Novel 3H-[1,2,3]triazolo[4,5-c]pyridine derivatives as GPR119 agonists: Synthesis and structure-activity/solubility relationships

Article abstract of DOI:10.1016/j.bmc.2017.06.014

We previously reported a novel series of 1H-pyrazolo[3,4-c]pyridine derivatives and the identification of compound 4b as a highly potent GPR119 agonist. However, the advancement of preclinical evaluations of compound 4b is expected to be difficult because of the compound's significantly poor aqueous solubility (0.71?μM at pH6.8). In this article, we describe the further optimization of compound 4b focusing on the improvement of its aqueous solubility. Optimization of the central spacer, left-hand aryl group and right-hand piperidine N-capping group led to the identification of a potent GPR119 agonist, 3H-[1,2,3]triazolo[4,5-c]pyridine derivative 32o, with improved solubility (15.9?μM at pH6.8).

Full text of DOI:10.1016/j.bmc.2017.06.014

Accepted Manuscript
Novel 3H-[1,2,3]triazolo[4,5-c]pyridine derivatives as GPR119 agonists: Syn-
thesis and structure-activity/solubility relationships
Daisuke Matsuda, Yohei Kobashi, Ayako Mikami, Madoka Kawamura,
Fumiyasu Shiozawa, Kenichi Kawabe, Makoto Hamada, Shinichi Nishimoto,
Kayo Kimura, Masako Miyoshi, Noriko Takayama, Hiroyuki Kakinuma,
Norikazu Ohtake
PII:
S0968-0896(17)30574-6
DOI:
http://dx.doi.org/10.1016/j.bmc.2017.06.014
BMC 13797
Reference:
Bioorganic & Medicinal Chemistry
To appear in:
Received Date:
Revised Date:
Accepted Date:
21 March 2017
10 June 2017
12 June 2017
Please cite this article as: Matsuda, D., Kobashi, Y., Mikami, A., Kawamura, M., Shiozawa, F., Kawabe, K., Hamada,
M., Nishimoto, S., Kimura, K., Miyoshi, M., Takayama, N., Kakinuma, H., Ohtake, N., Novel 3H-
[1,2,3]triazolo[4,5-c]pyridine derivatives as GPR119 agonists: Synthesis and structure-activity/solubility
relationships, Bioorganic & Medicinal Chemistry (2017), doi: http://dx.doi.org/10.1016/j.bmc.2017.06.014
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Novel 3H-[1,2,3]triazolo[4,5-c]pyridine derivatives as GPR119 agonists: Synthesis and
structure-activity/solubility relationships
Daisuke Matsuda a,*, Yohei Kobashi a, Ayako Mikami a, Madoka Kawamura a, Fumiyasu Shiozawaa,
a
a
b
c
b
Kenichi Kawabe , Makoto Hamada , Shinichi Nishimoto , Kayo Kimura , Masako Miyoshi ,
Noriko Takayama b, Hiroyuki Kakinuma a, Norikazu Ohtake a
a Chemistry Laboratories, Taisho Pharmaceutical Co., Ltd. ; 1-403 Yoshino-cho, Kita-ku, Saitama
331-9530, Japan.
b Pharmacology Laboratories, Taisho Pharmaceutical Co., Ltd. ; 1-403 Yoshino-cho, Kita-ku,
Saitama 331-9530, Japan.
c Research Support, Taisho Pharmaceutical Co., Ltd.; 1-403 Yoshino-cho, Kita-ku, Saitama
331-9530, Japan.
1. Introduction
Diabetes is a complex metabolic disorder afflicting more than 400 million people worldwide, and
the prevalence is expected to rise to 642 million by 2040.1 Type 2 diabetes mellitus (T2DM) is the
most common form of diabetes characterized by hyperglycemia resulting from impaired insulin
secretion and insulin resistance. Long-term hyperglycemia results in an increased risk of
microvascular and macrovascular complications which can lead to blindness, renal failure, diabetic
foot disorders, heart attacks and strokes. Although multiple oral antidiabetic agents, such as
sulfonylureas, meglitinides, biguanides, thiazolidinediones, α-glucosidase inhibitors and
dipeptidyl-peptidase-4 (DPP-4) inhibitors, have been used for the treatment of T2DM, many patients
fail to achieve the desired level of glycemic control.2,3 Recently, a sodium-dependent glucose
co-transporter 2 (SGLT2) inhibitor has been used clinically; this inhibitor exerts a glucose-lowering
effect without causing hypoglycemia or weight gain. However, a significant need for the
development of new antidiabetic agents with greater safety and efficacy continues to exist.
GPR119 is a G-protein coupled receptor (GPCR) that is predominantly expressed in the pancreatic
β-cells and gastrointestinal L-cells. Oleoyl-lysophosphatidylcholine and oleoylethanolamide (OEA)
have been identified as endogenous agonists for the GPR119 receptor.4,5 The activation of the
GPR119 receptor increases the cellular cAMP levels, leading to glucose-dependent insulin secretion
from pancreatic β-cells.6 In addition, the activation of the GPR119 receptor in the gut results in the
release of incretins, such as glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic
polypeptide (GIP), from enteroendocrine cells.7 GLP-1 and GIP stimulate insulin secretion from

β-cells in
a
glucose-dependent manner and protect β-cells against apoptosis.8,9 This
glucose-dependent dual mechanism of action suggests that GPR119 agonists can improve glycemic
control without inducing hypoglycemia.
To date, multiple small-molecule GPR119 agonists have been investigated by several research
groups,10,11 which has led to the development of some clinical compounds such as APD668,12
GSK1292263,13 and MBX-298214 (Figure 1).
Figure 1. Representative GPR119 receptor agonists.
We previously reported a series of 1H-pyrazolo[3,4-c]pyridine derivatives as a new class of
GPR119 agonists,15 and compound 4b (TP0456330) was found to be a highly potent GPR119
agonist with an EC50 of 4 nM (Figure 1). However, compound 4b had a poor aqueous solubility
(0.71 µM), leading to a low bioavailability in rats. Generally, a poor aqueous solubility does not only
cause low bioavailability, but also produces erratic assay results in in vitro studies (such as hERG
binding assays). In addition, researchers at AstraZeneca reported that the development of compounds
with a poor aqueous solubility (< 10 µM) carries a high risk of not advancing because of potential
toxicity that might not be recognized during preclinical studies.16 Therefore, we defined an aqueous
solubility of more than 10 µM as a goal for further optimization to generate a preclinical candidate.
Herein, we describe the synthesis and optimization of 1H-pyrazolo[3,4-c]pyridine and
3H-[1,2,3]triazolo[4,5-c]pyridine derivatives with improved aqueous solubilities obtained by
reducing lipophilicity and lowering the melting point.17
2. Chemistry
The 1H-pyrazolo[3,4-c]pyridine derivatives 4a-g shown in Tables 1 and 3 were synthesized as
described in our previous paper.15
The synthesis of the indazole derivatives 9, 17a and 17b in Table 1 is shown in Schemes 1 and 2.
For the synthesis of compound 9,
a
commercially available starting material,

4-bromo-2-methylaniline (5), was cyclized with NaNO2 under acidic conditions to form
5-bromo-1H-indazole (6); coupling reaction of with tert-butyl
a
6
4-[(methanesulfonyl)oxy]piperidine-1-carboxylate followed by separation of the mixture of
regioisomers using silica-gel column chromatography then provided 7. Subsequent Suzuki coupling
of 7 with arylboronic acid under microwave irradiation yielded 8. Finally, the removal of the
tert-butoxycarbonyl group (Boc) under acidic conditions followed by treatment with
N,N-diisopropylethylamine (DIPEA) and 2-chloro-5-ethylpyrimidine under heating conditions
yielded the desired product 9.
Scheme
1.
(a)
NaNO2,
AcOH,
H2O,
rt;
(b)
NaH,
tert-butyl
4-[(methanesulfonyl)oxy]piperidine-1-carboxylate, DMF, 90 ˚C; (c) [4-(methanesulfonyl)phenyl]boronic
acid, PdCl2(dppf)·CH2Cl2, Na2CO3, H2O, DMF, microwave, 110 ˚C; (d) (1) HCl, MeOH, 1,4-dioxane, rt;
(2) 2-chloro-5-ethylpyrimidine, DIPEA, DMF, 100 ˚C.
Methyl substituted indazole derivatives 17a and 17b were synthesized from commercially available
aminophenol derivatives 10a and 10b. The amino group was protected by a Boc group using
di-tert-butyl dicarbonate (Boc2O) and the phenol moiety was then trifluoromethanesulfonylated
using triflic anhydride (Tf2O) to yield 12a and 12b, respectively. After the removal of the Boc group
of 12a and 12b under acidic conditions, the resulting aniline was cyclized with NaNO2 to yield
indazole derivatives 14a and 14b; Suzuki coupling with [4-(methanesulfonyl)phenyl]boronic acid
under a condition similar to that of 7 in Scheme 1 was then performed, producing 15a and 15b.
Furthermore, the nitrogen atom of indazole structure was alkylated with tert-butyl
4-[(methanesulfonyl)oxy]piperidine-1-carboxylate to provide 16a and 16b, respectively. Finally, the
removal of the Boc group followed by treatment with 2-chioro-5-ethylpyrimidine yielded the methyl
substituted indazole derivatives 17a and 17b.

Scheme 2. (a) Et3N, Boc2O, MeOH, rt; (b)Tf2O, pyridine, CHCl3, rt; (c) HCl, EtOAc, rt; (d) NaNO2,
AcOH, H2O, rt; (e) [4-(methanesulfonyl)phenyl]boronic acid, PdCl2(dppf)·CH2Cl2, Na2CO3, H2O, DMF,
microwave, 130 ˚C; (f) Cs2CO3, tert-butyl 4-[(methanesulfonyl)oxy]piperidine-1-carboxylate, DMSO, 90
˚C; (g) (1) HCl, MeOH, 1,4-dioxane, rt; (2) 2-chloro-5-ethylpyrimidine, Cs2CO3, DMSO, 120 ˚C.
Scheme 3 shows the synthesis of the benzotriazole derivative 23 (Table 1). An SNAr reaction
between the commercially available 4-bromo-1-fluoro-2-nitrobenzene (18) and tert-butyl
4-aminopiperidine-1-carboxylate in the presence of Cs2CO3 yielded 19. Reduction of the nitro group
of 19 with iron powder and ammonium chloride, followed by the cyclization of the resulting aniline
20 with NaNO2, yielded benzotriazole derivative 21. Finally, Suzuki coupling, the removal of the
Boc group and an N-arylation reaction were performed to yield the desired product 23.
Scheme 3. (a) Cs2CO3, tert-butyl 4-aminopiperidine-1-carboxylate, DMSO, 100 ˚C; (b) Fe, NH4Cl, EtOH,
H2O, 78 ˚C; (c) NaNO2, AcOH, H2O, rt; (d) [4-(methanesulfonyl)phenyl]boronic acid,
PdCl2(dppf)·CH2Cl2, Na2CO3, H2O, DMF, microwave, 100 ˚C; (e) (1) HCl, MeOH, 1,4-dioxane, rt; (2)
2-chloro-5-ethylpyrimidine, DIPEA, IPA, 80 ˚C.

