2-(Phenylsulfonyl)quinoline N-hydroxyacrylamides as potent anticancer agents inhibiting histone deacetylase

Article abstract of DOI:10.1016/j.ejmech.2016.06.023

This study reports the design and synthesis of 2-(phenylsulfonyl)quinoline N-hydroxyacrylamides (8a–k). Structure-activity relationship studies focusing on regio-effect of N-hydroxyacrylamide moiety and influence of the sulfonyl linker revealed that N-hyd

Full text of DOI:10.1016/j.ejmech.2016.06.023

Accepted Manuscript
2-(Phenylsulfonyl)quinoline N-hydroxyacrylamides as potent anticancer agents
inhibiting histone deacetylase
Hsueh-Yun Lee, Chih-Yi Chang, Chih-Jou Su, Han-Li Huang, Samir Mehndiratta,
Yuh-Hsuan Chao, Chia-Ming Hsu, Sunil Kumar, Ting-Yi Sung, Yi-Zhen Huang, Yu-
Hsuan Li, Chia-Ron Yang, Jing-Ping Liou
PII:
S0223-5234(16)30501-3
10.1016/j.ejmech.2016.06.023
EJMECH 8684
DOI:
Reference:
To appear in: European Journal of Medicinal Chemistry
Received Date: 22 February 2016
Revised Date: 26 May 2016
Accepted Date: 14 June 2016
Please cite this article as: H.-Y. Lee, C.-Y. Chang, C.-J. Su, H.-L. Huang, S. Mehndiratta, Y.-
H. Chao, C.-M. Hsu, S. Kumar, T.-Y. Sung, Y.-Z. Huang, Y.-H. Li, C.-R. Yang, J.-P. Liou, 2-
(Phenylsulfonyl)quinoline N-hydroxyacrylamides as potent anticancer agents inhibiting histone
deacetylase, European Journal of Medicinal Chemistry (2016), doi: 10.1016/j.ejmech.2016.06.023.
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Table of Content
H
N
N
S
OH
O O
O
8f
GI50 = 0.08 μM (HCT116 cells)
The 2-(phenylsulfonyl)quinoline N-hydroxyacrylamide derivative 8f showed potent
antiproliferative activity with anti-HDAC activity.

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European Journal of Medicinal Chemistry
2-(Phenylsulfonyl)quinoline N-Hydroxyacrylamides as Potent Anticancer Agents
Inhibiting Histone Deacetylase
Hsueh-Yun Lee,a Chih-Yi Chang,a Chih-Jou Su,b Han-Li Huang,b Samir Mehndiratta,a Yuh-Hsuan
Chao,a Chia-Ming Hsu,b Sunil Kumar,a Ting-Yi Sung,b Yi-Zhen Huang,b Yu-Hsuan Li,a Chia-Ron
Yang*,c, Jing-Ping Liou*,a
,
* To whom correspondence should be addressed. For C. R. Yang: (Phone) 886-2-33668758; (e-mail)
cryang@ntu.edu.tw. For J. P. Liou: (Phone) 886-2-2736-1661 ext 6130; (e-mail) jpl@tmu.edu.tw
a.
School of Pharmacy, College of Pharmacy, Taipei Medical University, Taipei 11031, Taiwan.
The Ph.D. Program for Cancer Biology and Drug Discovery, College of Medical Science and
b.
Technology, Taipei Medical University, Taipei, Taiwan
School of Pharmacy, College of Medicine, National Taiwan University, Taipei, Taiwan
c.
Abstract. This study reports the design and synthesis of 2-(phenylsulfonyl)quinoline
N-hydroxyacrylamides (8a-k). Structure-activity relationship studies focusing on regio-effect of
N-hydroxyacrylamide moiety and influence of the sulfonyl linker revealed that
N-hydroxy-3-[3-(quinoline-2-sulfonyl)-phenyl]-acrylamide (8f) showed remarkable enzymatic and
cellular activity. The GI50 values of 8f for HL-60, HCT116, PC-3, and A549 cells were found to be
0.29, 0.08, 0.15, and 0.27 ꢀM, respectively. The compounds are therefore more potent than FDA
approved PXD-101 and SAHA. They also have an effect on the acetylation degree of histone H3 and
α-tubulin. In in vivo studies, 8f showed marked inhibition of the growth of HCT116 xenografts.
KEYWORDS. Anticancer agents, Histone Deacetylase Inhibitors, 2-(Phenylsulfonyl)quinoline
1. Introduction
Histone deacetylases (HDACs) which are involved with the degree of acetylation of histone, have
been identified as a crucial target for cancer therapy. Acetylation of histone, a covalent modification,
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also named an epigenetic process, is regulated by two classes of enzymes, histone acetyltransferase
(HAT) and histone deacetylase (HDAC) [1,2]. The balance between these controls is highly
correlated with development of cancer. The use of HDAC inhibitors helps restore the aberrant
epigenetic process and consequently, HDAC has become a significant target for cancer therapy. To
date, the U.S Food and Drug Administration has approved several HDAC inhibitors for various
indications. These include SAHA (vorinostat) and FK-228 (romidepsin) for the treatment of
refractory cutaneous T-cell lymphoma [3,4], PXD101 (belinostat) for treatment of refractory
peripheral T-cell lymphoma [5], and LBH589 (panobinostat) for the treatment of multiple myeloma
[6].
All of these compounds possess a distinct moiety such as hydroxamic acid or
2-aminophenylamide, and such moieties are felt to be characteristic of HDAC inhibitors [7].
Hydroxamic acid has been widely used in the development of HDAC inhibitors and the structures of
PXD-101 and LBH589, both possess a N-hydroxyacrylamide moiety (C=C-CO-NH-OH, bold in
Figure 2). Our previous work on 1-arylsulfonyl-5-(N-hydroxyacrylamide)indoles (5a) [8],
1-arylsulfonyl- 5-(N-hydroxyacrylamide)indolines (5b) [9,10], azaindolylsulfonamides (6) [11], and
1-arylsulfonyl-5-(N-hydroxyacrylamide)tetrahydroquinolines (7) [12], suggests that the
N-hydroxyacrylamide moiety is associated with significant HDAC inhibitory activity. Compounds
(5-7) that we reported previously have three components (Figure 2): a heterocycle (blue), a
benzenesulfonyl group (purplish red), and an N-hydroxyacrylamide moiety (bold). In these cases, the
heterocycles are linked to a benzenesulfonyl group forming a sulfonamide group. In the current study
our plan was to assemble these two components providing an alternative link between the
heterocycle and the benzenesulfonyl group, forming non-sulfonamide molecules. In this way, we
synthesized a series of 2-(phenylsulfonyl)quinoline N-hydroxyacrylamides (8a-k) and studied their
structure-activity relationships. The influence of the sulfonyl linker and the regio-effect of
N-hydroxyacrylamide on antiproliferative activity were also investigated.
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2. Results and Discussion
2.1. Chemistry
The general route used for the synthesis of 2-(phenylsulfonyl)quinoline N-hydroxyacrylamides
(8a-k) is described in Scheme 1. Different 2-chloroquinolines (9a-j) were reacted with substituted
thiophenols under basic conditions and this was followed by oxidation with m-CPBA, yielding the
2-(phenylsulfonyl)quinolines (10a-k). The resulting products underwent Heck olefination with
tert-butyl acrylate to afford compounds 11a-k, which were subjected to hydrolysis by TFA to yield
the corresponding carboxylic acids (12a-k). Compounds 12a-k were then reacted with NH2OTHP in
the presence of EDCꢁHCl followed by hydrolysis with 10% TFA to produce the target compounds
(8a-k). Compounds 18a-b, in which the sulfonyl has been replaced by a carbonyl group, were
synthesized according to the method shown in Scheme 2. Quinoline-2-carbaldehyde (13) underwent
nucleophilic
addition
with
(3-(diethoxymethyl)phenyl)magnesium
bromide
or
(4-(dimethoxymethyl)phenyl)- magnesium bromide followed by oxidation with pyridinium
dichromate (PDC) to obtain the 2-benzoylquinolines (14a-b). Subsequently, the dialkoxymethyl
groups in 14a and 14b were hydrolyzed under acidic condition to provide the corresponding
benzaldehydes (15a-b). The subsequent Wittig olefination of 15a-b with methyl
(triphenylphosphoranyl)acetate yielded compounds 16a-b, which underwent the hydrolysis,
amidation, and deprotection reactions shown in Scheme 1 to give compounds 18a-b. The synthetic
approach to compound 23 is shown in Scheme 3. The starting material, 2-chloropyridine, underwent
substitution, oxidation, Heck reaction, hydrolysis, amidation, and deprotection reactions similar to
those described in Scheme 1 to afford compound 23.
