 (d, J = 7.5 Hz, 1H), 6.58 (bs, 1H),
6.00 (bt, 1H), 5.37 (m, 2H), 4.34 (m, 2H), 3.41 (q, J = 7.1 Hz, 1H),
3.00 (s, 3H), 1.42 (d, J = 7.1 Hz, 3H), 1.30 (s, 9H), MS (FAB) m/z
532 (MH+).
4.3.16. N-((6-(tert-Butyl)-2-isobutoxypyridin-3-yl)methyl)-
2-(3-fluoro-4-(methylsulfonamido)phenyl)propanamide (16)
Yield 25%, white solid, 1H NMR (300 MHz, CDCl3) d d 7.34 (d,
J = 7.5 Hz, 1H), 6.86 (d, J = 7.9 Hz, 1H), 6.74 (m, 3H), 6.00 (bs, 1H),
5.65 (s, 1H), 4.27 (m, 4H), 6.80 (s, 3H), 3.48 (q, J = 7.0 Hz, 1H),
1.68 (m, 2H), 1.51 (m, 6H), 1.29 (s, 9H), 0.93 (d, J = 6.6 Hz, 6H),
MS (FAB) m/z 494 (MH+).
4.3.24. N-((6-(tert-Butyl)-2-((3-methoxybenzyl)oxy)pyridin-3-yl)
methyl)-2-(3-fluoro-4-(methylsulfonamido)phenyl)propanamide (24)
Yield 51%, white solid, 1H NMR (300 MHz, CDCl3) d 7.46–7.29
(m, 3H), 7.09–6.82 (m, 6H), 6.07 (bt, 1H), 5.39 (s, 2H), 4.34 (m,
2H), 3.82 (s, 3H), 3.39 (q, J = 7.1 Hz, 1H), 2.99 (s, 3H), 1.41 (d,
J = 7.1 Hz, 3H), 1.31 (s, 9H), MS (FAB) m/z 544 (MH+).
4.3.17. N-((6-(tert-Butyl)-2-(isopentyloxy)pyridin-3-yl)methyl)-
2-(3-fluoro-4-(methylsulfonamido)phenyl)propanamide (17)
Yield 60%, white solid, 1H NMR (300 MHz, CDCl3) d 7.43 (dd,
J = 8.1, 8.1 Hz, 1H), 7.30 (d, J = 7.5 Hz, 1H), 7.20 (dd, J = 11.4,
1.8 Hz, 1H), 7.09 (d, J = 8.4 Hz, 1H), 6.74 (d, J = 7.5 Hz, 1H), 6.25
(bt, 1H), 4.35–4.24 (m, 4H), 3.49 (q, J = 6.9 Hz, 1H), 2.97 (s, 3H),
1.74 (m, 1H), 1.58 (q, J = 6.9 Hz, 2H), 1.44 (d, J = 6.9 Hz, 2H), 1.25
(s, 9H), 0.89 (d, J = 6.6 Hz, 6H), MS (FAB) m/z 494 (MH+).
4.3.25. N-((6-(tert-Butyl)-2-(butylthio)pyridin-3-yl)methyl)-
2-(3-fluoro-4-(methylsulfonamido)phenyl)propanamide (25)
Yield 64%, white solid, 1H NMR (300 MHz, CDCl3) d 7.50 (t,
J = 8.3 Hz, 1H), 7.32 (d, J = 7.9 Hz, 1H), 7.15 (dd, J = 11.4, 1.8 Hz,
1H), 7.08 (d, J = 8.3 Hz, 1H), 6.94 (d, J = 7.9 Hz, 1H), 6.67 (bs, 1H),
6.00 (bt, 1H), 4.41–4.25 (m, 2H), 3.70 (s, 2H), 3.52 (q, J = 7.0 Hz,
1H), 3.22 (t, J = 7.4 Hz, 2H), 3.02 (s, 2H), 1.72–1.62 (m, 2H), 1.50–
1.47 (m, 12H), 0.94 (t, J = 7.3 Hz, 3H), MS (FAB) m/z 496 (MH+).
4.3.18. N-((6-(tert-Butyl)-2-(2-ethoxyethoxy)pyridin-3-yl)methyl)-
2-(3-fluoro-4-(methylsulfonamido)phenyl)propanamide (18)
Yield 68%, yellow solid, 1H NMR (300 MHz, CDCl3) d 7.48 (dd,
J = 8.4, 8.4 Hz, 1H), 7.40 (d, J = 3.8 Hz, 1H), 6.81 (d, J = 3.8 Hz, 1H),
6.51–6.47 (m, 2H), 4.58–4.25 (m, 4H), 3.76 (t, J = 4.8 Hz, 2H), 3.58
(q, J = 7.1 Hz, 1H), 3.48 (q, J = 7.0 Hz, 1H), 3.01 (s, 3H), 1.46 (d,
J = 7.1 Hz, 3H), 1.29 (s, 9H), 1.22 (t, d = 7.0 Hz, 3H), MS (FAB) m/z
495 (MH+).
