Synthesis of sorafenib analogues incorporating a 1,2,3-triazole ring and cytotoxicity towards hepatocellular carcinoma cell lines

Article abstract of DOI:10.1016/j.bioorg.2021.104831

A series of 1,2,3-triazole-containing Sorafenib analogues, in which the aryl urea moiety of Sorafenib (1) was replaced with a 1,2,3-triazole ring linking a substituted phenoxy fragment, were prepared successfully via Huisgen 1,3-dipolar cycloaddition and

Full text of DOI:10.1016/j.bioorg.2021.104831

Bioorganic Chemistry 112 (2021) 104831
Contents lists available at ScienceDirect
Bioorganic Chemistry
journal homepage: www.elsevier.com/locate/bioorg
Synthesis of sorafenib analogues incorporating a 1,2,3-triazole ring and
cytotoxicity towards hepatocellular carcinoma cell lines
Sarinya Palakhachanea, Yuwaporn Ketkaewb, Natthaya Chuaypenb, Jitnapa Siriraka,
,
Jutatip Boonsombatc, Somsak Ruchirawatc d, Pisit Tangkijvanichb, Apichart Suksamrarne,
,
*
Panupun Limpachayaporna
a Department of Chemistry, Faculty of Science, Silpakorn University, Nakhon Pathom 73000, Thailand
b Center of Excellence in Hepatitis and Liver Cancer, Department of Biochemistry, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
c Chulabhorn Research Institute, Bangkok 10210, Thailand
d Chulabhorn Graduate Institute, Chemical Biology Program, Chulabhorn Royal Academy, Kamphaeng Phet 6 Road, Bangkok 10210, Thailand
e Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Ramkhamhaeng University, Bangkok 10240, Thailand
A R T I C L E I N F O
A B S T R A C T
Keywords:
A series of 1,2,3-triazole-containing Sorafenib analogues, in which the aryl urea moiety of Sorafenib (1) was
replaced with a 1,2,3-triazole ring linking a substituted phenoxy fragment, were prepared successfully via
Huisgen 1,3-dipolar cycloaddition and nucleophilic aromatic substitution. The studies of cytotoxicity towards
human hepatocellular carcinoma (HCC) cell lines, HepG2 and Huh7, indicated that p-tert-butylphenoxy analogue
2m showed significant inhibitory activity against Huh7 with IC50 = 5.67 ± 0.57 µM. More importantly, 2m
showed low cytotoxicity against human embryonal lung fibroblast cell line, MRC-5, with IC50 > 100 µM, sug-
gesting its highly selective cytotoxic activity (SI > 17.6) towards Huh7 which is much superior to that of Sor-
afenib (SI = 6.73). The molecular docking studies revealed that the analogue 2m bound B-RAF near the binding
position of Sorafenib, while it interacted VEGFR2 efficiently at the same binding position of Sorafenib. However,
2m exhibited moderate inhibitory activity toward B-RAF, implying that its anti-Huh7 effect might not strictly
relate to inhibition of B-RAF. Wound healing and BrdU cell proliferation assays confirmed anti-cell migration and
anti-cell proliferative activities towards Huh7. With its inhibitory efficiency and high safety profile, 2m has been
identified as a promising candidate for the treatment of HCC.
Multi-kinase inhibitor
Triazole
1,3-Dipolar cycloaddition
Sorafenib analogue
Hepatocellular carcinoma (HCC)
1. Introduction
Therefore, they usually are unable to be treated efficiently, and thus
suffer from severe adverse effects of the treatments. Nowadays, the
Hepatocellular carcinoma (HCC) is one of the most common causes
of cancer death in the world [1,2] and tend to continuously rise. In 2018,
HCC ranked fifth in global cancer cases and ninth in cause of death in
men, while ranked second and sixth, respectively, in women [1]. HCC
can be caused by several factors, from both behavior and other diseases,
including alcoholism [3,4], unbeneficial eating [5], over of body mass
index (BMI) [6], chronic hepatitis B and C virus infection [4,7], fibrosis
and cirrhosis [8,9]. There are many treatment options for HCC, con-
sisted of curative resection, liver transplantation (LT), radiofrequency
ablation, transarterial chemoembolization and radioembolization [10],
depending on the states of cancer, patient readiness and severity of liver
function [11–13]. However, most of the HCC patients are diagnosed in
the late stages, which are malignant phases and in metastasis [14,15].
patients can be treated with targeted cancer drug therapy [12], which
inhibits cancerous cells selectively without affecting normal cells
resulting in less side effects and prolong of the patient’s life [11].
The first targeted cancer drug for HCC patients is Sorafenib (Nex-
avar®). It was approved by Food and Drug Administration of the United
States (US FDA) for the treatment of renal cell carcinoma (RCC) in 2005
[16,17], advanced HCC in 2007 [16,17] and thyroid cancer in 2013
[17]. Sorafenib can be used for the treatment of various cancers due to
its multi-kinase inhibitory properties in various pathways associated
with cancer development, especially vascular endothelial growth factor
receptor (VEGFR) [18], serine/threonine protein kinase (B-RAF), Ras
protein and Ras-mutation [15] and downstream of mitogen-activated
protein kinase (MAPK) pathway [18,19]. These inhibitory properties
* Corresponding author.
E-mail addresses: limpachayaporn_p@silpakorn.edu, panupun.lim@gmail.com (P. Limpachayaporn).
https://doi.org/10.1016/j.bioorg.2021.104831
Received 17 September 2020; Received in revised form 28 February 2021; Accepted 12 March 2021
Available online 17 March 2021
0045-2068/© 2021 Elsevier Inc. All rights reserved.

S. Palakhachane et al.
Bioorganic Chemistry 112 (2021) 104831
lead to supression of cell growth, angiogenesis and cell proliferation
[20]. The proper interactions between Sorafenib, and B-RAF and
VEGFR2 have been explained by X-ray co-crystal structure [21]. How-
ever, Sorafenib exhibits low bioavailability causing usage of high dose
[22]. In addition, the broad kinase inhibition also causes strong adverse
effects as reported by the FDA, such as dermatitis rash, hand-foot skin
reaction, diarrhea, fatigue and hypertension [23]. Although the HCC
patients may afford the treatment with Sorafenib, their life can be pro-
longed up to only almost a year [11]. Consequently, besides Sorafenib,
the more effective and safer targeted drugs are still in need for HCC
treatment.
Replacement of aryl urea with 4,5-dihydro-1H-pyrazole [29], pyrazole
[30], chalcone [31]. They showed similar to superior inhibition against
receptor tyrosine kinases (RTKs), VEGFR2, HepG2, MCF-7 and PC-3
when compared to Sorafenib. They are also promoting apoptosis of
cancer cells. From the previous works, the Sorafenib derivatives
exhibited broad inhibition towards various cancer cell lines. However,
only limited number of the derivatives have been tested against HCC cell
lines and showed good inhibitory activities. Nevertheless, these struc-
tural alterations orginated from Sorafenib leads to the discovery of drugs
for HCC treatment including Regorafenib, Lenvatinib and Tivozanib
[24] (Fig. 1). Moreover, Regorafenib and Lenvatinib were approved by
US FDA for the treatment of colorectal cancer [32] and differentiated
thyroid cancer [33] respectively, while Tivozanib was approved in Eu-
ropean Union (EU) for treatment of RCC [34].
The disclosure of the structure and cancer inhibitory properties of
Sorafenib has opened the opportunities not only to improve the inhibi-
tory efficiency, pharmacokinetic and safety profiles, but also to discover
the activities against various cancer cell lines other than HCC cell lines.
Thus, many organic and medicinal chemists are searching intensively for
appropriate structures, analogous to the Sorafenib structure, which can
potentially suppress the progression of cancers. Modification of Sor-
afenib’s structure might be classified roughly into three groups (Fig. 1):
1) Introduction of halogen atom such as chlorine and fluorine to the core
benzene [24]. These analogues were often active against the hepatocyte
growth factor receptor (c-MET, also known as tyrosine-protein kinase
MET) pathway, VEGFR1, VEGFR2, VEGFR3 and platelet-derived growth
factor receptor-β (PDGFRβ).; 2) Replacement of picolinamide with tri-
fluoromethyl imidazole [25], indazole ring [26], thieno[3,2-d]pyrimi-
dine [27] and 1,2,4-triazole [28]. They inhibited MDA-MB-231, SMMC-
7721, H460, HT-29 comparable to or better than Sorafenib; 3)
According to the structure–activity relationship (SAR) investigation
and molecular docking studies of the previous reports, aryl urea pro-
vided important binding interactions through the hydrogen bond with
Asp, Glu and Cys, and hydrophobic interactions with the lipophilic
pocket of the VEGFR2 and B-RAF [35]. Therefore, most Sorafenib ana-
logues usually contained aryl urea moiety which provides a good affinity
to the targets leading to inhibitory activities towards a broad spectrum
of cancer cell lines. However, the urea-containing drug was often
aggregated itself [36] and its hydrogen bond character also increased
interaction with various plasma proteins [36,37], incurring poor phar-
macokinetic properties and cell toxicity. Replacement of aryl urea of
Sorafenib with other suitable moiety is a challenging approach since the
loss of hydrogen bonding due to the absence of aryl urea would require
Fig. 1. The chemical structures of Sorafenib (1), 1,2,3-triazole-containing Sorafenib analogues (2), Regorafenib, Lenvatinib, Tivozanib and picolinamide derivatives.
2

S. Palakhachane et al.
Bioorganic Chemistry 112 (2021) 104831
compensation from other structural features. Instead of aryl urea of
Sorafenib, 1,2,3-triazole linking with a substituted phenoxy ring could
be a suitable counterpart (structure 2, Fig. 1). The triazole heterocycle
were transformed to the target Sorafenib analogues 2a-2ac in the yields
of 18–83%. In the synthesis of 2aa (R = p-OH), 4-((tert-butyldime-
thylsilyl)oxy)phenol (3aa; R = p-OTBS) was used as a starting material.
The corresponding alkyne 5aa (R = p-OTBS) and phenol 7aa (R = p-
OTBS) were obtained using the conditions described above. The final
target 2aa (R = p-OH) were obtained after coupling 7aa (R = p-OTBS)
and picolinamide 8 in moderate yield (31%). While, the preparation of
the analogue 2ad (R = p-NH2) was accomplished by Ni-catalyzed
reduction of the target compound 2g (R = p-NO2) in a good yield
(77%) (Scheme 1) [46]. Structures of the synthetic Sorafenib analogues
could provide hydrogen bonding, hydrophobic and π-π modes of binding
to the targets, whereas the terminal substituted phenoxy tether could
offer hydrophobic interaction with the lipophilic pocket. Additionally,
the triazole structure has been proved to be metabolically stable [38]
and this structure has been presented in a wide variety of bioactive
compounds including analgesic, anti-bacterial, anti-fungal, anti-
inflammatory, anti-malarial, anti-tubercular, anti-leishmanial, anti-
viral, anti-tumor agents [39–41].
1
2a-2ad were confirmed by NMR and HRMS techniques. Typically, H
Herein, we report the synthesis of the 1,2,3-triazole-containing
Sorafenib analogues and their cytotoxicity towards human hepatocel-
lular carcinoma (HCC) cell lines, HepG2 and Huh7, in order to study
their structure–activity relationships (SARs). The safety profile of ana-
logues was examined by testing with human embryonal lung fibroblast
cell line, MRC-5, and the selectivity index (SI) was evaluated. Addi-
tionally, the inhibitory activity of the selected active analogue(s) was
explained by molecular docking studies in B-RAF and VEGFR2 models
and confirmed by cell migration and cell proliferation assays.
NMR spectra showed a singlet peak of OCH2 and H on the triazole at δ
5.2 to 5.4 and 8.1 to 9.9 ppm, respectively. Two doublet peaks at δ 6.5 to
8.5 ppm with J ≈ 9 Hz confirmed the p-substituted benzene. 19F atom(s)
of F and CF3 were observed by 19F NMR spectra at δ ꢀ 165 to ꢀ 110 and
ꢀ 65 to ꢀ 60 ppm, respectively. The couplings of 13C and 19F were
appeared on the 13C NMR spectra with 1J = 235–270 Hz, 2J = 10–40 Hz
and 3J = 4–20 Hz. The NMR spectra of picolinamide part were consistent
with those reported in the literature [45].
2.2. Biological evaluation
2. Results and discussion
The biological activities towards HepG2 and Huh7 of the synthetic
triazole-containing analogues 2h-2ad were evaluated in in vitro model
using MTT assay [47,48] compared to 2a-2g [42]. These two HCC cell
lines are distinguishable by their origins and gene profiles leading to
different expressions and responses to the drug treatments [49,50].
Furthermore, their cytotoxicity towards MRC-5 of all target compounds
2a-2ad was also examined [51]. The results were reported as half-
maximal inhibitory concentration (IC50) values in micromolar range
(µM) and selectivity index (SI) of each compounds was calculated for
expression of their safety profile.
2.1. Chemistry
The designed triazole-containing Sorafenib analogues 2a-2g from
our preliminary work [42] and additional analogues 2h-2ac were syn-
thesized successfully via Huisgen 1,3-dipolar cycloaddition followed by
nucleophilic aromatic substitution, whereas the preparation of analogue
2ad was accomplished via reduction as illustrated in Scheme 1.
Initially, various phenols 3 were O-propargylated using propargyl
bromide (4) under basic conditions to give the corresponding alkynes 5
with moderate to excellent yields. Subsequently, the 1,2,3-triazole rings
were constructed using Huisgen 1,3-dipolar cycloaddition between the
obtained alkynes 5 and 4-azidophenol (6), which was prepared via
diazotization using the conditions described previously [43], leading to
the formation of the triazoles 7 in the yields of 25–96% [44]. After
coupling with 4-chloropicolinamide (8) [45] in the presence of tert-
butoxide and potassium carbonate, the triazole-containing phenols 7
2.2.1. Cytotoxicity towards HepG2 and Huh7
Several substituents (H, F, NO2, CF3 and t-Bu) were introduced to the
phenoxy ring linked with the triazole at o-, m- and p-position in order to
investigate positions and types of substituents impacting the inhibition
of the HCC cell lines. Their inhibitory activities were showed in Table 1.
In the first series of compounds 2a-2m, it was found that all the active
Scheme 1. The synthetic pathways to the triazole-containing Sorafenib analogues 2a-2ac starting from various phenols 3a-3ac and analogue 2ad from the target
compound 2g.
3

S. Palakhachane et al.
Bioorganic Chemistry 112 (2021) 104831
analogues showed moderate to no activity against HepG2 with the best
IC50 = 61.6 ± 5.2 µM. For Huh7, several compounds showed good
inhibitory activity, of which the p-analogue 2m (R = p-tBu) exhibited the
best inhibitory activity towards Huh7 with IC50 = 5.67 ± 0.57 µM,
followed by the p-analogue 2g (R = p-NO2) with IC50 = 21.1 ± 5.9 µM.
It should be noted that activated extracellular signal-regulated ki-
nase (phospho-ERK) is a clinical response biomarker to drug and
combinatorial treatment in HCC liver cancers [52]. Inhibition of Huh7,
which expresses high level of phospho-ERK, indicated that the agent 2m
could potentially suppress types of HCC that activated the phospho-ERK
level. Furthermore, with the possible different molecular inhibition
pathway to the mitogen-activated extracellular signal-regulated kinase
(MEK) inhibitor drug, compound 2m may possibly be used in the
combination for synergistic effect in the HCC treatment.
Table 1
In vitro inhibitory activities towards HCC cell lines, HepG2 and Huh7, and
human embryonal lung fibroblast cell line, MRC-5, of the synthetic Sorafenib
analogues 2a-2ad, compared to Sorafenib. The half-maximal inhibitory con-
centration (IC50) in micromolar (µM) scale and the selectivity index (SI) were
reported.
Compound
R
IC50 (µM)
SI
HepG2
Huh7
MRC-5
HepG2
Huh7
2a
2b
2c
2d
H
>100
>100
>100
>100
>100
>100
>100
64.4 ±
5.5
>100
>100
>100
>100
–
–
–
–
–
o-F
m-F
p-F
–
–
>1.55
2e
o-NO2
72.0 ±
5.5
52.5 ±
0.8
>100
>1.39
>1.90
2f
m-NO2
p-NO2
>100
>100
>100
21.1 ±
5.9
>100
94.4 ±
0.81
–
–
–
4.48
2g
2.2.2. Cytoxicity towards MRC-5 and selectivity index (SI)
Regarding compounds’ toxicity, the cytotoxicity against MRC-5 of all
the synthesized compounds was investigated using procedure described
previously [51]. The results showed that most of compounds were non-
cytotoxic at 100 µM as shown in Table 1. Only 2l (R = m-tBu) possessed
IC50 = 16.5 ± 2.49 µM for MRC-5, which was more toxic than Sorafenib
(IC50 = 19.7 ± 1.68 µM). The best anti-Huh7 agents 2g (R = p-NO2) and
2m (R = p-tBu) exhibited the cytotoxicity towards MRC-5 at IC50 = 94.4
± 0.81 µM and > 100 µM, respectively, which were much safer than
Sorafenib. More importantly, these two compounds (2g and 2m) have
highly selective cytotoxic activity towards Huh7 with SI = 4.48 and >
17.6, respectively. It is also worth mentioned that compound 2m (R = p-
tBu) showed much higer selectivity than Sorafenib (SI = 6.73) for Huh7.
With the promising inhibitory activity and safety profile, 2m (R = p-tBu)
and 2g (R = p-NO2) were selected for further molecular docking studies.
2h
2i
o-CF3
m-CF3
p-CF3
>100
>100
>100
>100
>100
50.9 ±
0.4
>100
>100
>100
–
–
–
–
–
2j
>1.96
2k
2l
o-tBu
>100
61.6 ±
5.2
>100
47.3 ±
1.1
>100
16.5 ±
2.49
–
0.27
–
0.35
m-tBu
2m
p-tBu
>100
5.67 ±
0.57
>100
–
>17.6
2n
2o
2p
2q
2r
2s
2t
2,3-F
2,4-F
2,5-F
2,6-F
3,4-F
3,5-F
3,5-CF3
3-CF3,
4-Cl
>100
>100
>100
>100
>100
>100
>100
>100
>100
>100
>100
>100
>100
>100
>100
>100
>100
>100
>100
>100
>100
>100
>100
68.7 ±
4.68
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
2u
2v
2w
2x
2y
p-Me
p-Et
>100
>100
>100
>100
>100
>100
>100
>100
>100
>100
>100
65.46 ±
0.99
–
–
–
–
–
–
–
–
2.3. Molecular docking studies with B-RAF and VEGFR2
p-iPr
p-Cl
To gain better understanding of intermolecular interactions between
our compounds and the cavity of important targets B-RAF and VEGFR2,
molecular docking was performed using iGEMDOCK v2.1 software [53].
Our first two compounds with the lowest IC50 (2m and 2g) were docked
into the active site of B-RAF co-crystallized with Sorafenib (PDB
ID:1uwh) and VEGFR2 co-crystallized with Sorafenib (PDB ID:4asd).
Sorafenib was also redocked into the B-RAF and VEGFR2, and its
binding energies were compared with those of our compounds.
2z
p-Br
>100
84.0 ±
4.6
>100
36.2 ±
4.4
>100
>100
–
–
2aa
p-OH
>1.19
>2.76
2ab
p-OMe
p-NHAc
p-NH2
>100
>100
>100
3.87 ±
1.74
>100
>100
>100
2.93 ±
0.65
>100
>100
>100
19.7 ±
1.68
–
–
2ac
–
–
2ad
–
–
Sorafenib
(1)
5.10
6.73
As illustrated in Figure S75 (supporting information), the redocked
Sorafenib had similar binding position to co-crystallized Sorafenib in B-
RAF and VEGFR2. For B-RAF, Fig. 2a-2b demonstrated that both 2m and
2g interacted efficiently with the active site of the B-RAF near the Sor-
afenib binding position. The p-tert-butyl phenoxy ring of 2m bound at
the same position as that of trifluoromethyl phenyl ring of Sorafenib.
The bulky substitution group on the phenoxy ring of 2m were at p-po-
sition, whereas trifluoromethyl group on the phenoxy ring of Sorafenib
was at 3-position. As a consequence, the rest of the molecule of 2m lay in
compounds 2d (R = p-F), 2e (R = o-NO2), 2g (R = p-NO2), 2j (R = p-
CF3), 2l (R = m-tBu) and 2m (R = p-tBu) inhibited Huh7 (IC50 < 100 µM)
with significantly higher activity than HepG2. Obviously, analogues
with p-substitution (2d (R = p-F), 2g (R = p-NO2), 2j (R = p-CF3) and 2m
(R = p-tBu)) exhibited superior IC50 against Huh7 compared to the
corresponding o- and m-substitution. Only compounds 2e (R = o-NO2)
and 2l (R = m-tBu) showed mild activity against both HepG2 and Huh7
with IC50 lower than 100 µM. We next investigated the disubstituted
analogues 2n-2u, consisting of diflouro-, di(trifluoromethyl)- and 3-tri-
fluoromethyl-4-chlorophenoxy (analogous to Sorafenib). It was found
that all these disubstituted analogues were inactive (IC50 > 100 µM)
towards both HCC cell lines. A plan for syntheses of other disubstituted
analogues was therefore terminated.
different direction, locating between αC-helix and P-loop of the B-RAF.
Additionally, pyridine of 2m bound very close to oxygen of Met483 with
2.76 Å (Fig. 2c). For compound 2g, the binding positions of pyridyl ring
and 1,2,3-triazole ring of 2g in B-RAF were similar to those of central
ring and trifluoromethyl phenyl ring of co-crystallized Sorafenib,
respectively, while its phenoxy ring was located near αC-helix of B-RAF.
In addition, the molecular docking in Fig. 2d revealed that nitro group of
2g was adjacent to the side chain of Ala496 with 2.52 Å. The binding
energies for 2m and 2g were ꢀ 113.79 and ꢀ 110.70 kcal/mol, respec-
tively, which were slightly higher than that of redocked Sorafenib
(ꢀ 117.29 kcal/mol) (Table 2).
Based on the first series of compounds 2a-2m, it was evident that p-
substituted analogues had a potential for further improvement. There-
fore, a variety of substituents were attached to the phenoxy ring at p-
position consisting of nonpolar alkyl, halogen, hydroxy, methoxy,
amino, N-acetamido groups as shown as 2v-2ad in Table 1. However,
the IC50 values of most compounds in this set were higher than 100 µM,
except the hydroxy-substituted analogue 2aa (R = p-OH) that showed
moderate inhibitory activities with IC50 = 84.0 ± 4.6 and 36.2 ± 4.4 µM
towards HepG2 and Huh7, respectively. In summary, the synthesized
As can be seen in Fig. 3a-3b, 2m and 2g fit well the active site of
VEGFR2 with more or less the same binding position to that of co-
crystallized Sorafenib and their binding energies were ꢀ 115.33 and
ꢀ 111.40 kcal/mol for 2m and 2g, respectively, which were higher than
that of Sorafenib (ꢀ 130.58 kcal/mol) (Table 2). Fig. 3c-3d revealed that
4