2.2. Biological evaluation
2.2.1. In vitro cell growth inhibitory activity
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All synthesized compounds (8a-k, 18a-b, and 23) together with the reference compounds,
PXD101 and SAHA, were tested for their antiproliferative activity in four cancer cell lines, human
promyelocytic leukemia HL-60, colon carcinoma HCT116, human prostate cancer PC-3, and human
lung cancer A549 (Table 1).
The results obtained from compounds 8a-k, shown in Table 1, revealed the regio-effect of the
N-hydroxyacrylamide moiety. Compounds 8f with N-hydroxyacrylamide groups at C3' position
showed the most potent antiproliferative activity against HL-60, HCT116, PC-3, and A549 cells with
GI50 values of 0.29, 0.08, 0.15, and 0.27 ꢀM, respectively. This cellular activity is better than that
obtained with PXD101 and SAHA. The shift of the N-hydroxyacrylamide moiety from C3' (8f) to
C4' (8g) led to a slight decrease of cellular activity, but the potency was still essentially sustained.
Compound 8g exhibited antiproliferative activity against tested cells with a mean GI50 value of 0.62
ꢀM, which is comparable to that of PXD101 and SAHA. The potencies of compounds 8c-e with a
C6-, C7-, and C8-N-hydroxyacrylamide moiety respectively, are somewhat less than those of
PXD101 and SAHA. Compounds 8a and 8b, which possess C3- and C5-N-hydroxyacrylamide
moiety, have negligible antiproliferative activity. These results indicate that N-hydroxyacrylamide is
most effective in the C3'- or C4'-position. The following discussion focuses on the substitution effect
of the quinoline ring on the cytotoxicity in compounds in which the N-hydroxyacrylamide group is at
the C3' position. Test data from compounds 8h-k showed that the presence of replacements such as
-OCH3, -Cl, and -F led to decrease of activity. This phenomena is also observed in the comparison of
compounds 18a and 18b with 8f and 8g. The replacement of -SO2- with -CO- also led to slight
decrease of antiproliferative activity. The change of the quinoline in 8f to a pyridine (23) led to a
dramatic decrease of cellular activity.
2.2.2. Upregulation Effect of Histone and α-Tubulin.
To evaluate the inhibitory activity of this series of molecules, compounds 8f and 8j were tested for
their effects on the levels of α-tubulin in HCT116 and PC-3 cells (Figure 3), using PXD101 and
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SAHA as reference compounds. The results show that compounds 8f and 8j can increase the amount
of acetylated histone H3 and α-tubulin in a dose-dependent manner, which is similar to the behavior
of PXD101 and SAHA. Notably, the effect of 8f and 8j on the acetylation degree of histone H3 was
observed at a concentration of 0.3 ꢀM, which is lower than the concentration of the reference
compounds that achieved the same effect.
2.2.3. HDAC Isoform Inhibition.
To understand the detailed effect of this series of compounds on isozymes of HDAC, the inhibitory
activity of 8f, 8j, PXD101, and SAHA on HDAC1, 2, 6, and 8 was assessed (Table 2). The IC50
values of 8f and 8j for the inhibition of HDAC1, 2, and 6 are smaller than that of PXD101, and
SAHA. However, compounds 8f and 8j failed to display selectivity toward any HDAC isozymes, and
these molecules therefore behave as pan-HDAC inhibitors.
2.2.4. Growth Inhibition of Human Colon Cancer Xenografts in Vivo.
Compound 8f was tested for its ability to suppress growth of HCT-116 xenografts in nude mice,
using SAHA as a reference compound. As shown in Figure 4, compound 8f inhibited tumor growth
in a dose-dependent manner. Oral administration of 100 mg/kg of compound 8f suppressed tumor
growth by a factor of 58.8%, which is similar to the result from treatment with 200 mg/kg of SAHA.
There was no change of body weight of tested animals after treatment with compound 8f or SAHA
(Figure 4).
3. Conclusion
A series of 2-(phenylsulfonyl)quinoline N-hydroxyacrylamides (8a-k) have been synthesized.
Structure-activity relationship studies revealed that the N-hydroxyacrylamide group is favored in the
C3' position and the sulfone linker, when compared to the carbonyl bridge plays a significant role in
the biological activity. The study found that compound 8f inhibits cancer proliferation with a mean
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GI50 value of 0.19 ꢀM, and is thus more potent than SAHA or PXD101. It also proved able to inhibit
HDAC in the study on the degree of acetylation of histone H3 and α-tubulin. In in vivo studies,
compound 8f inhibited tumor growth of HCT116 xenografts by a factor of 58.8% with no effect on
body weight.
In summary, this study has produced a series of novel 2-(phenylsulfonyl)quinoline
N-hydroxyacrylamides with potential as anticancer agents.
4. Experimental section
4.1. Chemistry
Nuclear magnetic resonance (1H NMR) spectra were obtained with Bruker Fourier 300 and
DRX-500 spectrometers, with chemical shift in parts per million (ppm, δ) downfield from TMS as an
internal standard. High-resolution mass spectra (HRMS) were recorded with a FINNIGAN MAT
95S Mass Spectrometer. The purity of the final compounds was determined using a Hitachi 2000
series HPLC system using C-18 column (Agilent ZORBAX Eclipse XDB-C18 5 ꢀm, 4.6 mm × 150
mm) with the solvent system (mobile phase A consisting of MeCN; mobile phase B consisting of
H2O containing 0.1% formic acid + 10 mmol NH4OAc) and was found in all cases to be ≥ 95%.
Flash column chromatography was done using silica gel (Merck Kieselgel 60, no. 9385, 230−400
mesh ASTM). All reactions were carried out under an atmosphere of dry nitrogen.
4.1.1. General procedure for synthesis of 2-phenylsulfonylquinoline (10a-k) and
2-phenylsulfonylpyridine (20)
A mixture of the 2-chloroquinoline or the 2-chloropyridine (1 equiv), substituted thiophenol (1.2
equiv), K2CO3 (1.5 equiv), and DMF (0.5 M) was heated to 110 oC under N2 for 12 h. The resulting
mixture was diluted with EtOAc and filtered. The filtrate was washed with H2O three times, and then
the organic layer was purified through column chromatography. The resulting product (1 equiv) was
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dissolved in DCM (0.1 M), and then meta-chloroperoxybenzoic acid (2.1 equiv, 70%) was added at 0
oC under N2 and the mixture was stirred at room temperature for additional 12 h. The reaction
mixture was washed with cold 2N NaOH solution three times, and then the organic layer was
collected and evaporated to provide the product.
4.1.1.1. 3-Bromo-2-(4-methoxyphenylsulfonyl)quinoline (10a)
o
1
Light yellow solid; yield: 62%; mp: 164-165 C. H NMR (300 MHz, DMSO-d6) δ 3.83 (s, 3H),
7.16-7.22 (m, 2H), 7.74-7.80 (m, 1H), 7.81-8.86 (m, 2H), 7.90-7.96 (m, 2H), 8.00-8.04 (m, 1H), 9.00
(s, 1H).
4.1.1.2. 5-Bromo-2-(4-methoxyphenylsulfonyl)quinoline (10b)
Colorless oily liquid; yield: 54%; 1H NMR (300 MHz, DMSO-d6) δ 3.82 (s, 3H), 7.13-7.19 (m, 2H),
7.75-7.82 (m, 1H), 7.95-8.00 (m, 2H), 8.06-8.12 (m, 2H), 8.33 (d, 1H, J = 8.7 Hz), 8.80 (dd, 1H, J =
0.6, 9.0 Hz).
4.1.1.3. 6-Bromo-2-((4-methoxyphenyl)sulfonyl)quinoline (10c)
Colorless oily liquid; yield: 59%; 1H NMR (300 MHz, DMSO-d6) δ 3.82 (s, 3H), 7.13-7.19 (m, 2H),
7.94-8.00 (m, 4H), 8.26 (d, 1H, J = 8.7 Hz), 8.42-8.44 (m, 1H), 8.68 (d, 1H, J = 8.7 Hz).
