Discovery and structure-activity relationship of novel 4-hydroxy-thiazolidine-2-thione derivatives as tumor cell specific pyruvate kinase M2 activators

Article abstract of DOI:10.1016/j.ejmech.2017.11.023

Pyruvate kinase M2 isoform (PKM2) is a crucial protein responsible for aerobic glycolysis of cancer cells. Activation of PKM2 may alter aberrant metabolism in cancer cells. In this study, we discovered a 4-hydroxy-thiazolidine-2-thione compound 2 as a novel PKM2 activator from a random screening of an in-house compound library. Then a series of novel 4-hydroxy-thiazolidine-2-thione derivatives were designed and synthesized for screening as potent PKM2 activators. Among these, some compounds showed higher PKM2 activation activity than lead compound 2 and also exhibited significant anti-proliferative activities on human cancer cell lines at nanomolar concentration. The compound 5w was identified as the most potent antitumor agent, which showed excellent anti-proliferative effects with IC₅₀ values from 0.46 μM to 0.81 μM against H1299, HCT116, Hela and PC3 cell lines. 5w also showed less cytotoxicity in non-tumor cell line HELF compared with cancer cells. In addition, Preliminary pharmacological studies revealed that 5w arrests the cell cycle at the G2/M phase in HCT116 cell line. The best PKM2 activation by compound 5t was rationalized through docking studies.

Full text of DOI:10.1016/j.ejmech.2017.11.023

Accepted Manuscript
Discovery and structure-activity relationship of novel 4-hydroxy-thiazolidine-2-thione
derivatives as tumor cell specific pyruvate kinase M2 activators
Ridong Li, Xianling Ning, Shuo Zhou, Zhiqiang Lin, Xingyu Wu, Hong Chen, Xinyu
Bai, Xin Wang, Zemei Ge, Runtao Li, Yuxin Yin
PII:
S0223-5234(17)30918-2
10.1016/j.ejmech.2017.11.023
EJMECH 9898
DOI:
Reference:
To appear in: European Journal of Medicinal Chemistry
Received Date: 7 September 2017
Revised Date: 18 October 2017
Accepted Date: 8 November 2017
Please cite this article as: R. Li, X. Ning, S. Zhou, Z. Lin, X. Wu, H. Chen, X. Bai, X. Wang, Z. Ge, R. Li,
Y. Yin, Discovery and structure-activity relationship of novel 4-hydroxy-thiazolidine-2-thione derivatives
as tumor cell specific pyruvate kinase M2 activators, European Journal of Medicinal Chemistry (2017),
doi: 10.1016/j.ejmech.2017.11.023.
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ACCEPTED MANUSCRIPT
Graphical abstract

ACCEPTED MANUSCRIPT
structure-activity relationship
Discovery
and
of
novel
4-hydroxy-thiazolidine-2-thione derivatives as tumor cell specific
pyruvate kinase M2 activators
a
Ridong Li a, b, e, Xianling Ning a, e, Shuo Zhouf, Zhiqiang Lin , Xingyu Wu a, d, Hong
Chen a, c, Xinyu Bai a, d, Xin Wang b, Zemei Ge b, Runtao Li b, *, Yuxin Yin a, b, c, d, *
aInstitute of Systems Biomedicine, School of Basic Medical Sciences, Peking University Health Science Center,
Beijing 100191, PR China
bState Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University
Health Science Center, Beijing 100191, PR China
cPeking-Tsinghua Center for Life Sciences, Peking University Health Science Center, Beijing 100191, PR China
dDepartment of Pathology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing
100191, PR China
eDepartment of Pharmacology, School of Basic Medical Sciences, Peking University Health Science Center,
Beijing 100191, PR China
fDepartment of Pharmaceutical Sciences, College of Pharmacy, University of Kentuchy, 789 South Lime-stone
Street, Lexington, KY 40536, USA
Abstract
Pyruvate kinase M2 isoform (PKM2) is a crucial protein responsible for aerobic
glycolysis of cancer cells. Activation of PKM2 may alter aberrant metabolism in
cancer cells. In this study, we discovered a 4-hydroxy-thiazolidine-2-thione
compound 2 as a novel PKM2 activator from a random screening of an in-house
compound library. Then a series of novel 4-hydroxy-thiazolidine-2-thione derivatives
were designed and synthesized for screening as potent PKM2 activators. Among these,
some compounds showed higher PKM2 activation activity than lead compound 2 and
also exhibited significant anti-proliferative activities on human cancer cell lines at
nanomolar concentration. The compound 5w was identified as the most potent
antitumor agent, which showed excellent anti-proliferative effects with IC50 values
from 0.46 µM to 0.81 µM against H1299, HCT116, Hela and PC3 cell lines. 5w also
showed less cytotoxicity in non-tumor cell line HELF compared with cancer cells. In
addition, Preliminary pharmacological studies revealed that 5w arrests the cell cycle
at the G2/M phase in HCT116 cell line. The best PKM2 activation by compound 5t
was rationalized through docking studies.
Keywords:
PKM2 activators; 4-Hydroxy-thiazolidine-2-thione derivatives; Anti-tumor activity;
Structure-activity relationship
*Corresponding author.
E-mail address: lirt@bjmu.edu.cn (R. Li), yinyuxin@hsc.pku.edu.cn (Y. Yin).
1

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1. Introduction
Many cancer cells exhibit elevated glucose uptake and lactate production,
regardless of oxygen availability. This phenomenon, known as aerobic glycolysis or
the Warburg effect, facilitates tumor cell growth [1]. Pyruvate kinase (PK), which
catalyzes the final rate-limiting step of glycolysis and converts phosphoenolpyruvate
(PEP) to pyruvate, has been recognized as a key regulator of this metabolic pathway
[2]. PK comprises a total of four isoforms, including PKM1, PKM2, PKL and PKR,
which have different kinetic properties and tissue distributions. The PKL and PKR
isoform are encoded by Pkrl gene and expressed in the liver and red blood cells
respectively. The PKM1 and PKM2 isoform are encoded by Pkm gene and differ at
only 23 amino acid residues [3]. In spite of their high sequence similarity, PKM1 and
PKM2 have different catalytic and regulatory properties. PKM1 is a constitutively
active tetrameric enzyme, which is found in most normal adult tissues. However,
PKM2 alternates between a high-activity tetramer form and a low-activity dimer form
in normal tissue, while exhibiting a distinctive tendency to exist as a dimer in cancer
cells [4]. Dimeric PKM2 has low enzymatic activity, which supports cell growth by
increasing glycolytic intermediates necessary for biosynthetic processes, and thus
promotes cancer cell proliferation [5]. Highly enzymatic PKM2 can be formed by the
binding of allosteric activators like fructose-1,6-biphosphate (FBP) and serine [6]. In
light of these findings, small molecule PKM2 activators, which induce tetramer
formation of PKM2, are expected to suppress tumor formation in vitro and in vivo,
providing a novel anti-cancer therapeutic strategy [7].
Currently, several PKM2 activators with different scaffolds have been reported,
including
a
series
of
diarylsulfonamides
(b,
(a,
Fig.1)
[8],
[9],
thieno[3,2-b]pyrrole[3,2-d]pyridazinones
Fig.1)
2-oxo-N-aryl-1,2,3,4-tetrahydroquinoline-6-sulfonamides (c, Fig.1) [10], quinoline
sulfonamides (d, Fig.1) [11], 1-(sulfonyl)-5-(arylsulfonyl)indolines (e, Fig.1) [12],
imidazolethiazolo
3-(trifluoromethyl)-1H-pyrazole-5-carboxamides (g, Fig.1) [14]. Recently, Y. Matsui
et al. reported structure-guided fragment-linking of
pyridopyrimidinones
(f,
Fig.1)
[13]
and
a
4-(2,3-dichlorobenzoyl)-1-methyl-pyrrole-2-carboxamide as a PKM2 activator (h,
Fig.1) [15].
Though the above compounds show significant PKM2 activation activity, they have
no significant anti-proliferative effects on tumor cell lines. The possible reason is that
these agents activate PKM2 by binding at the same site as FBP but are not released
after interaction with phosphotyrosine, which led to no potency against tumor cell
lines [16]. Fortunately, we found two novel scaffolds of PKM2 activators (Fig.2, 1a
and 2) with potent anti-proliferative activities from a random screening of an in-house
small molecule library (more than 1000 compounds) on the basis of the established
PKM2 model. Encouraged by these results, the optimization of compound 1a has
been carried out and the more potential compound 1b as PKM2 activators with
significant anti-proliferative effects on tumor cell lines was identified in our previous
work [17]. Here, we describe the identification of potent compound 5w as PKM2
activator with excellent anti-proliferative effects and lower toxicity from compound 2
2

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and the structure-activity relationships (SAR).
Fig. 1. Structures of several known PKM2 activators.
Fig. 2. Structures of compound 1a, 1b and 2.
2. Results and discussion
The SAR study of compound 2 was carried out in two aspects based on its structure.
At first, the phenyl group (called region A) was modified with various substituted
aromatic and heterocyclic rings, and the pyridin-3-ylmethyl moiety (called region B)
remained intact. Afterwards, with the most favored substitution at region A, region B
was modified with different derivatives of pyridin-3-ylmethyl (Fig. 3).
Fig. 3. Optimization strategy of lead compound 2.
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For the structural optimization of region A, a number of substituted phenyl groups
(5a-5p) were selected to replace the phenyl group of compound 2 to examine the
electronic or steric effects of substituents attached to the phenyl ring on the PKM2
activation activity. Furthermore, the phenyl ring was also modified with various
heterocyclic rings (5q-5y) to evaluate the effect of different heterocycles on the
bioactivity. As a comparison, in order to investigate the influence of arylalkyl and
alkyl group on the activation activity, we used benzyl group (5z) and methyl group
(5aa) to replace the phenyl group.
The modification of region A is mainly outlined in Scheme 1. A variety of
substituted sulfonyl chlorides, which were commercially available or prepared by
literature procedures [18-20], reacted with 4-aminoacetophenone using pyridine as
base in THF to provide the corresponding key intermediates 3a-3z or 3aa. The
intermediates 3a-3z or 3aa were respectively treated with phenyltrimethylammonium
tribromide in THF to afford the corresponding bromides 4a-4z or 4aa. Without further
purification, 4a-4z or 4aa reacted with pyridin-3-ylmethanamine and carbon disulfide
using triethylamine as base in acetone to generate the target compounds 5a-5z or 5aa.
The synthetic routes of intermediates 3n-3p have one more step than other
intermediates 3a-3m. The routes are specifically depicted in Scheme 2.
2-Bromobenzenesulfonyl chloride was treated with 4-aminoacetophenone and
pyridine in THF to obtain compound 6. The bromine moiety of 6 was replaced by
morpholine in DMSO at 100°C, catalyzed by CuI, L-proline and K2CO3, to afford the
intermediate 3n [21]. Compound 6 reacted with phenylboronic acid or
3-nitrophenylboronic acid using PdCl2(dppf)CH2Cl2 and K2CO3 as catalysts in
refluxing 1,4-dioxane and H2O to respectively provide the intermediate 3o or 3p [22].
Compd.
A
Compd.
A
Compd.
A
5a
5j
5s
5b
5c
5d
5k
5l
5t
5u
5v
5m
4

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5e
5f
5n
5w
5x
5y
5o
5p
5g
5h
5i
5q
5r
5z
5aa
Scheme 1. Synthesis of 5a-5z and 5aa. Reagents and conditions: (a) 4-Aminoacetophenone, Py, THF, rt; (b)
Phenyltrimethylammonium tribromide, THF; (c) Pyridin-3-ylmethanamine, CS2, Et3N, Acetone.
O
O
O
O
Cl
N
S
Br
S
b
a
O
O
O
S
Br
N
N
O
O
H
H
6
3n
c
R
O
O
S
N
O
H
R=H 3o
R=NO2 3p
Scheme 2. Synthetic routes for the intermediate 3o-3p and 3n. Reagents and conditions: (a) 4-Aminoacetophenone,
Py, THF, rt; (b) Morpholine, CuI, L-proline, K2CO3, DMSO, 100 °C;(c) Phenylboronic acid or
3-Nitrophenylboronic acid, PdCl2(dppf)CH2Cl2, K2CO3, 1,4-dioxane, H2O, reflux.
The PKM2 activation activity of target compounds (5a-5z, 5aa) was evaluated with
a fluorescent PK-LDH coupled assay as previously reported [17]. The lead compound
2 was used as the positive control. The results expressed as AC50 are shown in Table 1.
Part of target compounds exhibited moderate to excellent PKM2 activation activity.
Among them, some compounds, such as 5t and 5y with AC50 values of 0.52 µM and
0.74 µM respectively, displayed more potent activity than the positive control
compound 2 (AC50 = 2.96 µM). Different substituents in benzene ring markedly
5