S. Palakhachane et al.
Bioorganic Chemistry 112 (2021) 104831
Fig. 2. Comparison of binding positions of 2m (purple), 2g (light blue) and the co-crystallized Sorafenib (deep blue) in the cavity of B-RAF (PDB ID: 1uwh), (b) the
comparison of 2m (purple), 2g (light blue) and the co-crystallized Sorafenib (deep blue) (a,b), and the interacting residues with 2m (c) and 2g (d) in the binding site
of B-RAF. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)
2.4. Biochemistry
Table 2
Binding energies, amino acid residues and bond lengths of 2m, 2g and the
2.4.1. Inhibitory activity towards B-RAF
redocked Sorafenib in binding site of B-RAF and VEGFR2.
Compound
In order to gain information related to its anti-cancer activity,
Binding energy
(kcal/mol)
Amino acid residue
Bond length
(Å)
compound 2m was selected to investigate inhibitory activity towards B-
RAF in vitro compared to Sorafenib. As a result, 2m exhibited moderate
activity towards B-RAF, whereas Sorafenib inhibited B-RAF efficiently as
illustrated in Fig. 4. Based on the anti-Huh7 effect, and the docking study
in B-RAF model indicating that laying position of 2m was near but
differed from that of Sorafenib (Fig. 2b) and 2m had higher binding
energy, it could be implied that the anti-Huh7 activity of 2m might not
strictly be influenced by the inhibition of B-RAF. Potentially, 2m might
inhibit other kinases in the same pathway, for example VEGFR2, in
which 2m fit very well at the Sorafenib position (Fig. 3b), and/or,
possibly, involve in different mechanism of action or pathway from the
parent Sorafenib [54].
B-RAF
2m
ꢀ 113.79
ꢀ 110.70
ꢀ 117.29
Met483:O
2.76
2g
Ala496:H
2.52
Sorafenib
(1)
Glu500:O, Asp593:H
2.65, 2.10
VEGFR2
2m
ꢀ 115.33
ꢀ 111.40
ꢀ 130.58
Asp1046:H, Lys920:O,
Cys919:O, Glu885:O
Asp1046:H, His1026:O,
Glu885:O
2.50, 2.07,
1.97, 2.44
2.47, 2.80,
2.54
2g
Sorafenib
Cys1045:H, Cys919:O,
Glu917:O, Glu885:O
2.85, 2.23,
2.55, 2.67
(1)
2.4.2. Wound healing assay
both 2m and 2g formed hydrogen bonding with Asp1046 and Glu885.
Additionally, nitro group of 2g interacted with the side chain of His1026
while methyl amide of 2m bound very close to oxygen of Cys919 and
Lys920. Sorafenib also bound with Cys919 and Glu885 in the active site
of VEGFR2.
To investigate the effect of the candidate compound 2m, which had
the lowest IC50 with the highest SI among the series and comparable
binding energy to Sorafenib, on the migration of HCC cells, wound
healing assay was performed [55]. Huh7 cells were exposed to the
concentration of 3 µM of Sorafenib and 3, 6 and 12 µM of 2m for 0, 24
and 48 h. The results showed the suppression of cell migration of Huh7
with time- and dose-dependent manner as represented in Fig. 5. Wound
healing percentage of each compound and each concentration are
unidentical. Increasing of dose declined healing percentage and time
extension developed the recovery. Sorafenib at the concentration of 3
µM exhibited cell repair inhibition almost ten folds compared to control,
while 2m at the concentration of 12 µM suppressed wound repair only
two folds (see Figure S76, supporting information). These results
It can be noted that, comparing between 2g and 2m, compound 2m
with lower IC50 value displayed lower binding energies than those of 2g,
thus the molecular docking results were in agreement with the IC50
values.
5

S. Palakhachane et al.
Bioorganic Chemistry 112 (2021) 104831
Fig. 3. Comparison of binding positions of 2m (purple), 2g (light blue) and the co-crystallized Sorafenib (deep blue) in the cavity of VEGFR2 (PDB ID: 4asd), (b) the
comparison of 2m (purple), 2g (light blue) and the co-crystallized Sorafenib (deep blue) (a,b), and the interacting residues with 2m (c) and 2g (d) in the binding site
of VEGFR2. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)
Fig. 4. Inhibitory activity towards B-RAF of 2m (left) and Sorafenib (right).
suggested that 2m can inhibit the cell migration of Huh7 cell compared
to control; however, it was less potent inhibitor of cell migration than
Sorafenib.
dependent manner. However, Sorafenib showed superior anti-cell pro-
liferative properties significantly to the Sorafenib analogue 2m.
3. Conclusion
2.4.3. Anti-proliferative actvity
To demonstrate the effect of 2m on DNA synthesis in Huh7 cells,
BrdU cell proliferation was performed to identify the anti-cell prolifer-
ative activity [56]. As shown in Fig. 6, at 24 h, BrdU incorporation was
reduced in Sorafenib and 2m treated cells when compared to the un-
treated cells, suggesting DNA synthesis was inhibited. Similarly, at 48 h,
DNA synthesis was also inhibited by Sorafenib and 2m at 6 and 12 µM.
The time-dependent pattern of 2m was rather constant over time,
implying that 2m inhibited cell proliferation of Huh7 in a dose-
New triazole-containing Sorafenib analogues were synthesized suc-
cessfully with high yields via Huisgen 1,3-dipolar cycloaddition, nucle-
ophilic substitution and functional group transformation. The triazole-
containing analogues with bulky substituent at p-position on the ter-
minal phenoxy ring seems to be the necessary structural feature for se-
lective Huh7 inhibition with high safety profile. Among the compounds
in this series, analogue 2m expressed the best inhibitory activity against
Huh7, but it was inactive for HepG2. The different responses to the
6

S. Palakhachane et al.
Bioorganic Chemistry 112 (2021) 104831
Fig. 5. Wound healing assay in Huh7 of compound 2m at the concentration of 3, 6 and 12 µM for 0, 24 and 48 h, compared to control and Sorafenib at the
concentration of 3 µM.
Fig. 6. Cell proliferation activity assay in Huh7 of 2m at the concentration of 3, 6 and 12
μM for 24 and 48 h using BrdU cell proliferation kit, compared to Sorafenib
at the concentration of 3 M. Data are expressed as the percentage (Mean ± SD), n = 3, **P < 0.01 compared with the untreated cells (control).
μ
treatment might be due to different gene profiles. Although 2m
exhibited IC50 towards Huh7 ca. 2-fold less active than Sorafenib, the
cytotoxicity against normal human lung fibroblast cell line, MRC-5,
indicated that 2m was obviously less toxic than Sorafenib. The SI for
Huh7 of 2m was at least 2.6-fold superior to that of Sorafenib. The
molecular docking studies confirmed the efficient interaction of 2m with
B-RAF and VEGFR2, near and the same Sorafenib’s binding site,
respectively. In addition, the active analogue 2m showed the inhibition
of cell migration of Huh7 with time- and dose-dependent fashion and
anti-cell proliferative activity with dose-dependent fashion. However,
moderate inhibitory activity towards B-RAF of 2m was evident that its
anti-Huh7 activity might not directly relate to the inhibition of B-RAF.
The mechanism of action should be further investigated. The current
study evidently identified 2m as a promising candidate with high safety
profile for further development of anti-HCC agents. Its Huh7 inhibitory
property emphasized the potentiality of using 2m in treatment of the
HCC with high phospho-ERK level as well as using 2m as the drug
combination with other inhibitors in HCC clinical therapy.
4. Experimental part
4.1. Chemicals and materials
Chemicals and reagents used were purchased from Acros Organics,
Sigma-Aldrich and Tokyo Chemical Industry (TCI). All reagents received
were analytical grade and used without purification, unless stated
otherwise. Deionized water was used in this work. Preparative chro-
matographic separations were performed on silica gel 63–200 μm pur-
chased from Merck. All reactions were followed by TLC analysis using
precoated silica gel 60 TLC sheets (Merck) with fluorescent indicator
(254 nm) and visualized with a UV lamp (254 and 365 nm).
7

S. Palakhachane et al.
Bioorganic Chemistry 112 (2021) 104831
4.2. Instruments
(dd, J = 6.0, 3.0 Hz, 2H), 8.24 (dd, J = 6.0, 3.0 Hz, 2H) ppm.; 13C NMR
(75 MHz, CDCl3) δ 57.2, 77.1, 77.2, 115.5, 121.4, 125.7, 134.0, 140.4,
150.8 ppm.
1H, 13C and 19F NMR spectra were recorded on a Bruker AVANCE III
HD in Fourier transform mode at the field strength specified on a 300
MHz spectrometer. DEPT and 2D NMR spectra including COSY, HMQC
and HMBC of some compounds were collected for clearifying the
structures. Spectra were obtained in CDCl3 and DMSO‑d6 solutions using
5 mm diameter tubes, and chemical shifts in ppm (part per million) are
quoted relative to either the internal standards, TMS (δH 0.00) or
CF3COOH (δF ꢀ 76.55) or the residual signals of either CDCl3 (δH 7.26, or
δC 77.22) or DMSO‑d6 (δH 2.50, or δC 39.51). Data are reported as fol-
lows: chemical shifts, multiplicity, coupling constant. Multiplicities in
the 1H and 19F NMR spectra are described as: s = singlet, d = doublet, t
= triplet, q = quartet, m = multiplet, br = broad; coupling constants (J)
are reported in Hz. High-resolution mass spectra (HRMS) are recorded
using a Bruker Daltonics MicroTOF mass spectrometer with ESI + mode
and reported with ion mass/charge (m/z) ratios as values in atomic mass
units.
1-nitro-3-(prop-2-yn-1-yloxy)benzene (5f) [42]
Purification by silica gel column chromatography using 15% EtOAc:
n-hexane as eluent gave yellow solid with 97% yield. 1H NMR (300 MHz,
CDCl3) 2.59 (t, J = 2.4 Hz, 1H), 4.79 (d, J = 2.4 Hz, 2H), 7.31 (ddd, J =
8.3, 2.6, 0.9 Hz, 1H), 7.47 (t, J = 8.2 Hz, 1H), 7.83 (t, J = 2.3 Hz, 1H),
7.88 (ddd, J = 8.2, 2.1, 0.9 Hz, 1H) ppm.; 13C NMR (75 MHz, CDCl3) δ
56.3, 76.7, 77.3, 109.6, 116.6, 121.9, 130.1, 149.1, 157.9 ppm.
1-nitro-4-(prop-2-yn-1-yloxy)benzene (5g) [42]
Purification by silica gel column chromatography using 15% EtOAc:
1
n-hexane as eluent gave yellow solid with quantitative yield. H NMR
(300 MHz, CDCl3) δ 2.59 (t, J = 3.0 Hz, 1H), 4.81 (d, J = 3.0 Hz, 2H), 7.1
(dd, J = 6.0, 3.0 Hz, 2H), 8.24 (dd, J = 6.0, 3.0 Hz, 2H) ppm.; 13C NMR
(75 MHz, DMSO‑d6) δ 56.3, 78.2, 79.1, 115.0, 125.8, 141.4, 162.3 ppm.
1-(prop-2-yn-1-yloxy)-2-(trifluoromethyl)benzene (5h) [57]
Purification by silica gel column chromatography using n-hexane as
eluent gave colorless oil with 98% yield. 1H NMR (300 MHz, CDCl3) δ
2.53 (t, J = 2.3 Hz, 1H), 4.79 (d, J = 2.3 Hz, 2H), 7.06 (t, J = 7.6 Hz, 1H),
7.16 (d, J = 8.4 Hz, 1H), 7.51 (t, J = 7.6 Hz, 1H), 7.59 (d, J = 7.6 Hz, 1H)
ppm.; 13C NMR (75 MHz, CDCl3) δ 56.4, 76.2, 77.8, 113.6, 123.5 (q, 1JFC
= 270.7 Hz), 119.5 (q, 2JFC = 30.8 Hz), 121.0, 127.3 (q, 3JFC = 5.3 Hz),
133.1, 155.4 (q, 4JFC = 1.6 Hz) ppm.; 19F NMR (282 MHz CDCl3) δ ꢀ 62.9
(s, 3F) ppm.
4.3. Chemistry
4.3.1. Preparation of alkynes 5
General procedure A: Preparation of alkyne derivatives 5a-5ac
[42]
At room temperature, neat propargyl bromide or a solution of 80%
propargyl bromide (4) in THF (1.0–1.5 eq.) was added dropwise to a
stirred suspension of phenol derivatives (1.0 eq.) in CH3CN and Cs2CO3
(1.0–2.0 eq.). The resulting mixture was stirred at room temperature
overnight or heated to reflux for 2–24 h. The resulting mixture was
diluted with water and extracted with EtOAc. The organic phases were
combined and concentrated under reduced pressure to provide crude
propargyl derivatives. The residue was purified by silica gel column
chromatography to furnish the desired products 5a-5ac.
(pro-2-yn-1-yloxy)benzene (5a) [42]
1-(prop-2-yn-1-yloxy)-3-(trifluoromethyl)benzene (5i) [57]
Purification by silica gel column chromatography using n-hexane as
eluent gave colorless oil with 85% yield. 1H NMR (300 MHz, CDCl3) δ
3.61 (t, J = 2.4 Hz, 1H), 4.92 (d, J = 2.4 Hz, 2H), 7.32 (m, 3H), 7.55 (m,
1H) ppm.; 13C NMR (75 MHz, CDCl3) δ 55.9, 78.7, 78.7, 111.48 (q, 3JFC
= 3.8 Hz), 117.9 (q, 3JFC = 3.9 Hz), 119.3, 124.0 (q, 1JFC = 270.7 Hz),
2
130.4 (q, JFC = 31.6 Hz), 130.7, 157.5 ppm.; 19F NMR (282 MHz,
CDCl3) δ ꢀ 62.9 (s, 3F) ppm.
1-(prop-2-yn-1-yloxy)-4-(trifluoromethyl)benzene (5j) [58]
Purification by silica gel column chromatography using n-hexane as
eluent gave pale-yellow oil with quantitative yield. 1H NMR (300 MHz,
DMSO‑d6) δ 3.62 (t, J = 2.3 Hz, 1H), 4.91 (d, J = 2.3 Hz, 2H), 7.17 (d, J
= 8.8 Hz, 2H),7.66 (d, J = 8.8 Hz, 2H) ppm.; 13C NMR (75 MHz,
DMSO‑d6) δ 55.8, 78.6, 78.7, 115.3, 121.9 (q, 2JFC = 31.9 Hz), 124.5 (q,
1JFC = 269.4 Hz), 126.9 (q, 3JFC = 3.8 Hz), 160.0 ppm.; 19F- NMR (282
MHz, DMSO‑d6) δ ꢀ 61.5 (s, 3F) ppm.
Purification by silica gel column chromatography using n-hexane as
eluent gave a pale pink liquid with 44% yield. 1H NMR (300 MHz,
CDCl3) δ 2.52 (t, J = 2.4 Hz, 1H), 4.69 (d, J = 2.4 Hz, 2H), 6.99 (m, 3H),
7.31 (m, 2H) ppm.; 13C NMR (75 MHz, CDCl3) δ 30.9, 55.7, 76.7, 113.8,
121.9, 129.5, 157.6 ppm.
1-fluoro-2-(pro-2-yn-1-yloxy)benzene (5b) [42]
Purification by silica gel column chromatography using n-hexane as
eluent gave colorless oil with 92% yield. 1H NMR (300 MHz, DMSO‑d6) δ
3.61 (t, J = 2.3 Hz, 1H), 4.88 (d, J = 2.4 Hz, 2H), 6.98 (m, 3H), 7.19 (m,
3H) ppm.; 13C NMR (75 MHz, DMSO‑d6) δ 56.4, 78.7, 78.8, 115.7, 116.2
(d, 2JFC = 17.3 Hz), 121.9 (d, 3JFC = 6.8 Hz), 124.7 (d, 3JFC = 3.8 Hz),
145.0 (d, 2JFC = 9.8 Hz), 151.9 (d, 1JFC = 242.3 Hz) ppm.; 19F NMR (282
MHz, DMSO‑d6) δ ꢀ 136.4 (s, 1F) ppm.
1-(tert-butyl)-2-(prop-2-yn-1-yloxy)benzene (5k) [57]
Purification by silica gel column chromatography using n-hexane as
eluent gave colorless oil with quantitative yield. 1H NMR (300 MHz,
CDCl3) δ 1.39 (s, 9H), 2.47 (t, J = 2.4 Hz, 1H), 4.71 (d, J = 2.4 Hz, 2H),
6.93 (m, 2H), 7.18 (ddd, J = 8.2, 7.6, 1.7 Hz, 1H), 7.30 (dd, J = 7.6, 1.7
Hz, 1H) ppm.; 13C NMR (75 MHz, CDCl3) δ 29.9, 34.8, 55.5, 75.0, 78.9,
112.7, 121.2, 121.8, 126.9, 138.7, 156.5 ppm.
1-fluoro-3-(pro-2-yn-1-yloxy)benzene (5c) [42]
1-(tert-butyl)-3-(prop-2-yn-1-yloxy)benzene (5l) [57]
Purification by silica gel column chromatography using n-hexane as
eluent gave colorless liquid with 97% yield. 1H NMR (300 MHz, CDCl3) δ
2.53 (t, J = 2.3 Hz, 1H), 4.67 (d, J = 2.3 Hz, 2H), 6.67 (m, 3H), 7.24 (m,
Purification by silica gel column chromatography using n-hexane as
eluent gave colorless oil with 96% yield. 1H NMR (300 MHz, CDCl3) δ
1.31 (s, 9H), 2.51 (t, J = 2.4 Hz, 1H), 4.68 (d, J = 2.4 Hz, 2H), 6.79 (dd,
J = 7.9, 2.5 Hz, 1H), 7.03 (m, 1H), 7.24 (m, 1H) ppm.; 13C NMR (75
MHz, CDCl3) δ 31.7, 34.8, 55.7, 75.4, 78.8, 111.0, 113.0, 118.7, 128.9,
153.1, 157.4 ppm.
1H) ppm.; 13C NMR (75 MHz, CDCl3) δ 56.0, 75.9, 78.1, 102.8 (d, 2JFC
=
24.8 Hz), 108.4 (d, 2JFC = 21.8 Hz), 110.6 (d, 4JFC = 3.4 Hz), 130.3 (d,
3
JFC = 9.8 Hz), 158.8 (d, 3JFC = 3.8 Hz), 163.5 (d, 1JFC = 243.8 Hz) ppm.;
19F NMR (282 MHz, CDCl3) δ ꢀ 112.2 (s, 1F) ppm.
1-(tert-butyl)-4-(prop-2-yn-1-yloxy)benzene (5m) [59]
1-fluoro-4-(pro-2-yn-1-yloxy)benzene (5d) [42]
Purification by silica gel column chromatography using n-hexane as
eluent gave yellow oil with 85% yield. 1HNMR (300 MHz, CDCl3) δ 1.28
(s, 9H), 2.45 (t, J = 2.4 Hz, 1H), 4.61 (d, J = 2.4 Hz, 2H), 6.89 (d, J = 8.7
Hz, 2H), 7.29 (d, J = 8.7 Hz, 2H) ppm.; 13C NMR (75 MHz, CDCl3) δ
31.5, 34.0, 55.7, 75.3, 78.9, 114.3, 126.2, 144.1, 155.3 ppm.
1,2-difluoro-3-(prop-2-yn-1-yloxy)benzene (5n) [60]
Purification by silica gel column chromatography using n-hexane as
eluent gave colorless liquid with 76% yield. 1H NMR (300 MHz, CDCl3) δ
2.51 (t, J = 2.4 Hz, 1H), 4.64 (d, J = 2.4 Hz, 2H), 6.95 (m, 4H) ppm.; 13
C
2
NMR (75 MHz, CDCl3) δ 56.5, 75.7, 78.5, 115.9 (d, JFC = 23.2 Hz),
116.2 (d, 3JFC = 8.0 Hz), 153.7 (d, 4JFC = 2.2 Hz), 157.8 (d, 1JFC = 237.7
Hz) ppm.; 19F NMR (282 MHz, DMSO‑d6) δ ꢀ 124.8 (s, 1F) ppm.
1-nitro-2-(prop-2-yn-1-yloxy)benzene (5e) [42]
Purification by silica gel column chromatography using n-hexane as
eluent gave colorless oil with 77% yield. 1H NMR (300 MHz, CDCl3) δ
2.55 (t, J = 2.4 Hz, 1H), 4.78 (d, J = 2.4 Hz, 2H), 6.85 (m, 2H), 7.00 (m,
Purification by silica gel column chromatography using 15% EtOAc:
1
n-hexane as eluent gave yellow solid with quantitative yield. H NMR
1H) ppm.; 13C NMR (75 MHz, CDCl3) δ 57.1, 76.5, 77.7, 110.3 (d, 2JFC
=
(300 MHz, CDCl3) δ 2.59 (t, J = 3.0 Hz, 1H), 4.81 (d, J = 3.0 Hz, 2H), 7.1
8