The synthesis of the 3H-[1,2,3]triazolo[4,5-c]pyridine derivatives was performed using
commercially available 2-bromo-5-fluoropyridine (24), as shown in Schemes 4-6. After the
N-oxidation of 24 with urea hydrogen peroxide and trifluoroacetic anhydride (TFAA),18 nitration of
the resulting 25 with fuming nitric acid and concentrated sulfuric acid gave 26. Furthermore,
compounds 27a and 27b were obtained by the SNAr reaction of 26 with the corresponding amine,
and the resulting nitro groups were reduced by Fe to yield 28a and 28b respectively. The cyclization
reaction of 28a and 28b was accomplished in the presence of NaNO2 and trifluoroacetic acid (TFA)
to yield the 3H-[1,2,3]triazolo[4,5-c]pyridine intermediates 29a and 29b, respectively, although the
reaction did not proceed using AcOH instead of TFA, probably because of the lack of nucleophilicity
of the amines.
Scheme 4. (a) H2O2-urea, TFAA, CHCl3, rt; (b) fuming HNO3, H2SO4, 100 ˚C; (c) for 27a, Cs2CO3,
1-(5-ethylpyrimidin-2-yl)piperidin-4-amine,
DMSO,
rt;
for
27b,
Cs2CO3,
isopropyl
4-aminopiperidine-1-carboxylate, DMSO, rt; (d) Fe, AcOH, 100 ˚C; (e) NaNO2, TFA, H2O, rt.
Compounds 30a-c and 32a-o were synthesized as shown in Schemes 5 and 6. Suzuki coupling of
29a with arylboronic acids produced 30a-c. Amide compounds 32a-k were synthesized via the
corresponding carboxylic acid intermediates 31a-k prepared by Suzuki coupling between 29a and
COOH-substituted arylboronic acid derivatives, followed by condensation with ethylamine under a
standard condition (Scheme 5). The preparation of compounds 32l-o was also performed by Suzuki
coupling of 29b with a boronic acid pinacol ester followed by condensation with amines under
conditions similar to those described above (Scheme 6).

Scheme 5. (a) ArB(OH)2, PdCl2(dppf)·CH2Cl2, Na2CO3, H2O, DMF, 100˚C; (b) for 31a,
3-fluoro-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzoic acid, PdCl2(dppf)·CH2Cl2, Na2CO3, H2O,
DMF, 110 ˚C; for 31b-k, ArB(OH)2 or ArBpin, Pd(PPh3)4 , Cs2CO3, H2O, EtOH, microwave, 150-160˚C;
(c) EtNH2, EDCI·HCl, HOBt·H2O, Et3N, DMF, rt.
Scheme 6. (a) 2,5-difluoro-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzoic acid, Pd(PPh3)4
,
Na2CO3, H2O, EtOH, microwave, 160˚C; (b) R7R8NH, EDCI·HCl, HOBt·H2O, Et3N, DMF, rt.
3. Results and Discussion
The synthesized compounds were evaluated for their GPR119 agonist potency using a cAMP assay
in a human GPR119 cell line and their thermodynamic solubility was assessed in pH6.8 phosphate
buffer.
Initially we designed and synthesized compounds bearing various 5-6 fused ring spacers to
investigate the effect of the lipophilicity and methyl substitution of the whole molecules on both the
solubility and potency (Table 1). Compound 9 with an indazole spacer exhibited a potency
comparable to that of 1H-pyrazolo[3,4-c]pyridine 4a, while its thermodynamic solubility was at the

lower limit of quantitation and its ClogP value was higher than that of 4a. In order to evaluate the
effect of substitution in the spacer, 6- or 4-methyl-substituted indazole derivatives 17a and 17b were
prepared. 17a and 17b showed decreased potency by a factor of 5 and 245, respectively, compared
with 9. These results indicated that substitution at these positions of the spacer was unfavorable for
agonist activity. Benzotriazole derivative 23 was found to have not only a tolerable potency (EC50
=
31 nM) but also a lipophilicity lower than that of 9. Unfortunately, the solubility of 23 was
undetectable. Therefore, 3H-[1,2,3]triazolo[4,5-c]pyridine was designed and synthesized with the
aim of achieving a further reduction in the lipophilicity of the spacer,. The resulting derivative 30a
showed a comparable potency (EC50 = 21 nM) and solubility (0.28 µM), along with the lowest
ClogP value (1.73); therefore, we selected the 3H-[1,2,3]triazolo[4,5-c]pyridine spacer for used in a
further optimization study, described below.
Table 1
Structure-activity/solubility relationships of spacers
hGPR119
EC50 (nM)
Solubility
Cpd.
4a
Spacer
ClogPa
2.03
2.86
3.06
3.06
2.28
1.73
(µM)b
13
14
0.26
<0.11
NTc
9
17a
17b
23
70
3423
31
NTc
<0.13
0.28
30a
21
a The ClogP value was calculated using software from Daylight
Chemical Information Systems, Inc.
b Thermodynamic solubility in pH6.8 phosphate buffer.
c Not tested.

Next, we conducted an optimization study of 30a focusing on the substituent (R1) at the 6-position
of the 3H-[1,2,3]triazolo[4,5-c]pyridine spacer (Table 2). 30a was a crystalline compound possessing
a significantly high melting point (269-270 ˚C). We considered that this high melting point was one
of the causes of its poor solubility and hypothesized that it resulted from the strong molecular
interaction associated with its molecular planarity. Ishikawa and Hashimoto reported that a decrease
in the crystal packing energy (melting point) by the disruption of molecular planarity led to an
improvement in solubility.17 Additionally, researchers at AstraZeneca reported the improvement in
aqueous solubility of a series of GPR119 agonists through disruption of crystal packing.19,20
Therefore, in this study, we attempted to improve solubility by lowering the melting point without
loss of potency.
Installation of a fluorine atom into the 2- or 3-position of the 4-(methanesulfonyl)phenyl group of
30a yielded compounds 30b and 30c respectively, which ameliorated the potency by 3-fold and
2-fold compared with 30a21, but these compounds did not improve the aqueous solubility along with
the high melting point. In our previous study, a fluorine substituted ethylcarbamoylphenyl group as
an R1 moiety was shown to enhance potency.15 Therefore, the installment of a 2-fluoro (32a),
2,5-difluoro (32b), or 2,3-difluoro (32c) substituted ethylcarbamoylphenyl group into R1 was
successively examined. Among these three options, compound 32b showed excellent potency (EC50
= 2 nM), while its aqueous solubility was not improved and was almost equal to that of 30a. In this
case, the installation of a fluorine atom into an aryl ring was insufficient to lower the melting point.
Subsequently, the incorporation of a larger substituent than a fluorine atom at the 2-position of the
aryl ring was examined. While neither a 2-methyl (32d) nor a 2-chloro (32e) substitution improved
solubility, a 2-trifluoromethyl (32f) substitution produced a significant lowering of the melting point
(104-106 ˚C) and an improved solubility to a limited degree (1.20 µM). We next investigated
substitution at the 3-position of the aryl ring. Although 3-methyl (32g), 3-chloro (32h) and 3-CF3
(32i) substitution produced little or no improvement in solubility, the melting points of 32g and 32i
were slightly lower than that of 32b. Encouraged by the reduction in the melting points of
compounds 32d-g and 32i, we finally investigated di-substitution of the 4-ethylcarbamoylphenyl
group. Di-substitution of the methyl groups at the 2,6-position (32j) and the 3,5-position (32k) of the
aryl ring resulted in significant reductions in the melting points, compared with the mono-methyl
substitutions (32d and 32g). These results were speculated to be due to the disruption of molecular
planarity. Although 32k showed an improvement in solubility (5.01 µM), the solubility was still
insufficient for advancement to in vivo studies. We concluded that achieving the target solubility (10
µM) through the modification of this chemical class with a 4-ethylpyrimidine side chain was quite
difficult.

Table 2
Structure-activity/solubility relationships of R1 group
hGPR119
Melting point
(oC)
Solubility
Cpd.
30a
30b
30c
32a
32b
32c
32d
32e
32f
R1
ClogPa
1.73
1.95
1.95
2.92
2.70
2.63
2.86
3.24
3.81
2.82
2.66
2.60
3.06
2.98
EC50 (nM)
(µM)b
21
269-270
269-270
229-230
239
0.28
<0.12
<0.15
NTc
7
9
15
2
235-236
224-225
179-180
197-198
104-106
206-207
242-245
219-221
109-113
110-112
0.24
NTc
10
19
13
60
18
18
39
83
27
<0.09
0.24
1.20
1.79
<0.16
0.51
1.86
5.01
32g
32h
32i
32j
32k
a The ClogP value was calculated using software from Daylight Chemical

Information Systems, Inc.
b Thermodynamic solubility in pH6.8 phosphate buffer.
c Not tested.
Next, we focused on compounds possessing an alkyl carbamate moiety instead of
4-ethylpyrimidine as the right-hand N-capping group (R2) as shown in Table 3, since reducing the
number of aromatic rings in a compound is generally believed to have a positive impact on aqueous
solubility.22 In fact, 1H-pyrazolo[3,4-c]pyridine derivative 4c containing isopropyl carbamate
resulted in a slight increase in solubility, along with a reduction in the melting point (189-190 ˚C)
compared with 4a (243-244 ˚C). The replacement of isopropylcarbamate with tert-butylcarbamate
(4d) or isobutylcarbamate (4e) improved the potency, compared with 4c. While compound 4e had a
solubility that was comparable to that of 4c, it was unstable in a human liver microsomal assay,
probably because of the lability of the lipophilic isobutylcarbamate moiety. To prevent metabolism,
fluorine atoms were introduced into the alkyl group of carbamate. Fluorinated tert-butylcarbamate
(4f) was stable in human liver microsomes but had a low solubility (0.28 µM). Finally, we selected
the isopropyl group as an R2 moiety because of its solubility potential and low melting point. The
loss of potency was restored by the installment of a di-fluorine substituted ethylcarbamoylphenyl
group into R1. The resulting compound 4g exhibited a 4-fold improvement in potency (10 nM), as
expected, and a 2-fold improvement in solubility (2.84 µM) compared with 4c. Switching the spacer
to 3H-[1,2,3]triazolo[4,5-c]pyridine (32l) improved the solubility (5.50 µM) because of the lower
lipophilicity. Encouraged by this result, the ethylcarbamoyl moiety was optimized by replacement
with isopropylcarbamoyl (32m), azetidine-1-carbonyl (32n), and pyrrolidine-1-carbonyl (32o) to
evaluate the effects on agonist potency and aqueous solubility. As a result, the isopropylcarbamoyl
derivative 32m was equipotent to the ethylcarbamoyl derivative 32l, while the azetidine-1-carbonyl
derivative 32n was less potent than 32l and 32m. Regarding the solubility, 32m and 32n were lower
than 32l. In contrast, pyrrolidine-1-carbonyl (32o) exhibited a significant improvement in solubility
(15.9 µM) meeting the criteria of > 10 µM and good potency (EC50 = 65 nM). Since the melting
point of 32o was the lowest (147-148 ˚C) among these amide compounds, the relatively bulky
pyrrolidine moiety was thought to disrupt the coplanarity between the amide group and the phenyl
ring. Furthermore, compound 32o was stable in human liver microsomes.