4.1.1.4. 7-Bromo-2-((4-methoxyphenyl)sulfonyl)quinoline (10d)
Yellow solid; yield: 72%; mp: 160-162 oC. 1H NMR (500 MHz, CDCl3) δ 3.86 (s, 3H3), 7.01 (d, 2H,
J = 9.0 Hz), 7.72-7.74 (m, 2H), 8.04-8.07 (m, 2H), 8.21 (d, 1H, J = 8.5 Hz), 8.34 (d, 2H, J = 8.0 Hz).
4.1.1.5. 8-Bromo-2-((4-methoxyphenyl)sulfonyl)quinoline (10e)
o
1
Light yellow solid; yield: 65%; mp: 112-114 C. H NMR (300 MHz, DMSO-d6) δ 3.82 (s, 3H),
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7.16-7.20 (m, 2H), 7.60-7.66 (m, 1H), 8.02-8.07 (m, 2H), 8.12 (d, 1H, J = 8.1 Hz), 8.21-8.30 (m, 2H),
8.77 (d, 1H, J = 8.4 Hz).
4.1.1.6. 2-((3-Bromophenyl)sulfonyl)quinoline (10f)
o
1
Light yellow solid; yield: 63%; mp: 114-116 C. H NMR (300 MHz, DMSO-d6) δ 7.75-7.82 (m,
1H), 7.84-7.93 (m, 3H), 7.95-8.00 (m, 2H), 8.04-8.08 (m, 1H), 8.26 (d, 1H, J = 8.4 Hz), 8.76 (d, 1H,
J = 8.4 Hz).
4.1.1.7. 2-(4-Bromophenylsulfonyl)quinoline (10g)
o
1
Light yellow solid; yield: 80%; mp: 146-148 C. H NMR (300 MHz, DMSO-d6) δ 7.74-7.81 (m,
1H), 7.83-7.92 (m, 3H), 7.95-8.00 (m, 2H), 8.05 (d, 1H, J = 8.1 Hz), 8.11-8.15 (m, 1H), 8.26 (d, 1H,
J = 8.7 Hz), 8.76 (d, 1H, J = 8.7 Hz).
4.1.1.8. 2-(3-Bromophenylsulfonyl)-6-methoxyquinoline (10h)
o
1
Light yellow solid; yield: 67%; mp: 194-196 C. H NMR (500 MHz, DMSO-d6) δ 3.92 (s, 3H),
7.50-7.55 (m, 2H), 7.57-7.63 (m, 1H), 7.92-8.05 (m, 3H), 8.13-8.15 (m, 1H), 8.23 (d, 1H, J = 8.7 Hz),
8.60 (d, 1H, J = 8.7 Hz).
4.1.1.9. 2-((3-Bromophenyl)sulfonyl)-6-chloroquinoline (10i)
o
1
White solid; yield: 45%; mp: 116-118 C. H NMR (300 MHz, CDCl3) δ 7.13 (d, 1H, J = 8.7 Hz),
7.18-7.22 (m, 1H), 7.27-7.33 (m, 1H), 7.36-7.41 (m, 1H), 7.44 (t, 1H, J = 2.1 Hz), 7.56 (d, 1H, J =
2.4, 9.0 Hz), 7.70-7.76 (m, 2H). 8.06 (d, 1H, J = 9.0 Hz).
4.1.1.10. 2-((3-Bromophenyl)sulfonyl)-8-fluoroquinoline (10j)
White solid; yield: 72%; mp: 122-124 oC. 1H NMR (300 MHz, DMSO-d6) δ 7.29-7.34 (m, 1H), 7.36
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(d, 1H, J = 9.0 Hz), 7.40-7.56 (m, 4H), 7.58 (t, 1H, J = 1.8 Hz), 7.77-7.81 (m, 1H), 8.47-8.52 (m,
1H).
4.1.1.11. 2-((3-Bromophenyl)sulfonyl)-8-chloroquinoline (10k)
o
1
White solid; yield: 76%; mp: 104-106 C. H NMR (300 MHz, DMSO-d6) δ 7.34-7.51 (m, 5H),
7.71-7.73 (m, 1H), 7.86 (dd, 1H, J = 1.2, 7.5 Hz), 7.95 (dd, 1H, J = 1.2, 7.5 Hz), 8.50 (d, 1H, J = 4.5
Hz).
4.1.1.12. 2-((3-Bromophenyl)sulfonyl)pyridine (20)
o
1
White solid; yield: 66%; mp: 103-105 C. H NMR (300 MHz, DMSO-d6) δ 7.57-7.63 (m, 1H),
7.68-7.73 (m, 1H), 7.93-7.99 (m, 2H), 8.09 (t, 1H, J = 1.8 Hz), 8.13-8.19 (m, 1H), 8.23-8.26 (m, 1H),
8.70-8.73 (m, 1H).
4.1.2. General procedure for synthesis of (E)-tert-butyl acrylates (11a-k and 21)
A mixture of aryl bromide (1 equiv), tert-butyl acrylate (1.2 equiv), Pd2(dba)3 (0.06 equiv),
[(n-Bu)3PH]BF4 (0.12 equiv), Cy2NMe (1.1 equiv), and DMF (0.5 M) was heated to 100 oC under N2
for 12 h. The resulting mixture was diluted with EtOAc and filtered. The filtrate was washed with
H2O three times and the organic layer was collected and purified by chromatography (ethyl
acetate/hexane) to provide the corresponding acrylate.
4.1.2.1. (E)-tert-Butyl 3-(2-(4-methoxyphenylsulfonyl)quinolin-3-yl)acrylate (11a)
o
Yellow solid; yield: 85%; mp: 123 C. 1H NMR (300 MHz, DMSO-d6) δ 1.52(s, 9H), 3.87(s, 3H),
6.70 (d, 1H, J = 15.9 Hz), 7.16-7.22 (m, 2H), 7.75-7.82 (m, 1H), 7.84-7.92 (m, 4H), 8.08 (d, 1H, J =
8.1 Hz), 8.50 (d, 1H, J = 15.6 Hz), 9.12 (s, 1H).
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4.1.2.2. (E)-tert-Butyl 3-(2-((4-methoxyphenyl)sulfonyl)quinolin-5-yl)acrylate (11b)
o
Light yellow solid; yield: 86%; mp: 174-176 C. 1H NMR (300 MHz, DMSO-d6) δ 1.51(s, 9H),
3.83(s, 3H), 6.66 (d, 1H, J = 15.6 Hz), 7.15-7.19 (m, 2H), 7.86-7.93 (m, 1H), 7.96-8.01 (m, 2H), 8.10
(d, 1H, J = 8.4 Hz), 8.18-8.32 (m, 3H), 8.99-9.03 (m, 1H).
4.1.2.3. (E)-tert-Butyl 3-(2-((4-methoxyphenyl)sulfonyl)quinolin-6-yl)acrylate (11c)
1
Colorless oily liquid; yield: 89%; H NMR (300 MHz, DMSO-d6) δ 1.49 (s, 9H), 3.83 (s, 3H), 6.76
(d, 1H, J = 16.2 Hz), 7.13-7.19 (m, 2H), 7.72 (d, 1H, J = 15.9 Hz), 7.94-8.00 (m, 2H), 8.02 (d, 1H, J
= 9.0 Hz), 8.21-8.27 (m, 2H), 8.40 (d, 1H, J = 1.8 Hz), 8.68 (d, 1H, J = 8.4 Hz).