S. Palakhachane et al.
Bioorganic Chemistry 112 (2021) 104831
17.3 Hz), 111.0 (d, 4JFC = 3.0 Hz), 123.1 (dd, 3JFC, 4JFC = 9.0, 5.3 Hz),
141.8 (dd, 1JFC = 246.7, 14.3 Hz), 147.1 (dd,3JFC, 4JFC = 5.3, 3.0 Hz),
151.5 (dd, 1JFC, 2JFC = 246.0,10.5 Hz) ppm.; 19F NMR (282 MHz, CDCl3)
δ ꢀ 137.7 (s, 1F), ꢀ 137.8 (s, 1F) ppm.
132.4, 155.9 ppm.; 19F NMR (282 MHz CDCl3) δ ꢀ 63.5 (s, 3F) ppm.
1-methyl-4-(prop-2-yn-1-yloxy)benzene (5v) [65]
Purification by silica gel column chromatography using n-hexane as
eluent gave pale-yellow oil with 93% yield. 1H NMR (300 MHz, CDCl3) δ
2.29 (s, 3H), 2.50 (t, J = 2.4 Hz, 1H), 4.61 (d, J = 2.4 Hz, 2H), 6.83 (d, J
= 9.3 Hz, 2H), 6.92 (d, J = 9.3 Hz, 2H) ppm.; 13C NMR (75 MHz,
DMSO‑d6) δ 20.5, 55.9, 75.3, 78.8, 114.8, 129.9, 130.9, 155.4 ppm.
1-ethyl-4-(prop-2-yn-1-yloxy)benzene (5w) [66]
2,4-difluoro-1-(prop-2-yn-1-yloxy)benzene (5o) [61]
Purification by silica gel column chromatography using n-hexane as
eluent gave colorless oil with 78% yield. 1H NMR (300 MHz, CDCl3) δ
2.54 (t, J = 2.4 Hz, 1H), 4.72 (d, J = 2.4 Hz, 2H), 6.79 (m, 2H), 7.08 (m,
1H) ppm.; 13C NMR (75 MHz, CDCl3) δ 58.2, 76.3, 78.0, 105.1 (dd, 2JFC
,
Purification by silica gel column chromatography using n-hexane as
eluent gave colorless oil with quantitative yield. 1H NMR (300 MHz,
CDCl3) δ 1.21(t, J = 7.6 Hz, 3H), 2.49 (t, J = 2.4 Hz, 1H), 2.59 (q, J = 7.6
Hz, 2H), 4.65 (d, J = 2.4 Hz, 2H), 6.90 (d, J = 8.7 Hz, 2H), 7.2 (d, J = 8.7
Hz, 2H) ppm.; 13C NMR (75 MHz, DMSO‑d6) δ 15.8, 28.0, 55.9, 75.3,
78.8, 114.8, 128.7, 137.4, 155.6 ppm.
2JFC = 26.3, 21.8 Hz), 110.5 (dd, 2JFC, 4JFC = 22.5, 3.8 Hz), 117.6 (dd,
3JFC, 3JFC = 9.0, 2.3 Hz), 114.9 (dd, 2JFC, 4JFC = 10.5, 3.0 Hz), 153.2 (dd,
3
1
3
1JFC, JFC = 248.3, 12.0 Hz), 157.4 (dd, JFC, JFC = 241.5, 10.5 Hz)
ppm.; 19F NMR (282 MHz, CDCl3) δ ꢀ 119.0 (d, JFF = 3.4 Hz, 1F), ꢀ 129.2
(d, JFF = 3.4 Hz, 1F) ppm.
1,4-difluoro-2-(prop-2-yn-1-yloxy)benzene (5p) [62]
1-isopropyl-4-(prop-2-yn-1-yloxy)benzene (5x) [67]
Purification by silica gel column chromatography using n-hexane as
eluent gave colorless oil with 92% yield. 1H NMR (300 MHz, CDCl3) δ
2.58 (t, J = 2.4 Hz, 1H), 4.73 (d, J = 2.4 Hz, 2H), 6.63 (m, 1H), 6.85 (m,
1H), 7.01 (m, 1H) ppm.; 13C NMR (75 MHz, CDCl3) δ 57.3, 76.8, 77.5,
103.9 (dd, 2JFC, 3JFC = 42.8, 1.5 Hz), 107.9 (dd, 2JFC, 3JFC = 23.3, 6.8
Hz), 116.5 (dd, 2JFC, 3JFC = 21.0, 10.5 Hz), 146.1 (dd, 2JFC, 3JFC = 13.6,
Purification by silica gel column chromatography using n-hexane as
eluent gave colorless oil with quantitative yield. 1H NMR (300 MHz,
CDCl3) δ 1.23 (d, J = 6.9 Hz, 6H), 2.50 (t, J = 2.4 Hz, 1H), 2.86 (m, 1H),
4.66 (d, J = 2.4 Hz, 2H), 6.91 (d, J = 8.7 Hz, 2H), 7.16 (d, J = 8.7 Hz,
2H) ppm.; 13C NMR (75 MHz, CDCl3) δ 24.2, 33.3, 55.86, 75.3, 78.5,
114.7, 127.3, 142.0, 155.6 ppm.
11.9 Hz), 149.3 (dd, 1JFC, 4JFC = 240.8, 3.8 Hz), 158.6 (dd, 1JFC, 4JFC
=
1-chloro-4-(prop-2-yn-1-yloxy)benzene (5y) [65]
240.8, 2.3 Hz) ppm.; 19F NMR (282 MHz, CDCl3) δ ꢀ 117.3 (d, JFF = 14.1
Hz, 1F), ꢀ 140.2 (d, JFF = 14.1 Hz, 1F) ppm.
Purification by silica gel column chromatography using 5% EtOAc: n-
hexane as eluent gave colorless oil with 70% yield. 1H NMR (300 MHz,
CDCl3) δ 2.52 (t, J = 2.4 Hz, 1H), 4.66 (d, J = 2.4 Hz, 2H), 6.89 (d, J =
9.1 Hz, 2H), 7.24 (d, J = 9.1, 2H) ppm.; 13C NMR (75 MHz, CDCl3) δ
56.1, 75.8, 78.2, 116.3, 126.5, 129.4, 156.1 ppm.
1,3-difluoro-2-(prop-2-yn-1-yloxy)benzene (5q) [63]
Purification by silica gel column chromatography using n-hexane as
eluent gave colorless oil with 96% yield. 1H NMR (300 MHz, CDCl3) δ
2.51 (t, J = 2.4 Hz, 1H), 4.81 (d, J = 2.4 Hz, 2H), 6.96 (m, 3H) ppm.; 13
C
1-bromo-4-(prop-2-yn-1-yloxy)benzene (5z) [68]
NMR (75 MHz, CDCl3) δ 61.6 (t, 4JFC = 3.8 Hz), 76.3, 77.9, 112.2 (dd,
2JFC, 4JFC = 15.0, 6.8 Hz), 123.9 (t, 3JFC = 9.0 Hz), 133.9 (t, 3JFC = 14.3
Hz), 156.5 (dd, 1JFC, 3JFC = 247.5, 5.3 Hz) ppm.; 19F NMR (282 MHz,
CDCl3) δ ꢀ 128.1 (s, 2F) ppm.
Purification by silica gel column chromatography using n-hexane as
eluent gave colorless oil with 94% yield. 1H NMR (300 MHz, CDCl3) δ
2.52 (t, J = 3.0 Hz, 1H), 4.65 (d, J = 3.0 Hz, 2H), 6.86 (d, J = 9.1 Hz,
2H), 7.39 (d, J = 9.1 Hz, 2H) ppm.; 13C NMR (75 MHz, CDCl3) δ 55.9,
75.9, 78.1, 113.9, 116.7, 132.3, 156.6 ppm.
1,2-difluoro-4-(prop-2-yn-1-yloxy)benzene (5r) [64]
Purification by silica gel column chromatography using n-hexane as
eluent gave colorless oil with 88% yield. 1H NMR (300 MHz, CDCl3) δ
2.54 (t, J = 2.4 Hz, 1H), 4.65 (d, J = 2.4 Hz, 2H), 6.69 (m, 1H), 6.82 (m,
1H), 7.08 (m, 1H) ppm.; 13C NMR (75 MHz, CDCl3) δ 56.6, 76.1, 77.9,
tert-butyldimethyl(4-(prop-2-yn-1-yloxy)phenoxy)silane (5aa)
[69]
Purification by silica gel column chromatography using 5% EtOAc: n-
hexane as eluent gave white solid with 93% yield. 1H NMR (300 MHz,
CDCl3) δ 0.17 (s, 6H), 0.98 (s, 9H), 2.50 (t, J = 2.4 Hz, 1H), 4.63 (d, J =
104.9 (d, 2JFC = 20.3 Hz), 110.4 (dd, 2JFC = 63.8 Hz), 117.3 (dd, 3JFC
,
4JFC = 18.0, 1.5 Hz), 148.0 (dd, 1JFC, 2JFC = 240.0, 12.8 Hz), 150.4 (dd,
2.4 Hz, 2H), 6.77 (d, J = 9.2 Hz, 2H), 6.86 (d, J = 9.2 Hz, 2H) ppm.; 13
C
1
JFC, 2JFC = 246.8, 14.3 Hz), 153.7 (dd, 3JFC, 4JFC = 9.0, 2.3 Hz) ppm.;
NMR (75 MHz, CDCl3) δ ꢀ 4.1, 18.4, 25.9, 56.7, 75.4, 79.1, 116.1, 120.1,
150.4, 152.3 ppm.
19F NMR (282 MHz, CDCl3) δ ꢀ 136.0 (d, JFF = 19.7 Hz, 1F), ꢀ 147.9 (d,
JFF = 22.6 Hz, 1F) ppm.
1-methoxy-4-(prop-2-yn-1-yloxy)benzene (5ab) [63]
Purification by silica gel column chromatography using 5% EtOAc: n-
hexane as eluent gave pale-yellow oil with 93% yield. 1H NMR (300
MHz, CDCl3) δ 2.50 (t, J = 2.4 Hz, 1H), 3.75 (s, 3H), 4.61 (d, J = 2.4 Hz,
2H), 6.83 (d, J = 9.3 Hz, 2H), 6.92 (d, J = 9.3 Hz, 2H) ppm.; 13C NMR
(75 MHz, CDCl3) δ 55.6, 56.6, 75.3, 78.9, 114.6, 116.1, 151.7, 154.5
ppm.
1,3-difluoro-5-(prop-2-yn-1-yloxy)benzene (5s) [62]
Purification by silica gel column chromatography using n-hexane as
eluent gave colorless oil with 82% yield. 1H NMR (300 MHz, CDCl3) δ
2.56 (t, J = 2.4 Hz, 1H), 4.67 (d, J = 2.4 Hz, 2H), 6.45 (m, 1H), 6.52 (m,
2H) ppm.; 13C NMR (75 MHz, CDCl3) δ 56.3, 76.4, 77.5, 97.2 (t, 2JFC
=
25.70 Hz), 98.9 (dd, 2JFC, 4JFC = 27.8, 0.8 Hz), 159.4 (t, 3JFC = 13.6 Hz),
163.6 (dd, 1JFC, 3JFC = 245.3, 15.4 Hz) ppm.; 19F NMR (282 MHz, CDCl3)
δ ꢀ 109.7 (s, 2F) ppm.
N-(4-(prop-2-yn-1-yloxy)phenyl)acetamide (5ac) [70]
Purification by silica gel column chromatography using 30% EtOAc:
n-hexane as eluent gave colorless oil with 98% yield. 1H NMR (300 MHz,
CDCl3) δ 2.12 (s, 3H), 2.52 (t, J = 2.3 Hz, 1H), 4.65 (d, J = 2.3 Hz, 2H),
6.90 (d, J = 8.9 Hz, 2H), 7.80 (br s, 1H) ppm.; 13C NMR (75 MHz, CDCl3)
δ 24.2, 56.1, 75.6, 78.5, 115.3, 121.9, 131.9, 154.3, 168.7 ppm.
1-(prop-2-yn-1-yloxy)-3,5-bis(trifluoromethyl)benzene (5t)
Purification by silica gel column chromatography using n-hexane as
eluent gave colorless oil with quantitative yield. 1H NMR (300 MHz,
CDCl3) δ 2.59 (t, J = 2.4 Hz, 1H), 4.80 (d, J = 2.4 Hz, 2H), 7.40 (s, 2H),
7.52 (s, 1H) ppm.; 13C NMR (75 MHz, CDCl3) δ 56.2, 76.6, 76.9, 115.2
(m), 115.5 (d, 4JFC = 3.0 Hz), 123.1 (q, 1JFC = 271.0 Hz), 132.9 (q, 2JFC
= 33.3 Hz), 158.0 ppm.; 19F NMR (282 MHz, CDCl3) δ ꢀ 63.2 (s, 6F)
ppm.
4.3.2. Preparation of triazolyl phenols 7
General procedure B: Cycloaddition of alkynes 5 and azide 6 to
1,2,3-triazoles 7a-7ac [42]
1-chloro-4-(prop-2-yn-1-yloxy)-2-(trifluoromethyl)benzene
(5u)
To a stirred mixture of alkyne derivatives 5 and 4-azidophenol (6) in
n-BuOH:water was added sodium ascorbate and 1 M aq. CuSO4,
sequentially, at room temperature. The obtained mixture was stirred at
60 ◦C for 2–24 h. After that, the resulting solution was cooled down with
ice water, followed by addition of 10% aq. NH3. It was then stirred for
another 5 min. The formed precipitate was collected by a Büchner
filtration. Purification of the crude products was performed by silica gel
column chromatography to provide the desired products 7a-7ac.
Purification by silica gel column chromatography using n-hexane as
eluent gave colorless oil with 93% yield. 1H NMR (300 MHz, CDCl3) δ
2.56 (t, J = 2.4 Hz, 1H), 4.72 (d, J = 2.4 Hz, 2H), 7.09 (dd, J = 8.8, 3.0
Hz, 1H), 7.30 (d, J = 3.0 Hz, 1H), 7.42 (d, J = 8.8 Hz, 1H) ppm.; 13
C
3
NMR (75, MHz, CDCl3) δ 56.3, 76.5, 77.4, 114.7 (q, JFC = 5.3
Hz),119.1, 122.6 (q, 1JFC = 271.5 Hz), 124.3, 129.2 (q, 2JFC = 30.8 Hz),
9