Table 3
Structure-activity/solubility relationships of R1 and R2 group
hGPR119
EC50 (nM)
Melting point
(oC)
Solubility
hMS
(%)c
Cpd.
R1
X
R2
ClogPa
(µM)b
CH
CH
CH
CH
CH
N
i-Pr
t-Bu
42
20
11
23
10
37
33
61
65
2.21
2.60
2.82
2.65
3.18
2.87
3.18
2.40
2.95
189-190
NTd
1.51
NTd
1.18
0.28
2.84
5.50
0.84
2.7
24.1
NTd
79.8
3.9
4c
4d
i-Bu
212-213
204-205
150-151
183
4e
C(CH3)2CHF2
i-Pr
4f
12.4
11.0
NTd
5.4
4g
i-Pr
32l
32m
32n
32o
N
i-Pr
197-198
195-196
147-148
N
i-Pr
N
i-Pr
15.9
9.3
a The ClogP value was calculated using software from Daylight Chemical Information Systems, Inc.
b Thermodynamic solubility in pH6.8 phosphate buffer.
c % Metabolized after 15-min incubation with human liver microsomes (1 mg protein/mL).
d Not tested.
Given the promising solubility and good potency and metabolic stability, we conducted a
pharmacokinetic study of compound 32o (TP0459107) in SD rats. The resulting PK parameters of
32o and 4b are shown in Table 4. Unfortunately, the bioavailability of compound 32o was
comparable to that of 4b. On the other hand, the systemic clearance of compound 32o was higher
than that of 4b. Both compounds exhibited high membrane permeability in the PAMPA. These data
indicated that the increased solubility of compound 32o, compared with 4b, contributed to an

improvement in oral absorption but it was compromised by higher clearance than 4b. To identify
compounds for in vivo efficacy studies, further optimization would be required.
Table 4
Pharmacokinetic parameters in SD rats and permeability of 4b and 32o
IV (3 mg/kg)a
Vdss
PO (10 mg/kg)b
CL
t1/2
(h)
AUC0-
PAMPA
∞
Compound
%F
(mL/h/kg)
(mL/kg)
(ng · h/mL)
1930
(× 10-6 cm/s at pH6.2)
4b15
32o
759
537
0.617
12.6
16.7
112
97
1630
557
0.241
1030
a Dosing vehicle: 20% 2-hydroxypropyl-β-cyclodextrin (4b, 32o)
b Dosing vehicle: 0.5% methylcellulose (MC) (4b), 0.5% MC containing 0.1% Tween80 (32o)
4. Conclusion
In summary, in addition to the 1H-pyrazolo[3,4-c]pyridine derivatives that we previously reported,
a new series of 3H-[1,2,3]triazolo[4,5-c]pyridine derivatives was designed, synthesized and
evaluated for their GPR119 agonist potency and thermodynamic solubility in pH6.8 phosphate buffer.
To improve the aqueous solubility of the new series, we performed an optimization study based on a
strategy of lowering the melting point while simultaneously reducing molecular lipophilicity. While
a substitution into the left-hand aryl ring did not meet the solubility criteria, a reduction in the
number of aromatic rings in the compound and the optimization of the left-hand amide group
resulted in a sufficient improvement in solubility with a reduction in the melting point. The resulting
compound 32o had promising aqueous solubility (15.9 µM) and potency (EC50 = 65 nM). However,
its bioavailability in rats was insufficient for advancement to in vivo efficacy studies.
5. Experimental section
5.1. Human GPR119 agonist activity
GPR119 agonists were evaluated in Flp-In-T-Rex-HEK293 cells overexpressing human GPR119.
The cells were treated with tetracycline for 24 h and plated on to 96-well plates at 5000 cells/well in
assay buffer (D-MEM, 1 mM 3-isobutyl-1-methylxanthine, 0.01% bovine serum albumin), then
incubated with the test compound for 30 min at 37 ˚C. Changes in the cellular cAMP levels were
measured using a cAMP HiRange assay kit (Cisbio), according to the manufacturer’s protocol.
Responses were determined by subtracting the basal cAMP levels from agonist-stimulated cAMP
levels. The EC50 values were determined as the concentration of the test compound required to
achieve 50% of the maximal response. Data were calculated from the dose-response curves using

XLfit software (IDBS).
5.2. Thermodynamic Solubility
An excess amount of each compound was added to pH6.8 phosphate buffer and shaken on a shaker
(model SR-2DS; TAITEC) at 25 °C for 24 hours. The suspensions were centrifuged at 3000 and
11000 rpm for 10min and the resulting supernatant was diluted with 50% aqueous acetonitrile
solution. The concentrations were measured using HPLC. The HPLC analysis was performed using a
Shimadzu HPLC system composed of a LC-20AD, SPD-20A and SIL-20AC. The conditions for
HPLC were as follows: mobile phase, 0.1% phosphoric acid aqueous solution/acetonitrile; flow rate,
0.8 mL/min; column, reversed- phase (Shimpack XR-ODS , 2.2 µm, 3.0 x 75 mm; SHIMADZU) at
40 °C; and detection wavelength, 210 nm.
5.3. Pharmacokinetic evaluation
Pharmacokinetic profile of test article was investigated in fasted male Sprague-Dawley (SD) rats.
After a single intravenous or oral administration of test article, blood was taken from the tail vein at
each sampling time point and centrifuged to prepare plasma. The quantitative analysis of the target
analyte in plasma samples was performed using liquid chromatography-tandem mass spectrometry.
Pharmacokinetic parameters were calculated by a non-compartmental analysis with Phoenix
WinNonlin (pharmacokinetic analysis software).
5.4. Chemistry
All the solvents and reagents were obtained from commercial suppliers and were used without
further purification or were prepared according to published procedures. The melting points were
1
determined using a Yanaco micro-melting point apparatus MP-500D. The H NMR and 13C NMR
spectra were recorded using a JOEL JNM-ECA600, Varian Inova300 or Gemini2000, and all the
chemical shifts were reported in parts per million (ppm) relative to tetramethylsilane (TMS) as an
internal standard. Mass spectra were recorded using a Shimadzu LCMS 2010 EV spectrometer. High
resolution mass spectral data were acquired using a Shimadzu LCMS-IT-TOF equipped with an
ESI/APCI dual ion source.
5.4.1. 1-[1-(5-Ethylpyrimidin-2-yl)piperidin-4-yl]-5-[4-(methanesulfonyl)phenyl]-1H-pyrazolo[3,4-c
]pyridine (4a)
The title compound was synthesized as described in our previous paper.15 Purification of the crude
compound 4a by silica gel column chromatography (EtOAc/hexanes) and the combined fractions
containing 4a were concentrated in vacuo afforded a crystalline solid, which was not recrystallized.
1
Mp 243-244 ˚C (EtOAc/hexanes); H NMR (200 MHz, CDCl3) δ ppm 1.22 (t, J = 7.5 Hz, 3H),

2.14-2.25 (m, 2H), 2.26-2.45 (m, 2H), 2.50 (q, J = 7.5 Hz, 2H), 3.10 (s, 3H), 3.13-3.25 (m, 2H),
4.81-4.93 (m, 1H), 4.93-5.03 (m, 2H), 8.02-8.08 (m, 2H), 8.11-8.14 (m, 2H), 8.20-8.27 (m, 4H), 9.14
(s, 1H); 13C NMR (151 MHz, CDCl3) δ ppm 15.6, 22.8, 31.6, 43.5, 44.7, 58.2, 112.5, 124.9, 127.6,
127.9, 129.1, 133.1, 133.6, 135.4, 139.6, 145.2, 145.6, 157.3, 160.7; HRMS ESI/APCI Dual m/z
calcd for C24H26N6O2S 463.1911 [M+H]+ , found 463.1904.
5.4.2. 1-[1-(5-Ethylpyrimidin-2-yl)piperidin-4-yl]-5-[2-fluoro-4-(methanesulfonyl)phenyl]-1H-pyraz
olo[3,4-c]pyridine (4b)
The title compound was synthesized as described in our previous paper.15 Purification of the crude
compound 4b by silica gel column chromatography (CHCl3/hexanes) and the combined fractions
containing 4b were concentrated in vacuo afforded a crystalline solid, which was not recrystallized.
Mp 229-230 ˚C (CHCl3/hexanes); 1H NMR (600 MHz, CDCl3) δ ppm 1.22 (t, J = 7.6 Hz, 3 H),
2.17-2.23 (m, 2 H), 2.31-2.39 (m, 2 H) 2.50 (q, J = 7.6 Hz, 2 H), 3.11 (s, 3 H), 3.15-3.22 (m, 2 H),
4.85-4.91 (m, 1 H), 4.95-5.01 (m, 2 H), 7.78 (d, J = 8.5 Hz, 1 H), 7.85 (d, J = 8.5 Hz, 1 H), 8.13 (s, 1
H), 8.22 (s, 2 H), 8.24 (s, 1 H), 8.32-8.36 (m, 1 H) 9.15 (s, 1 H); 13C NMR (151 MHz, CDCl3) δ ppm
15.7, 22.8, 31.6, 43.5, 44.6, 58.2, 115.9 (d, J = 27.0 Hz), 116.7 (d, J = 9.0 Hz), 123.4, 125.0, 128.7,
132.6, 133.2 (d, J = 12.5 Hz), 133.3, 133.7, 135.1, 140.8, 141.0 (d, J = 9.2 Hz), 157.3, 159.8 (d, J =
243.3 Hz), 160.7; HRMS ESI/APCI Dual m/z calcd for C24H25FN6O2S 481.1816 [M+H]+ , found
481.1808.
5.4.3. Propan-2-yl 4-{5-[4-(methanesulfonyl)phenyl]-1H-pyrazolo[3,4-c]pyridin-1-yl}piperidine-1-
carboxylate (4c)
The title compound was synthesized as described in our previous paper.15 Purification of the crude
compound 4c by silica gel column chromatography gave a crystalline solid, which was dissolved in
CHCl3. To the solution were added hexanes, and the resulting solution was stirred at room
temperature. The precipitate was collected by filtration to afford 4c.
1
Mp 189-190 ˚C (CHCl3/hexanes); H NMR (300 MHz, CDCl3) δ ppm 1.29 (d, J = 6.4 Hz, 6 H),
2.06-2.19 (m, 2 H), 2.21-2.39 (m, 2 H), 2.98-3.15 (m, 5 H), 4.31-4.48 (m, 2 H), 4.68-4.84 (m, 1 H),
4.90-5.04 (m, 1 H), 8.01-8.09 (m, 2 H), 8.11-8.15 (m, 2 H), 8.21-8.27 (m, 2 H), 9.09-9.13 (m, 1 H);
13C NMR (151 MHz, CDCl3) δ ppm 22.3, 31.7, 43.0, 44.7, 57.3, 69.0, 112.5, 127.6, 128.0, 129.2,
133.3, 133.4, 135.3, 139.7, 145.1, 145.7, 155.1; HRMS ESI/APCI Dual m/z calcd for C22H26N4O4S
443.1748 [M+H]+ , found 443.1735.
5.4.4. tert-Butyl 4-{5-[4-(methanesulfonyl)phenyl]-1H-pyrazolo[3,4-c]pyridin-1-yl}piperidine-1-car
boxylate (4d)
The title compound was synthesized as described in our previous paper.15