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influenced PKM2 activation activity. Introduction of an ortho methyl on the benzene
ring (5a, AC50 = 1.19 µM) increased the activity compared to that of lead compound 2.
On the contrary, methyl at meta and para-position of the benzene ring led to a slight
decrease and a dramatic loss in potency (5b, AC50 = 6.25 µM; 5c, AC50 > 20 µM).
Introducing a meta or para methoxy on the benzene ring (5f and 5g) also resulted in
slight reduction of activity. In addition, introduction of multi-substituents (5d and 5e),
electron-withdrawing groups (5h-5m) and large steric hindrance groups (5n-5p) on
the benzene ring led to a complete loss of activity. These results suggested that both
the electronic and steric effects of the substituents at benzene rings play important
roles in generating the PKM2 activation activity. Replacing the benzene ring of lead
compound 2 with naphthalene ring (5q and 5r, AC50 > 20 µM) and benzyl (5z, AC50 =
7.24 µM) respectively resulted in significant and slight reduction of activity. The
different heterocyclic structures at region A also showed great impact on the PKM2
activation activity. Unlike naphthalene ring, N-containing bicyclic ring replacements
such as quinoline (5t, AC50 = 0.52 µM), azaindole (5v, AC50 = 1.41 µM) and
3,4-dihydroquinolin-2(1H)-one ring (5y, AC50 = 0.74 µM) resulted in a significant
improvement of activity, with the exception of 2H-benzo[b][1,4]oxazin-3(4H)-one (5x,
AC50 > 20 µM). These results showed that the hydrogen atom of these three
heterocycles might forms an important hydrogen bonding interaction with the target
protein. When the phenyl group was replaced with 2,3-dihydrobenzo[b][1,4]dioxine
and thiophene ring, the corresponding compounds (5w, AC50 = 3.14 µM; 5s, AC50 =
1.47 µM) exhibited similar or more potent activity comparing with the lead compound
2. However, compounds with coumarin (5u) showed complete loss of activity (AC50 >
20 µM). In addition, replacing the benzene ring of lead compound 2 with methyl also
resulted in significant loss in potency (5aa, AC50 > 20 µM).
Table 1
PKM2 activation activities and anti-proliferative activities of target compounds modified at region A.
Enzymatic activity
AC50a (µM)
PKM2
Antiproliferative activity
IC50b (µM)
Compd.
A
H1299
HCT116
Hela
PC3
2.96±0.57
1.19±0.25
1.44±0.22 1.70±0.25 0.45±0.04 0.99±0.17
1.63±0.23 2.41±0.03 0.55±0.03 1.58±0.29
2
5a
6

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6.25±0.90
>20
1.68±0.20 1.73±0.16 1.14±0.08 1.11±0.10
5b
5c
5d
Me
1.20±0.15 2.18±0.14 0.44±0.07 0.94±0.17
1.75±0.68 1.65±0.44 0.94±0.19 1.33±0.08
>20
>20
1.62±0.15 3.69±0.24 1.11±0.03 4.51±0.95
0.93±0.06 2.62±0.75 0.59±0.04 0.93±0.08
5e
5f
5.95±0.92
4.69±0.32
>20
0.96±0.10 1.75±0.13 0.48±0.02 1.07±0.24
1.75±0.15 2.30±0.02 0.61±0.04 3.87±0.49
5g
5h
>20
1.22±0.06 2.72±0.14 0.26±0.02 1.31±0.28
5i
>20
>20
1.47±0.58 1.80±0.33 0.77±0.08 4.11±0.25
1.45±0.12 1.18±0.03 0.55±0.04 2.68±0.46
5j
5k
>20
>20
1.14±0.01 4.11±0.69 0.48±0.02 2.19±0.31
1.31±0.12 3.50±0.02 0.57±0.02 1.40±0.02
5l
5m
>20
>20
1.24±0.18 3.45±0.60 1.33±0.11 8.62±0.73
2.70±0.14 6.11±0.51 1.10±0.12 2.81±0.05
5n
5o
>20
>20
2.96±0.20 3.89±0.27 1.40±0.04 3.26±0.14
0.81±0.04 1.65±0.08 0.46±0.04 1.52±0.06
5p
5q
7

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>20
1.53±0.07 2.61±0.09 0.63±0.08 1.69±0.09
5r
5s
5t
1.47±0.29
0.52±0.14
>20
1.23±0.17 1.44±0.25 0.42±0.03 1.25±0.26
2.43±0.33 2.11±0.26 0.84±0.11 2.35±0.76
1.65±0.49 1.41±0.04 0.69±0.10 2.40±0.48
2.00±0.21 1.55±0.33 0.76±0.02 1.26±0.08
5u
5v
O
O
1.41±0.47
3.14±0.55
>20
0.69±0.08 0.81±0.03 0.46±0.05 0.66±0.07
2.12±0.11 1.84±0.31 0.78±0.08 1.95±0.29
5w
5x
0.74±0.15
7.24±1.02
1.65±0.25 1.64±0.10 0.71±0.11 4.29±0.21
1.55±0.26 3.32±0.29 1.26±0.03 2.44±0.31
5y
5z
>20
----
1.25±0.37 1.56±0.30 0.86±0.09 2.20±0.39
7.83±1.15 1.37±0.64 6.42±0.70 4.57±0.47
5aa
Taxol (nM)
----
a AC50 values were determined using enzymatic PKM2 activity assay.
b Dose-response curves were determined at five concentrations. The IC50 values are the concentrations needed to
inhibit cell growth by 50% as determined from these curves.
To detect the efficacy of target compounds as anti-tumor agents, we evaluated the
antiproliferative activity of the synthesized compounds against four PKM2 high
expression human tumor cell lines derived from human lung cancer (H1299), colon
cancer (HCT116), cervical cancer (Hela) and prostate cancer (PC3). The well-known
anticancer drug paclitaxel was used as the positive control. The results of this
evaluation are also shown in Table 1. The IC50 values of tested compounds against
different tumor cells ranged between 0.26 and 8.62 µM. Among them, Hela cells were
the most sensitive to these compounds with most IC50 value in the nanomolar range.
Those compounds with better enzymatic activity also have significant
antiproliferative activity. In particular, compound 5w showed the greatest
anti-proliferative activity towards these cell lines ranging from 0.46 to 0.81 µM,
which is also potent at enzyme level. Structure-activity relationship (SAR) analysis
showed that the steric hindrance of substituents on the benzene ring (5o and 5p) result
in 2-fold or 3-fold decrease in anti-proliferative activity against four cell lines
comparing with lead compound 2. Different structural units in region A showed great
8

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impact on the anti-proliferative activities against PC3 cell line. Replacement of the
phenyl moiety with 2-methoxy-5-chlorophenyl (5e, 4.51 µM), 2-nitrophenyl (5h,
3.87µM), 4-cyanophenyl (5j, 4.11 µM), 2-morpholinylphenyl (5n, 8.62 µM) and
3,4-dihydroquinolin-2(1H)-one (5y, 4.29 µM) led to obvious decrease in potency
against PC3 cell line in comparison with compound 2 (0.99 µM).
In view of its excellent PKM2 activation activity, compound 5t was selected to
evaluate the SAR of this scaffold in depth. In order to investigate the role of NH
in sulfonamide fragment, we converted the NH to NMe and generated the compound
5ab. The design of dehydroxyl compound 5ac was to examine the effect of hydroxyl
group in 4-hydroxy-thiazolidine-2-thione moiety. The synthetic routes for target
compounds 5ab and 5ac are respectively depicted in Schemes 3 and 4. The front
synthesized intermediate 3t served as a starting material was treated with MeI using
Cs2CO3 as catalyst in DMF to obtain compound 3ab with high yields. Then 3ab was
bromized and treated with pyridin-3-ylmethanamine and carbon disulfide with the
same synthetic process as 5a-5z or 5aa to afford the target compound 5ab. Compound
5t was dehydrated in refluxing MeOH and 0.5% HCl for 24 h to generate the target
compound 5ac according to the literature method [23].
Scheme 3. Synthesis of compound 5ab. Reagents and conditions: (a) MeI, Cs2CO3, DMF, rt; (b)
Phenyltrimethylammonium tribromide, THF, rt; (c) Pyridin-3-ylmethanamine, CS2, Et3N, Acetone, rt.
Scheme 4. Synthesis of compound 5ac. Reagents and conditions: (a) 0.5% HCl, MeOH, reflux.
The PKM2 activation activities and anti-proliferative activities of compounds 5t,
5ab and 5ac were listed in Table 2. Methyltion of the NH to NMe (5ab) resulted in a
complete loss in enzyme potency, but retained the cellular activity. This suggested
that hydrogen atom in the sulfonamide is critical for achieving potent PKM2
9

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activation activity. The dehydration product 5ac of 5t exhibited the complete loss of
both enzymatic and cellular activities. This phenomenon showed that the 4-hydroxyl
group in the 4-hydroxy-thiazolidine-2-thione derivatives is the key factor to maintain
the enzymatic and cellular activities.
Table 2
PKM2 activation activities and anti-proliferative activities of compounds 5t, 5ab and 5ac.
Enzymatic activity
AC50a (µM)
PKM2
Antiproliferative activity
IC50b (µM)
Compd.
H1299
HCT116
Hela
PC3
0.52±0.14
>20
2.43±0.33 2.11±0.26 0.84±0.11 2.35±0.76
2.47±0.87 2.32±0.17 0.93±0.10 6.15±0.78
5t
5ab
>20
>20
>20
>20
>20
5ac
Taxol (nM)
----
7.83±1.15 1.37±0.64 6.42±0.70 4.57±0.47
a AC50 values were determined using enzymatic PKM2 activity assay.
b Dose-response curves were determined at five concentrations. The IC50 values are the concentrations needed to
inhibit cell growth by 50% as determined from these curves.
In view of the above results, we found that different structural units at region A and
the hydrogen atom in the sulfonamide showed great impact on the PKM2 activation
activity, and the 4-hydroxyl group in 4-hydroxy-thiazolidine-2-thione moiety is the
key pharmacophore for these kind of compounds. Compound 5w not only has potent
PKM2 activation activity, but also exhibits the highest inhibitory against the four
tested cancer cell lines among all the target compounds modified at region A.
Therefore, compound 5w represented a new starting point for further optimization.
The pyridin-3-ylmethyl moiety in region B was modified while maintaining
1,4-benzodioxane as region A. To investigate whether the length of carbon linker
between the 4-hydroxy-thiazolidine-2-thione scaffold and the pyridine ring might
affect the activation activity, compound 5ad was synthesized. The pyridin-3-ylmethyl
moiety was modified with pyridin-4-ylmethyl (5ae) to evaluate the influence of the
position of nitrogen atom in pyridine ring on the bioactivity. Replacement of pyridine
fragment of compound 5w with various pyridine derivatives (5af, 5aj and 5ak) to
determine whether the pyridine unit has an effect on the activity. To study the effect
of pyridine moiety in more detail, we synthesized compounds 5ag-5ai with various
substituents in the pyridine ring. The synthesis of target compounds 5ad-5ak is
outlined in Scheme 5. The front intermediate compound 4w reacted with carbon
disulfide and various amines, which were commercially available or prepared by
literature procedures [24, 25], using triethylamine as base in acetone to afford the
target compounds 5ad-5ak.
10

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O
O
HO
S
O
O
Br
O
O
a
N
S
S
O
S
R
N
N
O
O
H
H
5ad-5ak
4w
Compd.
R
Compd.
R
5ad
5ah
5ae
5ai
N
O
S
O
5af
5aj
5ag
5ak
Scheme 5. Synthesis of 5ad-5ak. Reagents and conditions: (a) RNH2, CS2, Et3N, Acetone, rt.
Table 3
PKM2 activation activities and anti-proliferative activities of target compounds modified at region B.
Enzymatic activity
AC50a (µM)
PKM2
Antiproliferative activity
IC50b (µM)
Compd.
R
H1299
HCT116
Hela
PC3
3.14±0.55
>20
0.69±0.08 0.81±0.03 0.46±0.05 0.66±0.07
1.28±0.14 1.04±0.01 0.62±0.01 2.16±0.45
5w
5ad
>20
0.75±0.02 0.66±0.01 0.47±0.01 0.70±0.04
1.72±0.06 0.85±0.03 0.55±0.01 0.92±0.20
5ae
5af
2.15±0.39
11