S. Palakhachane et al.
Bioorganic Chemistry 112 (2021) 104831
4-(4-(phenoxy methyl)-1H-1,2,3-triazol-1-yl)phenol (7a) [42]
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave white solid with 62% yield. 1H NMR (300 MHz,
DMSO‑d6) δ 5.21 (s, 2H), 6.91–7.68 (m, 9H), 8.75 (s, 1H) ppm.; 13C NMR
(75 MHz, DMSO‑d6) δ 61.0, 114.7, 116.1, 120.9, 122.0, 122.7, 129.2,
129.9, 143.5, 157.8, 158.0 ppm.
DMSO‑d6) δ 5.40 (s, 2H), 6.95 (d, J = 9.0 Hz, 2H), 7.31 (d, J = 9.0 Hz,
2H), 7.68 (d, J = 9.0 Hz, 2H), 8.24 (d, J = 9.0 Hz, 2H), 8.81 (s, 1H), 9.99
(br s, 1H) ppm.; 13C NMR (75 MHz, DMSO‑d6) δ 61.9, 115.4, 116.1,
122.1, 123.1, 125.9, 128.6. 141.1, 142.5. 157.9, 163.2 ppm.; HRMS
(ESI+) m/z: calcd. for C15H13N4O4 [M+H]+ 313.0937, found 313.0936.
4-(4-((2-(trifluoromethyl)phenoxy)methyl)-1H-1,2,3-triazol-1-
yl)phenol (7h)
4-(4-((2-fluorophenoxy)methyl)-1H-1,2,3-triazol-1-yl)phenol
(7b)[42]
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave brown solid with 66% yield. Mp. = 171–173 ◦C;
1H NMR (300 MHz, DMSO‑d6) δ 5.37 (s, 2H), 6.94 (d, J = 8.9 Hz, 2H),
7.11 (t, J = 7.5 Hz, 1H), 7.52 (d, J = 8.4 Hz, 1H), 7.65 (m, 4H), 8.72 (s,
1H), 9.94 (br s, 1H) ppm.; 13C NMR (75 MHz, DMSO‑d6) δ 62.0, 114.3,
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave brown solid with 57% yield. 1H NMR (300 MHz,
DMSO‑d6) δ 5.29 (s, 2H), 6.95 (d, J = 8.9 Hz, 2H), 6.95–7.01 (m, 1H),
7.13–7.19 (m, 1H), 7.23 (dd, J = 8.9, 1.6 Hz, 1H), 7.40 (td, J = 8.5, 1.5
Hz, 1H), 7.69 (d, J = 8.9, 2H), 8.79 (s, 1H), 9.98 (br s, 1H) ppm.; 13
C
116.2, 117.5 (q, JFC = 15.0 Hz), 123.8 (q, JFC = 270.8 Hz), 120.8,
2
1
2
3
NMR (75 MHz, DMSO‑d6) δ 62.0, 115.6, 116.1 (d, JFC = 18.0 Hz),
122.1, 122.9, 126.9 (q, JFC = 5.3 Hz), 128.7, 134.3, 143.0, 155.9,
116.1, 121.5 (d, 3JFC = 7.5 Hz), 122.1, 123.0, 124.8 (d, 3JFC = 3.8 Hz),
158.0 ppm.; 19F NMR (282 MHz, DMSO‑d6) δ ꢀ 62.3 (s, 3F) ppm.; HRMS
(ESI+) m/z: calcd for C16H12F3N3O2Na [M+Na]+ 358.0779, found
358.0774.
2
1
128.7, 143.0, 145.9 (d, JFC = 10.4 Hz), 151.8 (d, JFC = 242.0 Hz),
157.9 ppm.; 19F NMR (282 MHz, DMSO‑d6) δ ꢀ 136.4 (s, 1F) ppm.;
HRMS (ESI+) m/z: calcd. for C15H13FN3O2 [M+H]+ 286.0992, found
286.0987.
4-(4-((3-(trifluoromethyl)phenoxy)methyl)-1H-1,2,3-triazol-1-
yl)phenol (7i)
4-(4-((3-fluorophenoxy)methyl)-1H-1,2,3-triazol-1-yl)phenol
(7c) [42]
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave brown solid with 39% yield. Mp. = 184–186 ◦C;
1H NMR (300 MHz, DMSO‑d6) δ 5.32 (s, 2H), 6.95 (d, J = 8.9 Hz, 2H),
7.32 (d, J = 7.7 Hz, 1H), 7.40 (d, J = 7.1 Hz, 2H), 7.56 (m, 1H), 7.67 (d,
J = 8.9 Hz, 2H), 8.78 (s, 1H), 9.96 (br s, 1H) ppm.; 13C NMR (75 MHz,
DMSO‑d6) δ 61.5, 111.5 (q, 3JFC = 3.8 Hz), 116.2, 117.6 (q, 3JFC = 3.8
Hz), 119.1, 122.1, 124.2 (q, 1JFC = 270.0 Hz), 122.1, 123.0, 128.7, 130.5
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave brown solid with 81% yield. 1H NMR (300 MHz,
DMSO‑d6) δ 5.23 (s, 1H), 6.78 (td, J = 8.67, 2.37 Hz, 1H), 6.94 (m, 4H),
7.32 (m, 1H), 7.67 (d, J = 8.9 Hz, 2H), 8.75 (s, 1H), 9.97 (br s, 1H) ppm.;
13C NMR (75 MHz, DMSO‑d6) δ 61.5, 102.4, (d, 2JFC = 24.8 Hz), 107.7
(d, 2JFC = 21.0 Hz), 111.2 (d, 4JFC = 3.0 Hz), 116.2, 122.2, 123.0, 128.8,
130.8 (d, 3JFC = 10.5 Hz), 143.2, 158.0, 159.6 (d, 3JFC = 11.3 Hz), 163.1
(d, 1JFC = 241.5 Hz) ppm.; 19F NMR (282 MHz, DMSO‑d6) δ ꢀ 113.0 (s,
1F) ppm.; HRMS (ESI+) m/z: calcd. for C15H13FN3O2 [M+H]+
308.0809, found 308.0811.
2
(q, JFC = 31.5 Hz), 143.1, 157.9, 158.4 ppm.; 19F NMR (282 MHz,
DMSO‑d6)
δ ꢀ 62.7 (s, 3F) ppm.; HRMS (ESI+) m/z: calcd for
C
16H13F3N3O2 [M+H]+ 336.0960, found 336.0954.
4-(4-((4-(trifluoromethyl)phenoxy)methyl)-1H-1,2,3-triazol-1-
yl)phenol (7j)
4-(4-((4-fluorophenoxy)methyl)-1H-1,2,3-triazol-1-yl)phenol
(7d)[42]
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave pale-pink solid with 82% yield. Mp. =
225–226 ◦C; 1H NMR (300 MHz, DMSO‑d6) δ 5.32 (s, 2H), 6.95 (d, J =
8.9 Hz, 2H), 7.26 (d, J = 8.9 Hz, 2H), 7.67 (m, 4H), 8.79 (s, 1H), 9.98 (br
s, 1H) ppm.; 13C NMR (75 MHz, DMSO‑d6) δ 61.4, 115.4, 116.2, 124.7
(q, 1JFC = 270.0 Hz), 121.6 (q, 2JFC = 31.9 Hz) 122.2, 123.1, 127.12 (q,
3JFC = 3.5 Hz), 128.8, 123.1, 158.0, 160.9 ppm.; 19F NMR (282 MHz,
DMSO‑d6) δ ꢀ 61.4 (s, 3F) ppm.; HRMS (ESI+) m/z: calcd for
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave white solid with 62% yield. 1H NMR (300 MHz,
DMSO‑d6) δ 5.18 (s, 2H), 6.94 (dd, J = 6.0, 3.0 Hz, 2H), 7.12 (m, 4H),
7.66 (dd, J = 6.0, 3.0 Hz, 2H), 8.75 (3, 1H), 9.96 (br s, 1H) ppm.; 13
C
NMR (75 MHz, DMSO‑d6) δ 61.6, 115.9 (d, 2JFC = 25.1 Hz), 116.1 (d,
3JFC = 10.1 Hz), 116.1, 122.0, 122.8, 128.7, 143.4, 154.3 (d, 4JFC = 1.8
1
Hz), 156.7 (d, JFC = 234.6 Hz), 157.8 ppm.; 19F NMR (282 MHz,
C
16H12F3N3O2Na [M+Na]+ 358.0779, found 358.0777.
DMSO‑d6) δ ꢀ 125.2 (s, 1F) ppm.; HRMS (ESI+) m/z: calcd. for
4-(4-((2-(tert-butyl)phenoxy)methyl)-1H-1,2,3-triazol-1-yl)
C
15H13FN3O2 [M+H]+ 286.0992, found 286.0981.
phenol (7k)
4-(4-((2-nitrophenoxy)methyl)-1H-1,2,3-triazol-1-yl)phenol
Purification by silica gel column chromatography using 50% EtOAc:
(7e) [42]
n-hexane as eluent gave brown solid with 48% yield. Mp. = 226–227 ◦C;
1H NMR (300 MHz, DMSO‑d6) δ 1.31 (s, 9H), 5.23 (s, 2H), 6.91 (m, 1H),
6.96 (d, J = 8.9 Hz, 2H), 7.23 (m, 3H), 7.79 (d, J = 8.9 Hz, 2H), 8.76 (s,
1H), 9.97 (br s, 1H) ppm.; 13C NMR (75 MHz, DMSO‑d6) δ 29.7, 34.4,
61.1, 113.0, 116.1, 120.7, 122.0, 122.4, 126.3, 127.2, 128.7, 137.5,
143.7, 156.9, 157.8 ppm.; HRMS (ESI+) m/z: calcd for C19H22N3O2
[M+H]+ 324.1712, found 324.1697.
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave brown solid with 80% yield. 1H NMR (300 MHz,
DMSO‑d6) δ 5.43 (s, 2H), 6.94 (dd, J = 10.0, 3.3 Hz, 2H), 7.15 (ddd, J =
8.0, 7.2, 1.4 Hz, 1H), 7.67 (m, 4H), 7.88 (dd, J = 8.1, 1.6 Hz, 1H), 8.77
(s, 1H), 9.98 (br s, 1H) ppm.; 13C NMR (75 MHz, DMSO‑d6) δ 62.5,
115.7, 116.1, 121.1, 122.1, 123.1, 125.0, 128.6, 134.4, 139.9, 142.2,
150.6, 157.9 ppm.; HRMS (ESI+) m/z: calcd. for C16H13F3N3O2 [M+H]+
313.0937, found 313.0937.
4-(4-((3-(tert-butyl)phenoxy)methyl)-1H-1,2,3-triazol-1-yl)
phenol (7l)
4-(4-((3-nitrophenoxy)methyl)-1H-1,2,3-triazol-1-yl)phenol
(7f) [42]
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave brown solid with 47% yield. Mp. = 171–172 ◦C;
1H NMR (300 MHz, DMSO‑d6) δ 1.52 (s, 9H), 5.19 (s, 2H), 6.95 (m, 5H),
7.23 (t, J = 7.9 Hz, 1H), 7.67 (d, J = 8.9 Hz, 2H), 8.74 (s, 1H), 9.94 (br s,
1H) ppm.; 13C NMR (75 MHz, DMSO‑d6) δ 31.1, 34.5, 61.0, 111.2,
112.5, 116.2, 117.9, 122.1, 122.7, 128.8, 129.1, 143.9, 152.5, 157.9,
158.0 ppm.; HRMS (ESI+) m/z: calcd for C19H21N3O2Na [M+Na]+
346.1531, found 346.1528.
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave brown solid with 96% yield. 1H NMR (300 MHz,
DMSO‑d6) δ 5.38 (s, 2H), 6.95 (dd, J = 12.3, 5.5 Hz, 2H), 7.62 (m, 4H),
7.85 (ddd, J = 7.7, 2.1, 1.2 Hz, 1H), 7.91 (t, J = 2.1 Hz, 1H), 8.80 (s, 1H),
9.98 (br s, 1H) ppm.; 13C NMR (75 MHz, DMSO‑d6) δ 61.8, 109.2, 115.9,
116.1, 122.1, 122.2, 123.0, 128.7, 130.8, 142.8, 142.8, 157.9, 158.5
ppm.; HRMS (ESI+) m/z: calcd. for C15H13N4O4 [M+H]+ 313.0937,
found 313.0927.
4-(4-((4-(tert-butyl)phenoxy)methyl)-1H-1,2,3-triazol-1-yl)
phenol (7m)
4-(4-((4-nitrophenoxy)methyl)-1H-1,2,3-triazol-1-yl)phenol
(7g) [42]
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave pale-pink solid with 26% yield. Mp. =
237–238 ◦C; 1H NMR (300 MHz, DMSO‑d6) δ 1.25 (s, 9H), 5.17 (s, 2H),
6.96 (m, 4H), 7.31 (d, J = 8.7 Hz, 2H), 7.67 (d, J = 8.7 Hz, 2H), 8.74 (s,
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave brown solid with 63% yield. 1H NMR (300 MHz,
10

S. Palakhachane et al.
Bioorganic Chemistry 112 (2021) 104831
2
3
1H), 9.96 (br s, 1H) ppm.; 13C NMR (75 MHz, DMSO‑d6) δ 31.3, 33.8,
61.0, 114.2, 116.0, 122.0, 122.6, 126.1, 128.7, 143.1, 143.7, 155.8,
157.8 ppm.; HRMS (ESI+) m/z: calcd for C19H22N3O2 [M+H]+
324.1712, found 324.1715.
243.8, 13.5 Hz), 154.7 (dd, JFC, JFC = 8.9, 1.5 Hz), 158.0 ppm.; 19F
NMR (282 MHz, DMSO‑d6) δ ꢀ 137.9 (d, JFF = 22.8, 1F), ꢀ 150.4 (d, JFF
= 22.8, 1F) ppm.; HRMS (ESI+) m/z: calcd for C15H11F2N3O2Na
[M+Na]+ 326.0717, found 326.0712.
4-(4-((2,3-difluorophenoxy)methyl)-1H-1,2,3-triazol-1-yl)
phenol (7n)
4-(4-((3,5-difluorophenoxy)methyl)-1H-1,2,3-triazol-1-yl)
phenol (7s)
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave brown solid with 68% yield. Mp. = 185–187 ◦C;
1H NMR (300 MHz, DMSO‑d6) δ 5.33 (s, 2H), 6.94 (d, J = 8.9 Hz, 2H),
7.01 (m, 1H), 7.16 (m, 1H), 7.26 (m, 1H), 7.67 (d, J = 8.9 Hz, 2H), 8.78
(s, 1H), 9.96 (br s, 1H) ppm.; 13C NMR (75 MHz, DMSO‑d6) δ 62.5, 109.4
(d, 3JFC = 16.5 Hz), 111.1 (d, 3JFC = 3.0 Hz), 116.2, 122.2, 123.2, 124.2
(dd, 2JFC, 3JFC = 9.0, 5.3 Hz), 128.7, 140.4 (dd, 1JFC, 2JFC = 243.8, 14.3
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave brown solid with 77% yield. Mp. = 223–224 ◦C;
1H NMR (300 MHz, DMSO‑d6) δ 5.26 (s, 2H), 6.84 (m, 3H), 6.95 (d, J =
8.9 Hz, 2H), 7.67 (d, J = 8.9 Hz, 2H), 8.79 (s, 1H), 9.97 (br s, 1H) ppm.;
13C NMR (75 MHz, DMSO‑d6) δ 61.9, 96.6 (t, 2JFC = 26.3 Hz), 99.3 (dd,
2JFC
,
4JFC = 18.9, 9.4 Hz), 116.2, 122.2, 123.1, 128.7, 142.7, 158.0,
160.2 (t, 3JFC = 14.1 Hz), 163.1 (dd, 1JFC, 3JFC = 242.6, 16.2 Hz) ppm.;
19F NMR (282 MHz, DMSO‑d6) δ ꢀ 110.6 (s, 2F) ppm.; HRMS (ESI+) m/
z: calcd for C15H11F2N3O2 [M+H]+ 304.0898, found 304.0886.
4-(4-((3,5-bis(trifluoromethyl)phenoxy)methyl)-1H-1,2,3-tri-
azol-1-yl)phenol (7t)
Hz), 142.8, 147.5 (dd, 2JFC, 3JFC = 7.5, 3.1 Hz), 150.6 (dd, 1JFC, 2JFC
=
242.3, 9.3 Hz), 158.0 ppm.; 19F NMR (282 MHz, DMSO‑d6) δ ꢀ 139.8 (s,
1F), ꢀ 139.9 (s, 1F) ppm.; HRMS (ESI+) m/z: calcd for C15H11F2N3O2Na
[M+Na]+ 326.0717, found 326.0716.
4-(4-((2,4-difluorophenoxy)methyl)-1H-1,2,3-triazol-1-yl)
phenol (7o)
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave brown solid with 85% yield. Mp. = 199–200 ◦C;
1H NMR (300 MHz, DMSO‑d6) δ 5.45 (s, 2H), 6.95 (d, J = 8.9 Hz, 2H),
7.67 (m, 2H), 7.79 (s, 2H), 8.80 (s, 1H), 9.98 (br s, 1H) ppm.; 13C NMR
(75 MHz, DMSO‑d6) δ 62.1, 114.1, 116.0, 116.1, 123.1 (q, 1JFC = 270.8
Hz), 122.1, 123.1, 128.6, 131.6 (q, 2JFC = 33.4 Hz), 142.6, 157.9, 159.0
ppm.; 19F NMR (282 MHz, DMSO‑d6) δ ꢀ 62.9 (s, 6F) ppm.; HRMS
(ESI+) m/z: calcd for C17H12F6N3O2 [M+H]+ 404.0834, found
404.0838.
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave brown solid with 64% yield. Mp. = 183–184 ◦C;
1H NMR (300 MHz, DMSO‑d6) δ 5.27 (s, 2H), 6.94 (d, J = 8.9 Hz, 2H),
7.02 (m, 1H), 7.27 (m, 1H), 7.40 (m, 1H), 7.66 (d, J = 8.9 Hz, 2H) ppm.;
13C NMR (75 MHz, DMSO‑d6) δ 62.7, 105.0 (dd, 2JFC, 2JFC = 68.3, 22.5
Hz), 110.9 (dd, 2JFC, 4JFC = 21.8, 3.8 Hz), 116.16, 11.53 (dd, 3JFC, 3JFC
=
9.0, 2.3 Hz), 122.2, 123.1, 128.8, 142.6 (dd, 2JFC, 4JFC = 10.5, 3.8 Hz),
143.0, 151.69 (dd, 1JFC, JFC = 245.3, 10.5 Hz), 155.9 (dd, 1JFC, JFC
=
4-(4-((4-chloro-3-(trifluoromethyl)phenoxy)methyl)-1H-1,2,3-
triazol-1-yl)phenol (7u)
3
3
237.8, 10.5 Hz), 158.0 ppm.; 19F NMR (282 MHz, DMSO‑d6) δ ꢀ 121.3
(d, JFF = 28.2 Hz, 1F),-131.1 (d, JFF = 28.2 Hz, 1F) ppm.; HRMS (ESI+)
m/z: calcd for C15H11F2N3O2Na [M+Na]+ 326.0717, found 326.0719.
4-(4-((2,5-difluorophenoxy)methyl)-1H-1,2,3-triazol-1-yl)
phenol (7p)
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave brown solid with 41% yield. Mp. = 191–193 ◦C;
1H NMR (300 MHz, DMSO‑d6) δ 5.45 (s, 2H), 6.95 (d, J = 8.9 Hz, 2H),
7.67 (m, 2H), 7.79 (s, 2H), 8.80 (s, 1H), 9.98 (br s, 1H) ppm.; 13C NMR
(75 MHz, DMSO‑d6) δ 61.8, 114.6 (q, 3JFC = 5.5 Hz), 116.1, 122.4 (q,
1JFC = 270.0 Hz), 120.2, 121.9 (d, 4JFC = 2.3 Hz), 122.1, 123.0, 127.5 (q,
2JFC = 25.5 Hz), 128.6, 132.8, 142.8, 156.8, 158.0 ppm.; 19F NMR (282
MHz, DMSO‑d6) δ ꢀ 62.9 (s, 3F) ppm.; HRMS (ESI+) m/z: calcd for
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave brown solid with 73% yield. Mp. = 180–181 ◦C;
1H NMR (300 MHz, DMSO‑d6) δ 5.31 (s, 2H), 6.78 (m, 1H), 6.95 (d, J =
9.0 Hz, 2H), 7.25 (m, 1H), 7.36 (m, 1H), 7.68 (d, J = 9.0 Hz, 2H), 8.78 (s,
1H), 9.98 (br s, 1H) ppm.; 13C NMR (75 MHz, DMSO‑d6) δ 62.3, 103.5
C
16H13ClF3N3O2 [M+H]+ 370.0570, found 370.0565.
(dd, 2JFC, JFC = 27.8, 2.3 Hz), 107.0 (dd, 2JFC, JFC = 24.0, 17.5 Hz),
4-(4-((p-tolyloxy)methyl)-1H-1,2,3-triazol-1-yl)phenol (7v) [44]
Purification by silica gel column chromatography using 50% EtOAc:
3
3
116.2, 116.6 (dd, 2JFC, JFC = 20.3, 10.5 Hz), 122.2, 123.3, 128.7, 142.6,
3
146.7 (dd, 2JFC, 3JFC = 12.0, 11.3 Hz), 148.3 (dd, 1JFC, JFC = 242.3, 3.0
n-hexane as eluent gave brown solid with 31% yield. 1H NMR (300 MHz,
CDCl3) δ 2.24 (s, 3H), 5.16 (s, 2H), 7.00 (m, 8H), 8.74 (s, 1H), 9.97 (s,
1H) ppm.; 13C NMR (300 MHz, DMSO‑d6) δ 20.1, 61.0, 114.6, 116.0,
122.0, 122.6, 128.7, 128.6, 129.8, 143.6, 155.9, 157.8 ppm.
4-(4-((4-ethylphenoxy)methyl)-1H-1,2,3-triazol-1-yl)phenol
(7w) [44]
4
Hz), 158.3 (dd, 1JFC, JFC = 238.5, 2.3 Hz), 158.0 ppm.; 19F NMR (282
4
MHz, DMSO‑d6) δ ꢀ 117.5 (d, JFF = 15.2 Hz, 1F), ꢀ 141.3 (d, JFF = 15.2
Hz, 1F) ppm.; HRMS (ESI+) m/z: calcd for C15H11F2N3O2Na [M+Na]+
326.0717, found 326.0718.
4-(4-((2,6-difluorophenoxy)methyl)-1H-1,2,3-triazol-1-yl)
phenol (7q)
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave brown solid with 25% yield. Mp. = 182–186 ◦C;
1H NMR (300 M Hz, DMSO‑d6) δ 1.15 (t, J = 7.6 Hz, 3H), 2.54 (q, J = 7.6
Hz, 2H), 5.17 (s, 2H), 6.97 (m, 4H), 7.14 (d, J = 8.6 Hz, 2H), 7.67 (d, J =
8.9 Hz, 2H), 8.74 (s, 1H), 9.93 (br s, 1H) ppm.; 13C NMR (75 MHz,
DMSO‑d6) δ 15.9, 27.3, 61.1, 114.6, 116.1, 122.0, 122.6, 128.7, 128.8,
136.2, 143.7, 156.1, 157.8 ppm.; HRMS (ESI+) m/z: calcd for
C17H18N3O2 [M+H]+ 296.1399, found 296.1395.
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave brown solid with 50% yield. Mp. = 166–168 ◦C;
1H NMR (300 MHz, DMSO‑d6) δ 5.26 (s, 2H), 6.94 (d, J = 9.0 Hz, 2H),
7.10 (m, 3H), 7.65 (d, J = 9.0 Hz, 2H), 8.73 (s, 1H), 9.94 (br s, 1H) ppm.;
13C NMR (75 MHz, DMSO‑d6) δ 66.6 (t,4JFC = 3.0 Hz), 112.6 (dd, 3JFC
,
3JFC = 8.3, 6.8 Hz), 116.2, 122.0, 123.1, 124.3 (t, 3JFC = 9.0 Hz), 128.7,
134.0 (t, 2JFC = 14.3 Hz), 143.0, 155.8 (dd, 1JFC, 3JFC = 245.3, 5.3 Hz),
157.9 ppm.; 19F NMR (282 MHz, DMSO‑d6) δ ꢀ 129.2 (s, 2F) ppm.;
HRMS (ESI+) m/z: calcd for C15H11F2N3O2Na [M+Na]+ 326.0717,
found 326.0719.
4-(4-((4-isopropylphenoxy)methyl)-1H-1,2,3-triazol-1-yl)
phenol (7x) [44]
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave brown solid with 67% yield. Mp. = 214–215 ◦C;
1H NMR (300 M Hz, DMSO‑d6) δ 1.18 (d, J = 6.9, 6H), 2.83 (m, 1H), 5.17
(s, 2H), 6.65 (m, 4H), 7.17 (d, J = 8.7 Hz, 2H), 7.68 (d, J = 2.8 Hz, 2H),
8.75 (s, 1H) ppm.; 13C NMR (75 MHz, DMSO‑d6) δ 24.1, 32.6, 61.1,
114.6, 116.1, 122.0, 122.7, 127.2, 128.8, 140.9, 143.8, 156.2, 157.8
ppm.; HRMS (ESI+) m/z: calcd for C18H20N3O2 [M+H]+ 310.1556,
found 310.1539.
4-(4-((3,4-difluorophenoxy)methyl)-1H-1,2,3-triazol-1-yl)
phenol (7r)
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave brown solid with 80% yield. Mp. = 195–197 ◦C;
1H NMR (300 MHz, DMSO‑d6) δ 5.20 (s, 2H), 6.89 (m, 1H), 6.94 (d, J =
8.8 Hz, 2H), 7.21 (ddd, J = 12.5, 6.7, 2.8 Hz, 1H), 7.34 (q, J = 9.7 Hz,
1H), 7.66 (d, J = 8.7 Hz, 2H), 8.74 (s, 1H), 9.95 (br s, 1H) ppm.; 13C
NMR (75 MHz, DMSO‑d6) δ 61.9, 104.5 (d, 2JFC = 20.3 Hz), 111.2 (dd,
2JFC, 3JFC = 5.9, 3.2 Hz), 116.2, 117.7 (d, 3JFC = 18.8 Hz), 122.2,123.0,
4-(4-((4-chlorophenoxy)methyl)-1H-1,2,3-triazol-1-yl)phenol
(7y)
128.8, 144.3 (dd, 1JFC, 2JFC = 236.3, 12.8 Hz), 149.7 (dd, 1JFC, 2JFC
=
Purification by silica gel column chromatography using 50% EtOAc:
11