4.3.26. N-((6-(tert-Butyl)-2-(pentylthio)pyridin-3-yl)methyl)-
2-(3-fluoro-4-(methylsulfonamido)phenyl)propanamide (26)
Yield 28%, white solid, 1H NMR (300 MHz, CDCl3) d 7.50 (t,
J = 8.2 Hz, 1H), 7.32 (d, J = 7.9 Hz, 1H), 7.15 (dd, J = 11.3, 2.0 Hz,
1H), 7.08 (d, J = 8.2 Hz, 1H), 6.94 (d, J = 7.7 Hz, 1H), 5.95 (bt, 1H),
4.41–4.26 (m, 2H), 3.51 (q, J = 7.0 Hz, 1H), 3.21 (t, J = 7.3 Hz, 2H),
3.02 (s, 3H), 1.74–1.64 (m, 2H), 1.49 (d, J = 7.3 Hz, 3H), 1.44–1.24
(m, 11H), 0.90 (t, J = 7.1 Hz, 3H), MS (FAB) m/z 510 (MH+).
4.3.19. N-((6-(tert-Butyl)-2-(3-methoxypropoxy)pyridin-3-yl)methyl)-
2-(3-fluoro-4-(methylsulfonamido)phenyl)propanamide (19)
Yield 52%, yellow solid, 1H NMR (300 MHz, CDCl3) d 7.49 (dd,
J = 8.2, 8.2 Hz, 1H), 7.38 (d, J = 7.5 Hz, 1H), 7.12 (dd, J = 11.2,
2.0 Hz, 1H), 7.06 (d, J = 8.0 Hz, 1H), 6.79 (d, J = 7.5 Hz, 1H), 6.66
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10
S. Lee et al. / Bioorganic & Medicinal Chemistry xxx (2017) xxx–xxx
4.3.27. N-((6-(tert-Butyl)-2-(hexylthio)pyridin-3-yl)methyl)-2-(3-
fluoro-4-(methylsulfonamido)phenyl)propanamide (27)
4.3.34. N-((6-(tert-Butyl)-2-(cyclohexylthio)pyridin-3-yl)methyl)-2-
(3-fluoro-4-(methylsulfonamido)phenyl)propanamide (34)
Yield 91%, white solid, 1H NMR (300 MHz, CDCl3) d 7.51 (dd,
J = 8.4, 8.2 Hz, 1H), 7.33 (d, J = 7.7 Hz, 1H), 7.15 (dd, J = 11.3,
1.8 Hz, 1H), 7.08 (m, 1H), 6.95 (d, J = 7.9 Hz, 1H), 6.48 (bs, 1H),
5.91 (bt, 1H), 4.33 (m, 2H), 3.51 (q, J = 7.0 Hz, 1H), 3.21 (t,
J = 7.5 Hz, 2H), 3.02 (s, 3H), 1.74–1.25 (m, 10H), 0.89 (t, J = 6.8 Hz,
3H), MS (FAB) m/z 524 (MH+).
Yield 92%, white solid, 1H NMR (300 MHz, CDCl3) d 7.51 (t,
J = 8.2 Hz, 1H), 7.32 (d, J = 7.8 Hz, 1H), 7.14 (d, J = 11.3 Hz, 1H),
7.08 (d, J = 7.8 Hz, 1H), 6.94 (d, J = 7.6 Hz, 1H), 6.43 (bs, 1H), 5.90
(bt, 1H), 4.33–4.14 (m, 2H), 4.17 (m, 1H), 3.50 (q, J = 6.9 Hz, 1H),
3.02 (m, 4H), 1.89 (m, 2H), 1.75 (m, 2H), 1.60 (m, 1H), 1.49 (d,
J = 7.1 Hz, 3H), 1.36–1.24 (m, 14H), MS (FAB) m/z 522 (MH+).
4.3.35. N-((2-(Benzylthio)-6-(tert-butyl)pyridin-3-yl)methyl)-2-(3-
fluoro-4-(methylsulfonamido)phenyl)propanamide (35)
4.3.28. N-((6-(tert-Butyl)-2-(isopentylthio)pyridin-3-yl)methyl)-2-(3-
fluoro-4-(methylsulfonamido)phenyl)propanamide (28)
Yield 40%, white solid, 1H NMR (300 MHz, CDCl3) d 7.47 (t,
J = 8.2 Hz, 1H), 7.38–7.21 (m, 6H), 7.11 (dd, J = 11.4, 2.0 Hz, 1H),
7.05–6.99 (m, 2H), 6.52 (s, 1H), 5.89 (bt, 1H), 4.53 (d, J = 1.8 Hz,
2H), 4.40–4.24 (m, 2H), 3.46 (q, J = 7.1 Hz, 1H), 2.99 (s, 3H), 1.45
(d, J = 7.1 Hz, 3H), 1.34 (s, 9H), MS (FAB) m/z 530 (MH+).