4.1.2.4. (E)-tert-Butyl 3-(2-((4-methoxyphenyl)sulfonyl)quinolin-7-yl)acrylate (11d)
1
Colorless oily liquid; yield: 61%; H NMR (500 MHz, CDCl3) δ 1.55 (s, 9H), 3.86 (s, 3H), 6.54 (d,
1H, J = 16.0 Hz), 7.01 (d, 2H, J = 9.0 Hz), 7.72 (d, 1H, J = 16.0 Hz), 7.79 (d, 1H, J = 8.5 Hz), 7.85
(d, 1H, J = 8.5 Hz), 8.07 (d, 2H, J = 9.0 Hz), 8.19 (d, 1H, J = 8.5 Hz), 8.22 (s, 1H), 8.33 (d, 1H, J =
8.5 Hz).
4.1.2.5. (E)-tert-Butyl 3-(2-((4-methoxyphenyl)sulfonyl)quinolin-8-yl)acrylate (11e)
1
Yield: 89%; colorless oily liquid. H NMR (300 MHz, DMSO-d6) δ 1.54 (s, 9H), 3.84 (s, 3H), 6.88
(d, 1H, J = 16.2 Hz), 7.15-7.20 (m, 2H), 7.78 (t, 1H, J = 7.8 Hz), 7.98-8.03 (m, 2H), 8.17 (d, 1H, J =
8.1 Hz), 8.27 (d, 1H, J = 8.7 Hz), 8.33-8.43 (m, 2H), 8.77 (d, 1H, J = 8.4 Hz).
4.1.2.6. (E)-tert-Butyl 3-(3-(quinolin-2-ylsulfonyl)phenyl)acrylate (11f)
Light yellow solid; yield: 88%; mp: 194-196 oC. 1H NMR (300 MHz, DMSO-d6) δ 1.46 (s, 9H), 6.67
(d, 1H, J = 15.9 Hz), 7.59 (d, 1H, J = 15.9 Hz), 7.76-7.82 (m, 1H), 7.87-7.97 (m, 3H), 8.02-8.09 (m,
3H), 8.14 (d, 1H, J = 8.1 Hz), 8.28 (d, 1H, J = 8.7 Hz), 8.76 (d, 1H, J = 8.7 Hz).
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4.1.2.7. (E)-tert-Butyl 3-(4-(quinolin-2-ylsulfonyl)phenyl)acrylate (11g)
Light yellow solid; yield: 77%; mp: 199-200 oC. 1H NMR (300 MHz, DMSO-d6) δ 1.46 (s, 9H), 6.67
(d, 1H, J = 15.9 Hz), 7.59 (d, 1H, J = 16.2 Hz), 7.76-7.82 (m, 1H), 7.87-7.97 (m, 3H), 8.02-8.09 (m,
3H), 8.12-8.16 (m, 1H), 8.28 (d, 1H, J = 8.7 Hz) , 8.76 (d, 1H, J = 8.4 Hz).
4.1.2.8. (E)-tert-Butyl 3-(3-((6-methoxyquinolin-2-yl)sulfonyl)phenyl)acrylate (11h)
Light yellow solid; yield: 45%; mp: 71-73 oC. 1H NMR (500 MHz, DMSO-d6) δ 1.53 (s, 9H), 3.94 (s,
3H), 6.45 (d, 1H, J = 16.0 Hz), 7.09 (d, 1H, J = 3.0 Hz), 7.42 (dd, 1H, J = 2.5, 9.5 Hz), 7.51-7.59 (m,
2H), 7.68 (d, 1H, J = 7.5 Hz), 8.04 (d, 1H, J = 9.5 Hz), 8.09 (d, 1H, J = 8.0 Hz), 8.16 (d, 1H, J = 8.5
Hz), 8.23 (d, 2H, J = 8.0 Hz).
4.1.2.9. (E)-tert-Butyl 3-(3-((6-chloroquinolin-2-yl)sulfonyl)phenyl)acrylate (11i)
Brown oily liquid; yield: 89%; 1H NMR (300 MHz, CDCl3) δ 1.54 (s, 9H), 6.38 (d, 1H, J = 16.2 Hz),
7.13 (d, 1H, J = 8.7 Hz), 7.24-7.29 (m, 1H), 7.36-7.46 (m, 3H), 7.52-7.56 (m, 1H), 7.61 (d, 1H, J =
15.9 Hz), 7.68-7.74 (m, 2H), 8.04 (d, 1H, J = 8.7 Hz).
4.1.2.10. (E)-tert-Butyl 3-(3-((8-fluoroquinolin-2-yl)sulfonyl)phenyl)acrylate (11j)
Yellow solid; yield: 86%; mp: 69-71 oC. 1H NMR (300 MHz, DMSO-d6) δ 1.52 (s, 9H), 6.37 (d, 1H,
J = 15.9 Hz), 7.14 (d, 1H, J = 9.0 Hz), 7.31-7.38 (m, 4H), 7.40-7.48 (m, 2H), 7.53-7.62 (m, 2H),
8.13-8.17 (m, 1H).
4.1.2.11. (E)-tert-Butyl 3-(3-((8-chloroquinolin-2-yl)sulfonyl)phenyl)acrylate (11k)
Yellow oily liquid; yield: 90%; 1H NMR (300 MHz, DMSO-d6) δ 1.52 (s, 9H), 6.37 (d, 1H, J = 16.2
Hz), 7.14 (d, 1H, J = 9.0 Hz), 7.31-7.47 (m, 6H), 7.53-7.62 (m, 2H), 8.15 (dd, 1H, J = 1.8, 9.0 Hz).
11

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4.1.2.12. (E)-tert-Butyl 3-(3-(pyridin-2-ylsulfonyl)phenyl)acrylate (21)
1
Colorless oily liquid; yield: 90%; H NMR (300 MHz, DMSO-d6) δ 1.46 (s, 9H), 6.64 (d, 1H, J =
16.2 Hz), 7.61-7.71 (m, 3H), 7.96-8.00 (m, 1H), 8.06-8.09 (m, 1H), 8.12-8.18 (m, 1H), 8.20-8.22 (m,
1H), 8.23-8.27 (m, 1H), 8.67-8.70 (m, 1H).
4.1.3. General procedure for synthesis of (E)-acrylic acids (12a-k and 22)
To a stirred solution of (E)-tert-butyl acrylate in DCM (10 mL), trifluoroacetic acid (3-5 mL) was
added at room temperature and the mixture was stirred for 12 h. The solution was evaporated and
H2O was added. The pH value of the reaction mixture was adjusted to pH 4 by the addition of 2N
NaOH and the precipitate was collected by filtration to afford the product.
4.1.3.1. (E)-3-(2-((4-Methoxyphenyl)sulfonyl)quinolin-3-yl)acrylic acid (12a)
Brown solid; yield: 91%; mp: 142 oC. 1H NMR (300 MHz, DMSO-d6) δ 3.87(s, 3H), 6.71 (d, 1H, J =
15.9 Hz), 7.17-7.23 (m, 2H), 7.74-7.88 (m, 3H), 7.87-7.93 (m, 2H), 8.09 (d, 1H, J = 8.1 Hz), 8.56 (d,
1H, J = 15.3 Hz), 9.10 (s, 1H).
4.1.3.2. (E)-3-(2-((4-Methoxyphenyl)sulfonyl)quinolin-5-yl)acrylic acid (12b)
o
1
Light yellow solid; yield: 90%; mp: 141 C. H NMR (300 MHz, DMSO-d6) δ 3.83(s, 3H), 6.68 (d,
1H, J = 15.6 Hz), 7.14-7.20 (m, 2H), 7.88-7.94 (m, 1H), 7.95-8.01 (m, 2H), 8.11 (d, 1H, J = 8.4 Hz),
8.19 (d, 1H, J = 7.2 Hz), 8.24 (d, 1H, J = 9.0 Hz), 8.32 (d, 1H, J = 15.9 Hz), 9.02 (d, 1H, J = 8.7 Hz).
4.1.3.3. (E)-3-(2-(4-Methoxyphenylsulfonyl)quinolin-6-yl)acrylic acid (12c)
Brown solid; yield: 96%; mp: 168 oC. 1H NMR (300 MHz, DMSO-d6) δ 3.83(s, 3H), 6.76 (d, 1H, J =
16.2 Hz), 7.14-7.20 (m, 2H), 7.76 (d, 1H, J = 15.9 Hz), 7.94-8.00 (m, 2H), 8.04 (d, 1H, J = 9.0 Hz),
12

ACCEPTED MANUSCRIPT
8.21-8.26 (m, 2H), 8.39 (d, 1H, J = 1.5 Hz), 8.69 (d, 1H, J = 8.7 Hz).
4.1.3.4. (E)-3-(2-((4-Methoxyphenyl)sulfonyl)quinolin-7-yl)acrylic acid (12d)
1
Light brown solid; yield: 94%; mp: 169 oC. H NMR (300 MHz, DMSO-d6) δ 3.82 (s, 3H), 6.79 (d,
1H, J = 16.2 Hz), 7.16 (d, 2H, J = 8.7 Hz), 7.79 (d, 1H, J = 16.2 Hz), 7.97 (d, 2H, J = 9.0 Hz),
8.08-8.15 (m, 2H), 8.21 (d, 1H, J = 8.7 Hz), 8.29 (s, 1H), 8.70 (d, 1H, J = 8.7 Hz).