S. Palakhachane et al.
Bioorganic Chemistry 112 (2021) 104831
n-hexane as eluent gave pale-pink solid with 53% yield. Mp. =
223–224 ◦C; 1H NMR (300 MHz, DMSO‑d6) δ 5.21 (s, 2H), 6.94 (d, J =
9.0 Hz, 2H), 7.10 (d, J = 9.0 Hz, 2H), 7.35 (d, J = 9.0 Hz, 2H), 7.66 (d, J
= 9.0 Hz, 2H), 8.75(s, 1H), 9.96 (br s,1H) ppm.; 13C NMR (75 MHz,
DMSO‑d6) δ 61.4, 116.0, 116.6, 122.0, 122.8, 124.6, 128.7, 129.3,
143.2, 156.8, 157.8 ppm.; HRMS (ESI+) m/z: calcd for C15H13ClN3O2
[M+H]+ 302.0696, found 302.0688.
152.5, 154.1, 158.1, 164.3, 165.5 ppm.; HRMS (ESI+) m/z: calcd. for
C22H19N5O3Na [M+Na]+ 424.1386, found 424.1374.
4-(4-(4-((2-fluorophenoxy)methyl)-1H-1,2,3-triazol-1-yl)phe-
noxy)-N-methylpicolinamide (2b) [42]
Purification by silica gel column chromatography using 50% EtOAc:
1
n-hexane as eluent gave orange-brown solid with 27% yield. H NMR
(300 MHz, DMSO‑d6) δ 2.78 (d, J = 4.9 Hz, 3H), 5.31 (s, 2H), 6.97 (m,
1H), 7.19 (m, 3H), 7.38 (td, J = 8.5, 1.1 Hz, 1H), 7.46 (m, 3H), 8.02 (dd,
J = 6.8, 2.2 Hz, 2H), 8.55 (d, J = 5.6 Hz, 1H), 8.82 (q, J = 4.9 Hz, 1H),
8.94 (s, 1H) ppm.; 13C NMR (75 MHz, DMSO‑d6) δ 26.3, 62.1, 109.7,
114.9, 115.9, 116.4 (d, 2JFC = 17.3 Hz), 122.0 (d, 3JFC = 6.8 Hz), 122.5,
4-(4-((4-bromophenoxy)methyl)-1H-1,2,3-triazol-1-yl)phenol
(7z)
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave brown solid with 87% yield. Mp. = 236–238 ◦C;
1H NMR (300 MHz, DMSO‑d6) δ 5.21 (s, 2H), 6.94 (d, J = 8.9 Hz, 2H),
7.05 (d, J = 9.1 Hz, 2H), 7.47 (d, J = 9.1 Hz, 2H), 7.66 (d, J = 8.9 Hz,
2H), 8.75 (s, 1H), 10.01 (br s, 1H) ppm.; 13C NMR (75 MHz, DMSO‑d6) δ
61.3, 99.6, 112.5, 116.2, 117.2, 122.2, 123.0, 128.8, 132.3, 143.3,
157.9 ppm.; HRMS (ESI+) m/z: calcd for C15H13BrN3O2 [M+H]+
346.0191, found 346.0197.
122.9, 123.6, 125.2 (d, 3JFC = 3.8 Hz), 134.2, 143.8, 146.0 (d, 2JFC
=
10.5 Hz), 152.1 (d, 1JFC = 241.5 Hz), 151.0, 152.7, 153.7, 164.1, 165.4
ppm.; 19F NMR (282 MHz, DMSO‑d6) δ ꢀ 136.7 (s, 1F) ppm.; HRMS
(ESI+) m/z: calcd. for
C
22H19FN5O3 [M+H]+ 420.1472, found
420.1456.
4-(4-(4-((3-fluorophenoxy)methyl)-1H-1,2,3-triazol-1-yl)phe-
noxy)-N-methylpicolinamide (2c) [42]
4-(4-((4-((tert-butyldimethylsilyl)oxy)phenoxy)methyl)-1H-
1,2,3-triazol-1-yl)phenol (7aa)
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave white solid with 53% yield. 1H NMR (300 MHz,
DMSO‑d6) δ 2.79 (d, J = 4.9 Hz, 3H), 5.26 (s, 2H), 6.79 (td, J = 8.3, 1.9
Hz, 1H), 6.92 (dd, J = 8.2, 2.0 Hz, 1H), 6.98 (dt, J = 11.3, 2.3 Hz, 1H),
7.24 (dd, J = 5.6, 2.6 Hz, 1H), 7.35 (m, 1H), 7.47 (m, 3H), 8.03 (dd, J =
6.9, 2.0 Hz, 2H), 8.56 (d, J = 5.6 Hz, 1H), 8.81 (q, J = 8.4 Hz, 1H), 8.97
(s, 1H) ppm.; 13C NMR (75 MHz, DMSO‑d6) δ 26.2, 61.5, 102.5 (d, 2JFC
= 24.8 Hz) 107.8 (d, 3JFC = 21.0 Hz), 109.6, 111.3 (d, 4JFC = 3.0 Hz),
114.7, 122.4, 122.7, 123.3, 130.9, 131.0,134.1, 143.7, 150.7, 153.0 (d,
2JFC = 68.3 Hz), 159.5 (d, 3JFC = 10.5 Hz), 163.1 (d, 1JFC = 241.5 Hz),
163.8, 165.3 ppm.; 19F NMR (282 MHz, DMSO‑d6) δ ꢀ 113.2 (s, 1F)
ppm.; HRMS (ESI+) m/z: calcd. for C22H19FN5O3Na [M+H]+ 420.1472,
found 420.1473.
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave white solid with 58% yield. Mp. = 217–220 ◦C;
1H NMR (300 MHz, DMSO‑d6) δ 0.15 (s, 6H), 0.93 (s, 9H), 5.12 (s, 2H),
6.94 (d, J = 8.7 Hz, 2H), 6.98 (d, J = 8.7 Hz, 2H), 7.31 (d, J = 9.0 Hz),
7.67 (d, J = 9.0 Hz, 2H), 8.72 (s, 1H), 9.96 (s, 1H) ppm.; 13C NMR (75
MHz, DMSO‑d6) δ ꢀ 4.6, 17.9, 25.6, 61.5, 115.7, 116.1, 120.5, 122.0,
122.6, 128.8, 143.7, 149.0, 151.5, 157.8 ppm.; HRMS (ESI+) m/z: calcd
for C21H28N3O3Si [M+H]+ 398.1900, found 398.1883.
4-(4-((4-methoxyphenoxy)methyl)-1H-1,2,3-triazol-1-yl)phenol
(7ab)
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave brown solid with 89% yield. Mp. = 193–195 ◦C;
1H NMR (300 MHz, DMSO‑d6) δ 3.69 (s, 3H), 5.13 (s, 2H), 6.87 (d, J =
9.2 Hz, 2H), 6.97 (m, 4H), 7.67 (d, J = 8.8, 2H), 8.73 (s, 1H), 9.98 (br s,
1H) ppm.; 13C NMR (75 MHz, DMSO‑d6) δ 55.3, 61.6, 114.6, 115.7,
116.1, 120.0, 122.6, 128.8, 143.8, 152.0, 153.6, 157.8 ppm.; HRMS
(ESI+) m/z: calcd for C16H16N3O3 [M+H]+ 298.1192, found 298.1184.
N-(4-((1-(4-hydroxyphenyl)-1H-1,2,3-triazol-4-yl)methoxy)
phenyl)acetamide (7ac)
4-(4-(4-((4-fluorophenoxy)methyl)-1H-1,2,3-triazol-1-yl)phe-
noxy)-N-methylpicolinamide (2d) [42]
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave white solid with 35% yield. 1H NMR (300 MHz,
DMSO‑d6) δ 2.80 (d, J = 4.9 Hz, 3H), 5.24 (s, 2H), 7.13 (m, 4H), 7.26
(dd, J = 5.6, 2.6 Hz, 1H), 7.50 (m, 3H), 8.05 (dd, J = 6.8, 2.2 Hz, 2H),
8.57 (d, J = 5.6 Hz, 1H), 8.82 (q, J = 4.8 Hz, 1H), 9.00 (s, 1H) ppm.; 13C
Purification by silica gel column chromatography using 80% EtOAc:
n-hexane as eluent gave brown solid with 82% yield. Mp. = 237–239 ◦C;
1H NMR (300 MHz, DMSO‑d6) δ 2.01 (s, 3H), 3.63 (br s, 1H), 5.15 (s,
2H), 6.97 (m, 4H), 7.50 (d, J = 9.0 Hz, 2H), 7.66 (m, 2H), 8.12 (s, 1H),
9.82 (s, 1H) ppm.; 13C NMR (75 MHz, DMSO‑d6) δ 23.9, 61.3, 114.9,
116.2, 120.7, 122.1, 122.8, 128.8, 133.0, 143.7, 153.9, 157.9, 168.0
NMR (75 MHz, DMSO‑d6) δ 26.0, 61.6, 109.4, 114.6, 115.9 (d, 2JFC
=
23.0 Hz), 116.1 (d, 3JFC = 8.0 Hz), 121.9, 122.5, 123.1, 134.0, 143.7,
150.6, 152.6, 153.3, 154.3 (d, 4JFC = 2.3 Hz), 156.7 (d, 1JFC = 234.8 Hz),
163.7, 165.1 ppm.; 19F NMR (282 MHz, DMSO‑d6) δ ꢀ 125.8 (s, 1F)
ppm.; HRMS (ESI+) m/z: calcd. for
C
22H18FN5O3Na [M+Na]+
442.1291, found 442.1290.
ppm.; HRMS (ESI+) m/z: calcd for
C
17H16F3N4O3Na [M+Na]+
N-methyl-4-(4-(4-((2-nitrophenoxy)methyl)-1H-1,2,3-triazol-1-
yl)phenoxy)picolinamide (2e) [42]
347.1120, found 347.1124.
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave white solid with 38% yield. 1H NMR (300 MHz,
DMSO‑d6) δ 2.80 (d, J = 4.8 Hz, 3H), 5.46 (s, 2H), 7.16 (t, J = 7.5 Hz, 1H,
7.25 (dd, J = 5.6, 2.6 Hz, 1H), 7.47 (d, J = 8.7 Hz, 3H), 7.63 (d, J = 7.8
Hz, 1H), 7.70 (td, J = 8.6, 1.4 Hz, 1H), 7.87 (dd, J = 8.1, 1.4 Hz, 1H),
8.04 (d, J = 8.9 Hz, 2H), 8.56 (d, J = 5.6 Hz, 1H), 8.83 (q, J = 4.7 Hz,
1H), 8.96 (s, 1H) ppm.; 13C NMR (75 MHz, DMSO‑d6) δ 26.3, 62.6,
109.8, 114.9,115.9, 121.5, 122.5, 122.9, 123.7, 125.2, 134.1,
134.7,140.8, 143.2, 150.7, 150.9, 152.6, 153.7, 164.0, 165.4 ppm.;
HRMS (ESI+) m/z: calcd. for C22H18N6O5 [M+H]+ 447.1417, found
477.1413.
4.3.3. Synthesis of the target Sorafenib analogues 2
General procedure C: Synthesis of the triazole-containing Sor-
afenib analogues 2a-2ac [42]
To a stirred solution of triazole-containing phenol derivatives 7 in
dried DMF was added 4-chloro-N-methylpicolinamide (8), t-BuOK and
K2CO3. It was stirred under argon atmosphere at 80–85 ◦C for various
times. The resulting mixture was cooled to room temperature, diluted
with water and extracted with EtOAc. The combined organic phase was
dried over anh. Na2SO4, filtered and concentrated under reduced pres-
sure to obtain the crude product. It was purified by silica gel column
chromatography to afford the desired products 2a-2ac.
N-methyl-4-(4-(4-((3-nitrophenoxy)methyl)-1H-1,2,3-triazol-1-
yl)phenoxy)picolinamide (2f) [42]
N-methyl-4-(4-(4-(phenoxymethyl)-1H-1,2,3-triazol-1-yl)phe-
noxy)picolinamide (2a) [42]
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave white solid with 38% yield. 1H NMR (300 MHz,
DMSO‑d6) δ 2.79 (d, J = 4.8 Hz, 3H), 5.41 (s, 2H), 7.25 (dd, J = 5.6, 2.6
Hz, 1H), 7.48 (dd, J = 5.4, 2.6 Hz, 3H), 7.59 (m, 2H), 7.86 (d, J = 7.8 Hz,
1H), 7.91 (t, J = 2.2 Hz, 1H), 8.04 (d, J = 8.9 Hz, 2H), 8.56 (d, J = 5.6
Hz, 1H), 8.82 (q, J = 4.7 Hz, 1H), 8.99 (s, 1H) ppm.; 13C NMR (75 MHz,
DMSO‑d6) δ 26.0, 61.8, 109.3, 109.4, 114.6, 116.0, 122.2, 122.3, 122.6,
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave white solid with 76% yield. 1H NMR (300 MHz,
CDCl3) δ 3.20 (d, J = 6.0 Hz, 3H), 5.33 (s, 2H), 7.02 (m, 4H), 7.31 (m,
5H), 7.76 (d, J = 2.5 Hz, 1H), 7.78 (d, J = 9.0 Hz, 2H), 8.06 (s, 1H), 8.44
(d, J = 5.6 Hz, 1H) ppm.; 13C NMR (75 MHz, CDCl3) δ 26.2, 61.9, 110.4,
114.5, 114.8, 121.1, 121.4, 122.0, 122.7, 129.6, 134.3, 145.6, 150.0,
12