1H NMR (300 MHz, CDCl3) δ ppm 1.51 (s, 9 H), 2.06-2.17 (m, 2 H), 2.19-2.37 (m, 2 H), 2.95-3.09
(m, 2 H), 3.11 (s, 3 H), 4.25-4.42 (m, 2 H), 4.66-4.83 (m, 1 H), 8.01-8.08 (m, 2 H), 8.11-8.15 (m, 2
H), 8.21-8.27 (m, 2 H), 9.11 (s, 1 H); 13C NMR (151 MHz, CDCl3) δ ppm 28.5, 31.8, 42.7 (br), 44.7,
57.5, 80.1, 112.5, 127.6, 128.0, 129.1, 133.2, 133.5, 135.3, 139.6, 145.1, 145.7, 154.6; HRMS
ESI/APCI Dual m/z calcd for C23H28N4O4S 457.1904 [M+H]+ , found 457.1903.
5.4.5. 2-Methylpropyl 4-{5-[4-(methanesulfonyl)phenyl]-1H-pyrazolo[3,4-c]pyridin-1-yl}piperidine
-1-carboxylate (4e)
The title compound was synthesized as described in our previous paper.15 Purification of the crude
compound 4e by silica gel column chromatography afforded a crystalline solid, which was dissolved
in CHCl3. To the solution were added hexanes, and the resulting solution was stirred at room
temperature. The precipitate was collected by filtration to afford 4e as a colorless crystalline solid.
1
Mp 212-213 ˚C (CHCl3/hexanes); H NMR (300 MHz, CDCl3) δ ppm 0.97 (d, J = 6.7 Hz, 6 H),
1.88-2.06 (m, 1 H), 2.08-2.20 (m, 2 H), 2.22-2.41 (m, 2 H), 2.99-3.21 (m, 5 H), 3.92 (d, J = 6.5 Hz,
2 H), 4.26-4.52 (m, 2 H), 4.68-4.84 (m, 1 H), 8.02-8.08 (m, 2 H), 8.12-8.15 (m, 2 H), 8.21-8.27 (m, 2
H), 9.11 (t, J = 1.0 Hz, 1 H); 13C NMR (151 MHz, CDCl3) δ ppm 19.2, 28.1, 31.7, 43.1, 44.7, 57.2,
71.9, 112.5, 127.6, 128.0, 129.2, 133.3, 133.4, 135.4, 139.7, 145.1, 145.7, 155.5; HRMS ESI/APCI
Dual m/z calcd for C23H28N4O4S 457.1904 [M+H]+ , found 457.1893.
5.4.6. 1,1-Difluoro-2-methylpropan-2-yl 4-{5-[4-(methanesulfonyl)phenyl]-1H-pyrazolo[3,4-c]pyrid
in-1-yl}piperidine-1-carboxylate (4f)
The title compound was synthesized as described in our previous paper.15 Purification of the crude
compound 4f by silica gel column chromatography (CHCl3/MeOH) and the fractions containing 4f
were concentrated in vacuo afforded a colorless crystalline solid, which was not recrystallized.
Mp 204-205 ˚C (CHCl3/MeOH); 1H NMR (300 MHz, CDCl3) δ ppm 1.51-1.60 (m, 6 H), 2.07-2.19
(m, 2 H), 2.22-2.39 (m, 2 H), 2.98-3.20 (m, 2 H), 3.10 (s, 3 H), 4.17-4.46 (m, 2 H), 4.69-4.82 (m, 1
H), 5.98-6.39 (m, 1 H), 8.02-8.09 (m, 2 H), 8.12-8.16 (m, 2 H), 8.21-8.27 (m, 2 H), 9.11 (s, 1 H); 13
C
NMR (151 MHz, CDCl3) δ ppm 20.1, 31.6, 43.2 (br), 44.7, 57.0, 79.6 (d, J = 23.7 Hz), 112.5, 115.2
(t, J = 247.9 Hz), 127.6, 127.9, 129.1, 133.3, 135.3, 139.6, 145.0, 145.7, 153.4; HRMS ESI/APCI
Dual m/z calcd for C23H26F2N4O4S 493.1716 [M+H]+ , found 493.1707.
5.4.7. Propan-2-yl 4-{5-[4-(ethylcarbamoyl)-2,5-difluorophenyl]-1H-pyrazolo[3,4-c]pyridin-1-yl}pi
peridine-1-carboxylate (4g)
The title compound was synthesized as described in our previous paper.15 Purification of the crude
compound 4g by silica gel column chromatography to afford the crystalline solid, which was
dissolved in 2-propanol under heating and to the mixture were added hexanes. The resulting solution

was stirred and allowed to cool to room temperature. The precipitate was collected by filtration to
afford 4g as a colorless crystalline solid.
1
Mp 150-151 ˚C (2-propanol/hexanes); H NMR (600 MHz, CDCl3) δ ppm 1.24-1.30 (m, 9 H),
2.05-2.18 (m, 2 H), 2.22-2.33 (m, 2 H), 3.05 (br s, 2 H), 3.50-3.57 (m, 2 H), 4.29-4.48 (m, 2 H),
4.70-4.79 (m, 1 H), 4.96 (dt, J = 12.4, 6.2 Hz, 1 H), 6.75-6.85 (m, 1 H), 7.89-8.02 (m, 2 H), 8.12 (s,
1 H), 8.28 (s, 1 H), 9.08 (s, 1 H); 13C NMR (151 MHz, CDCl3) δ ppm 14.8, 22.3, 31.7, 35.1, 43.0,
57.3, 69.0, 116.5 (d, J = 12.1 Hz), 118.0 (d, J = 30.0 Hz), 119.4 (d, J = 28.2 Hz), 121.4 (dd, J = 8.5,
14.5 Hz), 128.8, 132.1 (dd, J = 9.2, 14.8 Hz), 133.3, 133.5, 135.1, 140.7, 155.1, 156.3 (d, J = 246.4
Hz), 156.6 (d, J = 243.8 Hz), 161.9; HRMS ESI/APCI Dual m/z calcd for C24H27F2N5O3 472.2155
[M+H]+ , found 472.2158.
5.4.8. 5-Bromo-1H-indazole (6)
To a solution of 4-bromo-2-methylaniline (10.5g, 56.3 mmol) in acetic acid (300 mL) were added
NaNO2 (3.89 g, 56.3 mmol) and water (10 mL). After stirring at room temperature for 5 h, the
reaction mixture was concentrated in vacuo. The residue was diluted with EtOAc and washed with
saturated aqueous NaHCO3 solution and brine. The organic layer was dried over anhydrous Na2SO4,
filtered, and concentrated in vacuo. The residue was purified by silica gel column chromatography
(0-50% EtOAc in hexanes) and solidified with hexanes to afford 6 as a brown solid (6.81 g, 61%
yield).
1H NMR (200 MHz, CDCl3) δ ppm 7.35-7.43 (m, 1H), 7.45-7.52 (m, 1H), 7.92 (d, J = 2.2 Hz, 1H),
8.03 (d, J = 0.9 Hz, 1H); MS ESI/APCI Dual m/z 195 [M-H]- .
5.4.9. tert-Butyl 4-(5-bromo-1H-indazol-1-yl)piperidine-1-carboxylate (7)
To a solution of 6 (6.81 g, 34.6 mmol) in N,N-dimethylformamide (DMF) (200 mL) was added NaH
(60% in oil, 2.12 g, 53.0 mmol). After the mixture being stirred at room temperature for 10 min,
tert-butyl 4-[(methanesulfonyl)oxy]piperidine-1-carboxylate (14.8 g, 53.0 mmol) was added to the
mixture. After stirring at 90 ˚C for 2 h, the reaction was quenched with water at 0 ˚C and extracted
with EtOAc. The organic layer was dried over anhydrous Na2SO4, filtered, and concentrated in
vacuo. The residue was purified by silica gel column chromatography (20-50% EtOAc in hexanes)
to afford 7 as a pale yellow solid (6.97 g, 53% yield).
1H NMR (600 MHz, CDCl3) δ ppm 1.48 (s, 9H), 1.95-2.03 (m, 2H), 2.15-2.25 (m, 2H), 2.88-3.02 (m,
2H), 4.21-4.38 (m, 2H), 4.48-4.55 (m, 1H), 7.33 (d, J = 8.8 Hz, 1H), 7.44 (dd, J = 8.8, 1.7 Hz, 1H),
7.87 (d, J = 1.7 Hz, 1H), 7.93 (s, 1H).
5.4.10. tert-Butyl 4-{5-[4-(methanesulfonyl)phenyl]-1H-indazol-1-yl}piperidine-1-carboxylate (8)
To
a
solution of
7
(200 mg, 0.526 mmol) in DMF (3.00 mL) were added

[4-(methanesulfonyl)phenyl]boronic acid (128 mg, 0.640 mmol), PdCl2(dppf)·CH2Cl2 (43 mg,
0.0526 mmol) and 2 M Na2CO3 aqueous solution (0.800 mL, 1.60 mmol). The mixture was stirred at
110 ˚C under microwave irradiation for 30 min. The reaction was quenched with water and extracted
with EtOAc. The organic layer was washed with brine, dried over anhydrous Na2SO4, filtered, and
concentrated in vacuo. The residue was purified by silica gel column chromatography (10-80%
EtOAc in hexanes) and solidified with hexanes and Et2O to afford 8 as a colorless solid (136 mg,
57% yield).
1H NMR (200 MHz, CDCl3) δ ppm 1.50 (s, 9H), 1.97-2.13 (m, 2H), 2.15-2.38 (m, 2H), 2.89-3.08 (m,
2H), 3.11 (s, 3H), 4.23-4.43 (m, 2H), 4.51-4.70 (m, 1H), 7.50-7.60 (m, 1H), 7.61-7.68 (m, 1H),
7.76-7.86 (m, 2H), 7.95-8.02 (m, 2H), 8.03-8.07 (m, 1H), 8.09 (s, 1H); MS ESI/APCI Dual m/z 478
[M+Na]+ .
5.4.11. 1-[1-(5-Ethylpyrimidin-2-yl)piperidin-4-yl]-5-[4-(methanesulfonyl)phenyl]-1H-indazole (9)
To a solution of 8 (239 mg, 0.525 mmol) in MeOH (30 mL) was added 4 N HCl in 1,4-dioxane (10
mL) and the mixture was stirred at room temperature for 1 h. The reaction was quenched with 8 M
NaOH aqueous solution and extracted with CHCl3. The organic layer was dried over anhydrous
Na2SO4, filtered, and concentrated in vacuo. The residue was purified by NH silica gel column
chromatography (10-100% EtOAc in hexanes, then 10% MeOH in CHCl3) to afford
5-[4-(methanesulfonyl)phenyl]-1-(piperidin-4-yl)-1H-indazole as a colorless gum (174 mg, 93%
yield).
To a solution of 5-[4-(methanesulfonyl)phenyl]-1-(piperidin-4-yl)-1H-indazole (70 mg, 0.197 mmol)
in DMF (2 mL) were added 2-chloro-5-ethylpyrimidine (43 mg, 0.302 mmol) and
N,N-diisopropylethylamine (78 mg, 0.604 mmol). The mixture was stirred at 100 ˚C overnight.
2-Chloro-5-ethylpyrimidine (43 mg, 0.302 mmol) and N,N-diisopropylethylamine (78 mg, 0.604
mmol) were added to the mixture and stirred at 100 ˚C for 6 h. The reaction was quenched with
water and extracted with EtOAc. The organic layer was washed with brine, dried over anhydrous
Na2SO4, filtered, and concentrated in vacuo. The residue was purified by silica gel column
chromatography (10-50% EtOAc in CHCl3), followed by NH silica gel column chromatography
(50-100% CHCl3 in hexanes) and solidified with hexanes and Et2O to afford 9 as a colorless solid
(63 mg, 69% yield).
1H NMR (600 MHz, CDCl3) δ ppm 1.21 (t, J = 7.6 Hz, 3H), 2.10-2.16 (m, 2H), 2.28-2.36 (m, 2H),
2.49 (q, J = 7.6 Hz, 2H), 3.10 (s, 3H), 3.11-3.17 (m, 2H), 4.71-4.78 (m, 1H), 4.95-4.99 (m, 2H),
7.58-7.61 (m, 1H), 7.63-7.65 (m, 1H), 7.80-7.83 (m, 2H), 7.97 (s, 1H), 8.00-8.03 (m, 2H), 8.07 (s,
1H), 8.20 (s, 2H); 13C NMR (151 MHz, CDCl3) δ ppm 15.7, 22.8, 31.4, 43.6, 44.7, 57.1, 109.8,
120.3, 124.8, 124.9, 125.9, 128.0, 128.1, 132.1, 133.7, 138.7, 147.1, 157.3, 160.7; HRMS ESI/APCI
Dual m/z calcd for C25H27N5O2S 462.1958 [M+H]+ , found 462.1947.