Yield 21%, white solid, 1H NMR (300 MHz, CDCl3) d 7.51 (t,
J = 8.4 Hz, 1H), 7.33 (d, J = 7.9 Hz, 1H), 7.17–7.07 (m, 2H), 6.95 (d,
J = 7.9 Hz, 1H), 6.43 (bs, 1H), 5.90 (bs, 1H), 4.36–4.30 (m, 2H),
3.51 (q, J = 7.3 Hz, 1H), 3.25–3.20 (m, 2H), 3.02 (s, 3H), 1.73–1.71
(m, 1H), 1.49 (d, J = 7.1 Hz, 3H), 1.32 (s, 9H), 0.94 (d, J = 6.6 Hz,
6H), MS (FAB) m/z 510 (MH+).
4.3.36. N-((6-(tert-Butyl)-2-((4-chlorobenzyl)thio)pyridin-3-yl)
methyl)-2-(3-fluoro-4-(methylsulfonamido)phenyl)propanamide (36)
Yield 53%, white solid, 1H NMR (300 MHz, CDCl3) d 7.48 (t,
J = 8.3 Hz, 1H), 7.37 (d, J = 7.8 Hz, 1H), 7.32–7.21 (m, 4H), 7.12
(dd, J = 11.3, 2.0 Hz, 1H), 7.05 (d, J = 8.6 Hz, 1H), 7.01 (d,
J = 7.9 Hz, 1H), 4.49 (s, 1H), 3.47 (q, J = 7.3 Hz, 1H), 3.01 (s, 1H),
1.58 (s, 2H), 1.47 (d, J = 7.1 Hz, 3H), 1.32 (s, 9H), MS (FAB) m/z
564 (M+).
4.3.29. N-((6-(tert-Butyl)-2-((2,2,2-trifluoroethyl)thio)pyridin-3-yl)
methyl)-2-(3-fluoro-4-(methylsulfonamido)phenyl)propanamide (29)
Yield 50%, white solid, 1H NMR (300 MHz, CDCl3) d 7.49 (t,
J = 8.3 Hz, 1H), 7.41 (d, J = 7. 9 Hz, 1H), 7.15–7.04 (m, 3H), 6.59
(bs, 1H), 5.91 (bt, 1H), 4.36 (t, J = 5.7 Hz, 2H), 4.12 (q, J = 9.8 Hz,
2H), 3.52 (q, 1H), 3.01 (s, 3H), 1.49 (d, J = 6.9 Hz, 3H), 1.32 (s,
9H), MS (FAB) m/z 522 (MH+).
4.3.37. N-((6-(tert-Butyl)-2-((2-chlorobenzyl)thio)pyridin-3-yl)
methyl)-2-(3-fluoro-4-(methylsulfonamido)phenyl)propanamide (37)
Yield 60%, white solid, 1H NMR (300 MHz, CDCl3) d 7.46 (t,
J = 8.4 Hz, 1H), 7.36 (d, J = 7.9 Hz, 1H), 7.31–7.25 (m, 2H), 7.11
(dd, J = 11.2, 2.0 Hz, 1H), 7.05–6.98 (m, 2H), 6.91–6.80 (m, 2H),
6.61 (bs, 1H), 5.04 (bt, 1H), 4.48 (d, J = 1.7 Hz, 2H), 4.38–4.23 (m,
2H), 3.45 (q, J = 7.1 Hz, 1H), 2.99 (s, 3H), 1.45 (d, J = 7.1 Hz, 3H),
1.34 (s, 9H), MS (FAB) m/z 564 (MH+).
4.3.30. N-((6-(tert-Butyl)-2-((3-(dimethylamino)propyl)thio)pyridin-
3-yl)methyl)-2-(3-fluoro-4-(methylsulfonamido)phenyl)propanamide
(30)
Yield 20%, white solid, 1H NMR (300 MHz, CDCl3) d 7.51 (t,
J = 8.2 Hz, 1H), 7.35 (d, J = 7.7 Hz, 1H), 7.18–7.08 (m, 2H), 6.99 (d,
J = 7.9 Hz, 1H), 6.60 (bs, 1H), 5.95 (bt, 1H), 4.37–4.31 (m, 2H),
3.54 (q, J = 7.1 Hz, 1H), 3.22 (t, J = 7.1 Hz, 2H), 3.03 (s, 3H), 2.92–
2.86 (m, 2H), 2.57 (s, 6H), 1.50 (d, J = 7.1 Hz, 3H), 1.33 (s, 9H), MS
(FAB) m/z 525 (MH+).
4.3.38. N-((6-(tert-Butyl)-2-((4-methoxybenzyl)thio)pyridin-3-yl)
methyl)-2-(3-fluoro-4-(methylsulfonamido)phenyl)propanamide (38)
Yield 62%, white solid, 1H NMR (300 MHz, CDCl3) d 7.47 (t,
J = 8.4 Hz, 1H), 7.37 (d, J = 7.9 Hz, 1H), 7.31–7.29 (m, 2H), 7.10
(dd, J = 11.3, 2.0 Hz, 1H), 7.05–6.98 (m, 2H), 6.86–6.82 (m, 2H),
6.48 (bs, 1H), 5.88 (bt, 1H), 4.48 (d, J = 1.8 Hz, 2H), 4.39–4.23 (m,
2H), 3.79 (s, 3H), 3.45 (q, J = 7.3 Hz, 1H), 2.99 (s, 3H), 1.45 (d,
J = 7.1 Hz, 3H), 1.35 (s, 9H), MS (FAB) m/z 560 (MH+).