4.1.3.5. (E)-3-(2-((4-Methoxyphenyl)sulfonyl)quinolin-8-yl)acrylic acid (12e)
1
Light brown solid; yield: 76%; mp: 185 oC. H NMR (300 MHz, DMSO-d6) δ 3.84 (s, 3H), 6.88 (d,
1H, J = 16.5 Hz), 7.17 (d, 1H, J = 9.0 Hz), 7.62-7.82 (m, 1H), 7.98-8.02 (m, 1H), 8.16 (d, 1H, J = 8.1
Hz), 8.25 (d, 1H, J = 8.7 Hz), 8.33 (d, 1H, J = 7.2 Hz), 8.42 (d, 1H, J = 8.1 Hz), 8.77 (d, 1H, J = 8.7
Hz).
4.1.3.6. (E)-3-(3-(Quinolin-2-ylsulfonyl)phenyl)acrylic acid (12f)
Light yellow solid; yield: 90%; mp: 182 oC. 1H NMR (300 MHz, DMSO-d6) δ 6.67 (d, 1H, J = 16.2
Hz), 7.65-7.72 (m, 2H), 7.75-7.81 (m, 1H), 7.86-7.92 (m, 1H), 8.05-8.15 (m, 4H), 8.29-8.32 (m, 2H),
8.76 (d, 1H, J = 8.7 Hz).
4.1.3.7. (E)-3-(4-(Quinolin-2-ylsulfonyl)phenyl)acrylic acid (12g)
o
1
White solid; yield: 95%; mp: 240 C. H NMR (300 MHz, DMSO-d6) δ 6.67 (d, 1H, J = 15.9 Hz),
7.62 (d, 1H, J = 16.2 Hz), 7.76-7.82 (m, 1H), 7.87-7.96 (m, 3H), 8.03-8.09 (m, 3H), 8.12-8.16 (m,
1H), 8.27 (d, 1H, J = 8.4 Hz), 8.76 (d, 1H, J = 8.7 Hz).
4.1.3.8. (E)-3-(3-((6-Methoxyquinolin-2-yl)sulfonyl)phenyl)acrylic acid (12h)
White solid; yield: 97%; mp: 216 oC. 1H NMR (300 MHz, DMSO-d6) δ 3.91 (s, 3H), 6.66 (d, 1H, J =
13

ACCEPTED MANUSCRIPT
15.9 Hz), 7.49-7.54 (m, 2H), 7.64-7.71 (m, 2H), 7.95-7.99 (m, 1H), 8.02-8.08 (m, 2H), 8.22-8.27 (m,
2H), 8.59 (d, 1H, J = 8.4 Hz).
4.1.3.9. (E)-3-(3-((6-Chloroquinolin-2-yl)sulfonyl)phenyl)acrylic acid (12i)
1
Colorless oily liquid; yield: 92%; H NMR (300 MHz, DMSO-d6) δ 6.67 (d, 1H, J = 16.2 Hz),
7.65-7.77 (m, 3H), 8.05-8.14 (m, 4H), 8.35-8.39 (m, 2H), 8.85 (d, 1H, J = 8.7 Hz), 12.58 (brs, 1H).
4.1.3.10. (E)-3-(3-((8-Fluoroquinolin-2-yl)sulfonyl)phenyl)acrylic acid (12j)
Light yellow solid; yield: 95%; mp: 212 oC. 1H NMR (300 MHz, DMSO-d6) δ 6.57 (d, 1H, J = 16.2
Hz), 7.31-7.38 (m, 2H), 7.42-7.54 (m, 3H), 7.58-7.67 (m, 3H), 7.77-7.81 (m, 1H) 8.49 (dd, 1H, J =
1.8, 9.0 Hz), 12.44 (brs, 1H).
4.1.3.11. (E)-3-(3-((8-Chloroquinolin-2-yl)sulfonyl)phenyl)acrylic acid (12k)
o
1
White solid; yield: 92%; mp: 220 C. H NMR (300 MHz, DMSO-d6) δ 6.58 (d, 1H, J = 16.2 Hz),
7.32-7.41 (m, 2H), 7.43-7.52 (m, 2H), 7.55-7.62 (m, 1H), 7.74-7.76 (m, 1H), 7.82-7.86 (m, 1H), 7.94
(dd, 1H, J = 8.1, 1.2 Hz), 8.49 (d, 1H, J = 4.5 Hz).
4.1.3.12. (E)-3-(3-(Pyridin-2-ylsulfonyl)phenyl)acrylic acid (22)
o
1
White solid; yield: 81%; mp: 203 C. H NMR (300 MHz, DMSO-d6) δ 6.65 (d, 1H, J = 16.2 Hz),
7.64-7.71 (m, 3H), 7.96-8.00 (m, 1H), 8.05-8.09 (m, 1H), 8.12-8.20 (m, 2H), 8.23-8.27 (m, 1H),
8.68-8.70 (m, 1H).
4.1.4. General procedure for synthesis of (E)-N-hydroxyacrylamide (8a-k, 18a-b, and 23)
A mixture of (E)-acrylic acid (1 equiv), NH2OTHP (1.2 equiv), EDCꢁHCl (2 equiv), DMAP (0.5
equiv), and DCM (0.1 M) was stirred at room temperature under N2 for 12 h. The reaction mixture
14

ACCEPTED MANUSCRIPT
was washed with H2O three times. The organic layer was collected and purified through column
chromatography. The resulting product was dissolved in MeOH and then 1N HCl solution (10-20 mL)
o
was added slowly at 0 C and the mixture was stirred at room temperature for 2 h. The reaction
mixture was diluted with H2O and the solid was collected to provide the desired product.
4.1.4.1. (E)-N-Hydroxy-3-(2-((4-methoxyphenyl)sulfonyl)quinolin-3-yl)acrylamide (8a)
o
1
White solid; yield: 57%; mp: 106-107 C. IR (KBr, cm-1): 3232, 1686. H NMR (500 MHz,
DMSO-d6) δ 3.87(s, 3H), 6.55 (d, 1H, J = 15.6 Hz), 7.19 (d, 2H, J = 8.7 Hz), 7.74-7.91 (m, 5H), 8.13
(d, 1H, J = 8.1 Hz), 8.40 (d, 1H, J = 15.6 Hz), 8.86 (s, 1H), 9.21 (s, 1H), 10.94 (s, 1H). 13C NMR (75
MHz, DMSO-d6) δ 56.79, 115.46, 125.40, 127.07, 129.34, 129.40, 130.01, 130.15, 130.70, 132.36,
132.87, 133.30, 138.43, 145.73, 156.70, 162.71, 164.68. HRMS-ESI calcd. for C19H17N2O5S [M +
H]+ 385.0858, found 385.0853.
4.1.4.2. (E)-N-Hydroxy-3-(2-((4-methoxyphenyl)sulfonyl)quinolin-5-yl)acrylamide (8b)
o
1
Light yellow solid; yield: 81%; mp: 74-75 C. IR (KBr, cm-1): 3196, 1662. H NMR (500 MHz,
DMSO-d6) δ 3.83 (s, 3H), 6.59 (d, 1H, J = 15.5 Hz), 7.17 (d, 1H, J = 8.0 Hz), 7.90-7.94 (m, 1H),
7.97-8.01 (m, 3H), 8.07 (d, 1H, J = 8.0 Hz), 8.16 (d, 1H, J = 15.5 Hz), 8.24 (d, 1H, J = 9.5 Hz), 8.99
13
(d, 1H, J = 8.5 Hz), 9.14 (s, 1H), 10.91 (s, 1H). C NMR (75 MHz, DMSO-d6) δ 56.77, 115.88,
118.67, 125.11, 127.48, 128.04, 130.60, 131.40, 131.93, 132.31, 133.97, 134.08, 137.04, 147.74,
159.29, 163.19, 164.70. HRMS-ESI calcd. for C19H17N2O5S [M + H]+ 385.0858, found 385.0852.
4.1.4.3. (E)-N-Hydroxy-3-(2-((4-methoxyphenyl)sulfonyl)quinolin-6-yl)acrylamide (8c)
White solid; yield: 67%. mp: 119 oC. IR (KBr, cm-1): 3208, 1653. 1H NMR (500 MHz, DMSO-d6) δ
3.83 (s, 3H), 6.67 (d, 1H, J = 15.5 Hz), 7.17 (d, 2H, J = 9.0 Hz), 7.63 (d, 1H, J = 15.5 Hz), 7.97 (d,
2H, J = 8.5 Hz), 8.05-8.07 (m, 2H), 8.22 (d, 1H, J = 8.5 Hz), 8.27 (s, 1H), 8.70 (d, 1H, J = 8.5 Hz).