5.4.12. tert-Butyl (4-hydroxy-2,5-dimethylphenyl)carbamate (11a)
To a solution of 4-amino-2,5-dimethylphenol (5.00 g, 36.4 mmol) in MeOH (73 mL) were added
triethylamine (10.2 mL, 72.8 mmol) and di-tert-butyl dicarbonate (8.75 g, 40.1 mmol). After stirring
at room temperature for 13 h, the mixture was concentrated in vacuo. The residue was purified by
silica gel column chromatography (5-30% EtOAc in hexanes) to afford 11a as a purple solid (6.96 g,
80% yield).
1H NMR (300 MHz, CDCl3) δ ppm 1.51 (s, 9H), 2.14 (s, 3H), 2.15 (s, 3H), 5.25 (br s, 1H), 6.02 (br s,
1H), 6.48 (s, 1H), 7.23 (s, 1H); MS ESI/APCI Dual m/z 236 [M-H]- .
5.4.13. 4-[(tert-Butoxycarbonyl)amino]-2,5-dimethylphenyl trifluoromethanesulfonate (12a)
To a solution of 11a (6.95 g, 29.3 mmol) and pyridine (3.55 mL, 44.0 mmol) in CHCl3 (100 mL) was
added trifluoromethanesulfonic anhydride (5.77 mL, 34.3 mmol) while maintaining the temperature
at below 18 ˚C. After stirring at room temperature for 5 min, the reaction was quenched with
ice-cooled water. The organic layer was washed with 2 N HCl aqueous solution and brine, dried over
anhydrous Na2SO4 and filtered. The solvent was removed in vacuo to afford 12a as a brown solid
(10.9 g, quantitative yield).
1H NMR (300 MHz, CDCl3) δ ppm 1.52 (s, 9H), 2.23 (s, 3H), 2.33 (s, 3H), 6.27 (br s, 1H), 7.01
(s,1H), 7.87 (s, 1H); MS ESI/APCI Dual m/z 368 [M-H]- .
5.4.14. 4-Amino-2,5-dimethylphenyl trifluoromethanesulfonate (13a)
To a suspension of 12a (10.8 g, 29.2 mmol) in EtOAc (20 mL) was added 4 N HCl in EtOAc (45
mL) and the mixture was stirred at room temperature for 15 h. The reaction was quenched with
saturated aqueous NaHCO3 solution. The organic layer was washed with brine, dried over anhydrous
Na2SO4 and filtered. The solvent was removed in vacuo to afford 13a as a brown oil (8.05 g,
quantitative yield).
1H NMR (300 MHz, CDCl3) δ ppm 2.13 (s, 3H), 2.26 (s, 3H), 3.65 (br s, 2H), 6.53 (s, 1H), 6.90 (s,
1H); MS ESI/APCI Dual m/z 270 [M+H]+ .
5.4.15. 6-Methyl-1H-indazol-5-yl trifluoromethanesulfonate (14a)
To a solution of 13a (8.05g, 29.9 mmol) in acetic acid (40 mL) were added NaNO2 (2.02 g, 29.2
mmol) in water (6.4 mL) at 4-9 ˚C and the mixture was stirred at room temperature for 20 h. The
reaction was quenched with water and extracted with EtOAc. The organic layer was washed with
brine, dried over anhydrous Na2SO4, filtered, and concentrated in vacuo. The residue was purified by
silica gel column chromatography (5-35% EtOAc in hexanes) to afford 14a as a brown solid (4.02 g,
48% yield).

1H NMR (300 MHz, CDCl3) δ ppm 2.51 (s, 3H), 7.42 (s, 1H), 7.67 (s, 1H), 8.09 (s, 1H); MS
ESI/APCI Dual m/z : 281 [M+H]+ , 279 [M-H]- , 315 [M+Cl]- .
5.4.16. 5-[4-(Methanesulfonyl)phenyl]-6-methyl-1H-indazole (15a)
To
a
solution of 14a (1.50 g, 5.35 mmol) in DMF (30 mL) were added
[4-(methanesulfonyl)phenyl]boronic acid (3.21 g, 16.0 mmol), PdCl2(dppf)·CH2Cl2 (437 mg, 0.535
mmol) and 2 M Na2CO3 aqueous solution (10.7 mL, 21.4 mmol). The mixture was stirred at 130 ˚C
under microwave irradiation for 30 min. The reaction was quenched with water and extracted with
EtOAc. The organic layer was washed with brine, dried over anhydrous Na2SO4, filtered, and
concentrated in vacuo. The residue was purified by silica gel column chromatography (5-50%
EtOAc in hexanes) to afford 15a as a pale yellow solid (1.16 g, 76% yield).
1H NMR (300 MHz, CDCl3) δ ppm 2.36 (s, 3H), 3.14 (s, 3H), 7.43 (d, J = 0.8 Hz, 1H), 7.53-7.61 (m,
3H), 7.98-8.04 (m, 2H), 8.05-8.11 (m, 1H); MS ESI/APCI Dual m/z : 287 [M+H]+ , 309 [M+Na]+ ,
285 [M-H]- .
5.4.17. tert-Butyl
4-{5-[4-(methanesulfonyl)phenyl]-6-methyl-1H-indazol-1-yl}piperidine-1-carboxylate (16a)
To a solution of 15a (300 mg, 1.05 mmol) in dimethyl sulfoxide (DMSO) (4.0 mL) were added
tert-butyl 4-[(methanesulfonyl)oxy]piperidine-1-carboxylate (579 mg, 2.07 mmol) and Cs2CO3 (1.02
g, 3.13 mmol). The mixture was stirred at 90 ˚C for 1.5 h. The reaction was quenched with water and
extracted with EtOAc. The organic layer was washed with water, dried over anhydrous Na2SO4,
filtered, and concentrated in vacuo. The residue was purified by NH silica gel column
chromatography (10-50% EtOAc in hexanes) to afford 16a as a pale yellow solid (204 mg, 41%
yield).
1H NMR (300 MHz, CDCl3) δ ppm 1.50 (s, 9H), 1.99-2.11 (m, 2H), 2.16-2.34 (m, 2H), 2.38 (s, 3H),
2.91-3.07 (m, 2H), 3.14 (s, 3H), 4.25-4.43 (m, 2H), 4.51-4.64 (m, 1H), 7.36 (s, 1H), 7.52-7.59 (m,
3H), 7.97-8.04 (m, 3H); MS ESI/APCI Dual m/z : 470 [M+H]+ , 492 [M+Na]+ , 504 [M+Cl]- .
5.4.18. 1-[1-(5-Ethylpyrimidin-2-yl)piperidin-4-yl]-5-[4-(methanesulfonyl)phenyl]-6-methyl-1H-ind
azole (17a)
To a suspension of 16a (200 mg, 0.426 mmol) in MeOH (0.85 mL) was added 4 N HCl in
1,4-dioxane (2.1 mL) and the mixture was stirred at room temperature for 13 h. The reaction was
concentrated
in
vacuo
to
afford
5-[4-(methanesulfonyl)phenyl]-6-methyl-1-(piperidin-4-yl)-1H-indazole hydrochloride as a pale
yellow solid (176 mg, quantitative yield).
To
a
suspension of 5-[4-(methanesulfonyl)phenyl]-6-methyl-1-(piperidin-4-yl)-1H-indazole

hydrochloride (82 mg, 0.202 mmol) in DMSO (2.0 mL) were added 2-chloro-5-ethylpyrimidine (43
mg, 0.302 mmol) and Cs2CO3 (329 mg, 1.01 mmol). The mixture was stirred at 120 ˚C for 4 h. The
reaction was quenched with water and extracted with EtOAc. The organic layer was washed with
water, dried over anhydrous Na2SO4, filtered, and concentrated in vacuo. The residue was purified
by silica gel column chromatography (5-50% EtOAc in hexanes) and recrystallized with MeOH to
afford 17a as a colorless solid (29 mg, 30% yield).
1H NMR (300 MHz, CDCl3) δ ppm 1.22 (t, J = 7.6 Hz, 3H), 2.07-2.19 (m, 2H), 2.24-2.36 (m, 2H),
2.38 (s, 3H), 2.49 (q, J = 7.6 Hz, 2H), 3.08-3.22 (m, 5H), 4.63-4.78 (m, 1H), 4.90-5.02 (m, 2H), 7.40
(s, 1H), 7.51-7.59 (m, 3H), 7.94-8.04 (m, 3H), 8.21 (s, 2H); 13C NMR (151 MHz, CDCl3) δ ppm
15.7, 16.6, 22.8, 31.4, 43.6, 44.7, 57.0, 106.9, 124.7, 125.4, 127.3, 128.4, 128.7, 130.9, 131.6, 132.5,
138.2, 138.7, 147.6, 157.2, 160.7; HRMS ESI/APCI Dual m/z calcd for C26H29N5O2S 476.2115
[M+H]+ , found 476.2111.
5.4.19. tert-Butyl (4-hydroxy-2,3-dimethylphenyl)carbamate (11b)
The title compound was synthesized according to the procedure described for compound 11a from
4-amino-2,3-dimethylphenol (84%yield).
1H NMR (300 MHz, CDCl3) δ ppm 1.51 (s, 9H), 2.13 (s, 3H), 2.15 (s, 3H), 5.23 (br s, 1H), 6.05 (br s,
1H), 6.52 (d, J = 8.5 Hz, 1H), 7.07 (d, J = 8.5 Hz, 1H); MS ESI/APCI Dual m/z 236 [M-H]- .
5.4.20. 4-[(tert-Butoxycarbonyl)amino]-2,3-dimethylphenyl trifluoromethanesulfonate (12b)
The title compound was synthesized according to the procedure described for compound 12a from
11b (99%yield).
1H NMR (300 MHz, CDCl3) δ ppm 1.52 (s, 9H), 2.20 (s, 3H), 2.30 (s, 3H), 6.28 (br s, 1H), 7.09 (d, J
= 9.0 Hz, 1H), 7.68 (d, J = 9.0 Hz, 1H); MS ESI/APCI Dual m/z 368 [M-H]- .
5.4.21. 4-Amino-2,3-dimethylphenyl trifluoromethanesulfonate (13b)
The title compound was synthesized according to the procedure described for compound 13a from
12b (quantitative yield).
1H NMR (300 MHz, CDCl3) δ ppm 2.10 (s, 3H), 2.26 (s, 3H), 3.68 (br s, 2H), 6.54 (d, J = 8.7 Hz,
1H), 6.92 (d, J = 8.7 Hz, 1H); MS ESI/APCI Dual m/z 270 [M+H]+ .
5.4.22. 4-Methyl-1H-indazol-5-yl trifluoromethanesulfonate (14b)
The title compound was synthesized according to the procedure described for compound 14a from
13b (64%yield).
1H NMR (300 MHz, CDCl3) δ ppm 2.65 (s, 3H), 7.24-7.31 (m, 1H), 7.35-7.42 (m, 1H), 8.17 (s,
1H;MS ESI/APCI Dual m/z : 281 [M+H]+ , 279 [M-H]- , 315 [M+Cl]- .