S. Palakhachane et al.
Bioorganic Chemistry 112 (2021) 104831
123.3, 130.8, 134.0, 143.3, 148.8, 150.6, 152.6, 153.4, 158.5, 163.7,
165.1 ppm.; HRMS (ESI+) m/z: calcd. for C22H18N6O5 [M+H]+
447.1417, found 477.1418.
4-(4-(4-((3-(tert-butyl)phenoxy)methyl)-1H-1,2,3-triazol-1-yl)
phenoxy)-N-methylpicolinamide (2l)
Purification by silica gel column chromatography using 30% EtOAc:
n-hexane as eluent gave white solid with 31% yield. Mp. = 119–121 ◦C;
1H NMR (300 MHz, DMSO‑d6) δ 1.25 (s, 9H), 2.79 (d, J = 4.9 Hz, 3H),
5.23 (s, 2H), 6.91 (d, J = 7.7, 1.9 Hz, 1H), 7.00 (m, 2H), 7.24 (m, 2H),
7.45 (s, 1H), 7.47 (d, J = 3.0 Hz, 2H), 8.03 (dd, J = 6.9, 2.0 Hz, 2H), 8.6
(d, J = 5.6 Hz, 1H), 8.81 (q, J = 8.4 Hz, 1H), 8.94 (s, 1H) ppm.; 13C NMR
(75 MHz, DMSO‑d6) δ 26.2, 31.2, 34.6, 61.0, 109.6, 111.3, 112.6, 114.8,
118.1, 122.4, 122.7, 123.2, 129.3, 134.2, 144.4, 150.8, 152.6, 152.7,
153.5, 158.0, 163.9, 165.4 ppm.; HRMS (ESI+) m/z: calcd for
N-methyl-4-(4-(4-((4-nitrophenoxy)methyl)-1H-1,2,3-triazol-1-
yl)phenoxy)picolinamide (2g) [42]
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave white solid with 18% yield. 1H NMR (300 MHz,
DMSO‑d6) δ 2.80 (d, J = 4.9 Hz, 3H), 5.45 (s, 2H), 7.26 (dd, J = 5.6, 2.6
Hz, 1H), 7.33 (d, J = 9.2 Hz, 2H), 7.50 (m, 3H), 8.06 (d, J = 8.9 Hz, 2H),
8.26 (d, J = 9.2 Hz, 2H), 8.57 (d, J = 5.6 Hz, 1H), 8.81 (q, J = 4.7 Hz,
1H), 9.05 (s, 1H) ppm.; 13C NMR (75 MHz, DMSO‑d6) δ 26.0, 61.9,
109.4, 114.6, 115.4, 122.3, 122.6, 123.5, 125.9, 134.0, 141.2, 143.0,
150.6, 152.6, 153.4, 163.2, 163.2, 165.1 ppm.; HRMS (ESI+) m/z: calcd.
for C22H18N6O5Na [M+Na]+ 469.1236, found 469.1229.
C
26H28N5O3 [M+H]+ 458.2192, found 458.2199.
4-(4-(4-((4-(tert-butyl)phenoxy)methyl)-1H-1,2,3-triazol-1-yl)
phenoxy)-N-methylpicolinamide (2m)
N-methyl-4-(4-(4-((2-(trifluoromethyl)phenoxy)methyl)-1H-
1,2,3-triazol-1-yl)phenoxy)picolinamide (2h)
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave white solid with 44% yield. Mp. = 157–159 ◦C;
1H NMR (300 MHz, DMSO‑d6) δ 1.25 (s, 9H), 2.79 (d, J = 4.9 Hz, 3H),
5.22 (s, 2H), 6.99 (d, J = 8.9 Hz, 2H), 7.24 (dd, J = 5.6, 2.6 Hz, 1H), 7.32
(d, J = 8.9 Hz, 2H), 7.48 (d, J = 9.0 Hz, 2H), 7.48 (d, J = 2.4 Hz, 1H),
8.05 (d, J = 9.0 Hz, 2H), 8.56 (d, J = 5.6 Hz, 1H), 8.81 (q, J = 4.9 Hz,
1H), 8.98 (s, 1H) ppm.; 13C NMR (75 MHz, DMSO‑d6) δ 26.0, 31.3, 33.8,
61.0, 109.4, 114.0, 114.6, 122.2, 122.5, 122.9, 126.1, 134.0, 143.1,
144.2, 150.6, 152.6, 153.3, 155.8, 163.7, 165.1 ppm.; HRMS (ESI+) m/
z: calcd for C26H28N5O3 [M+H]+ 458.2192, found 458.2196.
4-(4-(4-((2,3-difluorophenoxy)methyl)-1H-1,2,3-triazol-1-yl)
phenoxy)-N-methylpicolinamide (2n)
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave white solid with 47% yield. Mp. = 144–145 ◦C;
1H NMR (300 MHz, DMSO‑d6) δ 2.79 (d, J = 4.9 Hz, 3H), 5.42 (s, 2H),
7.14 (t, J = 7.6 Hz, 1H), 7.24 (dd, J = 5.9, 2.6 Hz, 1H), 7.49 (m, 3H),
7.55 (d, J = 8.3 Hz, 1H), 7.66 (q, J = 7.8 Hz, 2H), 8.04 (d, J = 9.0 Hz,
2H), 8.56 (d, J = 5.6 Hz, 1H), 8.80 (q, J = 4.9 Hz, 1H), 8.97 (s, 1H) ppm.;
13C NMR (75 MHz, DMSO‑d6) δ 26.0, 61.9, 109.4, 114.3, 114.6, 117.4
2
1
(q, JFC = 30.6 Hz), 123.7 (q, JFC = 270.6 Hz), 120.8, 122.3, 122.6,
3
123.2, 126.8 (q, JFC = 5.3 Hz), 133.9, 134.2, 143.3, 150.6, 152.6,
153.4, 156.8, 163.7, 165.1 ppm.; 19F NMR (282 MHz, DMSO‑d6) δ ꢀ 62.6
(s, 3F) ppm.; HRMS (ESI+) m/z: calcd for C23H19F3N5O3 [M+H]+
470.1440, found 470.1439.
Purification by silica gel column chromatography using 30% EtOAc:
n-hexane as eluent gave white solid with 18% yield. Mp. = 146–148 ◦C;
1H NMR (300 MHz, DMSO‑d6) δ 2.78 (d, J = 4.8 Hz, 3H), 5.39 (s, 2H),
7.04 (dd, J = 17.0, 8.5 Hz, 1H), 7.23 (m, 3H), 7.49 (m, 3H), 8.06 (d, J =
8.8 Hz, 2H), 8.56 (d, J = 5.6 Hz, 1H), 8.80 (q, J = 4.7 Hz, 1H), 9.03 (s,
N-methyl-4-(4-(4-((3-(trifluoromethyl)phenoxy)methyl)-1H-
1,2,3-triazol-1-yl)phenoxy)picolinamide (2i)
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave white solid with 53% yield. Mp. = 147–148 ◦C;
1H NMR (300 MHz, DMSO‑d6) δ 2.79 (d, J = 4.9 Hz, 3H), 5.36 (s, 2H),
7.26 (dd, J = 5.6, 2.6 Hz, 2H), 7.33 (d, J = 7.8 Hz, 1H), 7.40 (br s, 1H),
7.42 (s, 1H), 7.49 (m, 3H), 7.56 (t, J = 8.6 Hz, 1H), 8.04 (d, J = 9.0 Hz,
2H), 8.56 (d, J = 5.6 Hz, 1H), 8.81 (q, J = 4.9 Hz, 1H), 9.01 (s, 1H) ppm.;
13C NMR (75 MHz, DMSO‑d6) δ 26.1, 61.5, 109.4, 111.5 (q, 3JFC = 3.8
Hz), 114.6, 117.6 (q, 3JFC = 3.8 Hz), 124.0 (q, 1JFC = 270.8 Hz), 119.1,
1H) ppm.; 13C NMR (75 MHz, DMSO‑d6) δ 26.0, 62.4, 109.4 (d, 3JFC
=
5.3 Hz), 109.6, 111.1, 114.6, 122.2, 122.6, 123.5, 124.2 (dd, 2JFC, 3JFC
1
2
= 9.0, 5.3 Hz), 134.0, 140.3 (dd, JFC, JFC = 243.8, 15.0 Hz), 143.1,
147.4 (d, 3JFC = 4.5 Hz), 150.5 (dd, 1JFC, 2JFC = 243.0, 10.5 Hz), 150.6,
152.6, 153.4, 163.7, 165.1 ppm.; 19F NMR (282 MHz, DMSO‑d6) δ
ꢀ 140.2 (s, 1F), ꢀ 140.3 (s, 1F) ppm.; HRMS (ESI+) m/z: calcd for
C22H17F2N5O3Na [M+Na]+ 460.1197, found 460.1195.
2
122.3, 122.6, 123.3, 130.4 (q, JFC = 31.5 Hz), 130.8, 134.0, 143.6,
4-(4-(4-((2,4-difluorophenoxy)methyl)-1H-1,2,3-triazol-1-yl)
phenoxy)-N-methylpicolinamide (2o)
150.6, 152.3, 153.4, 158.3, 163.7, 165.2 ppm.; 19F NMR (282 MHz,
DMSO‑d6)
δ
ꢀ 62.6 (s, 3F) ppm.; HRMS (ESI+) m/z: calcd for
Purification by silica gel column chromatography using 30% EtOAc:
n-hexane as eluent gave white solid with 31% yield. Mp. = 179–180 ◦C;
1H NMR (300 MHz, DMSO‑d6) δ 2.79 (d, J = 4.8 Hz, 3H), 5.30 (s, 2H),
7.14 (m, 1H), 7.27 (m, 2H), 7.40 (m, 1H), 7.47 (m, 3H), 8.03 (d, J = 8.9
Hz, 2H), 8.80 (d, J = 5.6 Hz, 1H), 8.80 (q, J = 4.7 Hz, 1H), 8.95 (s, 1H)
ppm.; 13C NMR (75 MHz, DMSO‑d6) δ 26.2, 62.7, 105.0 (dd, 2JFC = 27.0,
21.8 Hz), 109.6, 111.1 (dd, 2JFC, 4JFC = 22.5, 3.8 Hz), 114.8, 116.8 (d,
C
23H19F3N5O3 [M+H]+ 470.1440, found 470.1437.
N-methyl-4-(4-(4-((4-(trifluoromethyl)phenoxy)methyl)-1H-
1,2,3-triazol-1-yl)phenoxy)picolinamide (2j)
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave white solid with 42% yield. Mp. = 173–173 ◦C;
1H NMR (300 MHz, DMSO‑d6) δ 2.80 (d, J = 4.9 Hz, 3H), 5.37 (s, 2H),
7.28 (m, 3H), 7.49 (m, 3H), 7.69 (d, J = 8.6 Hz, 2H), 8.05 (dd, J = 9.0
Hz, 2H), 8.56 (d, J = 5.6 Hz, 1H), 8.82 (q, J = 4.5 Hz, 1H), 9.02 (s, 1H)
ppm.; 13C NMR (75 MHz, DMSO‑d6) δ 26.0, 61.3, 109.4, 114.6, 115.3,
3JFC = 9.0 Hz), 122.4, 123.5, 134.1, 142.6 (dd, 2JFC, 4JFC = 10.5, 3.0 Hz),
1
143.5, 152.3 (dd, JFC
,
3JFC = 245.3, 12.8 Hz), 150.8, 152.6, 153.5,
156.1 (d, 1JFC, 3JFC = 238.5, 10.5 Hz), 157.7 (d, 2JFC = 36.5 Hz) 164.0,
165.3 ppm.; 19F NMR (282 MHz, DMSO‑d6) δ ꢀ 121.4 (d, JFF = 2.7 Hz,
1F), ꢀ 131.3 (d, JFF = 2.7 Hz, 1F) ppm.; HRMS (ESI+) m/z: calcd for
1
2
124.5 (q, JFC = 269.3 Hz), 121.6 (q, JFC = 31.9 Hz), 122.2, 122.6,
3
123.3, 126.0 (q, JFC = 3.8 Hz), 134.0, 143.4, 150.6, 152.6, 153.4,
160.8, 163.6, 165.1 ppm.; 19F NMR (282 MHz, DMSO‑d6) δ ꢀ 61.5 (s, 3F)
ppm.; HRMS (ESI+) m/z: calcd for C23H19FN5O3 [M+H]+ 470.1440,
found 470.1431.
C
22H18F2N5O3 [M+H]+ 438.1378, found 438.1376.
4-(4-(4-((2,5-difluorophenoxy)methyl)-1H-1,2,3-triazol-1-yl)phe-
noxy)-N-methylpicolinamide (2p)
4-(4-(4-((2-(tert-butyl)phenoxy)methyl)-1H-1,2,3-triazol-1-yl)
phenoxy)-N-methylpicolinamide (2k)
Purification by silica gel column chromatography using 30% EtOAc:
n-hexane as eluent gave white solid with 51% yield. Mp. = 184–185 ◦C;
1H NMR (300 MHz, DMSO‑d6) δ 2.79 (d, J = 4.8 Hz, 3H), 5.36 (s, 2H),
6.81 (tt, J = 8.5, 3.1 Hz, 1H), 7.25 (dd, J = 5.7, 2.7 Hz, 1H), 7.29 (m,
1H), 7.39 (m, 1H), 7.49 (m, 2H), 8.06 (d, J = 8.9 Hz, 2H), 8.56 (d, J =
5.6 Hz, 1H), 8.80 (q, J = 4.7 Hz, 1H), 9.03 (s, 1H) ppm.; 13C NMR (75
Purification by silica gel column chromatography using 30% EtOAc:
n-hexane as eluent gave white solid with 42% yield. Mp. = 139–140 ◦C;
1H NMR (300 MHz, DMSO‑d6) δ 1.30 (s, 9H), 2.79 (d, J = 4.8 Hz, 3H),
5.25 (s, 2H), 6.90 (m, 1H), 7.22 (m, 4H), 7.47 (m, 3H), 8.05 (d, J = 8.9
Hz, 2H), 8.56 (d, J = 5.6 Hz, 1H), 8.81 (q, J = 4.7 Hz, 1H), 8.94 (s, 1H)
ppm.; 13C NMR (75 MHz, DMSO‑d6) δ 24.5, 29.9, 34.6, 61.2, 109.71,
113.2, 114.8, 121.0, 122.5, 122.7, 123.0, 126.6, 127.4, 134.2, 137.8,
144.4, 150.8, 152.6, 153.6, 157.0, 164.0, 165.4 ppm.; HRMS (ESI+) m/
z: calcd for C26H27N5O3Na [M+Na]+ 480.2012, found 480.2017.
MHz, DMSO‑d6) δ 26.0, 62.2, 103.5 (d, 2JFC = 27.8 Hz), 107.0 (dd, 2JFC
,
3JFC = 23.3, 6.8 Hz), 109.4, 114.6, 116.5 (dd, 2JFC, 3JFC = 20.3, 19.5 Hz),
122.2, 122.6, 123.5, 134.0, 143.0, 148.2 (dd, 1JFC, 4JFC = 238.5, 2.8 Hz),
150.7, 152.6, 153.4, 158.2 (dd, 1JFC, 4JFC = 236.3, 2.6 Hz), 163.0, 163.7,
165.1 ppm.; 19F NMR (282 MHz, DMSO‑d6) δ ꢀ 117.9 (d, JFF = 15.3 Hz,
13