15

ACCEPTED MANUSCRIPT
13C NMR (75 MHz, DMSO-d6) δ 56.79, 115.90, 119.06, 123.07, 129.26, 129.72, 130.31, 130.68,
130.86, 131.91, 136.55, 137.90, 141.06, 147.78, 159.45, 164.70. HRMS-ESI calcd. for C19H17N2O5S
[M + H]+ 385.0858, found 385.0848.
4.1.4.4. (E)-N-Hydroxy-3-(2-((4-methoxyphenyl)sulfonyl)quinolin-7-yl)acrylamide (8d)
o
1
Light yellow solid; yield: 72%; mp: 125-126 C. IR (KBr, cm-1): 3196, 1659. H NMR (500 MHz,
DMSO-d6) δ 3.83 (s, 3H), 6.71 (d, 1H, J = 16.0 Hz), 7.17 (d, 2H, J = 9.0 Hz), 7.66 (d, 1H, J = 16.0
13
Hz), 7.95-7.99 (m, 3H), 8.13 (d, 1H, J = 8.5 Hz), 8.17-8.21 (m, 2H), 8.70 (d, 1H, J = 8.5 Hz). C
NMR (75 MHz, DMSO-d6) δ 55.77, 115.88, 118.78, 123.36, 128.08, 129.80, 129.88, 130.67, 131.88,
137.88, 139.02, 140.58, 147.76, 159.81, 164.66. HRMS-ESI calcd. for C19H17N2O5S [M + H]+
385.0858, found 385.0848.
4.1.4.5. (E)-N-Hydroxy-3-(2-((4-methoxyphenyl)sulfonyl)quinolin-8-yl)acrylamide (8e)
o
1
White solid; yield: 73%; mp: 198 C. IR (KBr, cm-1): 3322, 3112, 1671. H NMR (300 MHz,
DMSO-d6) δ 3.83 (s, 3H), 6.76 (d, 1H, J = 15.9 Hz), 7.14-7.20 (m, 2H), 7.77 (t, 1H, J = 7.8 Hz),
8.00-8.06 (m, 2H), 8.09-8.17 (m, 2H), 8.23 (d, 1H, J = 8.4 Hz), 8.40 (d, 1H, J = 16.2 Hz), 8.73 (d,
13
1H, J = 8.4 Hz). C NMR (75 MHz, DMSO-d6) δ 56.75, 115.78, 118.16, 123.02, 129.60, 129.73,
130.19, 130.39, 132.13, 133.86, 134.10, 141.23, 141.38, 144.88, 158.84, 163.60, 164.72. HRMS-ESI
calcd. for C19H17N2O5S [M + H]+ 385.0858, found 385.0850.
4.1.4.6. (E)-N-Hydroxy-3-(3-(quinolin-2-ylsulfonyl)phenyl)acrylamide (8f)
o
1
Light brown solid; yield: 78%; mp: 132-33 C. IR (KBr, cm-1): 3226, 1665. H NMR (300 MHz,
DMSO-d6) δ 6.62 (d, 1H, J = 15.6 Hz), 7.54 (d, 1H, J = 15.9 Hz), 7.69 (t, 1H, J = 7.5 Hz), 7.76-7.82
(m, 1H), 7.87-7.93 (m, 2H), 8.00-8.30 (m, 5H), 8.77 (d, 1H, J = 8.4 Hz), 9.15 (s, 1H), 10.79 (s, 1H).
13C NMR (75 MHz, DMSO-d6) δ 118.62, 122.79, 127.50, 129.28, 129.97, 130.23, 130.51, 131.32,
16

ACCEPTED MANUSCRIPT
132.68, 134.20, 137.31, 140.34, 140.97, 147.45, 158.30, 163.08. HRMS-ESI calcd. for C18H15N2O4S
[M + H]+ 355.0753, found 355.0749.
4.1.4.7. (E)-N-Hydroxy-3-(4-(quinolin-2-ylsulfonyl)phenyl)acrylamide (8g)
o
1
Light yellow solid; yield: 68%; mp: 133-34 C. IR (KBr, cm-1): 3316, 3172, 1668. H NMR (300
MHz, DMSO-d6) δ 6.59 (d, 1H, J = 15.9 Hz), 7.49 (d, 1H, J = 15.9 Hz), 7.76-7.88 (m, 3H),
7.88-7.93 (m, 1H), 8.04-8.08 (m, 3H), 8.12-8.16 (m, 1H), 8.26 (d, 1H, J = 8.4 Hz), 8.76 (d, 1H, J =
13
8.4 Hz). C NMR (75 MHz, DMSO-d6) δ 118.56, 124.00, 129.26, 129.34, 129.56, 130.13, 130.21,
130.47, 132.66, 137.34, 139.55, 140.95, 141.38, 147.47, 158.42, 162.93. HRMS-ESI calcd. for
C18H15N2O4S [M + H]+ 355.0753, found 355.0745.
4.1.4.8. (E)-N-Hydroxy-3-(3-(6-methoxyquinolin-2-ylsulfonyl)phenyl)acrylamide (8h)
White solid; yield: 65%; mp: 80-81 oC. IR (KBr, cm-1): 3202, 1668. 1H NMR (300 MHz, DMSO-d6)
δ 3.91 (s, 3H), 6.61 (d, 1H, J = 15.9 Hz), 7.49-7.56 (m, 3H), 7.67 (t, 1H, J = 7.8 Hz), 7.89 (d, 1H, J =
13
7.8 Hz), 7.95-8.01 (m, 2H), 8.22 (d, 2H, J = 8.7 Hz), 8.59 (d, 1H, J = 8.4 Hz), 10.80 (s, 1H). C
NMR (75 MHz, DMSO-d6) δ 56.79, 106.58, 119.14, 122.76, 125.60, 127.35, 129.82, 131.30, 131.38,
131.79, 134.04, 137.30, 138.98, 140.78, 143.62, 155.58, 160.42, 163.12. HRMS-ESI calcd. for
C19H17N2O5S [M + H]+ 385.0858, found 385.0855.
4.1.4.9. (E)-3-(3-((6-Chloroquinolin-2-yl)sulfonyl)phenyl)-N-hydroxyacrylamide (8i)
o
1
Light yellow solid; yield: 72%; mp: 167 C. IR (KBr, cm-1): 3274, 1659. H NMR (300 MHz,
DMSO-d6) δ 6.48 (d, 1H, J = 15.9 Hz), 7.24-7.28 (m, 1H), 7.36 (d, 1H, J = 8.7 Hz), 7.44-7.53 (m,
4H), 7.65 (d, 2H, J = 1.5 Hz), 8.09 (t, 1H, J = 1.5 Hz), 8.41 (d, 1H, J = 9.0 Hz), 9.05 (s, 1H), 10.72 (s,
1H). 13C NMR (75 MHz, DMSO-d6) δ 119.65, 122.79, 127.53, 128.00, 129.96, 130.35, 131.34,
132.31, 133.31, 133.21, 134.27, 134.99, 137.20, 137.33, 140.08, 140.40, 145.89, 158.68, 163.00.
17

ACCEPTED MANUSCRIPT
HRMS-ESI calcd. for C18H14ClN2O4S [M + H]+ 389.0363, found 389.0360.
4.1.4.10. (E)-3-(3-((8-Fluoroquinolin-2-yl)sulfonyl)phenyl)-N-hydroxyacrylamide (8j)
o
1
Light red solid; yield: 79%; mp: 130-131 C. IR (KBr, cm-1): 3190, 1662. H NMR (300 MHz,
DMSO-d6) δ 6.48 (d, 1H, J = 15.9 Hz), 7.27-7.31 (m, 1H), 7.36 (d, 1H, J = 8.7 Hz), 7.45-7.54 (m,
6H), 7.77-7.81 (m, 1H), 8.47-8.51 (m, 1H), 9.05 (s, 1H), 10.73 (s, 1H). 13C NMR (75 MHz,
DMSO-d6) δ 116.51, 116.75, 119.71, 122.81, 125.26, 125.32, 127.64, 130.07, 130.78, 130.88, 131.13,
131.38, 134.33, 137.17, 137.36, 140.00, 141.11, 141.15, 156.13, 158.56, 159.55, 162.98. HRMS-ESI
calcd. for C18H14FN2O4S [M + H]+ 373.0658, found 373.0653.