5.4.23. 5-[4-(Methanesulfonyl)phenyl]-4-methyl-1H-indazole (15b)
The title compound was synthesized according to the procedure described for compound 15a from
14b (72%yield).
1H NMR (300 MHz, CDCl3) δ ppm 2.56 (s, 3H), 3.14 (s, 3H), 7.24-7.33 (m, 1H), 7.39-7.46 (m, 1H),
7.54-7.62 (m, 2H), 7.98-8.05 (m, 2H), 8.19 (s, 1H); MS ESI/APCI Dual m/z : 287 [M+H]+ , 309
[M+Na]+ , 285 [M-H]- .
5.4.24. tert-Butyl
4-{5-[4-(methanesulfonyl)phenyl]-4-methyl-1H-indazol-1-yl}piperidine-1-carboxylate (16b)
The title compound was synthesized according to the procedure described for compound 16a from
15b (68%yield).
1H NMR (300 MHz, CDCl3) δ ppm 1.50 (s, 9H), 1.99-2.10 (m, 2H), 2.18-2.35 (m, 2H), 2.53 (s, 3H),
2.90-3.07 (m, 2H), 3.13 (s, 3H), 4.25-4.42 (m, 2H), 4.52-4.65 (m, 1H), 7.24-7.30 (m, 1H), 7.34-7.40
(m, 1H), 7.53-7.60 (m, 2H), 7.98-8.04 (m, 2H), 8.09 (s, 1H); MS ESI/APCI Dual m/z : 470 [M+H]+ ,
492 [M+Na]+ , 504 [M+Cl]- .
5.4.25. 1-[1-(5-Ethylpyrimidin-2-yl)piperidin-4-yl]-5-[4-(methanesulfonyl)phenyl]-4-methyl-1H-ind
azole (17b)
The title compound was synthesized according to the procedure described for compound 17a from
16b (38%yield).
1H NMR (300 MHz, CDCl3) δ ppm 1.22 (t, J = 7.6 Hz, 3H), 2.07-2.18 (m, 2H), 2.24-2.41 (m, 2H),
2.44-2.56 (m, 5H), 3.07-3.21 (m, 5H), 4.65-4.79 (m, 1H), 4.91-5.02 (m, 2H), 7.23-7.30 (m, 1H),
7.37-7.44 (m, 1H), 7.53-7.60 (m, 2H), 7.98-8.04 (m, 2H), 8.08 (s, 1H), 8.21 (s, 2H); 13C NMR (151
MHz, CDCl3) δ ppm 15.7, 21.8, 22.8, 31.4, 43.7, 44.7, 56.9, 110.0, 121.9, 122.8, 124.8, 127.3, 130.6,
133.1, 133.9, 134.0, 138.8, 138.9, 148.1, 157.3, 160.8; HRMS ESI/APCI Dual m/z calcd for
C26H29N5O2S 476.2115 [M+H]+ , found 476.2100.
5.4.26. tert-Butyl 4-(4-bromo-2-nitroanilino)piperidine-1-carboxylate (19)
To a solution of 4-bromo-1-fluoro-2-nitrobenzene (25.0 g, 114 mmol) in DMSO (114 mL) were
added tert-butyl 4-aminopiperidine-1-carboxylate (20.7 g, 103 mmol) and Cs2CO3 (37.1 g, 114
mmol). The mixture was stirred at 100 ˚C for 1 h. The reaction was diluted with water and extracted
with ethyl acetate. The organic layer was washed with brine, dried over anhydrous Na2SO4, filtered,
and concentrated in vacuo. The residue was recrystallized with hexanes and EtOAc to afford orange
solid. The filtrate was evaporated to dryness and recrystallized with hexanes and EtOAc to afford
orange solid. The resulting solids were combined to afford 19 as an orange solid (40.5 g, 98% yield).

1H NMR (200 MHz, CDCl3) δ ppm 1.48 (s, 9H), 1.43-1.69 (m, 2H), 1.96-2.13 (m, 2H), 2.94-3.15 (m,
2H), 3.54-3.76 (m, 1H), 3.93-4.12 (m, 2H), 6.79 (d, J = 9.2 Hz, 1H), 7.49 (dd, J = 9.2, 2.4 Hz, 1H),
8.00-8.13 (m, 1H), 8.32 (d, J = 2.4 Hz, 1H); MS ESI/APCI Dual m/z 422 [M+Na]+ , 398 [M-H]- .
5.4.27. tert-Butyl 4-(2-amino-4-bromoanilino)piperidine-1-carboxylate (20)
To a suspension of 19 (40.5 g, 101 mmol) in EtOH (337 mL) were added Fe powder (28.2g, 505
mmol) and NH4Cl (540 mg, 10.1 mmol) in water (101 mL). After stirring at 78 ˚C for 5 h, the
reaction was filtered and concentrated in vacuo. The residue was diluted with brine and extracted
with CHCl3. The organic layer was dried over anhydrous Na2SO4, filtered, and concentrated in vacuo
to afford 20 as a brown gum (37.4 g, quantitative yield).
1H NMR (200 MHz, CDCl3) δ ppm 1.24-1.51 (m, 2H), 1.47 (s, 9H), 1.91-2.09 (m, 2H), 2.84-3.03 (m,
2H), 3.24-3.45 (m, 1H), 3.94-4.12 (m, 2H), 6.52 (d, J = 8.4 Hz, 1H), 6.81-6.92 (m, 2H); MS
ESI/APCI Dual m/z : 392 [M+Na]+ , 404 [M+Cl]- .
5.4.28. tert-Butyl 4-(5-bromo-1H-benzotriazol-1-yl)piperidine-1-carboxylate (21)
To a solution of 20 (37.4g, 101 mmol) in acetic acid (337 mL) was added NaNO2 (10.5 g, 152
mmol) in water (33.7 mL) under ice cooling and the mixture was stirred at room temperature for 1 h.
The reaction mixture was diluted with water and stirred at room temperature for 1 h. The resulting
precipitate was filtered and washed with water and hexanes. The solid was dissolved in CHCl3 and
washed with brine. The organic layer was separated and concentrated in vacuo. The residue was
purified by NH silica gel column chromatography (CHCl3) and recrystallized with hexanes and
EtOAc to afford 21 as a brown solid (29.3 g, 76% yield).
1H NMR (200 MHz, CDCl3) δ ppm 1.50 (s, 9H), 2.08-2.46 (m, 4H), 2.92-3.14 (m, 2H), 4.24-4.44 (m,
2H), 4.71-4.90 (m, 1H), 7.45 (d, J = 8.8 Hz, 1H), 7.58 (dd, J = 8.8, 1.8 Hz, 1H), 8.24 (d, J = 1.8 Hz,
1H); MS ESI/APCI Dual m/z 381 [M+H]+ , 403 [M+Na]+ , 415 [M+Cl]- .
5.4.29. tert-Butyl 4-{5-[4-(methanesulfonyl)phenyl]-1H-benzotriazol-1-yl}piperidine-1-carboxylate
(22)
The title compound was synthesized according to the procedure described for compound 8 from 21
(25%yield).
1H NMR (200 MHz, CDCl3) δ ppm 1.52 (s, 9H), 2.15-2.27 (m, 2H), 2.29-2.47 (m, 2H), 2.98-3.15 (m,
2H), 3.12 (s, 3H), 4.29-4.43 (m, 2H), 4.82-4.96 (m, 1H), 7.68 (dd, J = 8.6, 0.8 Hz, 1H), 7.75 (dd, J =
8.6, 1.6 Hz, 1H), 7.81-7.87 (m, 2H), 8.04-8.09 (m, 2H), 8.29-8.31 (m, 1H); MS ESI/APCI Dual m/z
457 [M+H]+ , 479 [M+Na]+ , 491 [M+Cl]- .
5.4.30. 1-[1-(5-Ethylpyrimidin-2-yl)piperidin-4-yl]-5-[4-(methanesulfonyl)phenyl]-1H-benzotriazole

(23)
To a solution of 22 (694 mg, 1.52 mmol) in MeOH (5.07 mL) was added 4 N HCl in 1,4-dioxane
(15.2 mL). After stirring at room temperature for 3 h, the reaction was concentrated in vacuo. The
resulting
solid
was
washed
with
EtOAc
to
afford
5-[4-(methanesulfonyl)phenyl]-1-(piperidin-4-yl)-1H-benzotriazole hydrochloride as a pale pink
powder (612 mg, quantitative yield).
To
a
suspension
of
5-[4-(methanesulfonyl)phenyl]-1-(piperidin-4-yl)-1H-benzotriazole
hydrochloride (200 mg, 0.509 mmol) in 2-propanol (IPA) (5.09 mL) were added
2-chloro-5-ethylpyrimidine (145 mg, 1.02 mmol) and N,N-diisopropylethylamine (526 mg, 4.07
mmol). The mixture was stirred at 80 ˚C for 90 h. The reaction was quenched with water and
extracted with CHCl3. The organic layer was dried over anhydrous Na2SO4, filtered, and
concentrated in vacuo. The residue was purified by silica gel column chromatography (67% EtOAc
in hexanes) and recrystallized with hexanes and EtOAc to afford 23 as a colorless solid (74 mg, 31%
yield).
1H NMR (200 MHz, CDCl3) δ ppm 1.23 (t, J = 7.7 Hz, 3H), 2.20-2.60 (m, 6H), 3.12 (s, 3H),
3.12-3.30 (m, 2H), 4.90-5.12 (m, 3H), 7.65-7.79 (m, 2H), 7.80-7.89 (m, 2H), 8.01-8.11 (m, 2H), 8.24
(s, 2H), 8.29 (s, 1H); 13C NMR (151 MHz, CDCl3) δ ppm 15.6, 22.7, 31.4, 43.3, 44.7, 58.0, 110.4,
118.9, 125.1, 127.0, 128.2, 128.4, 132.3, 135.6, 139.5, 146.1, 146.9, 157.3, 160.5; HRMS ESI/APCI
Dual m/z calcd for C24H26N6O2S 463.1911 [M+H]+ , found 463.1904.
5.4.31. 2-Bromo-5-fluoropyridine 1-oxide (25)
To a solution of 2-bromo-5-fluoropyridine (2.00 g, 11.4 mmol) in CHCl3 (22.7 mL) were added
urea hydrogen peroxide (2.14 g, 22.7 mmol) and trifluoroacetic anhydride (4.77 g, 22.7 mmol). After
stirring at room temperature for 15 h, the reaction was quenched with saturated Na2SO3 aqueous
solution under ice cooing and stirred at room temperature for 15 min. Saturated aqueous NaHCO3
solution was added to the mixture and extracted with CHCl3. The organic layer was separated, dried
over anhydrous Na2SO4, filtered, and concentrated in vacuo to afford 25 as a colorless solid (2.18 g,
quantitative yield).
1H NMR (200 MHz, CDCl3) δ ppm 6.98 (ddd, J = 9.2, 6.6, 2.6 Hz, 1H), 7.63 (dd, J = 9.2, 6.6 Hz,
1H), 8.34 (dd, J = 4.0, 2.6 Hz, 1H); MS ESI/APCI Dual m/z 192 [M+H]+ , 190 [M-H]- .
5.4.32. 2-Bromo-5-fluoro-4-nitropyridine 1-oxide (26)
To a solution of 25 (3.79 g, 19.7 mmol) in H2SO4 (65.8 mL) was added fuming nitric acid (32.9
mL) under ice cooling and the mixture was stirred at 100 ˚C for 4 h. The reaction mixture was added
dropwise to ice cooled water and extracted with CHCl3. The organic layer was separated, dried over
anhydrous Na2SO4, filtered, and concentrated in vacuo to afford 26 as a pale yellow solid (3.72 g,