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>20
0.83±0.03 0.74±0.01 0.41±0.01 1.13±0.01
5ag
5ah
>20
0.51±0.01 0.41±0.09 0.34±0.01 1.53±0.08
1.02±0.04 0.92±0.02 0.51±0.02 1.35±0.28
5ai
N
17.61±2.19
O
S
O
1.75±0.33
7.07±1.46
1.81±0.14 1.28±0.01 0.55±0.01 1.28±0.13
0.79±0.01 0.77±0.01 0.45±0.01 1.33±0.02
5aj
5ak
a AC50 values were determined using enzymatic PKM2 activity assay.
b Dose-response curves were determined at five concentrations. The IC50 values are the concentrations needed to
inhibit cell growth by 50% as determined from these curves.
As shown in Table 3, increasing the length of carbon linker between the pyridine
scaffold and the 4-hydroxy-thiazolidine-2-thione scaffold from 1 to 2 carbon atoms
resulted in a significant decrease in PKM2 activation activity (AC50 > 20 µM).
Movement of nitrogen to the para position led to dramatic reduction in potency for
4-pyridyl analogue 5ae (AC50 > 20 µM) as compared to compound 5w. This indicated
that the position of nitrogen atom in the pyridine ring is critical for achieving potent
PKM2 activation activity. Introduction of different substituents (5ag-5ai) in pyridine
ring of compound 5w significantly decreased the activity (AC50 of 5ag and 5ah > 20
µM, AC50 of 5ai = 17.61µM). This suggested that introducing substituents into the
pyridine ring is unfavorable for the improvement of activity. The target compound 5af
(AC50 = 2.15 µM) and 5aj (AC50 = 1.75 µM) respectively with pyrazin-2-ylmethyl
and quinolin-3-ylmethyl showed more potent activity than compound 5w (AC50
=
3.14 µM). The imidazo[1,2-a]pyridin-6-ylmethyl (5ak, AC50 = 7.07 µM) instead of
pyridin-3-ylmethyl of compound 5w slightly reduced the activation activity. These
results suggested that there is still more optimization space for region B.
Anti-proliferative activities of the target compounds modified at region B were also
evaluated in the same four cancer cell lines (H1299, HCT116, Hela and PC3). The
results in Table 3 showed that most of the modifications at region B have no obvious
impact on the antiproliferative activities. In other words, region A of this series of
compounds is more crucial for antitumor activity.
To further explore the selectivity of target compounds against cancer cells, they
were also tested in HELF cells derived from normal human embryonic lung fibroblast
cells. As seen in Table 4, some tested compounds showed higher cytotoxicity in
cancer cells (H1299) than normal cells (HELF). The results indicate that target
compounds have highly safety index. This is consistent with our design objective,
pharmacological activation of PKM2 enables cancer cells to restore the metabolism of
normal cells, which has no side effects on normal cells.
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Table 4
Anti-proliferative activities of selected target compounds against H1299 cancer cell line and non-tumor cell line
HELF.
IC50 (µM)a
Compd.
H1299
HELF
0.93±0.06 6.90±0.60
0.96±0.10 8.63±0.52
0.81±0.04 8.05±0.26
0.69±0.08 11.85±0.83
0.75±0.02 8.31±1.47
0.83±0.03 10.44±1.35
0.51±0.01 7.21±0.54
0.79±0.01 4.91±0.62
5f
5g
5q
5w
5ae
5ag
5ah
5ak
a Dose-response curves were determined at five concentrations. The IC50 values are the concentrations needed to
inhibit cell growth by 50% as determined from these curves.
According to the optimization results of region A and region B, we found an
interesting phenomenon. Some compounds display excellent anti-proliferative
activities in spite of their poor PKM2 activation activities. PKM2 was reported to
translocate from the cytoplasm into the nucleus of cancer cells to interact with Bub3
and MCL2, which is required for cell division in tumors [26]. In order to identify
whether these compounds have an effect on cell cycle distribution, compound 5w was
chosen to investigate the effect of these 4-hydroxy-thiazolidine-2-thione derivatives
on the cell cycle of HCT-116 cells. Exposure of HCT116 cells to compound 5w for 8
h resulted in an interference with cell cycle distribution. As shown in Fig. 4, treatment
of 5w caused blockage of the cell cycle in the G2/M phase. Compared with control,
when HCT116 cells were treated with increasing concentrations (1.25 µM, 2.5 µM
and 5 µM) of 5w, the percentage of cells in the G2/M phase increased from 21.28% to
63.21%, and the percentages of cells in S and G0/G1 phase decreased concomitantly.
Our results suggest that this series of compounds may display antitumor activity by
inhibiting PKM2 to enter nucleus to induce cell cycle arrest.
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Fig. 4. Compound 5w induced cell cycle arrest in G2/M phase of HCT116 cells in a dose-dependent manner.
To get further insight into the binding profile and reveal the structure–activity
relationship of this series of compounds, molecular docking studies were performed.
Compound 5t was chosen as the representative compound as it has the lowest AC50
value. Both R and S configurations of 5t were calculated, based on the estimated
binding energy and possible binding modes, R configuration was considered to be
active. The predicted optimal binding mode is shown in Fig. 5.
Compound 5t was tightly fitted into the small cave same as where other reported
PKM2 activators located. The quinoline ring was inside the hydrophobic pocket
surrounded by F26, M30, Q393, L394 and L398. The 4-methylphenyl group of
compound 5c will be sterically unfavorable due to the existence of nearby E397 and
leads to the loss of activation activity. Replacing the sulfonamide hydrogen with a
methyl group will also clash with the phenyl side chain of F26 thus eliminates its
activity. The hydroxyl group is crucial as it can form a hydrogen bond with the
backbone oxygen of L353. Removal of this hydroxyl group in 5t will not only delete
this important interaction but also significantly change the conformation of the
thiazolidine-2-thione ring and the attached pyridine ring. The pyridine nitrogen will
14

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also build a hydrogen bond with the side chain NH of Q393, changing the position of
the nitrogen will likely lower the strength of this hydrogen bond and lower the
activity.
Fig. 5. Predicted binding mode of compound 5t with PKM2. 5t is shown in yellow sticks and PKM2 is shown in
green cartoon. Key residues are shown in green sticks. Polar interactions are shown in yellow dashed lines.
3. Conclusion
In this paper, we have described the discovery and SAR of a previously
undescribed chemical class of PKM2 activators. Systematic structural modification
was carried out based on the structure of the lead compound 2. A series of novel
4-hydroxy-thiazolidine-2-thione derivatives were synthesized and evaluated for their
in vitro PKM2 activation activities and anti-tumor activities. Among them, some
compounds, such as 5t and 5y, showed higher PKM2 activation activity than lead
compound 2 and also exhibited significant anti-proliferative activities on human
cancer cell lines. The compound 5w was identified as the most potent antitumor agent,
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which inhibited the growth of four types of tumor cells with IC50 from 0.46 µM to
0.81 µM. A flow cytometric study showed that compound 5w delayed cell cycle
progression by arresting cells in G2/M phase, which may be due to its ability to
prevent PKM2 from entering nucleus. The molecular docking studies revealed the
interaction mode between compound 5t and PKM2, and the results may inspire the
design of more potent PKM2 activators. Further mechanism studies of compound 5w
are currently in progress.
4. Experiment
4.1. General
All reagents and solvents were purchased from commercial sources and were used
without further purification. Melting points were determined on X4 microscope and
are uncorrected. 1H NMR and 13C NMR spectra were recorded on Bruker AVANCEⅢ
400 MHz and 100 MHz spectrometer respectively. High resolution mass spectrum
(HRMS) was recorded on a Thermo Scientific Orbitrap Elite MS.
4.2. General procedure for the synthesis of compounds 2a, 3a-3m, 3q-3z, 3aa and 6
To a solution of 4-aminoacetophenone (0.68 g, 5 mmol) and pyridine (1.6 ml, 20
mmol) in THF (10 mL) was slowly added the substituted sulfonyl chloride (5 mmol).
The reaction mixture was stirred at room temperature for 12 h. Water (50 mL) was
added and the mixture was extracted with ethyl acetate (10 mL×3), the combined
organic phase was washed with 1N hydrochloric acid (30 mL×2) and water (30
mL×2), dried over anhydrous Na2SO4 and concentrated under vacuum to afford the
product.
4.2.1. N-(4-Acetylphenyl)benzenesulfonamide (2a)
Yield 95%. Mp: 130-131°C. 1H NMR (400 MHz, CDCl3) δ 8.08 (s, 1H), 7.86 (dd, J =
18.4, 8.4 Hz, 4H), 7.55 (t, J = 7.4 Hz, 1H), 7.46 (t, J = 7.8 Hz, 2H), 7.21 (d, J = 8.8
Hz, 2H), 2.53 (s, 3H). 13C NMR (100 MHz, CDCl3) δ 197.45, 141.48, 138.98, 133.54,
133.24, 130.12, 129.39, 127.29, 119.09, 26.51.
4.2.2. N-(4-Acetylphenyl)-2-methylbenzenesulfonamide (3a)
Yield 76%. Mp: 173-174°C. 1H NMR (400 MHz, DMSO-d6) δ 11.02 (s, 1H), 7.98 (d,
J = 7.6 Hz, 1H), 7.82 (d, J = 8.4 Hz, 2H), 7.53 (t, J = 7.2 Hz, 1H), 7.42 – 7.38 (m, 2H),
7.18 (d, J = 8.8 Hz, 2H), 2.60 (s, 3H), 2.45 (s, 3H). 13C NMR (100 MHz, DMSO-d6) δ
196.37, 142.07, 137.20, 136.79, 133.39, 132.77, 131.54, 129.85, 129.47, 126.47,
116.93, 26.37, 19.63.
4.2.3. N-(4-Acetylphenyl)-3-methylbenzenesulfonamide (3b)
Yield 91%. Mp: 165-166°C. 1H NMR (400 MHz, DMSO-d6) δ 10.85 (s, 1H), 7.84 (d,
J = 8.8Hz, 2H), 7.67 – 7.62 (m, 2H), 7.45 (d, J = 5.6 Hz, 2H), 7.21 (d, J = 8.0 Hz, 2H),
2.46 (s, 3H), 2.35 (s, 3H). 13C NMR (100 MHz, DMSO-d6) δ 196.45, 142.27, 139.94,
139.22, 133.90, 131.91, 129.81, 129.29, 126.83, 123.85, 117.83, 26.40, 20.81.
4.2.4. N-(4-Acetylphenyl)-4-methylbenzenesulfonamide (3c)
Yield 85%. Mp: 203-204°C. 1H NMR (400 MHz, DMSO-d6) δ 10.81 (s, 1H), 7.83 (d,
J = 8.4 Hz, 2H), 7.72 (d, J = 8.0 Hz, 2H), 7.37 (d, J = 8.0 Hz, 2H), 7.20 (d, J = 8.4 Hz,
16