4.3.31. N-((6-(tert-Butyl)-2-((3-(pyrrolidin-1-yl)propyl)thio)pyridin-
3-yl)methyl)-2-(3-fluoro-4-(methylsulfonamido)phenyl)propanamide
(31)
Yield 28%, white solid, 1H NMR (300 MHz, CDCl3) d 7.51 (t,
J = 8.3 Hz, 1H), 7.35 (d, J = 7.9 Hz, 1H), 7.15 (dd, J = 11.3, 1.8 Hz,
1H), 7.09 (d, J = 9.4 Hz, 1H), 6.98 (d, J = 7.9 Hz, 1H), 6.51 (bs, 1H),
5.92 (bt, 1H), 4.42–4.26 (m, 2H), 3.53 (q, J = 7.1 Hz, 1H), 3.30–
3.19 (m, 4H), 3.04 (s, 3H), 2.91–2.82 (m, 2H), 2.73–2.65 (m, 2H),
2.28–2.14 (m, 4H), 1.87–1.85 (m, 2H), 1.49 (d, J = 7.3 Hz, 3H),
1.34 (s, 9H), MS (FAB) m/z 551 (MH+).
4.3.39. N-((6-(tert-Butyl)-2-pentylpyridin-3-yl)methyl)-2-(3-fluoro-
4-(methylsulfonamido)phenyl)propanamide (39)
Yield 37%, white solid, 1H NMR (300 MHz, CDCl3) d 7.51 (dd,
J = 7.8 Hz, 1H), 7.30 (d, J = 8.1 HZ, 1H), 7.17 (m, 1H), 7.08 (m, 1H),
7.02 (d, J = 7.8 H, 1H), 4.39 (m, 2H), 3.50 (q, J = 6.9 Hz, 1H), 3.01
(s, 3H), 2.06 (t, J = 8.25 Hz, 2H), 1.54 (m, 5H), 1.33 (m, 4H), 1.30
(s, 9H), 0.89 (m, 3H), MS (FAB) m/z 478 (MH+).
4.3.32. N-((6-(tert-Butyl)-2-((3-morpholinopropyl)thio)pyridin-3-yl)
methyl)-2-(3-fluoro-4-(methylsulfonamido)phenyl)propanamide (32)
Yield 32%, white solid, 1H NMR (300 MHz, CDCl3) d 7.48 (t,
J = 8.4 Hz, 1H), 7.36 (d, J = 7.5 Hz, 1H), 7.10 (m, 2H), 6.96 (d,
J = 8.1 Hz, 1H), 5.92 (bt, 1H), 4.03 (m, 2H), 3.76 (m, 4H), 3.54 (m,
1H), 3.17 (m, 2H), 3.00 (s, 3H), 2.44 (m, 6H), 1.74 (m, 2H), 1.50
(d, J = 7.1 Hz, 3H), 1.32 (s, 9H), MS (FAB) m/z 567 (MH+).
4.3.40. N-((6-(tert-Butyl)-2-cyclohexylpyridin-3-yl)methyl)-2-(3-
fluoro-4-(methylsulfonamido)phenyl)propanamide (40)
Yield 42%, white solid, 1H NMR (300 MHz, CDCl3) d 7.51 (dd,
J = 7.8 Hz, 1H), 7.30 (d, J = 8.1 HZ, 1H), 7.17 (m, 1H), 7.08 (m, 1H),
7.02 (d, J = 7.8 H, 1H), 4.39 (m, 2H), 3.50 (q, J = 6.9 Hz, 1H), 3.01
(s, 3H), 1.75 (m, 5H), 1.58–1.44(m, 5H), 1.33–1.23 (m, 13H), MS
(FAB) m/z 490 (MH+).
4.3.33. N-((6-(tert-Butyl)-2-(cyclopentylthio)pyridin-3-yl)methyl)-2-
(3-fluoro-4-(methylsulfonamido)phenyl)propanamide (33)
Yield 59%, yellow solid, 1H NMR (300 MHz, CDCl3) d 7.51 (t,
J = 8.2 Hz, 1H), 7.32 (d, J = 7.8 Hz, 1H), 7.14 (d, J = 11.3 Hz, 1H),
7.08 (d, J = 7.8 Hz, 1H), 6.94 (d, J = 7.6 Hz, 1H), 6.43 (s, 1H), 5.90
(bt, 1H), 4.33–4.14 (m, 2H), 4.17 (m, 1H), 3.50 (q, J = 6.9 Hz, 1H),
3.02 (s, 3H), 2.17 (m, 2H), 1.80–1.63 (m, 6H), 1.49 (d, J = 7.1 Hz,
3H), 1.32 (s, 9H), MS (FAB) m/z 508 (MH+).