4.1.4.11. (E)-3-(3-((8-Chloroquinolin-2-yl)sulfonyl)phenyl)-N-hydroxyacrylamide (8k)
White solid; yield: 73%; mp: 110 oC. IR (KBr, cm-1): 3196, 1665. 1H NMR (300 MHz, DMSO-d6) δ
6.49 (d, 1H, J = 15.9 Hz), 7.34-7.38 (m, 2H), 7.44-7.59 (m, 5H), 7.83-7.87 (m, 1H), 7.95 (dd, 1H, J
13
= 1.2, 8.1 Hz), 8.50 (d, 1H, J = 9.0 Hz), 10.74 (s, 1H). C NMR (75 MHz, DMSO-d6) δ 122.63,
128.02, 128.64, 130.21, 130.63, 131.04, 131.16, 132.50, 133.51, 134.54, 137.16, 137.33, 139.75,
141.84, 143.48, 158.96, 163.11. HRMS-ESI calcd. for C18H14ClN2O4S [M + H]+ 389.0363, found
389.0355.
4.1.4.12. N-Hydroxy-3-[3-(quinoline-2-carbonyl)-phenyl]-acrylamide (18a)
o
1
White solid; yield: 73%; mp: 128-129 C. IR (KBr, cm-1): 3304, 1677. H NMR (300 MHz,
DMSO-d6) δ 6.54 (d, 1H, J = 15.6 Hz), 7.51-7.64 (m, 2H), 7.74-7.80 (m, 1H), 7.85-7.90 (m, 2H),
8.04-8.14 (m, 4H), 8.27-8.31 (m, 1H), 8.64 (d, 1H, J = 8.7 Hz). 13C NMR (75 MHz, DMSO-d6) δ
121.21, 121.39, 128.99, 129.60, 129.72, 129.92, 130.07, 130.82, 131.59, 132.61, 133.09, 135.86,
137.51, 138.70, 146.95, 155.05, 194.03. HRMS-ESI calcd. for C19H15N2O3 [M + H]+ 319.1083,
found 319.1069.
18

ACCEPTED MANUSCRIPT
4.1.4.13. N-Hydroxy-3-[4-(quinoline-2-carbonyl)-phenyl]-acrylamide (18b)
o
1
Light yellow solid; yield: 70%; mp: 132-133 C. IR (KBr, cm-1): 3346, 1650. H NMR (300 MHz,
DMSO-d6) δ 6.62 (d, 1H, J = 15.9 Hz), 7.56 (d, 1H, J = 15.9 Hz), 7.73-7.80 (m, 3H), 7.84-7.90 (m,
13
1H), 8.05-8.14 (m, 5H), 8.63 (d, 1H, J = 8.1 Hz), 9.13 (s, 1H), 10.88 (s, 1H). C NMR (75 MHz,
DMSO-d6) δ 121.37, 122.83, 128.22, 129.01, 129.56, 129.66, 130.74, 131.55, 132.45, 137.18, 138.22,
138.68, 140.22, 145.93, 155.24, 163.27, 193.66. HRMS-ESI calcd. for C19H15N2O3 [M + H]+
319.1083, found 319.1065.
4.1.4.14. (E)-N-Hydroxy-3-(3-(pyridin-2-ylsulfonyl)phenyl)acrylamide (23)
o
1
White solid; yield: 63%; mp: 156-157 C. IR (KBr, cm-1): 3196, 1662. H NMR (300 MHz,
DMSO-d6) δ 6.59 (d, 1H, J = 15.9 Hz), 7.53 (d, 1H, J = 15.9 Hz), 7.64-7.72 (m, 2H), 7.89-7.95 (m,
2H), 8.12-8.19 (m, 2H), 8.22-8.26 (m, 1H), 8.68-8.71 (m, 1H), 9.13 (s, 1H), 10.79 (s, 1H). 13C NMR
(75 MHz, DMSO-d6) δ 122.71, 123.10, 127.27, 128.93, 129.89, 131.30, 134.20, 137.22, 140.20,
140.26, 151.63, 158.52. HRMS-ESI calcd. for C14H13N2O4S [M + H]+305.0596, found 305.0578.
4.1.5. General procedure for synthesis of acetals (14a-b)
Grignard reagent (1.2 equiv 3.82 mL, 1 M in dry THF) was added slowly to a solution of
quinoline-2-carbaldehyde (0.5 g, 3.18 mmol) in dry THF (20 mL) at 0 oC. The resulting solution was
stirred at room temperature for 12 h. The reaction was quenched with NH4Cl solution and extracted
with EtOAc. The organic layer was collected and purified through column chromatography to afford
the benzhydrol compound. Pyridinium dichromate (1.5 equiv 1.8 g, 4.77 mmol) and 4 Å molecular
sieves was added to a solution of the benzhydrol compound in DCM (0.2 M) and the mixture was
stirred at room temperature for 12 h. The reaction mixture was filtered through a pad of Celite and
the filtrate was purified by column chromatography to yield the desired product.
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4.1.5.1. (3-Diethoxymethyl-phenyl)-quinolin-2-yl-methanone (14a)
1
Colorless oily liquid; yield: 23.4%; H NMR (300 MHz, DMSO-d6) δ 1.10-1.16 (m, 6H), 3.44-3.63
(m, 4H), 5.57 (s, 1H), 7.53-7.59 (m, 1H), 7.69-7.78 (m, 2H), 7.83-7.89 (m, 1H), 8.03-8.15 (m, 6H),
8.59-8.65 (m, 1H).
4.1.5.2. (4-Dimethoxymethyl-phenyl)-quinolin-2-yl-methanone (14b)
Colorless oily liquid; yield: 65%; 1H NMR (300 MHz, CDCl3) δ 3.62 (s, 6H), 5.48 (s, 1H), 7.59-7.68
(m, 3H), 7.74-7.81 (m, 1H), 7.87-7.91 (m, 1H), 8.10 (d, 1H, J = 8.4 Hz), 8.18 (d, 1H, J = 8.7 Hz),
8.23-8.27 (m, 2H), 8.33 (d, 1H, J = 8.4 Hz).
4.1.6. General procedure for hydrolysis of acetal groups to afford the corresponding benzaldehyde
derivatives (15a-b)
1N HCl was added to a stirring solution of the acetal compound in THF at room temperature and
stirred for 12 h. The solvent was evaporated in vacuo and the pH value of the mixture was adjusted
to pH 7 by addition of 1N NaOH. The precipitate was collected by filtration to afford the anticipated
product.
4.1.6.1. 3-(Quinoline-2-carbonyl)-benzaldehyde (15a)
o
1
White solid; yield: 92%; mp: 140-141 C; H NMR (300 MHz, DMSO-d6) δ 7.75-7.91 (m, 3H),
8.09-8.17 (m, 3H), 8.19-8.23 (m, 1H), 8.42 (dt, 1H, J = 1.5, 7.8 Hz), 8.61-8.63 (m, 1H), 8.66 (d, 1H,
J = 8.4 Hz), 10.12 (s, 1H).
4.1.6.2. 4-(Quinoline-2-carbonyl)-benzaldehyde (15b)
o
1
White solid; yield: 88%; mp: 171-173 C; H NMR (300 MHz, DMSO-d6) δ 7.74-7.80 (m, 1H),
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7.84-7.90 (m, 1H), 8.06-8.16 (m, 5H), 8.22-8.25 (m, 2H), 8.65 (d, 1H, J = 8.4 Hz), 10.15 (s, 1H).
4.1.7. General procedure for Wittig reaction to afford the corresponding methyl acrylates (16a-b)
A mixture of benzaldehyde (1.0 equiv), methyl (triphenylphosphoranylidene)acetate (1.0 equiv), and
DCM was stirred at room temperature for 4 h. The resulting solution was washed with H2O three
times. The organic layer was collected and purified by column chromatography to provide the
desired product.
4.1.7.1. 3-[3-(Quinoline-2-carbonyl)-phenyl]-acrylic acid methyl ester (16a)
Yello solid; yield: 90%; mp: 100-101 oC; 1H NMR (300 MHz, CDCl3) δ 3.81 (s, 3H), 6.51 (d, 1H, J =
15.9 Hz), 7.55 (t, 1H, J = 7.8 Hz), 7.66-7.72 (m, 1H), 7.74-7.84 (m, 3H), 7.93 (dd, 1H, J = 1.2, 8.1
Hz), 8.14-8.21 (m, 2H), 8.24-8.28 (m, 1H), 8.38 (d, 1H, J = 8.4 Hz), 8.43 (t, 1H, J = 1.5 Hz).