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2H), 2.46 (s, 3H), 2.33 (s, 3H). 13C NMR (100 MHz, DMSO-d6) δ 196.43, 143.70,
142.36, 136.44, 131.89, 129.87, 129.80, 126.75, 117.84, 26.37, 20.95.
4.2.5. N-(4-Acetylphenyl)-2,4,6-trimethylbenzenesulfonamide (3d)
Yield 47%. Mp: 223-225°C. 1H NMR (400 MHz, DMSO-d6) δ 10.85 (s, 1H), 7.82 (d,
J = 8.0 Hz, 2H), 7.06 – 7.03 (m, 4H), 2.61 (s, 6H), 2.45 (s, 3H), 2.22 (s, 3H). 13C
NMR (100 MHz, DMSO-d6) δ 196.35, 142.50, 142.34, 138.72, 133.43, 131.96,
131.32, 129.88, 116.57, 26.35, 22.36, 20.37.
4.2.6. N-(4-Acetylphenyl)-5-chloro-2-methoxybenzenesulfonamide (3e)
Yield 71%. Mp: 206-208°C. 1H NMR (400 MHz, DMSO-d6) δ 10.79 (s, 1H), 7.85 –
7.81 (m, 3H), 7.66 (dd, J = 9.0, 2.6 Hz, 1H), 7.22 (d, J = 8.8 Hz, 3H), 3.87 (s, 3H),
13
2.47 (s, 3H). C NMR (100 MHz, DMSO-d6) δ 196.47, 155.32, 142.04, 135.01,
131.95, 129.76, 129.43, 127.52, 123.80, 117.82, 115.21, 56.70, 26.40.
4.2.7. N-(4-Acetylphenyl)-3-methoxybenzenesulfonamide (3f)
Yield 93%. Mp: 151-152°C. 1H NMR (400 MHz, DMSO-d6) δ 10.85 (s, 1H), 7.84 (d,
J = 8.8 Hz, 2H), 7.48 (t, J = 8.0 Hz, 1H), 7.39 (d, J = 7.6 Hz, 1H), 7.33 (d, J = 1.6 Hz,
1H), 7.24 – 7.18 (m, 3H), 3.78 (s, 3H), 2.47 (s, 3H). 13C NMR (100 MHz, DMSO-d6)
δ 196.50, 159.42, 142.18, 140.48, 132.10, 130.70, 129.82, 118.94, 118.73, 118.08,
111.72, 55.61, 26.41.
4.2.8. N-(4-Acetylphenyl)-4-methoxybenzenesulfonamide (3g)
Yield 86%. Mp: 178-179°C. 1H NMR (400 MHz, DMSO-d6) δ 10.77 (d, J = 2.4 Hz,
1H), 7.84 (d, J = 8.4 Hz, 2H), 7.79 (dd, J = 8.8, 2.0 Hz, 2H), 7.22 (dd, J = 8.6, 2.6 Hz,
13
2H), 7.08 (d, J = 8.8 Hz, 2H), 3.79 (s, 3H), 2.47 (s, 3H). C NMR (100 MHz,
DMSO-d6) δ 196.46, 162.70, 142.48, 131.81, 130.82, 129.82, 129.00, 117.75, 114.58,
55.67, 26.40.
4.2.9. N-(4-Acetylphenyl)-2-nitrobenzenesulfonamide (3h)
Yield 89%. Mp: 153-155°C. 1H NMR (400 MHz, DMSO-d6) δ 11.33 (s, 1H), 8.06 (dd,
J = 7.6, 1.6 Hz, 1H), 8.02 (dd, J = 7.6, 1.6 Hz, 1H), 7.90 – 7.84 (m, 4H), 7.24 (d, J =
8.8 Hz, 2H), 2.49 (s, 3H). 13C NMR (100 MHz, DMSO-d6) δ 196.53, 147.89, 141.22,
135.04, 132.83, 132.50, 131.09, 129.96, 129.89, 124.90, 118.38, 26.46.
4.2.10. N-(4-Acetylphenyl)-4-nitrobenzenesulfonamide (3i)
Yield 86%. Mp: 191-192°C. 1H NMR (400 MHz, DMSO-d6) δ 11.18 (s, 1H), 8.39 (dd,
J = 6.8, 2.0 Hz, 2H), 8.07 (dd, J = 6.8, 2.0 Hz, 2H), 7.86 (dd, J = 6.8, 2.0 Hz, 2H),
7.24 (dd, J = 6.8, 2.0 Hz, 2H), 2.48 (s, 3H). 13C NMR (100 MHz, DMSO-d6) δ 196.50,
150.04, 144.55, 141.43, 132.55, 129.93, 128.30, 124.86, 118.57, 26.45.
4.2.11. N-(4-Acetylphenyl)-4-cyanobenzenesulfonamide (3j)
Yield 97%. Mp: 207-208°C. 1H NMR (400 MHz, DMSO-d6) δ 11.12 (s, 1H), 8.08 (d,
J = 8.4 Hz, 2H), 7.99 (d, J = 8.4 Hz, 2H), 7.86 (d, J = 8.8 Hz, 2H), 7.22 (d, J = 8.4 Hz,
2H), 2.48 (s, 3H). 13C NMR (100 MHz, DMSO-d6) δ 196.50, 143.22, 141.50, 133.69,
132.49, 129.92, 127.43, 118.49, 117.47, 115.73, 26.45.
4.2.12. N-(4-Acetylphenyl)-2-fluorobenzenesulfonamide (3k)
Yield 56%. Mp: 181-182°C. 1H NMR (400 MHz, DMSO-D6) δ 11.22 (s, 1H), 7.94 (td,
J = 7.6, 1.2 Hz, 1H), 7.84 (d, J = 8.8 Hz, 2H), 7.74 – 7.69 (m, 1H), 7.45 – 7.38 (m,
2H), 7.21 (d, J = 8.8 Hz, 2H), 2.46 (s, 3H).
4.2.13. N-(4-acetylphenyl)-3-fluorobenzenesulfonamide (3l)
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Yield 92%. Mp: 146-147°C. 1H NMR (400 MHz, DMSO-d6) δ 11.02 (s, 1H), 7.88 (d,
J = 8.8 Hz, 2H), 7.73 – 7.64 (m, 3H), 7.54 (s, 1H), 7.27 (dd, J = 8.4, 2.4 Hz, 2H), 2.49
(s, 3H). 13C NMR (100 MHz, DMSO-d6) δ 196.48, 161.70 (d, J = 249.1 Hz), 141.82,
141.29 (d, J = 6.7 Hz), 132.33, 131.94, 129.89, 123.00, 120.54 (d, J = 22.0 Hz),
118.33, 113.91, 113.79 (d, J = 24.5 Hz), 26.41.
4.2.14. N-(4-Acetylphenyl)-4-fluorobenzenesulfonamide (3m)
Yield 88%. Mp: 139-140°C. 1H NMR (400 MHz, DMSO-d6) δ 10.96 (s, 1H), 7.97 –
7.93 (m, 2H), 7.88 (d, J = 8.4 Hz, 2H), 7.45 – 7.41 (m, 2H), 7.27 (d, J = 8.8 Hz, 2H),
2.49 (s, 3H). 13C NMR (101 MHz, DMSO-d6) δ 196.46, 164.53 (d, J = 252.1 Hz),
142.07, 135.66, 132.19, 129.88, 129.81, 118.18, 116.71 (d, J = 22.8 Hz), 26.39.
4.2.15. N-(4-Acetylphenyl)naphthalene-2-sulfonamide (3q)
Yield 95%. Mp: 198-199°C. 1H NMR (400 MHz, DMSO-d6) δ 11.05 (d, J = 11.6 Hz,
1H), 8.61 (d, J = 5.6 Hz, 1H), 8.18 – 8.11 (m, 2H), 8.02 – 8.00 (m, 1H), 7.88 – 7.82
(m, 3H), 7.71 – 7.65 (m, 2H), 7.30 (t, J = 9.2 Hz, 2H), 2.43 (s, 3H). 13C NMR (100
MHz, DMSO-d6) δ 196.38, 142.22, 136.21, 134.37, 131.96, 131.53, 129.82, 129.76,
129.32, 129.19, 129.16, 128.30, 127.83, 121.82, 117.93, 26.35.
4.2.16. N-(4-Acetylphenyl)naphthalene-1-sulfonamide (3r)
Yield 83%. Mp: 239-240°C. 1H NMR (400 MHz, DMSO-d6) δ 11.30 (s, 1H), 8.73 (d,
J = 8.4 Hz, 1H), 8.33 (d, J = 7.2 Hz, 1H), 8.25 (d, J = 8.0 Hz, 1H), 8.08 (d, J = 8.0 Hz,
1H), 7.79 – 7.75 (m, 3H), 7.69 – 7.65 (m, 2H), 7.16 (d, J = 8.8 Hz, 2H), 2.41 (s, 3H).
13C NMR (100 MHz, DMSO-d6) δ 196.31, 142.01, 134.82, 133.79, 131.56, 130.30,
129.77, 129.20, 128.39, 127.26, 127.11, 124.51, 123.97, 117.01, 26.32.
4.2.17. N-(4-Acetylphenyl)thiophene-2-sulfonamide (3s)
Yield 73%. Mp: 149-151°C. 1H NMR (400 MHz, DMSO-d6) δ 11.03 (s, 1H), 7.95 –
7.89 (m, 3H), 7.69 – 7.68 (m, 1H), 7.29 (dd, J = 8.8, 2.4 Hz, 2H), 7.14 (t, J = 4.4 Hz,
1H), 2.50 (s, 3H). 13C NMR (100 MHz, DMSO-d6) δ 196.55, 141.96, 139.66, 133.93,
133.03, 132.28, 129.84, 127.80, 118.26, 26.47.
4.2.18. N-(4-Acetylphenyl)quinoline-8-sulfonamide (3t)
Yield 84%. Mp: 257-258°C. 1H NMR (400 MHz, DMSO-d6) δ 10.79 (s, 1H), 9.13 (dd,
J = 4.0, 1.6 Hz, 1H), 8.52 – 8.47 (m, 2H), 8.30 (dd, J = 8.0, 1.2 Hz, 1H), 7.78 – 7.69
13
(m, 4H), 7.20 (d, J = 8.8 Hz, 2H), 2.39 (s, 3H). C NMR (100 MHz, DMSO-d6) δ
196.35, 151.56, 142.64, 142.39, 137.00, 134.89, 134.63, 132.56, 131.55, 129.50,
128.46, 125.65, 122.70, 117.61, 26.31.
4.2.19. N-(4-Acetylphenyl)-2-oxo-2H-chromene-6-sulfonamide (3u)
Yield 80%. Mp: 190-191°C. 1H NMR (400 MHz, DMSO-d6) δ 11.02 (s, 1H), 8.33 (d,
J = 2.4 Hz, 1H), 8.19 (d, J = 9.6 Hz, 1H), 7.98 (dd, J = 8.6, 2.2 Hz, 1H), 7.85 (d, J =
8.8 Hz, 2H), 7.58 (d, J = 8.8 Hz, 1H), 7.25 (d, J = 8.8 Hz, 2H), 6.63 (d, J = 9.6 Hz,
1H), 2.47 (s, 3H). 13C NMR (100 MHz, DMSO-d6) δ 196.48, 159.06, 156.05, 143.35,
141.90, 135.15, 132.15, 129.89, 129.53, 127.84, 119.06, 118.12, 117.99, 117.95,
26.43.
4.2.20. N-(4-Acetylphenyl)-1H-pyrrolo[2,3-b]pyridine-3-sulfonamide (3v)
Yield 31%. Mp: 151-153°C. 1H NMR (400 MHz, DMSO-d6) δ 12.67 (s, 1H), 10.45 (s,
1H), 8.35 (d, J = 4.8 Hz, 2H), 8.25 – 8.17 (m, 3H), 7.71 (d, J = 5.6 Hz, 1H), 7.45 –
7.43 (m, 1H), 7.28 – 7.18 (m, 3H), 7.09 – 7.00 (m, 3H), 4.71 (d, J = 15.6 Hz, 1H),
18

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4.43 (d, J = 15.6 Hz, 1H), 3.61 (d, J = 7.6 Hz, 2H). 13C NMR (100 MHz, DMSO-d6) δ
195.65, 148.98, 148.04, 147.67, 144.62, 138.69, 135.25, 134.95, 132.25, 131.84,
127.56, 126.54, 122.70, 118.07, 117.63, 115.57, 111.97, 99.95, 46.33, 42.37. HRMS
m/z: calcd for C22H20N5O3S3 [M+H]+: 498.0728; found: 498.0723.
4.2.21. N-(4-Acetylphenyl)-2,3-dihydrobenzo[b][1,4]dioxine-6-sulfonamide (3w)
Yield 78%. Mp: 161-162°C. 1H NMR (400 MHz, DMSO-d6) δ 10.81 (s, 1H), 7.85 (d,
J = 8.4 Hz, 2H), 7.35 – 7.30 (m, 2H), 7.24 (dd, J = 8.4, 6.4 Hz, 2H), 7.02 (dd, J = 8.4,
1.6 Hz, 1H), 4.28 (d, J = 2.8 Hz, 4H), 2.47 (s, 2H). 13C NMR (100 MHz, DMSO-d6) δ
196.46, 147.51, 143.38, 142.43, 131.86, 131.63, 129.87, 120.44, 117.73, 115.71,
64.38, 64.05, 26.39.
4.2.22.
N-(4-Acetylphenyl)-3-oxo-3,4-dihydro-2H-benzo[b][1,4]oxazine-6-sulfonamide (3x)
Yield 97%. Mp: 277-279°C. 1H NMR (400 MHz, DMSO- d6) δ 10.99 (s, 1H), 10.86 (s,
1H), 7.85 (d, J = 8.4 Hz, 2H), 7.40 – 7.36 (m, 2H), 7.20 (d, J = 8.8 Hz, 2H), 7.08 (d, J
= 8.4 Hz, 1H), 4.66 (s, 2H), 2.48 (s, 3H). 13C NMR (100 MHz, DMSO-d6) δ 196.48,
164.13, 146.77, 142.25, 132.75, 131.91, 129.85, 127.72, 122.19, 117.83, 116.71,
114.12, 66.64, 26.42.
4.2.23. N-(4-Acetylphenyl)-2-oxo-1,2,3,4-tetrahydroquinoline-6-sulfonamide (3y)
Yield 91%. Mp: 250-251°C. 1H NMR (400 MHz, DMSO-d6) δ 10.76 (s, 1H), 10.46 (s,
1H), 7.84 (d, J = 8.8 Hz, 2H), 7.66 – 7.62 (m, 2H), 7.20 (d, J = 8.8 Hz, 2H), 6.94 (d, J
= 8.0 Hz, 1H), 2.93 (t, J = 7.6 Hz, 2H), 2.49 – 2.45 (m, 5H). 13C NMR (100 MHz,
DMSO-d6) δ 196.43, 170.29, 142.64, 142.43, 131.98, 131.69, 129.82, 126.54, 126.51,
124.37, 117.56, 115.11, 29.68, 26.40, 24.39.
4.2.24. N-(4-Acetylphenyl)-1-phenylmethanesulfonamide (3z)
Yield 85%. Mp: 192-193°C. 1H NMR (400 MHz, DMSO-d6) δ 10.36 (s, 1H), 7.92 (d,
J = 8.4 Hz, 2H), 7.36 – 7.4 (m, 3H), 7.27 (d, J = 8.4 Hz, 4H), 4.58 (s, 2H), 2.53 (s,
13
3H). C NMR (100 MHz, DMSO-d6) δ 196.49, 143.11, 131.40, 130.95, 129.96,
129.30, 128.46, 128.37, 117.13, 57.17, 26.45.
4.2.25. N-(4-Acetylphenyl)methanesulfonamide (3aa)
Yield 66%. Mp: 155-156°C. 1H NMR (400 MHz, DMSO-d6) δ 10.34 (s, 1H), 7.94 (d,
J = 8.8 Hz, 2H), 7.29 (d, J = 8.8 Hz, 2H), 3.11 (s, 3H), 2.53 (s, 3H). 13C NMR (100
MHz, DMSO-d6) δ 196.53, 143.00, 131.65, 129.99, 117.50, 39.87, 26.47.
4.2.26. N-(4-Acetylphenyl)-2-bromobenzenesulfonamide (6)
Yield 92%. Mp: 198-200°C. 1H NMR (400 MHz, DMSO-d6) δ 11.22 (s, 1H), 8.17 (dd,
J = 8.0, 1.6 Hz, 1H), 7.83 (d, J = 8.4 Hz, 3H), 7.63 – 7.53 (m, 2H), 7.18 (d, J = 8.8 Hz,
2H), 2.45 (s, 3H). 13C NMR (100 MHz, DMSO-d6) δ 196.41, 141.53, 137.83, 135.61,
134.95, 131.94, 131.80, 129.82, 128.41, 119.17, 117.20, 26.39.
4.3. The procedure for the synthesis of N-(4-Acetylphenyl)-2-morpholinobenzenesulfo-
namide (3n)
To a solution of compound 6 (0.36 g, 1 mmol) in DMSO (10ml) was added
morpholine (0.26 g, 3 mmol), CuI (19 mg, 0.1 mmol), L-proline (23 mg, 0.2 mmol)
and K2CO3 (0.42 g, 3 mmol). The mixture was heated 24 h at 100 °C under argon
followed by cooling to room temperature. Water (50 mL) was added and the mixture
19