4.3.41. N-((6-(tert-Butyl)-2-(4-fluorophenyl)pyridin-3-yl)methyl)-2-
(3-fluoro-4-(methylsulfonamido)phenyl)propanamide (41)
Yield 64%, white solid, 1H NMR (300 MHz, CDCl3) d 7.51–7.42
(m, 4H), 7.26 (d, J = 8.0 Hz, 1H), 7.11–6.98 (m, 4H), 6.53 (bs, 1H),
5.48 (bt, 1H), 4.45 (d, J = 5.3 Hz, 2H), 3.43 (q, J = 7.1 Hz, 1H), 3.02
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S. Lee et al. / Bioorganic & Medicinal Chemistry xxx (2017) xxx–xxx
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(s, 3H), 1.44 (d, J = 7.1 Hz, 3H), 1.35 (s, 9H), MS (FAB) m/z 502
4.3.49. N-(2-Butoxy-4-(tert-butyl)benzyl)-2-(3-fluoro-4-
(methylsulfonamido)phenyl)propanamide (49)
(MH+).
Yield 61%, white solid, 1H NMR (300 MHz, CDCl3) d 7.48 (t,
J = 8.2 Hz, 1H), 7.16–7.04 (m, 3H), 6.90 (dd, J = 7.8, 1.8 Hz, 1H),
6.80 (d, J = 1.6 Hz, 1H), 6.59 (bs, 1H), 5.98 (bt, 1H), 4.45–4.29 (m,
2H), 4.01–3.90 (m, 2H), 3.46 (q, J = 7.1 Hz, 1H), 3.01 (s, 3H), 1.75–
1.65 (m, 2H), 1.51–1.39 (m, 5H), 1.30 (s, 9H), 0.97 (t, J = 7.3 Hz,
3H), MS (FAB) m/z 479 (MH+).
4.3.42. N-(4-(tert-Butyl)-2-(butyl(methyl)amino)benzyl)-2-(3-fluoro-
4-(methylsulfonamido)phenyl)propanamide (42)
Yield 15%, white solid, 1H NMR (300 MHz, CDCl3) d 7.51 (t,
J = 8.2 Hz, 1H), 7.29 (s, 1H), 7.12 (m, 2H), 6.47 (m, 2H), 4.52 (m,
2H), 3.52 (d, J = 7.1 Hz, 1H), 3.01 (s, 3H), 2.08 (m, 2H), 2.60 (s,
3H), 1.50 (d, J = 7.1 Hz, 3H), 1.41 (m, 2H), 1.29 (m, 11H), 0.90 (t,
J = 7.2 Hz, 3H), MS (FAB) m/z 492 (MH+).
4.3.50. N-(4-(tert-Butyl)-2-(pentyloxy)benzyl)-2-(3-fluoro-4-
(methylsulfonamido)phenyl)propanamide (50)
Yield 64%, white solid, 1H NMR (300 MHz, CDCl3) d 7.49 (t,
J = 8.2 Hz, 1H), 7.16–7.04 (m, 3H), 6.90 (m, 2H), 6.52 (bs, 1H),
5.99 (bt, 1H), 4.45–4.29 (m, 2H), 4.01–3.89 (m, 2H), 3.46 (q,
J = 7.1 Hz, 1H), 3.01 (s, 3H), 1.77–1.68 (m, 2H), 1.48 (d, J = 7.1 Hz,
3H), 1.46–1.34 (m, 4H), 1.30 (s, 9H), 0.93 (t, J = 7.1 Hz, 3H), MS
(FAB) m/z 493 (MH+).
4.3.43. N-(4-(tert-Butyl)-2-(pyrrolidin-1-yl)benzyl)-2-(3-fluoro-4-
(methylsulfonamido)phenyl)propanamide (43)
Yield 44%, white solid, 1H NMR (300 MHz, CDCl3) d 7.50 (dd,
J = 8.2, 8.2 Hz, 1H), 7.16 (dd, J = 11.2, 1.8 Hz, 1H), 7.08–7.02 (m,
2H), 7.00 (d, J = 1.8 Hz, 1H), 6.93 (dd, J = 8.1, 2.0 Hz, 1H), 6.49 (bs,
1H), 4.45 (m, 2H), 3.49 (q, J = 7.0 Hz, 1H), 3.06 (m, 4H), 3.02 (s,
3H), 1.86–1.81 (m, 4H), 1.49 (d, J = 7.1 Hz, 3H), 1.30 (s, 9H), MS
(FAB) m/z 476 (MH+).
4.3.51. N-(4-(tert-Butyl)-2-(hexyloxy)benzyl)-2-(3-fluoro-4-
(methylsulfonamido)phenyl)propanamide (51)
Yield 70%, white solid, 1H NMR (300 MHz, CDCl3) d 7.16–7.04
(m, 3H), 6.90 (m, 2H), 6.52 (bs, 1H), 5.99 (bt, 1H), 4.45–4.29 (m,
2H), 4.01–3.89 (m, 2H), 3.46 (q, J = 7.1 Hz, 1H), 3.01 (s, 3H), 1.77–
1.68 (m, 2H), 1.48 (d, J = 7.1 Hz, 3H), 1.46–1.25 (m, 6H), 1.30 (s,
9H), 0.93 (t, J = 7.1 Hz, 3H), MS (FAB) m/z 507 (MH+).