S. Palakhachane et al.
Bioorganic Chemistry 112 (2021) 104831
1
1F), ꢀ 141.6 (d, JFF = 15.3 Hz, 1F) ppm.; HRMS (ESI+) m/z: calcd for
NMR (75 MHz, DMSO‑d6) δ 26.1, 61.8, 109.4, 120.6 (q, JFC = 266.8
C
22H17F2N5O3Na [M+Na]+ 460.1197, found 460.1194.
Hz), 114.7, 120.3, 122.0, 122.3, 122.6, 123.4, 127.3, 132.8, 134.0,
2
4-(4-(4-((2,6-difluorophenoxy)methyl)-1H-1,2,3-triazol-1-yl)
143.3, 150.6 152.5, 153.4, 156.8, 158.3 (q, JFC = 37.0 Hz), 163.7,
phenoxy)-N-methylpicolinamide (2q)
165.2 ppm.; 19F NMR (282 MHz, DMSO‑d6) δ ꢀ 63.0 (s, 3F) ppm.; HRMS
(ESI+) m/z: calcd for C23H18ClF3N5O3 [M+H]+ 504.1050, found
504.1045.
Purification by silica gel column chromatography using 30% EtOAc:
n-hexane as eluent gave white solid with 61% yield. Mp. = 167–169 ◦C;
1H NMR (75 MHz, DMSO‑d6) δ 2.80 (d, J = 4.9 Hz, 3H), 5.30 (s, 2H),
7.16 (m, 3H), 7.25 (dd, J = 5.6, 2.6 Hz, 1H), 7.48 (m, 3H), 8.04 (d, J =
8.9 Hz, 2H), 8.56 (d, J = 5.6 Hz, 1H), 8.80 (q, J = 4.8 Hz, 1H), 9.00 (s,
1H) ppm.; 13C NMR (75 MHz, DMSO‑d6) δ 26.0, 66.4 (t, 4JFC = 2.9 Hz),
109.9, 112.6 (d, 2JFC = 22.5 Hz), 112.5 (d, 3JFC = 9.0 Hz), 114.6, 122.3,
N-methyl-4-(4-(4-((p-tolyloxy)methyl)-1H-1,2,3-triazol-1-yl)
phenoxy)picolinamide (2v)
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave white solid with 77% yield. Mp. = 152–154 ◦C;
1H NMR (300 MHz, DMSO‑d6) δ 2.24 (s, 3H), 2.80 (d, J = 9.0 Hz, 2H),
5.20 (s, 2H), 6.97 (d, J = 9.0 Hz, 2H), 7.12 (d, J = 9.0 Hz, 2H), 7.24 (dd,
J = 5.6, 2.6 Hz, 1H), 7.49 (m, 3H), 8.05 (d, J = 8.9 Hz, 2H), 8.56 (d, J =
5.6 Hz, 1H), 8.80 (q, J = 7.7, 4.9 Hz, 1H), 8.97 (s, 1H) ppm.; 13C NMR
(75 MHz, DMSO‑d6) δ 20.1, 26.0, 61.0, 109.4, 114.6, 114.6, 122.2,
122.5, 123.0, 129.7, 129.9, 134.0, 144.1, 150.6, 152.6, 153.3, 155.9,
163.6, 165.2 ppm.; HRMS (ESI+) m/z: calcd for C23H22N5O3 [M+H]+
416.1723, found 416.1717.
3
122.4, 123.4, 124.3 (t, JFC = 9.4 Hz), 133.9, 143.3, 150.6, 153.0 (d,
2JFC = 55.8 Hz), 154.1 (d, 2JFC = 5.4 Hz) 155.7 (dd, 1JFC, 3JFC = 245.3,
5.3 Hz), 163.7, 165.1 ppm.; 19F NMR (282 MHz, DMSO‑d6) δ ꢀ 130.1 (s,
2F) ppm.; HRMS (ESI+) m/z: calcd for C22H17F2N5O3Na [M+Na]+
460.1197, found 460.1199.
4-(4-(4-((3,4-difluorophenoxy)methyl)-1H-1,2,3-triazol-1-yl)
phenoxy)-N-methylpicolinamide (2r)
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave white solid with 31% yield. Mp. = 179–181 ◦C;
1H NMR (300 MHz, DMSO‑d6) δ 2.80 (d, J = 4.8 Hz, 3H), 5.26 (s, 2H),
6.93 (m, 1H), 7.25 (dd, J = 19.4, 3.1 Hz, 1H), 7.26 (dd, J = 5.6, 2.6 Hz,
1H), 7.39 (dd, J = 19.7, 9.5 Hz, 1H), 7.49 (d, J = 8.9 Hz, 2H), 7.50 (d, J
= 2.9 Hz, 1H), 8.05 (d, J = 8.9 Hz, 2H), 8.57 (d, J = 5.6 Hz, 1H), 8.80 (q,
J = 4.8 Hz, 1H), 8.99 (s, 1H) ppm.; 13C NMR (75 MHz, DMSO‑d6) δ 26.0,
61.9, 104.5 (d, 2JFC = 20.3 Hz), 109.4, 111.2 (dd, 3JFC, 4JFC = 5.3, 3.0
Hz), 114.6, 117.6 (d, 2JFC = 18.0 Hz), 122.2, 122.6, 123.3, 134.0, 144.2
(dd, 1JFC, 2JFC = 236.3, 12.8 Hz), 143.4, 149.6 (dd, 1JFC, 2JFC = 243.0,
4-(4-(4-((4-ethylphenoxy)methyl)-1H-1,2,3-triazol-1-yl)phe-
noxy)-N-methylpicolinamide (2w)
Purification by silica gel column chromatography using 30% EtOAc:
n-hexane as eluent gave light-yellow solid with 39% yield. Mp. =
143–145 ◦C; 1H NMR (300 MHz, DMSO‑d6) δ 1.14 (t, J = 7.6 Hz, 3H),
2.54 (q, J = 7.6 Hz, 2H), 2.79 (d, J = 4.8 Hz, 3H), 5.21 (s, 2H), 6.99 (d, J
= 8.6 Hz, 2H), 7.14 (d, J = 8.6 Hz, 2H), 7.25 (dd, J = 5.6, 2.6 Hz, 1H),
7.28 (dd, J = 7.1, 2.0 Hz, 3H), 8.04 (d, J = 8.9 Hz, 2H), 8.56 (d, J = 5.6
Hz, 1H), 8.81 (dq, J = 5.1 Hz, 1H), 8.97 (s, 1H) ppm.; 13C NMR (75 MHz,
DMSO‑d6) δ 15.9, 26.1, 27.3, 61.1, 109.4, 114.6, 114.7, 122.3, 122.5,
123.0, 128.7, 134.1, 136.2, 144.2, 150.6, 152.5, 153.3, 156.1, 163.7,
165.2 ppm.; HRMS (ESI+) m/z: calcd for C24H23N5O3Na [M+Na]+
452.1699, found 452.1691.
3
13.5 Hz), 150.6, 152.6, 153.4, 154.6 (d, JFC = 9.0 Hz), 163.7, 165.1
ppm.; 19F NMR (282 MHz, DMSO‑d6) δ ꢀ 164.0 (d, JFF = 22.6 Hz, 1F),
ꢀ 138.3 (d, JFF = 22.6 Hz, 1F) ppm.; HRMS (ESI+) m/z: calcd for
C22H18F2N5O3 [M+H]+ 438.1378, found 438.1379.
4-(4-(4-((4-isopropylphenoxy)methyl)-1H-1,2,3-triazol-1-yl)
phenoxy)-N-methylpicolinamide (2x)
4-(4-(4-((3,5-difluorophenoxy)methyl)-1H-1,2,3-triazol-1-yl)
phenoxy)-N-methylpicolinamide (2s)
Purification by silica gel column chromatography using 30% EtOAc:
n-hexane as eluent gave white solid with 44% yield. Mp. = 140–142 ◦C;
1H NMR (300 MHz, DMSO‑d6) δ 1.16 (d, J = 6.9 Hz, 6H), 2.79 (d, J = 4.6
Hz, 3H), 2.85 (m, 1H), 5.20 (s, 2H), 6.98 (d, J = 8.7 Hz, 2H), 7.17 (d, J =
8.6 Hz, 2H), 7.24 (dd, J = 5.6, 2.6 Hz, 1H), 7.47 (m, 3H), 8.03 (d, J = 9.0
Hz, 2H), 8.56 (d, J = 5.6 Hz, 1H), 8.81 (q, J = 4.8 Hz, 1H), 8.94 (s, 1H)
ppm.; 13C NMR (75 MHz, DMSO‑d6) δ 24.2, 26.2, 32.7, 61.1, 109.6,
114.7, 114.8, 122.4, 122.7, 123.1, 127.4, 134.2, 141.2, 144.4, 150.8,
152.6, 153.5, 156.2, 163.9, 165.4 ppm.; HRMS (ESI+) m/z: calcd for
Purification by silica gel column chromatography using 30% EtOAc:
n-hexane as eluent gave white solid with 42% yield. Mp. = 199–201 ◦C;
1H NMR (300 MHz, DMSO‑d6) δ 2.79 (d, J = 4.9 Hz, 3H), 5.28 (s, 2H),
6.84 (m, 3H), 7.25 (dd, J = 5.6, 2.9 Hz, 1H), 7.48 (m, 3H), 8.03 (d, J =
8.9 Hz, 2H), 8.56 (d, J = 5.6 Hz, 1H), 8.82 (q, J = 4.9 Hz, 1H), 8.98 (s,
2
1H) ppm.; 13C NMR (75 MHz, DMSO‑d6) δ 26.2, 61.9, 96.7 (t, JFC
=
26.3 Hz), 99.2 (d, 2JFC = 28.5 Hz), 109.6, 114.8, 122.4, 122.8, 123.6,
134.1, 143.3, 150.8, 152.6, 153.6, 160.2 (t, 3JFC = 14.3 Hz), 163.2 (dd,
1JFC, JFC = 242.3, 15.8 Hz), 163.9, 165.3 ppm.; 19F NMR (282 MHz,
C
25H26N5O3 [M+H]+ 444.2036, found 444.2034.
3
DMSO‑d6) δ ꢀ 110.7 (s, 2F) ppm.; HRMS (ESI+) m/z: calcd for
4-(4-(4-((4-chlorophenoxy)methyl)-1H-1,2,3-triazol-1-yl)phe-
C
22H17F2N5O3Na [M+Na]+ 460.1197, found 460.1196.
noxy)-N-methylpicolinamide (2y)
4-(4-(4-((3,5-bis(trifluoromethyl)phenoxy)methyl)-1H-1,2,3-
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave white solid with 97% yield. Mp. = 215–217 ◦C;
1H NMR (300 MHz, DMSO‑d6) δ 2.79 (d, J = 4.9 Hz, 3H), 5.26 (s, 2H),
7.13 (d, J = 9.0 Hz, 2H), 7.25 (dd, J = 5.6, 2.6 Hz, 1H), 7.36 (d, J = 9.0
Hz, 2H), 7.48 (d, J = 8.9 Hz, 2H), 8.04 (d, J = 8.9 Hz, 2H), 8.80 (q, J =
4.9 Hz, 1H), 8.99 (s, 1H) ppm.; 13C NMR (75 MHz, DMSO‑d6) δ 26.1,
61.3, 109.5, 114.7, 116.7, 122.4, 122.7, 123.3, 124.8, 129.4, 134.1,
143.8, 150.7, 154.6, 153.5, 156.9, 163.8, 166.2 ppm.; HRMS (ESI+) m/
z: calcd for C22H18ClN5O3Na [M+Na]+ 458.0996, found 458.0989.
4-(4-(4-((4-bromophenoxy)methyl)-1H-1,2,3-triazol-1-yl)phe-
noxy)-N-methylpicolinamide (2z)
triazol-1-yl)phenoxy)-N-methylpicolinamide (2t)
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave white solid with 62% yield. Mp. = 174–175 ◦C;
1H NMR (300 MHz, DMSO‑d6) δ 2.80 (d, J = 4.9 Hz, 3H), 5.50 (s, 2H),
7.26 (dd, J = 5.6, 2.6 Hz, 1H), 7.50 (dd, J = 6.1, 3.3 Hz, 3H), 7.68 (s,
1H), 7.80 (s, 2H), 8.05 (d, J = 8.9 Hz, 2H), 8.57 (d, J = 5.6 Hz, 1H), 8.81
(q, J = 4.8 Hz, 1H), 9.03 (s, 1H) ppm.; 13C NMR (75 MHz, DMSO‑d6) δ
26.1, 62.1, 109.5, 114.2 (m), 114.7, 116.1, 123.2 (q, 1JFC = 271.2 Hz),
2
122.3, 122.6, 123.5, 131.6 (q, JFC = 32.8 Hz), 134.0, 143.1, 150.6,
152.6, 153.5, 159.0, 163.7, 165.2 ppm.; 19F NMR (282 MHz, DMSO‑d6)
δ ꢀ 63.0 (s, 6F) ppm.; HRMS (ESI+) m/z: calcd for C24H18F6N5O3
[M+H]+ 538.1314, found 538.1301.
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave white solid with 47% yield. Mp. = 217–218 ◦C;
1H NMR (300 MHz, CDCl3) δ 3.02 (s, 3H), 5.28 (s, 2H), 6.93 (d, J = 9.0
Hz, 2H), 7.06 (dd, J = 5.6, 2.6 Hz, 1H), 7.29 (d, J = 9.0 Hz, 2H), 7.34 (s,
1H), 7.42 (d, J = 9.1 Hz, 2H), 7.73 (d, J = 2.5 Hz, 1H), 7.84 (d, J = 9.0
Hz, 2H), 8.17 (s, 1H), 8.46 (d, J = 5.6 Hz, 1H) ppm.; 13C NMR (75 MHz,
CDCl3) δ 26.1, 62.7, 110.7, 113.8, 114.8, 116.8, 121.6, 122.1, 123.0,
132.6, 134.3, 144.8, 150.3, 152.4, 154.3, 157.3, 164.8, 165.7 ppm.;
HRMS (ESI+) m/z: calcd for C22H19BrN5O3 [M+H]+ 480.0671,
482.0651, found 480.0652, 482.0664.
4-(4-(4-((4-chloro-3-(trifluoromethyl)phenoxy)methyl)-1H-
1,2,3-triazol-1-yl)phenoxy)-N-methylpicolinamide (2u)
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave pale-pink solid with 36% yield. Mp. =
172–174 ◦C; 1H NMR (300 MHz, DMSO‑d6) δ 2.79 (d, J = 4.9 Hz, 3H),
5.38 (s, 2H), 7.26 (dd, J = 5.6, 2.6 Hz, 1H), 7.44 (dd, J = 9.0, 3.0 Hz,
1H), 7.50 (m, 4H), 7.67 (d, J = 8.9 Hz, 1H), 8.04 (d, J = 9.0 Hz, 2H),
8.56 (d, J = 5.6 Hz, 1H), 8.81 (q, J = 4.9 Hz, 1H), 9.00 (s, 1H) ppm.; 13
C
14

S. Palakhachane et al.
Bioorganic Chemistry 112 (2021) 104831
4-(4-(4-((4-hydroxyphenoxy)methyl)-1H-1,2,3-triazol-1-yl)phe-
noxy)-N-methylpicolinamide (2aa)
(≈ 100 µM) assumes no cytotoxic effects).
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave white solid with 31% yield. Mp. = 213–214 ◦C;
1H NMR (300 MHz, DMSO‑d6) δ 2.78 (d, J = 4.8 Hz, 3H), 5.25 (s, 2H),
6.94 (d, J = 8.9 Hz, 2H), 7.13 (dd, J = 5.6, 2.6 Hz, 1H), 7.36 (d, J = 2.5
Hz, 1H), 7.68 (d, J = 8.9 Hz, 2H), 8.49 (d, J = 5.6 Hz, 1H), 8.77 (m, 2H),
9.97 (br s, 1H) ppm.; 13C NMR (75 MHz, DMSO‑d6) δ 26.0, 61.5, 108.6,
113.9, 116.1, 116.4, 122.0, 122.3, 122.9, 128.7, 143.4, 146.8, 150.4,
152.4, 155.8, 157.9, 163.8, 166.2 ppm.; HRMS (ESI+) m/z: calcd for
4.5. Inhibitory activity assay towards B-RAF [71]
Huh7 cell lines (6.5 × 105 cells/well) were seeded overnight in 12-
well plates and treated with the indicated compound concentrations
for 24 h at 37 ◦C under 5% CO2. The cell lysate was performed imme-
diately and transferred to B-RAF ELISA Kit (Aviva Systems Biology
Corporation, San Diego, USA). Assays were performed according to the
manufacturer’s instruction. Then the concentration of B-RAF was
determined by measuring the absorbance at 450 nm. The B-RAF con-
centration contained in the samples can be interpolated by using linear
regression of each mean sample Relative OD450 against the standard
curve. Nonlinear regression analysis (curve fitting analysis) was per-
formed by GraphPad Prism software version 9.0 (GraphPad Software
Inc. San Diego, CA, USA)
C
22H19N5O4Na [M+Na]+ 440.1335, found 440.1338.
4-(4-(4-((4-methoxyphenoxy)methyl)-1H-1,2,3-triazol-1-yl)
phenoxy)-N-methylpicolinamide (2ab)
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave white solid with 62% yield. Mp. = 181–183 ◦C;
1H NMR (300 MHz, DMSO‑d6) δ 2.79 (d, J = 4.9 Hz, 3H), 3.69 (s, 3H),
5.17 (s, 2H), 6.86 (d, J = 9.2 Hz, 2H), 7.00 (d, J = 9.2 Hz, 2H), 7.24 (dd,
J = 5.6, 2.6 Hz, 1H), 7.47 (m, 3H), 8.03 (d, J = 9.0 Hz, 2H), 8.56 (d, J =
5.6 Hz, 1H), 8.82 (dq, J = 4.9 Hz, 1H), 8.93 (s, 1H) ppm.; 13C NMR (75
MHz, DMSO‑d6) δ 26.2, 55.5, 61.7, 109.6, 114.8, 114.8, 116.0, 122.4,
122.7, 123.1, 134.2, 144.4, 150.8, 152.1, 152.6, 153.5, 153.8, 163.9,
165.3 ppm.; HRMS (ESI+) m/z: calcd for C23H22N5O4 [M+H]+
432.1672, found 432.1673.
4.6. Wound healing assay [55]
Huh7 cells at 5 × 105 cells/well (2 mL) were seeded in completed
DMEM medium in 12-well plates. Cells were incubated at 37◦ C in the
presence of 5% CO2 for 24 h. The medium was removed from plates
followed by scratching a wound with a sterile pipette tip at an angle
about 30◦ in three parallel vertical lines then the wound was double
washed with PBS. The wounded cell was treated with 2 mL of IC50
concentration of the inhibitor diluted in the medium. Their cell migra-
tion was monitored with a microscope at 0, 24 and 48 h by calculated
the cell repair percentage compared with control and Sorafenib, which is
a positive control.
4-(4-(4-((4-acetamidophenoxy)methyl)-1H-1,2,3-triazol-1-yl)
phenoxy)-N-methylpicolinamide (2ac)
Purification by silica gel column chromatography using 50% EtOAc:
n-hexane as eluent gave white solid with 42% yield. Mp. = 221–222 ◦C;
1H NMR (300 MHz, DMSO‑d6) δ 2.00 (s, 3H), 2.79 (d, J = 4.8 Hz, 3H),
5.19 (s, 2H), 7.00 (d, J = 8.9 Hz, 2H), 7.24 (dd, J = 5.6, 2.6 Hz, 1H), 7.48
(m, 5H), 8.03 (d, J = 8.9 Hz, 2H), 8.55 (d, J = 5.6 Hz, 1H), 8.82 (q, J =
4.80 Hz, 1H), 8.94 (s, 1H), 9.84 (s, 1H) ppm.; 13C NMR (75 MHz,
DMSO‑d6) δ 23.8, 26.0, 61.2, 109.4, 114.6, 114.8, 120.5, 122.2, 122.5,
123.0, 133.0, 134.0, 144.1, 150.6, 152.6, 153.3, 153.7, 163.6, 165.1,
167.8 ppm.; HRMS (ESI+) m/z: calcd for C24H22N6O4Na [M+Na]+
481.160.0, found 481.1617.
4.7. BrdU cell proliferative activity assay [56]
BrdU cell proliferative activity was performed by BrdU Cell Prolif-
eration Assay kit (Cell signalling, 6813) according to the manufacturer’s
protocol. Huh7 cells at 4.5 × 104 cells/200 µL were seeed into 96-well
4-(4-(4-((4-aminophenoxy)methyl)-1H-1,2,3-triazol-1-yl)phe-
noxy)-N-methylpicolinamide (2ad)
plate and incubated with Sorafenib at the concentration of 3 μM and
2 m at 3, 6 and 12 μM for 0, 24 and 48 h then evaluated the absorbance
To a stirred solution of N-methyl-4-(4-(4-((4-nitrophenoxy)methyl)-
1H-1,2,3-triazol-1-yl)phenoxy)picolinamide (2g) (210 mg, 0.47 mmol)
in THF and MeOH (1.7:0.6 mL) was added NaBH4 (213 mg, 5.63 mmol)
and NiCl2⋅5H2O (17.7 mg, 0.075 mmol) at ꢀ 5 ◦C, respectively. The re-
action mixture was stirred for 2 h and filtered to remove the catalyst.
The filtrate was partitioned with water (20 mL) and EtOAc (20 mL)
followed by extracted with EtOAc (3x20 mL). The combined organic
layer was dried over anh. Na2SO4, filtered and concentrated under
reduced pressure to provide crude product, which was purified by silica
gel column chromatography (70% EtOAc: n-hexane) to provide 2ad
(151 mg, 0.36 mmol, 77%) as a brown solid. Mp. = 177–179 ◦C; 1H NMR
(300 MHz, DMSO‑d6) δ 2.80 (d, J = 4.9 Hz, 3H), 5.17 (s, 2H), 6.87 (d, J
= 8.9 Hz, 2H), 6.97 (d, J = 9.0 Hz, 2H), 7.27 (dd, J = 5.6, 2.6 Hz, 1H),
7.50 (m, 3H), 8.05 (d, J = 9.0 Hz, 2H), 8.57 (d, J = 5.8 Hz, 1H), 8.82 (q,
J = 5.0 Hz, 1H), 8.97 (s, 1H) ppm.; 13C NMR (75 MHz, DMSO‑d6) δ 26.1,
61.6, 109.4, 114.7, 115.9, 119.1, 122.3, 122.5, 123.0, 134.1, 134.9,
144.2, 150.7, 152.7, 152.9, 153.4, 163.8, 165.2 ppm.; HRMS (ESI+) m/
z: calcd for C22H21N6O3 [M+H]+ 417.1675, found 417.1664.
at 450 nm by Thermo Scientific™ Multiskan™ GO Microplate
Spectrophotometer.
Declaration of Competing Interest
The authors declared that there is no conflict of interest.
Acknowledgements
This research was financially supported by the Research Fund for
DPST Graduate with First Placement (Grant Number 19/2558) from the
Institute for the Promotion of Teaching Science and Technology (IPST),
The Thailand Research Fund (RTA6280004), Department of Chemistry,
Faculty of Science, Silpakorn University and Center of Excellence in
Hepatitis and Liver Cancer, Department of Biochemistry, Faculty of
Medicine, Chulalongkorn University.
Appendix A. Supplementary data
4.4. In vitro cytotoxicity towards HepG2, Huh7 and MRC-5
Supplementary data to this article can be found online at https://doi.
org/10.1016/j.bioorg.2021.104831.
The assay of cytotoxic activities against human HCC cell lines,
HepG2 and Huh7, were performed using MTT method according to the
procedure described by Nagel et al. and Zhang et al. [47,48]. The cyto-
toxic activity against normal human lung fibroblast (MRC-5) was eval-
uated by means of MTT assay as previously described [51]. Sorafenib
was used as the reference drug. All experiments were carried out three
times with three replicates for each concentration tested. Where appli-
cable, IC50 values were calculated by linear regression (IC50 > 50 µg/mL
References
[1] F. Bray, J. Ferlay, I. Soerjomataram, R.L. Siegel, L.A. Torre, A. Jemal, Global cancer
statistics 2018: GLOBOCAN estimates of incidence and mortality worldwide for 36
cancers in 185 countries, CA Cancer J. Clin. 68 (2018) 394–424, https://doi.org/
10.3322/caac.21492.
[2] D.M. Parkin, F. Bray, J. Ferlay, P. Pisani, Global cancer statistics, 2002, CA Cancer
J. Clin. 55 (2005) 74–108, https://doi.org/10.3322/canjclin.55.2.74.
15