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was extracted with ethyl acetate (10 mL×3), the combined organic phase was washed
with brine (30 mL×2), dried over anhydrous Na2SO4 and concentrated. The residue
was purified by column chromatography (eluent: petroleum ether/ethyl acetate = 2:1)
1
to provide 3n as a yellow solid (0.16 g, 44%). Mp: 216-217°C. H NMR (400 MHz,
DMSO-d6) δ 10.27 (s, 1H), 8.01 (d, J = 7.6 Hz, 1H), 7.78 (d, J = 8.4 Hz, 2H), 7.63 (t,
J = 7.8 Hz, 1H), 7.49 (d, J = 8.0 Hz, 1H), 7.35 (t, J = 7.6 Hz, 1H), 7.12 (d, J = 8.8 Hz,
2H), 3.86 (s, 4H), 2.80 (s, 4H), 2.43 (s, 3H). 13C NMR (100 MHz, DMSO-d6) δ
196.36, 151.96, 142.30, 134.94, 134.34, 131.36, 131.21, 129.72, 125.36, 124.54,
116.87, 65.76, 53.65, 26.35.
4.4. General procedure for the synthesis of compounds 3o-3p
To a solution of compound 6 (1.24 g, 3.5 mmol) in 1,4-dioxane (20ml) was added
substituted phenylboronic acid (5.25 mmol), PdCl2(dppf)CH2Cl2 (0.29 g, 0.35 mmol),
K2CO3 (1.45 g, 10.5 mmol) and 0.5ml H2O. The mixture was reflux under argon for
24 h followed by cooling to room temperature. Water (100 mL) was added and the
mixture was extracted with ethyl acetate (15 mL×3), the combined organic phase was
washed with brine (30 mL×2), dried over anhydrous Na2SO4 and concentrated. The
residue was purified by column chromatography (eluent: petroleum ether/ethyl acetate
= 3:1) to provide the product.
4.4.1. N-(4-Acetylphenyl)-[1,1'-biphenyl]-2-sulfonamide (3o)
Yield 81%. Mp: 187-189°C. 1H NMR (400 MHz, CDCl3) δ 8.27 (d, J = 7.6 Hz, 1H),
7.75 (d, J = 8.4 Hz, 2H), 7.60 – 7.42 (m, 5H), 7.30 – 7.24 (m, 3H), 6.75 (d, J = 8.8 Hz,
2H), 6.08 (s, 1H), 2.49 (s, 3H). 13C NMR (100 MHz, CDCl3) δ 196.84, 140.87, 140.71,
138.59, 137.30, 133.22, 132.73, 132.58, 130.23, 129.89, 129.51, 128.80, 128.19,
128.04, 117.15, 26.41.
4.4.2. N-(4-Acetylphenyl)-3'-nitro-[1,1'-biphenyl]-2-sulfonamide (3p)
Yield 63%. Mp: 195-196°C. 1H NMR (400 MHz, DMSO-d6) δ 10.52 (s, 1H), 8.31 (dd,
J = 8.2, 1.4 Hz, 1H), 8.17 (dd, J = 7.4, 1.4 Hz, 1H), 7.98 (t, J = 1.8 Hz, 1H), 7.79 (d, J
= 8.8 Hz, 2H), 7.74 – 7.69 (m, 3H), 7.61 (d, J = 8.0 Hz, 1H), 7.40 – 7.37 (m, 1H),
6.91 (d, J = 8.8 Hz, 2H), 2.46 (s, 3H). 13C NMR (100 MHz, DMSO-d6) δ 196.36,
147.13, 141.59, 139.81, 138.39, 137.39, 135.76, 133.38, 132.80, 131.52, 129.71,
129.48, 129.42, 129.16, 123.58, 122.95, 116.93, 26.36.
4.5. The procedure for the synthesis of N-(4-Acetylphenyl)-N-methylquinoline-8-
sulfonamide (3ab)
To a solution of compound 3t (0.93 g, 2.85 mmol) in DMF (10ml) was added
Cs2CO3 (1.86 g, 5.70 mmol) and MeI (0.45 g, 3.14 mmol). The reaction mixture was
stirred at room temperature for 19 h. Water (50 mL) was added and the mixture was
extracted with ethyl acetate (15 mL×3), the combined organic phase was washed with
water (50 mL×3), dried over anhydrous Na2SO4 and concentrated to afford 3ab as a
yellow solid (0.87 g, 89%), Mp: 127-128 °C. 1H NMR (400 MHz, DMSO-d6) δ 9.05
(dd, J = 4.2, 1.4 Hz, 1H), 8.52 – 8.49 (m, 1H), 8.43 (d, J = 7.2 Hz, 1H), 8.30 – 8.28
(m, 1H), 7.79 – 7.67 (m, 4H), 7.34 (d, J = 8.8 Hz, 2H), 3.66 (s, 3H), 2.45 (s, 3H). 13C
NMR (100 MHz, DMSO-d6) δ 196.66, 151.63, 145.42, 143.00, 136.94, 135.78,
134.67, 133.32, 132.90, 128.90, 128.54, 125.70, 122.68, 122.13, 38.15, 26.48.
20

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4.6. General procedure for the synthesis of compounds 2, 5a-5z and 5aa-5ab
To a solution of compound 2a, 3a-3z and 3aa-3ab (4.5 mmol) in THF (10ml) was
added phenyltrimethylammonium tribromide (1.69 g, 4.5 mmol). The reaction
mixture was stirred at room temperature for 12 h. Water (50 mL) was added and the
mixture was extracted with ethyl acetate (10 mL×3), the combined organic phase was
washed with water (30 mL×2), dried over anhydrous Na2SO4 and concentrated to
afford the intermediates 2b, 4a-4z and 4aa-4ab. To
a
solution of
pyridin-3-ylmethanamine (0.49 g, 4.5 mmol) in acetone (10ml) was added Et3N (0.91
g, 9 mmol). The reaction mixture was stirred for 5 min and was added CS2 (0.52 g,
6.75 mmol) to continuously stir for 30 min. The intermediates 2b, 4a-4z and 4aa-4ab
were added respectively and this mixture was stirred at room temperature for 4 h.
Water (50 mL) was added and the mixture was extracted with ethyl acetate (10 mL×3),
the combined organic phase was washed with brine (30 mL×2), dried over anhydrous
Na2SO4 and concentrated. The residue was purified by column chromatography to
provide the product.
4.6.1.
N-(4-(4-Hydroxy-3-(pyridin-3-ylmethyl)-2-thioxothiazolidin-4-yl)phenyl)benzenesulf-
onamide (2)
Yield 27%. Mp: 129-130°C. 1H NMR (400 MHz, DMSO-d6) δ 10.51 (s, 1H), 8.32 (d,
J = 3.2 Hz, 2H), 7.81 – 7.78 (m, 3H), 7.64 – 7.56 (m, 3H), 7.49 (d, J = 7.6 Hz, 1H),
7.26 (d, J = 7.2 Hz, 2H), 7.14 – 7.05 (m, 3H), 4.71 (d, J = 15.6 Hz, 1H), 4.49 (d, J =
15.6 Hz, 1H), 3.64 (s, 2H). 13C NMR (100 MHz, DMSO-d6) δ 195.87, 148.93, 147.78,
139.64, 138.26, 135.66, 135.27, 133.05, 132.24, 129.39, 126.82, 126.64, 122.82,
118.99, 99.84, 46.35, 42.40. HRMS m/z: calcd for C21H20N3O3S3 [M+H]+: 458.0667;
found: 458.0655.
4.6.2.
N-(4-(4-Hydroxy-3-(pyridin-3-ylmethyl)-2-thioxothiazolidin-4-yl)phenyl)-2-methylbe-
nzenesulfonamide (5a)
Yield 46%. Mp: 176-177°C. 1H NMR (400 MHz, DMSO-d6) δ 10.62 (s, 1H), 8.31 (d,
J = 2.8 Hz, 2H), 7.93 – 7.91 (m, 1H), 7.73 (s, 1H), 7.53 (t, J = 7.0 Hz, 1H), 7.46 (d, J
= 8.0 Hz, 1H), 7.39 (t, J = 6.8 Hz, 2H), 7.22 (d, J = 8.8 Hz, 2H), 7.11 (dd, J = 7.6, 4.8
Hz, 1H), 7.01 (d, J = 8.8 Hz, 2H), 4.69 (d, J = 15.2 Hz, 1H), 4.47 (d, J = 15.2 Hz, 1H),
3.62 (s, 2H), 2.58 (s, 3H). 13C NMR (100 MHz, DMSO-d6) δ 195.78, 148.89, 147.72,
138.19, 137.71, 136.76, 135.21, 135.02, 133.13, 132.69, 132.22, 129.26, 126.74,
126.42, 122.76, 117.65, 99.83, 46.30, 42.31, 19.67. HRMS m/z: calcd for
C22H22N3O3S3 [M+H]+: 472.0823; found: 472.0823.
4.6.3.
N-(4-(4-Hydroxy-3-(pyridin-3-ylmethyl)-2-thioxothiazolidin-4-yl)phenyl)-3-methylbe-
nzenesulfonamide (5b)
Yield 41%. Mp: 154-155°C. 1H NMR (400 MHz, CDCl3) δ 8.25 (d, J = 1.6 Hz, 1H),
8.04 – 8.03 (m, 1H), 7.72 – 7.63 (m, 3H), 7.72 – 7.63 (m, 4H), 7.10 (d, J = 8.8 Hz,
2H), 7.03 (dd, J = 7.8, 5.0 Hz, 1H), 5.09 (d, J = 15.2 Hz, 1H), 4.31 (d, J = 15.2 Hz,
1H), 3.66 (d, J = 12.0 Hz, 1H), 3.55 (d, J = 12.4 Hz, 1H), 2.36 (s, 3H). 13C NMR (100
21