4.3.44. N-(4-(tert-Butyl)-2-(piperidin-1-yl)benzyl)-2-(3-fluoro-4-
(methylsulfonamido)phenyl)propanamide (44)
Yield 94%, white solid, 1H NMR (300 MHz, CDCl3) d 7.50 (dd,
J = 8.3, 8.3 Hz, 1H), 7.17 (dd, J = 11.4, 1.8 Hz, 1H), 7.12–7.03 (m,
4H), 7.01 (bt, 1H), 6.49 (bs, 1H), 4.54–4.39 (m, 2H), 3.50 (q,
J = 7.1 Hz, 1H), 3.01 (s, 3H), 2.84–2.75 (m, 4H), 1.64–1.54 (m, 6H),
1.50 (d, J = 7.1 Hz, 3H), 1.29 (s, 9H), MS (FAB) m/z 490 (MH+).
4.3.52. N-(4-(tert-Butyl)-2-isobutoxybenzyl)-2-(3-fluoro-4-
(methylsulfonamido)phenyl)propanamide (52)
Yield 60%, white solid, 1H NMR (300 MHz, CDCl3) d 7.48 (t,
J = 8.4 Hz, 1H), 7.16–7.10 (m, 2H), 7.05 (d, J = 8.0 Hz, 1H), 6.90
(dd, J = 7.6, 1.6 Hz, 1H), 6.84 (d, J = 1.6 Hz, 1H), 6.54 (bs, 1H), 5.94
(bt, 1H), 4.99–4.30 (m, 2H), 3.77–3.68 (m, 2H), 3.45 (q, J = 6.9 Hz,
1H), 3.01 (s, 3H), 2.00 (heptet, J = 6.6 Hz, 1H), 1.47 (d, J = 7.1 Hz,
3H), 1.30 (s, 9H), 0.99 (d, J = 6.6 Hz, 6H), MS (FAB) m/z 479 (MH+).
4.3.45. N-(2-(Azepan-1-yl)-4-(tert-butyl)benzyl)-2-(3-fluoro-4-
(methylsulfonamido)phenyl)propanamide (45)
Yield 48%, white solid, 1H NMR (300 MHz, CDCl3) d 7.50 (dd,
J = 8.2, 8.2 Hz, 1H), 7.32 (s, 1H), 7.23 (s, 2H), 7.14 (dd, J = 11.2,
1.8 Hz, 1H),7.08 (d, J = 8.2 Hz, 1H), 6.52 (bs, 1H), 6.43 (bt, 1H),
4.53 (m, 2H), 3.50 (q, J = 7.0 Hz, 1H), 3.04–3.00 (m, 7H), 1.72–
1.64 (m, 8H), 1.50 (d, J = 7.0 Hz, 3H), 1.29 (s, 9H), MS (FAB) m/z
504 (MH+).
4.3.53. N-(4-(tert-Butyl)-2-(neopentyloxy)benzyl)-2-(3-fluoro-4-
(methylsulfonamido)phenyl)propanamide (53)
Yield 59%, white solid, 1H NMR (300 MHz, CDCl3) d 7.47 (t,
J = 8.2 Hz, 1H), 7.16–7.11 (m, 2H), 7.04 (d, J = 8.2 Hz, 1H), 6.91
(dd, J = 7.7, 1.8 Hz, 1H), 6.84 (d, J = 1.6 Hz, 1H), 6.52 (bs, 1H), 5.90
(bt, 1H), 4.50–4.31 (m, 2H), 3.63–3.57 (m, 2H), 3.44 (q, J = 7.1 Hz,
1H), 3.01 (s, 3H), 1.47 (d, J = 6.9 Hz, 3H), 1.31 (s, 9H), 1.00 (s, 9H),
MS (FAB) m/z 493 (MH+).
4.3.46. N-(4-(tert-Butyl)-2-(4-methylpiperidin-1-yl)benzyl)-2-(3-
fluoro-4-(methylsulfonamido)phenyl)propanamide (46)
Yield 88%, white solid, 1H NMR (300 MHz, CDCl3) d 7.50 (dd,
J = 8.3, 8.3 Hz, 1H), 7.17 (dd, J = 11.2, 1.8 Hz, 1H), 7.13–7.05 (m,
4H), 6.95 (bt, 1H), 6.47 (bs, 1H), 4.54–4.39 (m, 2H), 3.49 (q,
J = 7.1 Hz, 1H), 3.01 (s, 3H), 3.00–2.92 (m, 2H), 2.72–2.60 (m, 2H),
1.79–1.65 (m, 2H), 1.50 (d, J = 7.0 Hz, 3H), 1.29 (s, 9H), 1.26–1.18
(m, 3H), 0.98 (d, J = 6.4 Hz, 3H), MS (FAB) m/z 504 (MH+).