80%yield).
1H NMR (200 MHz, CDCl3) δ ppm 8.43 (d, J = 5.8 Hz, 1H), 8.45 (d, J = 8.6 Hz, 1H); MS ESI/APCI
Dual m/z 237 [M+H]+ , 235 [M-H]- .
5.4.33. 6-Bromo-N-[1-(5-ethylpyrimidin-2-yl)piperidin-4-yl]-4-nitropyridin-3-amine 1-oxide (27a)
To a solution of 26 (700 mg, 2.95 mmol) in dimethyl sulfoxide (DMSO) (9.83 mL) were added
1-(5-ethylpyrimidin-2-yl)piperidin-4-amine (609 mg, 2.95 mmol) and Cs2CO3 (1.15 g, 3.53 mmol).
The mixture was stirred at room temperature for 1 h. The reaction was quenched with water and
extracted with ethyl acetate. The organic layer was washed with brine, dried over anhydrous Na2SO4,
filtered, and concentrated in vacuo to afford 27a as a yellow solid (1.08 g, 86% yield).
1H NMR (200 MHz, CDCl3) δ ppm 1.20 (t, J = 7.6 Hz, 3H), 1.50-1.73 (m, 2H), 2.07-2.24 (m, 2H),
2.49 (q, J = 7.6 Hz, 2H), 3.11-3.32 (m, 2H), 3.51-3.73 (m, 1H), 4.54-4.71 (m, 2H), 7.71-7.82 (m,
1H), 8.20 (s, 3H), 8.42 (s, 1H); MS ESI/APCI Dual m/z 423 [M+H]+ , 445 [M+Na]+ , 421 [M-H]- .
5.4.34. 6-Bromo-N3-[1-(5-ethylpyrimidin-2-yl)piperidin-4-yl]pyridine-3,4-diamine (28a)
To a solution of 27a (1.08 g, 2.55 mmol) in AcOH (8.51 mL) was added Fe powder (712 mg, 12.8
mmol) and the mixture was stirred at 100 ˚C for 2 h. The reaction was quenched with water and
extracted with ethyl acetate. The organic layer was washed with brine, dried over anhydrous Na2SO4,
filtered, and concentrated in vacuo. The residue was purified by silica gel column chromatography
(50% EtOAc in CHCl3) to afford 28a as a pale yellow solid (696 mg, 72% yield).
1H NMR (200 MHz, CDCl3) δ ppm 1.19 (t, J = 7.6 Hz, 3H), 1.32-1.54 (m, 2H), 1.99-2.16 (m, 2H),
2.47 (q, J = 7.6 Hz, 2H), 3.00-3.17 (m, 2H), 3.29-3.48 (m, 1H), 4.05-4.18 (m, 2H), 4.55-4.69 (m,
2H), 6.74 (s, 1H), 7.69 (s, 1H), 8.18 (s, 2H); MS ESI/APCI Dual m/z 377 [M+H]+ .
5.4.35. 6-Bromo-3-[1-(5-ethylpyrimidin-2-yl)piperidin-4-yl]-3H-[1,2,3]triazolo[4,5-c]pyridine (29a)
To a solution of 28a (50 mg, 0.133 mmol) in trifluoroacetic acid (TFA) (1.33 mL) was added NaNO2
(13.7 mg, 0.199 mmol) in water (0.133 mL). After stirring at room temperature for 1 h, the reaction
mixture was concentrated in vacuo. The residue was diluted with saturated aqueous NaHCO3
solution and extracted with CHCl3. The organic layer was separated, dried over anhydrous Na2SO4,
filtered, and concentrated in vacuo. The residue was purified by NH silica gel column
chromatography (CHCl3) and recrystallized with hexanes and EtOAc to afford 29a as a pale yellow
solid (34 mg, 66% yield).
1H NMR (200 MHz, CDCl3) δ ppm 1.23 (t, J = 7.6 Hz, 3H), 2.23-2.45 (m, 4H), 2.51 (q, J = 7.6 Hz,
2H), 3.11-3.30 (m, 2H), 4.92-5.19 (m, 3H), 8.17 (d, J = 1.3 Hz, 1H), 8.23 (s, 2H), 8.93 (d, J = 1.3 Hz,
1H); MS ESI/APCI Dual m/z 388 [M+H]+ , 410 [M+Na]+ .

5.4.36. Propan-2-yl 4-[(6-bromo-4-nitro-1-oxidepyridin-3-yl)amino]piperidine-1-carboxylate (27b)
The title compound was synthesized according to the procedure described for compound 27a from
26 and isopropyl 4-aminopiperidine-1-carboxylate (quantitative yield).
1H NMR (300 MHz, CDCl3) δ ppm 1.06-1.34 (m, 6H), 1.43-1.65 (m, 2H), 1.98-2.24 (m, 2H),
2.96-3.16 (m, 2H), 3.42-3.66 (m, 1H), 3.94-4.28 (m, 2H), 4.70-5.15 (m, 1H), 7.74 (d, J = 7.6 Hz,
1H), 8.17 (s, 1H), 8.42 (s, 1H); MS ESI/APCI Dual m/z 421 [M+Na]+ , 433 [M+Cl]- .
5.4.37. Propan-2-yl 4-[(4-amino-6-bromopyridin-3-yl)amino]piperidine-1-carboxylate (28b)
The title compound was synthesized according to the procedure described for compound 28a from
27b (quantitative yield).
1H NMR (300 MHz, CDCl3) δ ppm 1.06-1.53 (m, 8H), 1.89-2.01 (m, 2H), 2.93 (br t, J = 11.4 Hz,
2H), 3.31 (br s, 1H), 3.98-4.23 (m, 3H), 4.91 (dt, J = 12.2, 5.9 Hz, 2H), 6.74 (s, 1H), 7.65 (s, 1H);
MS ESI/APCI Dual m/z 357 [M+H]+ , 391 [M+Cl]- .
5.4.38. Propan-2-yl
4-(6-bromo-3H-[1,2,3]triazolo[4,5-c]pyridin-3-yl)piperidine-1-carboxylate
(29b)
The title compound was synthesized according to the procedure described for compound 29a from
29b (35% yield).
1H NMR (300 MHz, CDCl3) δ ppm 1.29 (d, J = 6.2 Hz, 6H), 2.17-2.46 (m, 4H), 3.10 (br s, 2H),
4.29-4.55 (m, 2H), 4.89-5.07 (m, 2H), 8.18 (d, J = 1.1 Hz, 1H), 8.93 (d, J = 1.1 Hz, 1H); MS
ESI/APCI Dual m/z : 390 [M+Na]+ , 402 [M+Cl]- .
5.4.39. 3-[1-(5-Ethylpyrimidin-2-yl)piperidin-4-yl]-6-[4-(methanesulfonyl)phenyl]-3H-[1,2,3]triazol
o[4,5-c]pyridine (30a)
To
a solution of 29a (35 mg, 0.0901 mmol) in DMF (0.901 mL) were added
[4-(methanesulfonyl)phenyl]boronic acid (27 mg, 0.135 mmol), PdCl2(dppf)·CH2Cl2 (7.36 mg,
0.00901 mmol) and 2 M Na2CO3 aqueous solution (0.135 mL). After stirring at 100 ˚C for 2 h, the
reaction was quenched with water and extracted with EtOAc. The organic layer was separated, dried
over anhydrous Na2SO4, filtered, and reduced under pressure. The residue was purified by silica gel
column chromatography (67-80% EtOAc in CHCl3) to afford 30a as a colorless crystalline solid (20
mg, 48% yield), which was not recrystallized.
1
Mp 269-270 ˚C (EtOAc/CHCl3); H NMR (600 MHz, CDCl3) δ ppm 1.24 (t, J = 7.6 Hz, 3H),
2.34-2.41 (m, 2H), 2.41-2.50 (m, 2H), 2.53 (q, J = 7.6 Hz, 2H), 3.11 (s, 3H), 3.21-3.34 (m, 2H), 5.03
(d, J = 13.6 Hz, 2H), 5.13-5.21 (m, 1H), 8.08 (d, J = 8.7 Hz, 2H), 8.23-8.31 (m, 4H), 8.43 (s, 1H),
9.26 (s, 1H); 13C NMR (151 MHz, CDCl3) δ ppm 15.6, 22.8, 31.7, 43.3, 44.7, 59.1, 111.1, 125.3,
128.0, 128.1, 129.5, 134.7, 140.4, 144.2, 149.1, 151.0, 157.4, 160.6; HRMS ESI/APCI Dual m/z

calcd for C23H25N7O2S 464.1863 [M+H]+ , found 464.1848.
5.4.40. 3-[1-(5-Ethylpyrimidin-2-yl)piperidin-4-yl]-6-[2-fluoro-4-(methanesulfonyl)phenyl]-3H-[1,2,
3]triazolo[4,5-c]pyridine (30b)
The title compound was synthesized according to the procedure described for compound 30a from
29a and [2-fluoro-4-(methanesulfonyl)phenyl]boronic acid (56% yield).
1
Mp 269-270 ˚C (EtOAc/CHCl3); H NMR (600 MHz, CDCl3) δ ppm 1.22 (t, J = 7.6 Hz, 3H),
2.32-2.38 (m, 2H), 2.39-2.48 (m, 2H), 2.51 (q, J = 7.6 Hz, 2H), 3.11 (s, 3H), 3.19-3.26 (m, 2H),
4.98-5.04 (m, 2H), 5.12-5.19 (m, 1H), 7.80 (dd, J = 10.1, 1.7 Hz, 1H), 7.86 (dd, J = 8.2, 1.7 Hz, 1H),
8.23 (s, 2H), 8.33 (dd, J = 8.2, 7.6 Hz, 1H), 8.54 (s, 1H), 9.26 (d, J = 1.2 Hz, 1H); 13C NMR (151
MHz, CDCl3) δ ppm 15.6, 22.8, 31.7, 43.3, 44.5, 59.1, 115.4 (d, J = 12.0 Hz), 116.1 (d, J = 27.0 Hz),
123.4, 125.4, 129.4, 132.3 (d, J = 9.0 Hz), 132.8, 134.7, 141.8 (d, J = 9.0 Hz), 144.3, 150.6, 157.4,
159.9 (d, J = 204.3 Hz), 160.9; HRMS ESI/APCI Dual m/z calcd for C23H24FN7O2S 482.1769
[M+H]+ , found 482.1762.
5.4.41. 3-[1-(5-Ethylpyrimidin-2-yl)piperidin-4-yl]-6-[3-fluoro-4-(methanesulfonyl)phenyl]-3H-[1,2,
3]triazolo[4,5-c]pyridine (30c)
The title compound was synthesized according to the procedure described for compound 30a from
29a and [3-fluoro-4-(methanesulfonyl)phenyl]boronic acid (51% yield).
Mp 229-230 ˚C (EtOAc/CHCl3); 1H NMR (600 MHz, CDCl3) δ ppm 1.22 (t, J = 7.6 Hz, 3H),
2.32-2.38 (m, 2H), 2.39-2.47 (m, 2H), 2.51 (q, J = 7.6 Hz, 2H), 3.19-3.25 (m, 2H), 3.27 (s, 3H),
4.98-5.04 (m, 2H), 5.11-5.19 (m, 1H), 7.99-8.10 (m, 3H), 8.23 (s, 2H), 8.42 (d, J = 1.2 Hz, 1H), 9.24
(d, J = 1.2 Hz, 1H); 13C NMR (151 MHz, CDCl3) δ ppm 15.6, 22.8, 31.7, 43.3, 44.0, 59.2, 111.3,
115.7 (d, J = 24.1 Hz), 122.7, 125.4, 128.0 (d, J = 15.0 Hz), 129.8, 130.3, 134.8, 147.1 (d, J = 9.0
Hz), 147.7, 157.4, 159.8 (d, J = 213.0 Hz), 160.8; HRMS ESI/APCI Dual m/z calcd for
C23H24FN7O2S 482.1769 [M+H]+ , found 482.1764.
5.4.42. 4-{3-[1-(5-Ethylpyrimidin-2-yl)piperidin-4-yl]-3H-[1,2,3]triazolo[4,5-c]pyridin-6-yl}-3-fluor
obenzoic acid (31a)
To
a
solution of 29a (500 mg, 1.29 mmol) in DMF (12.9 mL) were added
3-fluoro-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzoic acid (514 mg, 1.94 mmol),
PdCl2(dppf)·CH2Cl2 (52.3 mg, 0.0645 mmol) and 2 M Na2CO3 aqueous solution (1.93 mL). After
stirring at 110 ˚C for 3 h, the reaction was quenched with water, filtered, and concentrated in vacuo.
The resulting residue was dissolved in 10% NaOH aqueous solution. The aqueous layer was washed
with EtOAc, neutralized with 1 M HCl aqueous solution and extracted with 10% MeOH in CHCl3.
The organic layer was separated, dried over anhydrous Na2SO4, filtered, and concentrated in vacuo.