ACCEPTED MANUSCRIPT
MHz, CDCl3) δ 196.82, 148.64, 146.93, 139.60, 139.27, 138.08, 138.00, 136.51,
134.16, 133.52, 129.18, 127.64, 127.08, 124.48, 123.64, 120.62, 100.77, 46.90, 43.59,
21.51. HRMS m/z: calcd for C22H22N3O3S3 [M+H]+: 472.0823; found: 472.0823.
4.6.4.
N-(4-(4-Hydroxy-3-(pyridin-3-ylmethyl)-2-thioxothiazolidin-4-yl)phenyl)-4-methylbe-
nzenesulfonamide (5c)
Yield 46%. Mp: 132-133°C. 1H NMR (400 MHz, DMSO-d6) δ 10.42 (s, 1H), 8.32 (s,
2H), 7.75 (s, 1H), 7.67 (d, J = 7.6 Hz, 2H), 7.49 (d, J = 8.0 Hz, 1H), 7.36 (d, J = 8.0
Hz, 2H), 7.25 (d, J = 8.24 Hz, 2H), 7.13 (dd, J = 7.6, 4.8 Hz, 1H), 7.05 (d, J = 8.0 Hz,
2H), 4.71 (d, J = 15.2 Hz, 1H), 4.47 (d, J = 15.6 Hz, 1H), 3.64 (s, 2H), 2.34 (s, 3H).
13C NMR (100 MHz, DMSO-d6) δ 195.82, 148.91, 147.74, 143.36, 138.36, 136.81,
135.50, 135.24, 132.21, 129.77, 126.74, 126.66, 122.77, 118.84, 99.83, 46.33, 42.36,
20.96. HRMS m/z: calcd for C22H22N3O3S3 [M+H]+: 472.0823; found: 472.0811.
4.6.5.
N-(4-(4-Hydroxy-3-(pyridin-3-ylmethyl)-2-thioxothiazolidin-4-yl)phenyl)-2,4,6-trimet-
hylbenzenesulfonamide (5d)
Yield 46%. Mp: 181-183°C. 1H NMR (400 MHz, DMSO-d6) δ 10.44 (d, J = 4.4 Hz,
1H), 8.35 – 8.32 (m, 2H), 7.76 – 7.74 (m, 1H), 7.47 (d, J = 8.0 Hz, 1H), 7.24 (dd, J =
8.8, 2.8 Hz, 2H), 7.12 (dd, J = 8.0, 4.8 Hz, 1H), 7.03 (d, J = 3.6 Hz, 2H), 6.94 – 6.91
(m, 2H), 4.73 (dd, J = 15.4, 3.0 Hz, 1H), 4.46 (d, J = 15.6 Hz, 1H), 3.63 (s, 2H), 2.58
(s, 6H), 2.22 (s, 3H). 13C NMR (100 MHz, DMSO-d6) δ 195.69, 148.95, 147.74,
142.19, 138.64, 138.42, 135.24, 134.91, 133.91, 132.24, 131.91, 126.76, 122.78,
117.63, 99.91, 46.35, 42.38, 22.44, 20.40. HRMS m/z: calcd for C24H26N3O3S3
[M+H]+: 500.1136; found: 500.1137.
4.6.6.
N-(4-(4-Hydroxy-3-(pyridin-3-ylmethyl)-2-thioxothiazolidin-4-yl)phenyl)-5-Chloro-2-
methoxybenzenesulfonamide (5e)
Yield 27%. Mp: 121-122°C. 1H NMR (400 MHz, DMSO-d6) δ 10.33 (s, 1H), 8.31 (d,
J = 6.0 Hz, 2H), 7.73 (s, 2H), 7.66 (dd, J = 8.8, 2.4 Hz, 1H), 7.48 (d, J = 8.0 Hz, 1H),
7.24 (t, J = 8.0 Hz, 3H), 7.13 (dd, J = 7.8, 5.0 Hz, 1H), 7.05 (d, J = 8.4 Hz, 2H), 4.70
(d, J = 15.6 Hz, 1H), 4.46 (d, J = 15.6 Hz, 1H), 3.85 (s, 3H), 3.63 (s, 2H). 13C NMR
(100 MHz, DMSO-d6) δ 195.80, 155.29, 148.86, 147.69, 138.00, 135.60, 135.18,
134.65, 132.15, 129.13, 128.04, 126.63, 123.67, 122.71, 118.95, 115.12, 99.81, 56.57,
46.29, 42.33. HRMS m/z: calcd for C22H21ClN3O4S3 [M+H]+: 522.0383; found:
522.0367.
4.6.7.
N-(4-(4-Hydroxy-3-(pyridin-3-ylmethyl)-2-thioxothiazolidin-4-yl)phenyl)-3-methoxyb-
enzenesulfonamide (5f)
Yield 64%. Mp: 91-92°C. 1H NMR (400 MHz, CDCl3) δ 8.24 (d, J = 1.6 Hz, 1H), 8.05 (dd, J
= 4.9, 1.3 Hz, 1H), 7.73 (d, J = 8.0 Hz, 1H), 7.44 – 7.33 (m, 5H), 7.15 – 7.04 (m, 4H), 5.10 (d, J =
15.1 Hz, 1H), 4.31 (d, J = 15.1 Hz, 1H), 3.66 (d, J = 12.6 Hz, 1H), 3.57 (d, J = 12.2 Hz, 1H). 13C
NMR (100 MHz, CDCl3) δ 196.87, 160.02, 148.69, 146.99, 140.50, 138.10, 137.90,
136.70, 133.53, 130.41, 127.12, 123.66, 120.90, 119.58, 119.47, 112.17, 100.75,
55.83, 46.90, 43.60. HRMS m/z: calcd for C22H22N3O4S3 [M+H]+: 488.0772; found:
22

ACCEPTED MANUSCRIPT
488.0759.
4.6.8.
N-(4-(4-Hydroxy-3-(pyridin-3-ylmethyl)-2-thioxothiazolidin-4-yl)phenyl)-4-methoxyb-
enzenesulfonamide (5g)
Yield 53%. Mp: 125-126°C. 1H NMR (400 MHz, DMSO-d6) δ 10.37 (s, 1H), 8.33 (d,
J = 2.8 Hz, 2H), 7.77 – 7.72 (m, 3H), 7.50 (d, J = 8.0 Hz, 1H), 7.26 (d, J = 8.8 Hz,
2H), 7.14 (dd, J = 7.6, 4.8 Hz, 1H), 7.10 – 7.04 (m, 4H), 4.72 (d, J = 15.2 Hz, 1H),
4.48 (d, J = 15.6 Hz, 1H), 3.80 (s, 3H), 3.64 (s, 2H). 13C NMR (100 MHz, DMSO-d6)
δ 195.84, 162.51, 148.94, 147.77, 138.50, 135.41, 135.28, 132.24, 131.23, 128.90,
126.77, 122.82, 118.75, 114.49, 99.88, 55.67, 46.37, 42.41. HRMS m/z: calcd for
C22H22N3O4S3 [M+H]+: 488.0772; found: 488.0772.
4.6.9.
N-(4-(4-Hydroxy-3-(pyridin-3-ylmethyl)-2-thioxothiazolidin-4-yl)phenyl)-2-nitrobenz-
enesulfonamide (5h)
Yield 29%. Mp: 102-104°C. 1H NMR (400 MHz, DMSO-d6) δ 10.94 (s, 1H), 8.32 –
8.30 (m, 2H), 8.01 (dd, J = 8.6, 1.4 Hz, 2H), 7.90 – 7.85 (m, 2H), 7.80 (s, 1H), 7.51 (d,
J = 8.0 Hz, 1H), 7.30 (d, J = 8.8 Hz, 2H), 7.14 (dd, J = 8.0, 4.8 Hz, 1H), 7.08 (d, J =
8.8 Hz, 2H), 4.71 (d, J = 15.2 Hz, 1H), 4.51 (d, J = 15.6 Hz, 1H), 3.65 (s, 2H). 13
C
NMR (100 MHz, DMSO-d6) δ 195.89, 148.91, 147.87, 147.77, 137.30, 136.32, 135.29, 134.77,
132.74, 132.24, 131.50, 129.86, 126.93, 124.81, 122.82, 119.44, 99.78, 46.33, 42.34. HRMS m/z:
calcd for C21H19N4O5S3 [M+H]+: 503.0518; found: 503.0503.
4.6.10.
N-(4-(4-Hydroxy-3-(pyridin-3-ylmethyl)-2-thioxothiazolidin-4-yl)phenyl)-4-nitrobenz-
enesulfonamide (5i)
Yield 43%. Mp: 154-155°C. 1H NMR (400 MHz, DMSO-d6) δ 10.81 (s, 1H), 8.40 (d,
J = 8.4 Hz, 2H), 8.31 (d, J = 4.0 Hz, 1H), 8.24 (s, 1H), 8.02 (d, J = 8.7 Hz, 2H), 7.82
(s, 1H), 7.54 (d, J = 7.6 Hz, 1H), 7.30 (d, J = 8.4 Hz, 2H), 7.16 (dd, J = 8.0, 4.8 Hz,
1H), 7.07 (d, J = 8.4 Hz, 2H), 4.68 (d, J = 15.6 Hz, 1H), 4.52 (d, J = 15.6 Hz, 1H),
13
3.65 (s, 2H). C NMR (100 MHz, DMSO-d6) δ 196.00, 149.93, 148.85, 147.76,
144.91, 137.48, 136.41, 135.35, 132.23, 128.25, 127.03, 124.77, 122.83, 119.68,
99.72, 46.32, 42.39. HRMS m/z: calcd for C21H19N4O5S3 [M+H]+: 503.0518; found:
503.0505.
4.6.11.
N-(4-(4-Hydroxy-3-(pyridin-3-ylmethyl)-2-thioxothiazolidin-4-yl)phenyl)-4-cyano-be-
nzenesulfonamide (5j)
Yield 42%. Mp: 105-107°C. 1H NMR (400 MHz, DMSO-d6) δ 10.73 (s, 1H), 8.32 (dd,
J = 4.8, 1.6 Hz, 1H), 8.27 (s, 1H), 8.07 (d, J = 8.4 Hz, 2H), 7.93 (d, J = 8.4 Hz, 2H),
7.79 (s, 1H), 7.52 (d, J = 7.6 Hz, 1H), 7.28 (d, J = 8.8 Hz, 2H), 7.15 (dd, J = 8.0, 4.8
Hz, 1H), 7.04 (d, J = 8.8 Hz, 2H), 4.68 (d, J = 15.6 Hz, 1H), 4.51 (d, J = 15.6 Hz, 1H),
13
3.65 (s, 2H). C NMR (100 MHz, DMSO-d6) δ 195.96, 148.83, 147.72, 143.54,
137.52, 136.30, 135.31, 133.59, 132.22, 127.37, 126.97, 122.81, 119.55, 117.58,
115.49, 99.70, 46.29, 42.35. HRMS m/z: calcd for C22H19N4O3S3 [M+H]+: 483.0619;
found: 483.0600.
4.6.12.
23