4.3.54. N-(4-(tert-Butyl)-2-(isopentyloxy)benzyl)-2-(3-fluoro-4-
(methylsulfonamido)phenyl)propanamide (54)
Yield 54%, white solid, 1H NMR (300 MHz, CDCl3) d 7.48 (t,
J = 8.4 Hz, 1H), 7.16–7.10 (m, 2H), 7.05 (d, J = 8.0 Hz, 1H), 6.90
(dd, J = 7.6, 1.6 Hz, 1H), 6.84 (d, J = 1.6 Hz, 1H), 6.54 (bs, 1H), 5.94
(bt, 1H), 4.99–4.30 (m, 2H), 3.77–3.68 (m, 2H), 3.45 (q, J = 6.9 Hz,
1H), 3.01 (s, 3H) 1.74 (heptet, J = 6.6 Hz, 1H), 1.58 (q, J = 6.9 Hz,
2H), 1.47 (d, J = 7.1 Hz, 3H), 1.30 (s, 9H), 0.90 (d, J = 6.6 Hz, 6H),
MS (FAB) m/z 493 (MH+).
4.3.47. N-(4-(tert-Butyl)-2-(4-phenylpiperazin-1-yl)benzyl)-2-(3-
fluoro-4-(methylsulfonamido)phenyl)propanamide (47)
Yield 87%, white solid, 1H NMR (300 MHz, CDCl3) d 7.46 (dd,
J = 8.3, 8.3 Hz, 1H), 7.28–7.35 (m, 5H), 7.13 (m, 1H), 7.07 (d,
J = 8.4 Hz, 1H), 6.89–6.99 (m, 3H), 6.32 (bt, 1H), 4.53–4.67 (m,
2H), 3.55 (q, J = 7.1 Hz, 1H), 3.20–3.28 (m, 4H), 3.00–3.08 (m,
4H), 2.94 (s, 3H), 1.49 (d, J = 6.9 Hz, 3H), 1.30 (s, 9H), MS (FAB)
m/z 567 (MH+).
4.3.55. N-(4-(tert-Butyl)-2-(cyclopentyloxy)benzyl)-2-(3-fluoro-4-
(methylsulfonamido)phenyl)propanamide (55)
Yield 60%, white solid, 1H NMR (300 MHz, CDCl3) d 7.49 (t,
J = 8.2 Hz, 1H), 7.16–7.04 (m, 3H), 6.90–6.86 (m, 2H), 6.51 (bs,
1H), 5.94 (bt, 1H), 4.78 (m, 1H), 4.41–4.25 (m, 2H), 3.45 (q,
J = 7.1 Hz, 1H), 3.01 (s, 3H), 1.90–1.61 (m, 8H), 1.47 (d, J = 7.1 Hz,
3H), 1.29 (s, 9H), MS (FAB) m/z 491 (MH+).
4.3.48. N-(4-(tert-Butyl)-2-propoxybenzyl)-2-(3-fluoro-4-
(methylsulfonamido)phenyl)propanamide (48)
Yield 74%, white solid, 1H NMR (300 MHz, CDCl3) d 7.49 (t,
J = 8.2 Hz, 1H), 7.16–7.04 (m, 3H), 6.91 (d, J = 7.7 Hz, 1H), 6.85 (s,
1H), 6.44 (s, 1H), 5.95 (bt, 1H), 4.41–4.35 (m, 2H), 3.92 (t,
J = 4.0 Hz, 2H), 3.46 (q, J = 7.5 Hz, 1H), 3.01 (s, 3H), 1.77–1.70 (m,
2H), 1.48 (d, J = 6.9 Hz, 3H), 1.30 (s, 9H), 1.00 (t, J = 7.3 Hz, 3H),
MS (FAB) m/z 465 (MH+).
4.3.56. N-(4-(tert-Butyl)-2-(cyclohexyloxy)benzyl)-2-(3-fluoro-4-
(methylsulfonamido)phenyl)propanamide (56)
Yield 63%, white solid, 1H NMR (300 MHz, CDCl3) d 7.50 (t,
J = 8.4 Hz, 1 h), 7.17–6.86 (m, 5H), 6.44 (bs, 1H), 6.01 (bt, 1 h),
Please cite this article in press as: Lee S., et al. Bioorg. Med. Chem. (2017), http://dx.doi.org/10.1016/j.bmc.2017.03.004

12
S. Lee et al. / Bioorganic & Medicinal Chemistry xxx (2017) xxx–xxx
4.45–4.30 (m, 3H), 3.46 (q, J = 6.9 Hz, 1H), 3.01 (s, 3H), 1.86 (m, 2H),
1.71 (m, 2H), 1.60–1.29 (m, 18H), MS (FAB) m/z 505 (MH+).
Centre, Cambridge, UK), which employees a genetic algorithm
(GA) and allows for full ligand flexibility and partial protein flexi-
bility. The binding site was defined as 8 Å around the capsaicin
docked in the hTRPV1 model. The side chains of the nine residues
(i.e., Tyr511, Ser512, Met514, Leu515, Leu518, Phe543, Leu547,
Thr550, and Asn551) were set to be flexible with ‘crystal mode’
in GOLD. Compound 7S was docked using the GoldScore scoring
function with 30 GA runs, and the other parameters were set as
the default values. All the computation calculations were under-
taken on an IntelÒ XeonTM Quad-core 2.5 GHz workstation with
Linux Cent OS release 5.5.