The resulting solid was washed with EtOAc-hexanes to afford 31a as a pale purple solid (376 mg,
65% yield).
1H NMR (600 MHz, DMSO-d6) δ ppm 1.16 (t, J = 7.6 Hz, 3H), 2.13-2.23 (m, 2H), 2.30-2.37 (m,
2H), 2.47 (q, J = 7.6 Hz, 2H), 3.19-3.26 (m, 2H), 4.80-4.87 (m, 2H), 5.42-5.51 (m, 1H), 7.80-7.84
(m, 1H), 7.90-7.94 (m, 1H), 8.13-8.18 (m, 1H), 8.31 (s, 2H), 8.48 (s, 1H), 9.66 (d, J = 1.2 Hz, 1H);
MS ESI/APCI Dual m/z 448 [M+H]+ .
5.4.43. 4-{3-[1-(5-Ethylpyrimidin-2-yl)piperidin-4-yl]-3H-[1,2,3]triazolo[4,5-c]pyridin-6-yl}-2,5-dif
luorobenzoic acid (31b)
To
a
solution of 29a (500 mg, 1.29 mmol) in EtOH (12.9 mL) were added
2,5-difluoro-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzoic acid (549 mg, 1.93 mmol),
Pd(PPh3)4 (74.5 mg, 0.0645 mmol) and 2 M Cs2CO3 aqueous solution (1.29 mL). After the mixture
being stirred at 150˚C under microwave irradiation for 30 min, 2 M Cs2CO3 aqueous solution was
added to the mixture. The aqueous layer was washed with EtOAc, neutralized with 1 M HCl aqueous
solution and extracted with 10% MeOH in CHCl3. The organic layer was separated, dried over
anhydrous Na2SO4, filtered, and concentrated in vacuo. The resulting solid was washed with
EtOAc-hexanes to afford 31b as a colorless solid (290 mg, 48% yield).
1H NMR (600 MHz, DMSO-d6) δ ppm 1.16 (t, J = 7.6 Hz, 3H), 2.13-2.22 (m, 2H), 2.30-2.36 (m,
2H), 2.47 (q, J = 7.6 Hz, 4H), 3.19-3.26 (m, 2H), 4.80-4.86 (m, 2H), 5.44-5.52 (m, 1H), 7.78-7.83
(m, 1H), 7.92-7.97 (m, 1H), 8.32 (s, 2H), 8.54 (s, 1H), 9.66-9.68 (m, 1H).
5.4.44. 4-{3-[1-(5-Ethylpyrimidin-2-yl)piperidin-4-yl]-3H-[1,2,3]triazolo[4,5-c]pyridin-6-yl}-2,3-dif
luorobenzoic acid (31c)
The title compound was synthesized according to the procedure described for compound 31b from
29a and 4-borono-2,3-difluorobenzoic acid (46% yield).
1H NMR (300 MHz, DMSO-d6) δ ppm 1.16 (t, J = 7.6, 3H), 2.03-2.38 (m, 4H), 2.39-2.47 (m, 2H),
3.13-3.28 (m, 2H), 4.75-4.92 (m, 2H), 5.37-5.55 (m, 1H), 7.39-7.44 (m, 1H), 7.58-7.67 (m, 1H), 8.31
(s, 2H), 8.39 (s, 1H), 9.62 (d, J = 1.4 Hz, 1H); MS ESI m/z 465 [M+H]+ .
5.4.45. 4-{3-[1-(5-Ethylpyrimidin-2-yl)piperidin-4-yl]-3H-[1,2,3]triazolo[4,5-c]pyridin-6-yl}-3-met
hylbenzoic acid (31d)
The title compound was synthesized according to the procedure described for compound 31b from
29a and 3-methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzoic acid (81% yield).
1H NMR (300 MHz, DMSO-d6) δ ppm 1.16 (t, J = 7.6 Hz, 3H), 2.08-2.34 (m, 4H), 2.37 (s, 3H),
2.41-2.47 (m, 2H), 3.17-3.28 (m, 2H), 4.78-4.90 (m, 2H), 5.37-5.52 (m, 1H), 7.47 (d, J = 8.2 Hz,
1H), 7.77-7.90 (m, 2H), 8.17 (s, 1H), 8.32 (s, 2H), 9.58 (s, 1H); MS ESI/APCI Dual m/z 442

[M-H]- .
5.4.46. 3-Chloro-4-{3-[1-(5-ethylpyrimidin-2-yl)piperidin-4-yl]-3H-[1,2,3]triazolo[4,5-c]pyridin-6-
yl}benzoic acid (31e)
To a solution of 29a (500 mg, 1.29 mmol) in EtOH (13 mL) were added 4-borono-3-chlorobenzoic
acid (387 mg, 1.93 mmol), Pd(PPh3)4 (74 mg, 0.064 mmol) and 2 M Cs2CO3 aqueous solution (1.3
mL). After the mixture being stirred at 80 ˚C for 5 h, 2 M KOH aqueous solution and EtOAc were
added to the mixture. The aqueous layer was separated, washed with EtOAc, and neutralized with
saturated NH4Cl aqueous solution. The resulting precipitate was filtered and dried to afford 31e as a
pale yellow solid (466 mg, 78% yield).
1H NMR (300 MHz, DMSO-d6) δ ppm 1.16 (t, J = 7.6 Hz, 3H), 2.07-2.27 (m, 2H), 2.28-2.39 (m,
2H), 2.41-2.48 (m, 2H), 3.13-3.29 (m, 2H), 4.77-4.93 (m, 2H), 5.37-5.54 (m, 1H), 7.59 (d, J = 7.6
Hz, 1H), 7.89 (d, J = 7.6 Hz, 1H), 7.98 (s, 1H), 8.25-8.36 (m, 3H), 9.60 (s, 1H); MS ESI/APCI Dual
m/z 464 [M+H]+ , 462 [M-H]- .
5.4.47. 4-{3-[1-(5-Ethylpyrimidin-2-yl)piperidin-4-yl]-3H-[1,2,3]triazolo[4,5-c]pyridin-6-yl}-3-(trifl
uoromethyl)benzoic acid (31f)
The title compound was synthesized according to the procedure described for compound 31b from
29a and 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3-(trifluoromethyl)benzoic acid (33%
yield).
1H NMR (300 MHz, DMSO-d6) δ ppm 1.22-1.34 (m, 3H), 2.31-2.59 (m, 6H), 3.19-3.33 (m, 2H),
4.96-5.09 (m, 2H), 5.12-5.27 (m, 1H), 7.59-7.70 (m, 1H), 7.83-7.91 (m, 1H), 8.25-8.32 (m, 1H),
8.35-8.40 (m, 2H), 8.56 (s, 1H), 9.28 (d, J = 1.2 Hz, 1H); MS ESI/APCI Dual m/z 498 [M+H]+ .
5.4.48. 4-{3-[1-(5-Ethylpyrimidin-2-yl)piperidin-4-yl]-3H-[1,2,3]triazolo[4,5-c]pyridin-6-yl}-2-met
hylbenzoic acid (31g)
The title compound was synthesized according to the procedure described for compound 31b from
29a and 2-methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzoic acid (58% yield).
1H NMR (300 MHz, DMSO-d6) δ ppm 1.09-1.25 (m, 3H), 2.08-2.38 (m, 4H), 2.41-2.47 (m, 2H),
2.63 (s, 3H), 3.13-3.30 (m, 2H), 4.78-4.89 (m, 2H), 5.44 (br s, 1H), 7.93 (d, J = 8.2 Hz, 1H),
8.04-8.19 (m, 2H), 8.32 (s, 2H), 8.71 (s, 1H), 9.59 (s, 1H); MS ESI/APCI Dual m/z : 444 [M+H]+ ,
442 [M-H]- .
5.4.49. 2-Chloro-4-{3-[1-(5-ethylpyrimidin-2-yl)piperidin-4-yl]-3H-[1,2,3]triazolo[4,5-c]pyridin-6-
yl}benzoic acid (31h)
The title compound was synthesized according to the procedure described for compound 31e from

29a and 4-borono-2-chlorobenzoic acid (72% yield).
1H NMR (300 MHz, DMSO-d6) δ ppm 1.16 (t, J = 7.6 Hz, 3H), 2.07-2.23 (m, 2H), 2.25-2.38 (m,
2H), 2.39-2.47 (m, 2H), 3.16-3.28 (m, 2H), 4.78-4.89 (m, 2H), 5.34-5.50 (m, 1H), 7.49 (d, J = 7.9
Hz, 1H), 8.04 (d, J = 7.9 Hz, 1H), 8.13 (s, 1H), 8.32 (s, 2H), 8.65 (s, 1H), 9.56 (s, 1H); MS
ESI/APCI Dual m/z 464 [M+H]+ , 462 [M-H]- .
5.4.50. 4-{3-[1-(5-Ethylpyrimidin-2-yl)piperidin-4-yl]-3H-[1,2,3]triazolo[4,5-c]pyridin-6-yl}-2-(trifl
uoromethyl)benzoic acid (31i)
The title compound was synthesized according to the procedure described for compound 31b from
29a and 4-borono-2-(trifluoromethyl)benzoic acid (81% yield).
1H NMR (300 MHz, DMSO-d6) δ ppm 1.11-1.21 (m, 3H), 2.07-2.38 (m, 4H), 2.41-2.46 (m, 2H),
3.17-3.23 (m, 4H), 4.77-4.89 (m, 2H), 5.39-5.54 (m, 1H), 7.96 (d, J = 8.1 Hz, 1H), 8.32 (s, 2H), 8.58
(d, J = 8.1 Hz, 1H), 8.65 (s, 1H), 8.91 (s, 1H), 9.64 (s, 1H); MS ESI/APCI Dual m/z 496 [M-H]- .
5.4.51. 4-{3-[1-(5-Ethylpyrimidin-2-yl)piperidin-4-yl]-3H-[1,2,3]triazolo[4,5-c]pyridin-6-yl}-3,5-di
methylbenzoic acid (31j)
The title compound was synthesized according to the procedure described for compound 31b from
29a and 3,5-dimethyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzoic acid (30% yield).
1H NMR (300 MHz, CDCl3) δ ppm 1.17-1.27 (m, 3H), 2.09 (s, 6H), 2.22-2.59 (m, 6H), 3.14-3.33 (m,
2H), 4.93-5.29 (m, 3H), 7.82-7.95 (m, 3H), 8.17-8.32 (m, 2H), 9.25-9.33 (m, 1H); MS ESI m/z 458
[M+H]+ , 456 [M-H]- .
5.4.52. 4-{3-[1-(5-Ethylpyrimidin-2-yl)piperidin-4-yl]-3H-[1,2,3]triazolo[4,5-c]pyridin-6-yl}-2,6-di
methylbenzoic acid (31k)
The title compound was synthesized according to the procedure described for compound 31b from
29a and 2,6-dimethyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzoic acid (62% yield).
1H NMR (300 MHz, DMSO-d6) δ ppm 1.16 (t, J = 7.6 Hz, 3H), 2.07-2.54 (m, 12H), 3.11-3.30 (m,
2H), 4.75-4.90 (m, 2H), 5.36-5.52 (m, 1H), 7.90 (s, 2H), 8.32 (s, 2H), 8.61 (s, 1H), 9.55 (s, 1H); MS
ESI m/z 456 [M-H]- .
5.4.53. N-Ethyl-4-{3-[1-(5-ethylpyrimidin-2-yl)piperidin-4-yl]-3H-[1,2,3]triazolo[4,5-c]pyridin-6-yl
}-3-fluorobenzamide (32a)
To a solution of 31a (50.0 mg, 0.112 mmol) in DMF (1.12 mL) were added 70% ethylamine aqueous
solution (10.8 mg, 0.168 mmol), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride
(EDCI·HCl) (32.2 mg, 0.168 mmol), 1,2,3-benzotriazol-1-ol monohydrate (HOBt·H2O) (25.7 mg,
0.168 mmol) and triethylamine (34.0 mg, 0.335 mmol). After stirring at room temperature overnight,