ACCEPTED MANUSCRIPT
N-(4-(4-hydroxy-3-(pyridin-3-ylmethyl)-2-thioxothiazolidin-4-yl)phenyl)-2-fluoroben-
zenesulfonamide (5k)
Yield 36%. Mp: 92-93°C. 1H NMR (400 MHz, DMSO-d6) δ 10.83 (s, 1H), 8.32 (d, J
= 8.0 Hz, 2H), 7.89 (t, J = 7.6 Hz, 1H), 7.77 (s, 1H), 7.74 – 7.69 (m, 1H), 7.49 – 7.46
(m, 1H), 7.43 – 7.37 (m, 2H), 7.27 (d, J = 8.4 Hz, 2H), 7.14 – 7.07 (m, 3H), 4.72 (d, J
13
= 15.6 Hz, 1H), 4.49 (d, J = 15.6 Hz, 1H), 3.64 (s, 2H). C NMR (100 MHz,
DMSO-d6) δ 195.81, 158.15 (d, J = 254.9 Hz), 148.92, 147.71, 137.77, 135.98 (d, J =
8.6 Hz), 135.70, 135.24, 132.20, 130.36, 127.18 (d, J = 13.7 Hz), 126.77, 125.02 (d, J
= 3.4 Hz), 122.73, 118.57, 117.35 (d, J = 20.7 Hz), 99.80, 46.32, 42.34. HRMS m/z:
calcd for C21H19FN3O3S3 [M+H]+: 476.0573; found: 476.0560.
4.6.13.
N-(4-(4-hydroxy-3-(pyridin-3-ylmethyl)-2-thioxothiazolidin-4-yl)phenyl)-3-fluoroben-
zenesulfonamide (5l)
Yield 41%. Mp: 119-120°C. 1H NMR (400 MHz, DMSO-d6) δ 10.60 (s, 1H), 8.33 (s,
2H), 7.81 (s, 1H), 7.65 – 7.60 (m, 3H), 7.52 (d, J = 7.2 Hz, 2H), 7.31 (d, J = 8.4 Hz,
2H), 7.16 – 7.08 (m, 3H), 4.73 (d, J = 15.6 Hz, 1H), 4.53 (d, J = 15.2 Hz, 1H), 3.66 (s,
2H). 13C NMR (100 MHz, DMSO-d6) δ 195.88, 161.67 (d, J = 249.0 Hz), 148.93,
147.72, 141.64 (d, J = 6.6 Hz), 137.84, 136.13, 135.30, 132.23, 131.76 (d, J = 8.0 Hz),
126.86, 122.91 (d, J = 2.5 Hz), 122.75, 120.22 (d, J = 21.3 Hz), 119.44, 113.69 (d, J =
24.2 Hz), 99.78, 46.33, 42.38. HRMS m/z: calcd for C21H19FN3O3S3 [M+H]+
:
476.0573; found: 476.0570.
4.6.14.
N-(4-(4-Hydroxy-3-(pyridin-3-ylmethyl)-2-thioxothiazolidin-4-yl)phenyl)-4-fluoroben-
zenesulfonamide (5m)
Yield 27%. Mp: 93-94°C. 1H NMR (400 MHz, DMSO-d6) δ 10.50 (s, 1H), 8.33 – 8.30
(m, 2H), 7.85 (dd, J = 8.6, 5.0 Hz, 2H), 7.78 (s, 1H), 7.51 (d, J = 8.0 Hz, 1H), 7.41 (t,
J = 8.8 Hz, 2H), 7.28 (d, J = 8.8 Hz, 2H), 7.15 (dd, J = 8.0, 4.8 Hz, 1H), 7.05 (d, J =
8.4 Hz, 2H), 4.71 (d, J = 15.6 Hz, 1H), 4.51 (d, J = 15.6 Hz, 1H), 3.65 (s, 2H). 13C
NMR (100 MHz, DMSO-d6) δ 195.88, 164.34 (d, J = 251.7 Hz), 148.88, 147.70,
138.01, 135.90, 135.25, 132.18, 129.72, 129.62, 126.79, 122.74, 119.23, 116.51 (d, J
= 22.8 Hz), 99.75, 46.30, 42.35. HRMS m/z: calcd for C21H19FN3O3S3 [M+H]+
:
476.0573; found: 476.0566.
4.6.15.
N-(4-(4-Hydroxy-3-(pyridin-3-ylmethyl)-2-thioxothiazolidin-4-yl)phenyl)-2-morpholi-
nobenzenesulfonamide (5n)
Yield 26%. Mp: 116-118°C. 1H NMR (400 MHz, DMSO-d6) δ 9.83 (s, 1H), 8.32 –
8.27 (m, 2H), 7.93 (d, J = 6.8 Hz, 1H), 7.70 (s, 1H), 7.63 (t, J = 7.6 Hz, 1H), 7.48 (t, J
= 8.0 Hz, 2H), 7.33 (t, J = 7.6 Hz, 1H), 7.20 (d, J = 8.4 Hz, 2H), 7.15 – 7.12 (m, 1H),
6.97 (d, J = 8.4 Hz, 2H), 4.64 (d, J = 15.6 Hz, 1H), 4.45 (d, J = 15.6 Hz, 1H), 3.82 (t,
J = 4.4 Hz, 4H), 3.61 (d, J = 2.0 Hz, 2H), 2.80 (t, J = 4.2 Hz, 4H). 13C NMR (100
MHz, DMSO-d6) δ 196.16, 151.84, 148.72, 148.37, 147.64, 138.39, 135.23, 134.88,
134.60, 132.14, 130.82, 126.61, 125.26, 124.41, 122.79, 117.89, 99.76, 65.80, 53.63,
46.26, 42.38. HRMS m/z: calcd for C25H27N4O4S3 [M+H]+: 543.1194; found:
543.1191.
24

ACCEPTED MANUSCRIPT
4.6.16.
N-(4-(4-Hydroxy-3-(pyridin-3-ylmethyl)-2-thioxothiazolidin-4-yl)phenyl)-[1,1'-biphe-
nyl]-2-sulfonamide (5o)
Yield 42%. Mp: 110-112°C. 1H NMR (400 MHz, CDCl3) δ 8.40 (s, 1H), 8.24 – 8.22
(m, 2H), 7.93 (dd, J = 5.0, 1.4 Hz, 1H), 7.69 (d, J = 8.0 Hz, 1H), 7.59 (td, J = 7.6, 1.2
Hz, 1H), 7.52 (td, J = 7.6, 1.2 Hz, 1H), 7.46 – 7.43 (m, 3H), 7.37 – 7.34 (m, 2H), 7.30
– 7.28 (m, 3H), 7.00 (dd, J = 7.8, 5.0 Hz, 1H), 6.78 (d, J = 8.8 Hz, 2H), 5.13 (d, J =
15.2 Hz, 1H), 4.19 (d, J = 15.2 Hz, 1H), 3.66 (d, J = 12.0 Hz, 1H), 3.51 (d, J = 12.4
Hz, 1H). 13C NMR (100 MHz, CDCl3) δ 196.59, 148.61, 146.79, 140.92, 138.74,
137.99, 137.70, 137.33, 135.84, 133.40, 132.99, 132.74, 130.05, 129.57, 128.72,
128.18, 128.04, 126.79, 123.48, 118.64, 100.82, 46.84, 43.49. HRMS m/z: calcd for
C27H24N3O3S3 [M+H]+: 534.0980; found: 534.0979.
4.6.17.
N-(4-(4-Hydroxy-3-(pyridin-3-ylmethyl)-2-thioxothiazolidin-4-yl)phenyl)-3'-nitro-[1,1
'-biphenyl]-2-sulfonamide (5p)
Yield 62%. Mp: 121-123°C. 1H NMR (400 MHz, DMSO-d6) δ 10.20 (s, 1H), 8.32 –
8.27 (m, 3H), 8.13 – 8.10 (m, 1H), 8.04 (d, J = 2.0 Hz, 1H), 7.76 (s, 1H), 7.75 – 7.69
(m, 3H), 7.61 (d, J = 7.6 Hz, 1H), 7.51 (d, J = 8.0 Hz, 1H), 7.41 – 7.39 (m, 1H), 7.21
(d, J = 8.8 Hz, 2H), 7.12 (dd, J = 8.0, 4.8 Hz, 1H), 6.80 (d, J = 8.4 Hz, 2H), 4.68 (d, J
= 15.6 Hz, 1H), 4.55 (d, J = 15.6 Hz, 1H), 3.65 (d, J = 4.8 Hz, 2H). 13C NMR (100
MHz, DMSO-d6) δ 195.99, 148.83, 147.71, 147.13, 140.04, 138.37, 137.80, 137.76,
135.76, 135.23, 134.97, 133.13, 132.76, 132.30, 129.38, 129.26, 129.09, 126.75,
123.68, 122.85, 122.78, 117.54, 99.73, 46.27, 42.36. HRMS m/z: calcd for
C27H23N4O5S3 [M+H]+: 579.0831; found: 579.0839.
4.6.18. N-(4-(4-Hydroxy-3-(pyridin-3-ylmethyl)-2-thioxothiazolidin-4-yl)phenyl)
naphthalene-2-sulfonamide (5q)
Yield 34%. Mp: 152-153°C. 1H NMR (400 MHz, DMSO-d6) δ 10.58 (s, 1H), 8.49 (s,
1H), 8.28 (s, 1H), 8.21 (d, J = 4.0 Hz, 1H), 8.16 (d, J = 8.0 Hz, 1H), 8.11 (d, J = 8.8
Hz, 1H), 8.02 (d, J = 8.0 Hz, 1H), 7.79 (d, J = 8.8 Hz, 1H), 7.72 – 7.64 (m, 3H), 7.42
(d, J = 8.0 Hz, 1H), 7.22 (d, J = 8.8 Hz, 2H), 7.09 (d, J = 8.8 Hz, 2H), 7.01 (dd, J =
8.0, 4.8 Hz, 1H), 4.66 (d, J = 15.6 Hz, 1H), 4.42 (d, J = 15.6 Hz, 1H), 3.60 (s, 2H).
13C NMR (100 MHz, DMSO-d6) δ 195.74, 148.88, 147.61, 138.17, 136.57, 135.65,
135.17, 134.26, 132.14, 131.54, 129.53, 129.24, 129.00, 127.94, 127.80, 127.69,
126.70, 122.64, 121.91, 118.97, 99.76, 46.25, 42.27. HRMS m/z: calcd for
C25H22N3O3S3 [M+H]+: 508.0823; found: 508.0806.
4.6.19. N-(4-(4-Hydroxy-3-(pyridin-3-ylmethyl)-2-thioxothiazolidin-4-yl)phenyl)
naphthalene-1-sulfonamide (5r)
Yield 46%. Mp: 112-113°C. 1H NMR (400 MHz, DMSO-d6) δ 10.94 (s, 1H), 8.72 (d,
J = 8.4 Hz, 1H), 8.33 – 8.23 (m, 4H), 8.09 (d, J = 8.4 Hz, 1H), 7.78 – 7.74 (m, 2H),
7.70 – 7.65 (m, 2H), 7.42 (d, J = 8.0 Hz, 1H), 7.19 (d, J = 8.8 Hz, 2H), 7.03 – 6.98 (m,
3H), 4.69 (d, J = 15.6Hz, 1H), 4.44 (d, J = 15.6 Hz, 1H), 3.59 (d, J = 7.6 Hz, 2H). 13C
NMR (100 MHz, DMSO-d6) δ 195.68, 148.81, 147.56, 138.20, 135.37, 135.12,
134.57, 134.39, 133.83, 132.31, 130.01, 129.16, 128.26, 127.43, 127.08, 126.72,
124.61, 124.24, 122.77, 117.80, 99.85, 46.31, 42.30. HRMS m/z: calcd for
25

ACCEPTED MANUSCRIPT
C25H22N3O3S3 [M+H]+: 508.0823; found: 508.0808.
4.6.20. N-(4-(4-Hydroxy-3-(pyridin-3-ylmethyl)-2-thioxothiazolidin-4-yl)phenyl) thio-
phene-2-sulfonamide (5s)
Yield 24%. Mp: 149-150°C. 1H NMR (400 MHz, DMSO-d6) δ 10.64 (s, 1H), 8.35 (s,
2H), 7.92 (d, J = 4.8 Hz, 1H), 7.81 (d, J = 4.4 Hz, 1H), 7.59 (s, 1H), 7.52 (d, J = 7.2
Hz, 1H), 7.33 – 7.31 (m, 2H), 7.18 – 7.13 (m, 4H), 4.74 (d, J = 15.6 Hz, 1H), 4.53 (d,
J = 15.2 Hz, 1H), 3.67 (s, 2H). 13C NMR (100 MHz, DMSO-d6) δ 195.93, 148.93,
147.80, 140.06, 138.01, 136.02, 135.29, 133.52, 132.61, 132.24, 127.71, 126.85,
122.86, 119.30, 99.84, 46.39, 42.44. HRMS m/z: calcd for C19H18N3O3S4 [M+H]+
464.0231; found: 464.0224.
:
4.6.21. N-(4-(4-Hydroxy-3-(pyridin-3-ylmethyl)-2-thioxothiazolidin-4-yl)phenyl) quin-
olone-8-sulfonamide (5t)
Yield 24%. Mp: 135-136°C. 1H NMR (400 MHz, DMSO-d6) δ 10.34 (s, 1H), 9.13 (dd,
J = 4.4, 1.6 Hz, 1H), 8.54 – 8.49 (m, 1H), 8.41 (d, J = 7.6 Hz, 1H), 8.29 (s, 2H), 8.23
– 8.22 (m, 1H), 4.66 (d, J = 15.6 Hz, 1H), 4.39 (d, J = 15.6 Hz, 1H), 3.56 (d, J = 3.2
Hz, 2H). 13C NMR (100 MHz, DMSO-d6) δ 195.68, 151.50, 148.83, 147.60, 142.76,
138.43, 137.00, 135.36, 135.18, 134.34, 132.17, 132.09, 129.66, 128.48, 126.44,
125.72, 123.49, 122.67, 118.65, 99.84, 46.28, 42.29. HRMS m/z: calcd for
C24H21N4O3S3 [M+H]+: 509.0776; found: 509.0781.
4.6.22.
N-(4-(4-Hydroxy-3-(pyridin-3-ylmethyl)-2-thioxothiazolidin-4-yl)phenyl)-2-oxo-2H-
chromene-6-sulfonamide (5u)
Yield 38%. Mp: 136-137°C. 1H NMR (400 MHz, DMSO-d6) δ 10.62 (s, 1H), 8.29 –
8.15 (m, 3H), 8.16 (d, J = 9.6 Hz, 1H), 7.94 (dd, J = 8.6, 2.2 Hz, 1H), 7.80 (s, 1H),
7.54 (t, J = 8.0 Hz, 2H), 7.27 (d, J = 8.8 Hz, 2H), 7.14 – 7.07 (m, 3H), 6.58 (d, J =
10.0 Hz, 1H), 4.69 (d, J = 15.6 Hz, 1H), 4.49 (d, J = 15.6 Hz, 1H), 3.63 (s, 2H). 13C
NMR (100 MHz, DMSO-d6) δ 195.94, 159.15, 155.95, 148.85, 147.68, 143.42,
137.98, 135.99, 135.48, 132.32, 129.61, 127.75, 126.93, 122.86, 119.36, 119.02,
117.84, 99.83, 46.37, 42.44. HRMS m/z: calcd for C24H20N3O5S3 [M+H]+: 526.0565;
found: 526.0549.
4.6.23.
N-(4-(4-Hydroxy-3-(pyridin-3-ylmethyl)-2-thioxothiazolidin-4-yl)phenyl)-1H-pyrrolo
[2,3-b]pyridine-3-sulfonamide (5v)
Yield 31%. Mp: 151-153°C. 1H NMR (400 MHz, DMSO-d6) δ 12.67 (s, 1H), 10.45 (s,
1H), 8.35 (d, J = 4.8 Hz, 2H), 8.25 – 8.17 (m, 3H), 7.71 (d, J = 5.6 Hz, 1H), 7.45 –
7.43 (m, 1H), 7.28 – 7.18 (m, 3H), 7.09 – 7.00 (m, 3H), 4.71 (d, J = 15.6 Hz, 1H),
4.43 (d, J = 15.6 Hz, 1H), 3.61 (d, J = 7.6 Hz, 2H). 13C NMR (100 MHz, DMSO-d6) δ
195.65, 148.98, 148.04, 147.67, 144.62, 138.69, 135.25, 134.95, 132.25, 131.84,
127.56, 126.54, 122.70, 118.07, 117.63, 115.57, 111.97, 99.95, 46.33, 42.37. HRMS
m/z: calcd for C22H20N5O3S3 [M+H]+: 498.0728; found: 498.0723.
4.6.24.
N-(4-(4-Hydroxy-3-(pyridin-3-ylmethyl)-2-thioxothiazolidin-4-yl)phenyl)-2,3-dihydro-
benzo[b][1,4]dioxine-6-sulfonamide (5w)
Yield 18%. Mp: 102-103°C. 1H NMR (400 MHz, DMSO-d6) δ 10.37 (s, 1H), 8.33 (d,
26