4.3.57. N-(2-(Benzyloxy)-4-(tert-butyl)benzyl)-2-(3-fluoro-4-
(methylsulfonamido)phenyl)propanamide (57)
Yield 65%, white solid, 1H NMR (300 MHz, CDCl3) d 7.41 (m, 6H),
7.15 (d, J = 7.7 Hz, 1H), 7.07 (d, J = 11.2 Hz, 1H), 6.94 (m, 3H), 6.47
(bs, 1H), 6.00 (bt, 1H), 5.06 (s, 2H), 4.49–4.33 (m, 2H), 3.37 (q,
J = 7.0 Hz, 1H), 2.97 (s, 3H), 1.41 (d, J = 7.1 Hz, 3H), 1.29 (s, 9H),
MS (FAB) m/z 513 (MH+).
4.3.58. N-(4-(tert-Butyl)-2-((4-fluorobenzyl)oxy)benzyl)-2-(3-fluoro-
4-(methylsulfonamido)phenyl)propanamide (58)
4.5. Biological assay
Yield 70%, white solid, 1H NMR (300 MHz, CDCl3) d 7.42 (t,
J = 8.1 Hz, 1H), 7.36–7.21 (m, 4H), 7.12–7.03 (m, 4H), 6.98 (m,
1H), 6.43 (s, 1H), 4.45 (bs, 1H), 3.40 (q, J = 7.1 Hz, 1H), 3.00 (s,
3H), 1.42 (d, J = 7.1 Hz, 3H), 1.29 (s, 9H), MS (FAB) m/z 531 (MH+).
The methods for in vitro and in vivo assays were reported previ-
ously. All animal protocols were approved by the institutional
review committee at Grünenthal Innovations.
4.3.59. N-(4-(tert-Butyl)-2-(butylthio)benzyl)-2-(3-fluoro-4-
(methylsulfonamido)phenyl)propanamide (59)
Acknowledgments
Yield 50%, white solid, 1H NMR (300 MHz, CDCl3) d 7.51 (t,
J = 8.2 Hz, 1H), 7.35 (s, 1H), 7.13 (m, 4H), 6.47 (bs, 1H), 5.90 (bt,
1H), 4.47 (m, 2H), 3.50 (q, J = 7.0 Hz, 1H), 3.02 (s, 3H), 2.87 (t,
J = 7.2 Hz, 2H), 1.58 (m, 2H), 1.49 (d, J = 7.1 Hz, 3H), 1.18 (m, 2H),
1.30 (s, 9H), 0.92 (t, J = 7.2 Hz, 3H), MS (FAB) m/z 495 (MH+).
This research was supported by research grants from Grünen-
thal in Germany, a grant from the National Research Foundation
(NRF) of Korea (NRF-2016M3A9B5939892), a grant from the
National Leading Research Lab (NLRL) program (2011-0028885)
funded by the Ministry of Science, ICT and Future Planning (MSIP)
and the NRF, and in part by the Intramural Research Program of the
National Institutes of Health, Center for Cancer Research, National
Cancer Institute (Project Z1A BC 005270) in the USA.
4.3.60. N-(4-(tert-Butyl)-2-(cyclohexylthio)benzyl)-2-(3-fluoro-4-
(methylsulfonamido)phenyl)propanamide (60)
Yield 85%, white solid, 1H NMR (300 MHz, CDCl3) d 7.51 (dd,
J = 8.3, 8.3 Hz, 1H), 7.43 (s, 1H), 7.21 (m, 2H), 7.14 (dd, J = 11.3,
1.8 Hz, 1H), 7.08 (d, J = 8.4 Hz, 1H), 6.44 (bs, 1H), 5.94 (bt, 1H),
4.50 (m, 2H), 3.49 (q, J = 7.1 Hz, 1H), 3.02 (m, 4H), 1.89 (m, 2H),
1.75 (m, 2H), 1.60 (m, 1H), 1.49 (d, J = 7.1 Hz, 3H), 1.36–1.24 (m,
14H), MS (FAB) m/z 521 (MH+).
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1H), 4.50 (m, 2H), 3.50 (q, J = 6.90 Hz, 1H), 3.01 (s, 3H), 2.65 (m,
1H), 1.82–1.23 (m, 22H), MS (FAB) m/z 489 (MH+)
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4.4. Molecular modeling
The 3D structures of the molecules were generated using
Concord and energy minimized with an MMFF94s force field and
MMFF94 charge until the rms of the Powell gradient was
0.05 kcal molÀ1 AÀ1 in SYBYL-X 2.0 (Tripos Int., St. Louis, MO,
USA). The flexible docking study on our hTRPV1 model9 was
carried out using GOLD v.5.2 (Cambridge Crystallographic Data
Please cite this article in press as: Lee S., et al. Bioorg. Med. Chem. (2017), http://dx.doi.org/10.1016/j.bmc.2017.03.004