S. Palakhachane et al.
Bioorganic Chemistry 112 (2021) 104831
[3] H.O. Adami, A.W. Hsing, J.K. McLaughlin, D. Trichopoulos, D. Hacker, A. Ekbom,
I. Persson, Alcoholism and liver cirrhosis in the etiology of primary liver cancer,
Int. J. Cancer 51 (1992) 898–902, https://doi.org/10.1002/ijc.2910510611.
[4] B. Charrez, L. Qiao, L. Hebbard, Hepatocellular carcinoma and non-alcoholic
steatohepatitis: The state of play, World J. Gastroenterol. 22 (2016) 2494–2502,
https://doi.org/10.3748/wjg.v22.i8.2494.
[29] M. Wang, S. Xu, H. Lei, C. Wang, Z. Xiao, S. Jia, J. Zhi, P. Zheng, W. Zhu, Design,
synthesis and antitumor activity of Novel Sorafenib derivatives bearing pyrazole
scaffold, Bioorg. Med. Chem. 25 (2017) 5754–5763, https://doi.org/10.1016/j.
bmc.2017.09.003.
[30] F. Chen, Y. Fang, R. Zhao, J. Le, B. Zhang, R. Huang, Z. Chen, J. Shao, Evolution in
medicinal chemistry of sorafenib derivatives for hepatocellular carcinoma, Eur. J.
Med. Chem. 179 (2019) 916–935, https://doi.org/10.1016/j.ejmech.2019.06.070.
[31] M. Wang, S. Xu, C. Wu, X. Liu, H. Tao, Y. Huang, Y. Liu, P. Zheng, W. Zhu, Design,
synthesis and activity of novel sorafenib analogues bearing chalcone unit, Bioorg.
Med. Chem. Lett. 26 (2016) 5450–5454, https://doi.org/10.1016/j.
bmcl.2016.10.029.
[5] K.A. Steinmetz, J.D. Potter, Vegetables, fruit, and cancer I. Epidemiology, Cancer
Causes Control 2 (1991) 325–357, https://doi.org/10.1007/bf00051672.
[6] K. Rapp, J. Schroeder, J. Klenk, S. Stoehr, H. Ulmer, H. Concin, G. Diem,
W. Oberaigner, S.K. Weiland, Obesity and incidence of cancer: a large cohort study
of over 145,000 adults in Austria, Br. J. Cancer 93 (2005) 1062–1067, https://doi.
org/10.1038/sj.bjc.6602819.
[32] E.M. Gordon, N.S. Chawla, F.L. Hall, S.P. Chawla, A two decade review of approved
drugs and drugs in development in the United States, New Cancer Therapies for the
21st (2015).
[7] S.-C. Chuang, C. La Vecchia, P. Boffetta, Liver cancer: descriptive epidemiology and
risk factors other than HBV and HCV infection, Cancer Lett. 286 (2009) 9–14.
[8] E.R. Schiff, S.S. Lee, Y.C. Chao, S. Kew Yoon, F. Bessone, S.S. Wu, W. Kryczka,
Y. Lurie, A. Gadano, G. Kitis, et al., Long-term treatment with entecavir induces
reversal of advanced fibrosis or cirrhosis in patients with chronic hepatitis B, Clin.
Gastroenterol. Hepatol. 9 (2011) 274–276, https://doi.org/10.1016/j.
cgh.2010.11.040.
[33] L.J. Scott, Lenvatinib: first global approval, Drugs 75 (2015) 553–560, https://doi.
org/10.1007/s40265-015-0383-0.
[34] E.S. Kim, Tivozanib: First Global Approval, Drugs 77 (2017) 1917–1923, https://
doi.org/10.1007/s40265-017-0825-y.
[35] Y. Tian, S. Yu, L. Cai, G. Gong, G. Wu, H. Qi, Y. Zhao, M. Qin, Synthesis and
Antitumor Activity of Sorafenib Analogs Containing a Tetrazole Moiety, Chem.
Res. Chin. Univ. 35 (2019) 41–46.
[9] J. Balogh, D. Victor 3rd, E.H. Asham, S.G. Burroughs, M. Boktour, A. Saharia, X. Li,
R.M. Ghobrial, H.P. Monsour Jr., Hepatocellular carcinoma: a review,
J. Hepatocell. Carcinoma 3 (2016) 41–53, https://doi.org/10.2147/JHC.S61146.
[10] J.-W. Jang, Y. Song, K.M. Kim, J.-S. Kim, E.K. Choi, J. Kim, H. Seo, Hepatocellular
carcinoma-targeted drug discovery through image-based phenotypic screening in
co-cultures of HCC cells with hepatocytes, BMC Cancer 16 (2016) 810.
[11] S. Daher, M. Massarwa, A.A. Benson, T. Khoury, Current and Future Treatment of
Hepatocellular Carcinoma: An Updated Comprehensive Review, J. Clin. Transl.
Hepatol. 6 (2018) 69–78, https://doi.org/10.14218/JCTH.2017.00031.
[12] A. Raza, G.K. Sood, Hepatocellular carcinoma review: current treatment, and
evidence-based medicine, World J. Gastroenterol. 20 (2014) 4115–4127, https://
doi.org/10.3748/wjg.v20.i15.4115.
[36] P. Alam, S.K. Chaturvedi, T. Anwar, M.K. Siddiqi, M.R. Ajmal, G. Badr, M.
H. Mahmoud, R.H. Khan, Biophysical and molecular docking insight into the
interaction of cytosine β-D arabinofuranoside with human serum albumin,
J. Lumin. 164 (2015) 123–130.
[37] J. Vallner, Binding of drugs by albumin plasma protein, J. Pharm. Sci. 66 (1977)
447–465.
[38] S.G. Agalave, S.R. Maujan, V.S. Pore, Click chemistry: 1, 2, 3-triazoles as
pharmacophores, Chem. Asian J. 6 (2011) 2696–2718.
[39] S. Haider, M.S. Alam, H. Hamid, 1,2,3-Triazoles: scaffold with medicinal
significance, Inflamm. Cell Signal. 1 (2014), e95.
[13] F. Wang, W. Dai, Y. Wang, M. Shen, K. Chen, P. Cheng, Y. Zhang, C. Wang, J. Li,
Y. Zheng, et al., The synergistic in vitro and in vivo antitumor effect of combination
therapy with salinomycin and 5-fluorouracil against hepatocellular carcinoma,
PLoS ONE 9 (2014), e97414, https://doi.org/10.1371/journal.pone.0097414.
[14] P. Michl, S. Pauls, T.M. Gress, Evidence-based diagnosis and staging of pancreatic
cancer, Best Pract. Res. Clin. Gastroenterol. 20 (2006) 227–251, https://doi.org/
10.1016/j.bpg.2005.10.005.
[40] C.S. Santos, R.J. de Oliveira, R.N. de Oliveira, J.C.R. Freitas, 1,2,3-Triazoles:
general and key synthetic strategies, Arkivoc (2020).
[41] H.C. Zhou, Y. Wang, Recent researches in triazole compounds as medicinal drugs,
Curr. Med. Chem. 19 (2012) 239–280.
[42] S. Palakhachane, Y. Ketkaew, N. Chuaypen, P. Tangkijvanich, A. Suksamrarn,
P. Limpachayaporn, The preliminary studies on the synthesis and the cytotoxicity
towards HepG2 and Huh7 of a new series of sorafenib analogues: Replacement of
aryl urea with a triazole ring. The 45th Congress on Science and Technology of
Thailand, Mae Fah Luang University, Chiang Rai, Thailand, 2019.
[43] B.-Y. Ryu, T. Emrick, Bisphenol-1, 2, 3-triazole (BPT) epoxies and cyanate esters:
synthesis and self-catalyzed curing, Macromolecules 44 (2011) 5693–5700.
[44] G. Munagala, K.R. Yempalla, S. Singh, S. Sharma, N.P. Kalia, V.S. Rajput, S. Kumar,
S.D. Sawant, I.A. Khan, R.A. Vishwakarma, Synthesis of new generation triazolyl-
and isoxazolyl-containing 6-nitro-2, 3-dihydroimidazooxazoles as anti-TB agents:
in vitro, structure–activity relationship, pharmacokinetics and in vivo evaluation,
Org. Biomol. Chem. 13 (2015) 3610–3624.
[15] Z. Zhang, B. Niu, J. Chen, X. He, X. Bao, J. Zhu, H. Yu, Y. Li, The use of lipid-coated
nanodiamond to improve bioavailability and efficacy of sorafenib in resisting
metastasis of gastric cancer, Biomaterials 35 (2014) 4565–4572.
[16] W. Jeong, J.H. Doroshow, S. Kummar, US FDA approved oral kinase inhibitors for
the treatment of malignancies, Curr. Probl. Cancer 37 (2013) 110–144.
[17] P.T. White, M.S. Cohen, The discovery and development of sorafenib for the
treatment of thyroid cancer, Expert Opin. Drug Discov. 10 (2015) 427–439,
https://doi.org/10.1517/17460441.2015.1006194.
[18] S. Wilhelm, C. Carter, M. Lynch, T. Lowinger, J. Dumas, R.A. Smith, B. Schwartz,
R. Simantov, S. Kelley, Discovery and development of sorafenib: a multikinase
inhibitor for treating cancer, Nat. Rev. Drug Discovery 5 (2006) 835–844, https://
doi.org/10.1038/nrd2130.
[45] Y-y Wang, J-z Liu, X-y Yu, D-z Yang, L-n Zhang, G-s Zhao, Design and synthesis of
hydrazine and oxadiazole-containing derivatives of Sorafenib as antitumor agents,
Chem. Res. Chin. Univ. 29 (2013) 454–459.
`
[19] M.B. Toaldo, V. Salvatore, S. Marinelli, C. Palama, M. Milazzo, L. Croci,
[46] L. Tan, Z. Zhang, D. Gao, J. Luo, Z.-C. Tu, Z. Li, L. Peng, X. Ren, K. Ding, 4-Oxo-1, 4-
dihydroquinoline-3-carboxamide derivatives as new Axl kinase inhibitors, J. Med.
Chem. 59 (2016) 6807–6825.
L. Venerandi, M. Cipone, L. Bolondi, F. Piscaglia, Use of VEGFR-2 targeted
ultrasound contrast agent for the early evaluation of response to sorafenib in a
mouse model of hepatocellular carcinoma, Mol. Imaging Biol. 17 (2015) 29–37.
[20] J.M. Llovet, S. Ricci, V. Mazzaferro, P. Hilgard, E. Gane, J.F. Blanc, A.C. de
Oliveira, A. Santoro, J.L. Raoul, A. Forner, et al., Sorafenib in advanced
hepatocellular carcinoma, N. Engl. J. Med. 359 (2008) 378–390, https://doi.org/
10.1056/NEJMoa0708857.
[47] C. Nagel, S. Armeanu-Ebinger, A. Dewerth, S.W. Warmann, J. Fuchs, Anti-tumor
activity of sorafenib in a model of a pediatric hepatocellular carcinoma, Exp. Cell
Res. 331 (2015) 97–104.
[48] S.S. Zhang, Y.H. Ni, C.R. Zhao, Z. Qiao, H.X. Yu, L.Y. Wang, J.Y. Sun, C. Du, J.
H. Zhang, L.Y. Dong, et al., Capsaicin enhances the antitumor activity of sorafenib
in hepatocellular carcinoma cells and mouse xenograft tumors through increased
ERK signaling, Acta Pharmacol. Sin. 39 (2018) 438–448, https://doi.org/10.1038/
aps.2017.156.
[21] P. Wu, T.E. Nielsen, M.H. Clausen, FDA-approved small-molecule kinase inhibitors,
Trends Pharmacol. Sci. 36 (2015) 422–439.
[22] A.T. Wecksler, S.H. Hwang, J.Y. Liu, H.I. Wettersten, C. Morisseau, J. Wu, R.
H. Weiss, B.D. Hammock, Biological evaluation of a novel sorafenib analogue, t-
CUPM, Cancer Chemother. Pharmacol. 75 (2015) 161–171, https://doi.org/
10.1007/s00280-014-2626-2.
[49] M. Cervello, D. Bachvarov, N. Lampiasi, A. Cusimano, A. Azzolina, J.A. McCubrey,
G. Montalto, Molecular mechanisms of sorafenib action in liver cancer cells, Cell
Cycle 11 (2012) 2843–2855, https://doi.org/10.4161/cc.21193.
´
´
´
[23] L.S. Wood, Management of vascular endothelial growth factor and multikinase
inhibitor side effects, Clin. J. Oncol. Nurs. 13 (Suppl) (2009) 13–18, https://doi.
org/10.1188/09.CJON.S2.13-18.
[50] M.A. Rodríguez-Hernandez, R. Chapresto-Garzon, M. Cadenas, E. Navarro-Villaran,
´
´
M. Negrete, M.A. Gomez-Bravo, V.M. Victor, F.J. Padillo, J. Muntane, Differential
effectiveness of tyrosine kinase inhibitors in 2D/3D culture according to cell
differentiation, p53 status and mitochondrial respiration in liver cancer cells, Cell
Death Dis. 11 (2020) 1–10.
[24] M. Mannion, S. Raeppel, S. Claridge, N. Zhou, O. Saavedra, L. Isakovic, L. Zhan,
F. Gaudette, F. Raeppel, R. Deziel, et al., N-(4-(6,7-Disubstituted-quinolin-4-yloxy)-
3-fluorophenyl)-2-oxo-3-phenylimidazoli dine-1-carboxamides: a novel series of
dual c-Met/VEGFR2 receptor tyrosine kinase inhibitors, Bioorg. Med. Chem. Lett.
19 (2009) 6552–6556, https://doi.org/10.1016/j.bmcl.2009.10.040.
[25] W. Zhan, Y. Li, W. Huang, Y. Zhao, Z. Yao, S. Yu, S. Yuan, F. Jiang, S. Yao, S. Li,
Design, synthesis and antitumor activities of novel bis-aryl ureas derivatives as Raf
kinase inhibitors, Bioorg. Med. Chem. 20 (2012) 4323–4329.
[51] S. Thongnest, J. Boonsombat, H. Prawat, C. Mahidol, S. Ruchirawat, Ailanthusins
AG and nor-lupane triterpenoids from Ailanthus triphysa, Phytochemistry 134
(2017) 98–105.
[52] C. Wang, H. Jin, D. Gao, C. Lieftink, B. Evers, G. Jin, Z. Xue, L. Wang, R.
L. Beijersbergen, W. Qin, Phospho-ERK is a biomarker of response to a synthetic
lethal drug combination of sorafenib and MEK inhibition in liver cancer,
J. Hepatol. 69 (2018) 1057–1065.
[26] C.-r. Zhao, R.-q. Wang, G. Li, X.-x. Xue, Sun C-j, Qu X-j, Li W-b. Synthesis of
indazole based diarylurea derivatives and their antiproliferative activity against
tumor cell lines, Bioorg. Med. Chem. Lett. 23 (2013) 1989–1992.
[27] Z. Liu, Y. Wang, H. Lin, D. Zuo, L. Wang, Y. Zhao, P. Gong, Design, synthesis and
biological evaluation of novel thieno [3, 2-d] pyrimidine derivatives containing
diaryl urea moiety as potent antitumor agents, Eur. J. Med. Chem. 85 (2014)
215–227.
[53] K.-C. Hsu, Y.-F. Chen, S.-R. Lin, J.-M. Yang, iGEMDOCK: a graphical environment
of enhancing GEMDOCK using pharmacological interactions and post-screening
analysis, BMC Bioinf. 12 (2011) S33.
[54] W. Gao, A.P.-C. Chen, C.-H. Leung, E.A. Gullen, A. Fürstner, Q. Shi, L. Wei, K.-
H. Lee, Y.-C. Cheng, Structural analogs of tylophora alkaloids may not be
functional analogs, Bioorg. Med. Chem. Lett. 18 (2008) 704–709.
[55] S. Elsawa, X. Zheng, N.B.R. Vittar, X. Gai, M.G. Fernandez-Barrena, C.D. Moser,
C. Hu, L.L. Almada, A.L. McCleary-Wheeler, A.M. Vrabel, The Transcription Factor
GLI1 Mediates TGFb1 Driven EMT in Hepatocellular Carcinoma via a SNAI1-
Dependent Mechanism, PLoS ONE (2012).
[28] M. Qin, S. Yan, L. Wang, H. Zhang, Y. Zhao, S. Wu, D. Wu, P. Gong, Discovery of
novel diaryl urea derivatives bearing a triazole moiety as potential antitumor
agents, Eur. J. Med. Chem. 115 (2016) 1–13.
16

S. Palakhachane et al.
Bioorganic Chemistry 112 (2021) 104831
[56] T. Song, C. Wang, C. Guo, Q. Liu, X. Zheng, Pentraxin 3 overexpression accelerated
tumor metastasis and indicated poor prognosis in hepatocellular carcinoma via
driving epithelial-mesenchymal transition, J. Cancer 9 (2018) 2650–2658, https://
doi.org/10.7150/jca.25188.
[64] K. Lu, L.D. Cai, X. Zhang, G.D. Wu, C.J. Xu, Y.F. Zhao, P. Gong, Design, synthesis,
and biological evaluation of novel substituted benzamide derivatives bearing a
1,2,3-triazole moiety as potent human dihydroorotate dehydrogenase inhibitors,
Bioorg. Chem. 76 (2018) 528–537, https://doi.org/10.1016/j.bioorg.2017.12.025.
[65] D. Prasad, N. Aggarwal, R. Kumar, M. Nath, Synthesis of novel heteroarenes based
[1,2,3]-triazoles via click chemistry and their evaluation for antibacterial activity,
Indian J. Chem. B 51B (2012) 731–738.
[57] R.G. Schmidt, E.K. Bayburt, S.P. Latshaw, J.R. Koenig, J.F. Daanen, H.
A. McDonald, B.R. Bianchi, C.M. Zhong, S. Joshi, P. Honore, et al., Chroman and
tetrahydroquinoline ureas as potent TRPV1 antagonists, Bioorg. Med. Chem. Lett.
21 (2011) 1338–1341, https://doi.org/10.1016/j.bmcl.2011.01.056.
[58] C. Ferroni, A. Pepe, Y.S. Kim, S. Lee, A. Guerrini, M.D. Parenti, A. Tesei,
A. Zamagni, M. Cortesi, N. Zaffaroni, et al., 1,4-Substituted Triazoles as
Nonsteroidal Anti-Androgens for Prostate Cancer Treatment, J. Med. Chem. 60
(2017) 3082–3093, https://doi.org/10.1021/acs.jmedchem.7b00105.
[59] S. Kotha, D. Bansal, R.V. Kumar, Synthesis of symmetrical and unsymmetrical
trisubstituted benzene derivatives through ring-closing alkyne metathesis strategy
and depropargylation with various catalysts, Indian J. Chem. B 48B (2009)
225–230.
[66] J. Chen, L. Ma, R. Zhang, J. Tang, H. Lai, J. Wang, G. Wang, Q. Xu, T. Chen,
F. Peng, Semi-Synthesis and Biological Evaluation of 1, 2, 3-Triazole-Based
Podophyllotoxin Congeners as Potent Antitumor Agents Inducing Apoptosis in
HepG2 Cells, Arch. Pharm. 345 (2012) 945–956.
[67] M. Irfan, B. Aneja, U. Yadava, S.I. Khan, N. Manzoor, C.G. Daniliuc, M. Abid,
Synthesis, QSAR and anticandidal evaluation of 1,2,3-triazoles derived from
naturally bioactive scaffolds, Eur. J. Med. Chem. 93 (2015) 246–254, https://doi.
org/10.1016/j.ejmech.2015.02.007.
[68] Y. Tsuzuki, T.K.N. Nguyen, D.R. Garud, B. Kuberan, M. Koketsu, 4-Deoxy-4-fluoro-
xyloside derivatives as inhibitors of glycosaminoglycan biosynthesis, Bioorg. Med.
Chem. Lett. 20 (2010) 7269–7273, https://doi.org/10.1016/j.bmcl.2010.10.085.
[69] J. Li, F. Yang, Y.T. Ma, K. Ji, Gold (III)-Catalyzed Intermolecular Oxidation-
Cyclization of Ynones: Access to 4-Substituted Chroman-3-ones, Adv. Synth. Catal.
361 (2019) 2148–2153.
[60] F. Khurshid, M. Jeyavelan, K. Takahashi, M.S.L. Hudson, S. Nagarajan, Aryl
fluoride functionalized graphene oxides for excellent room temperature ammonia
sensitivity/selectivity, RSC Adv. 8 (2018) 20440–20449, https://doi.org/10.1039/
c8ra01818a.
[61] V.S.P.R. Lingam, R. Vinodkumar, K. Mukkanti, A. Thomas, B. Gopalan, A simple
approach to highly functionalized benzo[b]furans from phenols and aryl iodides
via aryl propargyl ethers, Tetrahedron Lett. 49 (2008) 4260–4264, https://doi.org/
10.1016/j.tetlet.2008.04.150.
[70] R. Balasubramanian, K. Kumutha, M. Sarojadevi, Mechanical, thermal and
electrical properties of polyimides containing 1,2,3-triazole ring prepared by click
reaction, Polym. Bull. 73 (2016) 309–330.
[62] J. Kong, T. Meng, J. Su, A Unique Synthesis of 5, 8-Difluoro-2 H-chromene Using
Silicone Oil as a Solvent, Org. Process Res. Dev. 19 (2015) 681–683.
[63] I. Volchkov, D. Lee, Asymmetric Total Synthesis of (-)-Amphidinolide V through
Effective Combinations of Catalytic Transformations, J. Am. Chem. Soc. 135
(2013) 5324–5327, https://doi.org/10.1021/ja401717b.
[71] D.A. Volpe, S.S. Hamed, L.K. Zhang, Use of different parameters and equations for
calculation of IC50 values in efflux assays: potential sources of variability in IC50
determination, The AAPS journal 16 (2014) 172–180.
17