ACCEPTED MANUSCRIPT
J = 2.8 Hz, 2H), 7.77 (s, 1H), 7.50 (d, J = 8.0 Hz, 1H), 7.27 – 7.24 (m, 4H), 7.15 (dd,
J = 7.6, 4.8 Hz, 1H), 7.06 – 7.00 (m, 3H), 4.72 (d, J = 15.6 Hz, 1H), 4.47 (d, J = 15.6
Hz, 1H), 4.28 (d, J = 4.4 Hz, 4H), 3.64 (s, 2H). 13C NMR (100 MHz, DMSO-d6) δ
195.80, 148.90, 147.73, 147.27, 143.30, 138.40, 135.46, 135.30, 132.24, 132.00,
126.78, 122.81, 120.30, 118.73, 117.65, 115.60, 99.87, 64.37, 64.04, 46.34, 42.36.
HRMS m/z: calcd for C23H22N3O5S3 [M+H]+: 516.0722; found: 516.0707.
4.6.25.
N-(4-(4-Hydroxy-3-(pyridin-3-ylmethyl)-2-thioxothiazolidin-4-yl)phenyl)-3-oxo-3,4-
dihydro-2H-benzo[b][1,4]oxazine-6-sulfonamide (5x)
Yield 37%. Mp: 143-144°C. 1H NMR (400 MHz, DMSO-d6) δ 11.00 (s, 1H), 10.47 (s,
1H), 8.33 – 8.31 (m, 2H), 7.79 (s, 1H), 7.53 (d, J = 7.6 Hz, 1H), 7.34 – 7.33 (m, 2H),
7.27 (d, J = 8.8 Hz, 2H), 7.17 – 7.15 (m, 1H), 7.06 (dd, J = 8.8, 6.4 Hz, 3H), 4.73 (d, J
= 15.6 Hz, 1H), 4.67 (s, 2H), 4.49 (d, J = 15.6 Hz, 1H), 3.65 (s, 2H). 13C NMR (100
MHz, DMSO-d6) δ 195.90, 164.21, 148.92, 147.77, 146.61, 138.34, 135.63, 135.43,
133.18, 132.33, 127.66, 126.85, 122.90, 122.17, 118.95, 116.69, 114.21, 99.91, 66.70,
46.41, 42.45. HRMS m/z: calcd for C23H21N4O5S3 [M+H]+: 529.0674; found:
529.0681.
4.6.26.
N-(4-(4-Hydroxy-3-(pyridin-3-ylmethyl)-2-thioxothiazolidin-4-yl)phenyl)-2-oxo-1,2,3,
4-tetrahydroquinoline-6-sulfonamide (5y)
Yield 46%. Mp: 185-187°C. 1H NMR (400 MHz, DMSO-d6) δ 10.50 (s, 1H), 10.41 (s,
1H), 8.35 (s, 2H), 7.82 (s, 1H), 7.66 – 7.62 (m, 2H), 7.55 (d, J = 7.6 Hz, 1H), 7.30 (d,
J = 8.4 Hz, 2H), 7.18 – 7.10 (m, 3H), 6.99 (d, J = 8.4 Hz, 1H), 4.77 (d, J = 15.6 Hz,
1H), 4.52 (d, J = 15.6 Hz, 1H), 3.67 (s, 2H), 2.96 (t, J = 7.4 Hz, 2H), 2.50 (t, J = 7.6
Hz, 2H). 13C NMR (100 MHz, DMSO-d6) δ 195.86, 170.41, 149.00, 147.80, 142.46,
138.55, 135.41, 132.49, 132.33, 126.83, 126.52, 124.32, 122.87, 118.79, 115.17,
99.96, 46.44, 42.49, 29.82, 24.51. HRMS m/z: calcd for C24H23N4O4S3 [M+H]+
:
527.0881; found: 527.0870.
4.6.27.
N-(4-(4-Hydroxy-3-(pyridin-3-ylmethyl)-2-thioxothiazolidin-4-yl)phenyl)-1-phenylme-
thanesulfonamide (5z)
Yield 34%. Mp: 78-79°C. 1H NMR (400 MHz, DMSO-d6) δ 9.98 (s, 1H), 8.35 – 8.33
(m, 1H), 8.27 (s, 1H), 7.83 (s, 1H), 7.65 (d, J = 8.0 Hz, 1H), 7.37 – 7.35 (m, 4H), 7.33
(s, 1H), 7.27 – 7.23 (m, 3H), 7.11 (d, J = 8.4 Hz, 2H), 4.69 (q, J = 15.6 Hz, 2H), 4.45
(s, 2H), 3.76 (d, J = 12.0 Hz, 1H), 3.67 (d, J = 12.4 Hz, 1H). 13C NMR (100 MHz,
DMSO-d6) δ 196.06, 148.78, 147.66, 138.94, 135.60, 135.04, 132.48, 130.99, 129.46,
128.42, 128.26, 126.96, 123.00, 118.27, 99.75, 56.93, 46.27, 42.44. HRMS m/z: calcd
for C22H22N3O3S3 [M+H]+: 472.0823; found: 472.0823.
4.6.28. N-(4-(4-hydroxy-3-(pyridin-3-ylmethyl)-2-thioxothiazolidin-4-yl)phenyl) meth-
anesulfonamide (5aa)
Yield 27%. Mp: 171-173°C. 1H NMR (400 MHz, DMSO-d6) δ 9.89 (s, 1H), 8.34 (dd,
J = 4.8, 1.2 Hz, 1H), 8.26 (d, J = 0.8 Hz, 1H), 7.85 – 7.84 (m, 1H), 7.60 (d, J = 8.0 Hz,
1H), 7.34 (d, J = 8.8 Hz, 2H), 7.22 (dd, J = 7.4, 5.0 Hz, 1H), 7.14 – 7.12 (m, 2H), 4.69
(q, J = 15.4 Hz, 2H), 3.71 (q, J = 12.4 Hz, 2H), 3.00 (s, 3H). 13C NMR (100 MHz,
27

ACCEPTED MANUSCRIPT
DMSO-d6) δ 195.95, 148.94, 147.77, 138.90, 135.51, 135.42, 132.41, 126.98, 122.93,
118.85, 99.76, 46.28, 42.42, 39.38. HRMS m/z: calcd for C16H18N3O3S3 [M+H]+
:
396.0510; found: 396.0496.
4.6.29.
N-(4-(4-Hydroxy-3-(pyridin-3-ylmethyl)-2-thioxothiazolidin-4-yl)phenyl)-N-methylqu-
inoline-8-sulfonamide (5ab)
Yield 39%. Mp: 106-108°C. 1H NMR (400 MHz, DMSO-d6) δ 9.04 (dd, J = 4.2, 1.8
Hz, 1H), 8.54 (dd, J = 8.4, 1.6 Hz, 1H), 8.32 – 8.28 (m, 4H), 7.80 (s, 1H), 7.73 – 7.69
(m, 2H), 7.48 (d, J = 8.0 Hz, 1H), 7.22 (d, J = 8.8 Hz, 2H), 7.15 (dd, J = 7.8, 4.6 Hz,
1H), 7.10 (d, J = 8.8 Hz, 2H), 4.68 (d, J = 15.6 Hz, 1H), 4.46 (d, J = 15.6 Hz, 1H),
3.63 (d, J = 1.6 Hz, 2H), 3.54 (s, 3H). 13C NMR (100 MHz, DMSO-d6) δ 195.80,
151.50, 148.84, 147.69, 143.14, 141.87, 137.55, 136.92, 136.36, 135.36, 134.37,
132.88, 132.31, 128.60, 126.25, 125.71, 124.18, 122.87, 122.62, 99.70, 46.25, 42.22,
38.94. HRMS m/z: calcd for C25H23N4O3S3 [M+H]+: 523.0932; found: 523.0921.
4.7. The procedure for the synthesis of N-(4-(3-(Pyridin-3-ylmethyl)-2-thioxo-2,3-
dihydrothiazol-4-yl)phenyl)quinoline-8-sulfonamide (5ac)
A mixture of 5t (0.20 g, 0.39 mmol) and 5% hydrochloric acid (20ml) in methanol
(4 mL) was heated under reflux for 24 h. The reaction mixture was cooled to room
temperature and was extracted with ethyl acetate (15 mL×3), the combined organic
phase was washed with water (30 mL×2), dried over anhydrous Na2SO4 and
concentrated. The residue was purified by recrystallization (petroleum ether and ethyl
acetate) to provide 5ac as a yellow solid (0.15, 77%). Mp: 253-254 °C. 1H NMR (400
MHz, DMSO-d6) δ 10.50 (s, 1H), 9.11 (d, J = 3.2 Hz, 1H), 8.52 (d, J = 8.0 Hz, 1H),
8.43 (d, J = 6.8 Hz, 1H), 8.40 – 8.28 (m, 2H), 7.92 (s, 1H), 7.77 – 7.69 (m, 2H), 7.13
– 7.04 (m, 6H), 6.94 (s, 1H), 5.29 (s, 2H). 13C NMR (100 MHz, DMSO-d6) δ 187.74,
151.47, 148.45, 147.85, 143.28, 142.66, 139.35, 136.98, 134.99, 134.46, 134.17,
132.28, 130.95, 130.08, 128.43, 125.62, 124.84, 123.22, 122.64, 118.61, 110.04,
47.58. HRMS m/z: calcd for C24H19N4O2S3 [M+H]+: 491.0670; found: 491.0660.
4.8. General procedure for the synthesis of compounds 5ad-5ak
To a solution of compound 3w (0.70 g, 2.1 mmol) in THF (10ml) was added
phenyltrimethylammonium tribromide (0.79 g, 2.1 mmol). The reaction mixture was
stirred at room temperature for 12 h. Water (50 mL) was added and the mixture was
extracted with ethyl acetate (10 mL×3), the combined organic phase was washed with
water (30 mL×2), dried over anhydrous Na2SO4 and concentrated to afford the
intermediate 4w. To a solution of different pyridin-3-ylmethanamine derivatives (2.1
mmol) in acetone (10ml) was added Et3N (0.43 g, 4.2 mmol). The reaction mixture
was stirred for 5 min and was added CS2 (0.24 g, 3.15 mmol) to continuously stir for
30 min. The intermediate 4w were added respectively and this mixture was stirred at
room temperature for 4 h. Water (50 mL) was added and the mixture was extracted
with ethyl acetate (10 mL×3), the combined organic phase was washed with brine (30
mL×2), dried over anhydrous Na2SO4 and concentrated. The residue was purified by
column chromatography to provide the product.
28