4.1.7.2. 3-[4-(Quinoline-2-carbonyl)-phenyl]-acrylic acid methyl ester (16b)
White solid; yield: 89%; mp: 118-120 oC; 1H NMR (300 MHz, CDCl3) δ 3.84 (s, 3H), 6.57 (d, 1H, J
= 15.9 Hz), 7.64-7.83 (m, 5H), 7.92 (d, 1H, J = 8.4 Hz), 8.14 (d, 1H, J = 8.4 Hz), 8.20 (d, 1H, J = 8.4
Hz), 8.28 (d, 2H, J = 8.4 Hz), 8.36 (d, 1H, J = 8.4 Hz).
4.1.8. General procedure for hydrolysis of methyl acrylates to afford the corresponding acrylic acids
(17a-b)
1N LiOH (1.0 equiv) was added to a solution of methyl acrylate (1.0 equiv) in THF (0.1 M ), at room
temperature and the mixture was stirred for 12 h. The solvent was evaporated in vacuo. The pH value
of the resulting mixture was adjusted to pH 4 by addition of 1N HCl and the precipitate was collected
to afford the product.
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4.1.8.1. 3-[3-(Quinoline-2-carbonyl)-phenyl]-acrylic acid (17a)
o
1
White solid; yield: 89%; mp: 168 C; H NMR (300 MHz, DMSO-d6) δ 6.59 (d, 1H, J = 16.2 Hz),
7.58-7.71 (m, 2H), 7.73-7.79 (m, 1H), 7.83-7.90 (m, 1H), 8.01-8.14 (m, 5H), 8.32 (s, 1H), 8.63 (d,
1H, J = 8.4 Hz).
4.1.8.2. 3-[4-(Quinoline-2-carbonyl)-phenyl]-acrylic acid (17b)
Light yellow solid; yield: 88%; mp: 180 oC; 1H NMR (300 MHz, DMSO-d6) δ 6.70 (d, 1H, J = 15.9
Hz), 7.68 (d, 1H, J = 15.9 Hz), 7.73-7.79 (m, 1H), 7.83-7.89 (m, 3H), 8.06-8.12 (m, 5H), 8.63 (d, 1H,
J = 8.4 Hz).
4.2. Biology
4.2.1 Cell Culture
The human leukaemia cell line HL-60, colon cancer cell line HCT116, prostate cancer cell line PC-3
and non-small cell lung cancer cell line were maintained in RPMI 1640 medium containing 10%
fetal bovine serum, 100 units/mL penicillin, 100 ꢀg/mL streptomycin and 2.5 ꢀg/mL amphotericin B.
Cells were cultured in tissue culture flasks in a humidified incubator at 37 °C, in an atmosphere of
5% CO2 and 95% air.
4.2.2 Sulforhodamine B (SRB) Assays
Counted cells were seeded in 96-well plates in medium with 5% FBS. After 24 h, cells were fixed
with 10% trichloroacetic acid (TCA) to represent cell population at the time of compound addition
(T0). After additional incubation of DMSO or test compound for 48 h, cells were fixed with 10%
TCA and then stained with SRB at 0.4 % (w/v) in 1% acetic acid. Unbound SRB was washed out by
1% acetic acid and SRB-containing cells were solubilized with 10 mM Trizma base. The absorbance
was read at a wavelength of 515 nm. Using the following absorbance measurements, such as time
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zero (T0), control growth (C), and cell growth in the presence of the compound (Tx), the percentage
of growth was calculated at each of the compound concentration levels. Growth inhibition of 50%
(GI50) was calculated from the equation [(Ti-Tz)/(C-Tz)] x 100 = 50, which provides the compound
concentration resulting in a 50% reduction in the net protein increase (as measured by SRB staining)
in control cells during the incubation with the compound.
4.2.3 HDAC Biochemical Assays
The in vitro HDACs activities of recombinant human HDAC 1, 2, 6, and 8 (BPS Biosciences) were
detected by fluorogenic release of 7-amino-4-methylcoumarin from substrate upon deacetylase
enzymatic activity. The half maximum inhibitory concentration (IC50) is determined at the drug
concentration resulting in 50% reduction of enzyme activity.
4.2.4 Western Blot Analysis
HCT116 and PC3 cells were treated with 0.1% DMSO or indicated test compound at 0.03, 0.1, 0.3, 1,
and 3 µM in RPMI 1640 supplemented with 10% FBS for 48 h. The cells were then collected in
ice-cold lysis buffer [10 mmol/L Tris-HCl (pH 7.4), 150 mmol/L NaCl, 1 mmol/L EGTA, 1 mmol/L
phenylmethylsulfonyl fluoride, 10 mg/mL aprotinin, 10 mg/mL leupeptin, 1 mM sodium
orthovanadate, 1 mM NaF, and 1% Triton X-100] and sonicated. Protein concentrations in the
resultant lysates were determined by a Bradford protein assay kit (Bio-Rad, Hercules, CA). The
protein lysates, containing the same amount of proteins, were subjected to 10% SDS-polyacrylamide
gel electrophoresis. The proteins were then transferred to a polyvinylidene difluoride (PVDF)
membrane (Millipore, Bellerica, MA). After 1 h incubation at room temperature in 5% nonfat milk in
PBS, transblotted membrane was washed twice with tris-buffered saline containing 0.1% Tween 20
(TBST). Membrane was then incubated with a primary antibody specific to Acetyl-H3 (Millipore,
Billerica, M), H3 (Cell signalling, Beverly, MA), Acetyl-α-tubulin (Cell signalling, Beverly, MA),
α-tubulin (Cell signalling, Beverly, MA) and GAPDH (Novus Biologicals, Littleton, CO) in
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TBST/1% nonfat milk at 4 °C overnight. The membrane was washed three times with TBST for a
total of 15 min and then incubated with a goat anti-rabbit (Santa Cruz Biotechnology, Santa Cruz,
CA) or anti-mouse (Santa Cruz Biotechnology, Santa Cruz, CA) IgG antibody conjugated with
horseradish (diluted 1:3000) for 1 h at room temperature. After washing the membrane at least three
times with TBST, the signal intensity for each protein band was determined using an enhanced
chemiluminescence detection kit (Amersham, Buckinghamshire, UK).
4.2.5 Antitumor Activity in vivo
8 week old male nude mice (TMU Animal Facility) were fed ad libitum H2O (reverse osmosis, 1
ppm Cl) and PicoLab Rodent Diet 20 Modified and Irradiated Lab Diet® consisting of 20.0% crude
protein, 9.9% crude fat, and 4.7% crude fiber. The mice were housed at the Taipei Medical
University Laboratory Animal Center, on a 12-hour light cycle at 21–23 °C and 60–85% humidity.
Nude mice were maintained in accordance with the Institutional Animal Care and Use Committee
procedures and guidelines. The human HCT116 colorectal adenocarcinoma cells used for
implantation were harvested during log phase growth and resuspended in phosphate-buffered saline
at 5 x 107 cells/mL. Each mouse was injected s.c. in the right flank with 1 x 107 cells (0.2 mL cell
suspension). Mice arranged in four groups of 7 mice were examined frequently for overt signs of any
adverse, drug-related side effects. All doses were administered at a volume of 10 mL/kg (0.2 mL/20
g mouse), scaled to the body weight of each animal. Control group mice received vehicle daily p.o.
to endpoint. Group 2 received reference 8f daily p.o. at 50 mg/kg to endpoint. Group 3 received
compound 8f daily p.o. at 100 mg/kg to end schedule. Group 4 received SAHA daily p.o. at 200
mg/kg to end schedule. Tumor size, in mm3, was calculated from: Tumor Volume = (w2 × l)/2, where
w = width and l = length in mm of the tumor. Tumor weight can be estimated with the assumption
that 1 mm3 of tumor volume is equivalent to 1 mg.
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Acknowledgments
This research were supported by the Ministry Science Technology of the Republic of China
(grant no. MOST 103-2113-M-038 -001 -MY3)
References
[1] M. H. Kuo, C. D. Allis, Roles of histone acetyltransferases and deacetylases in gene regulation.
BioEssays 20 (1998) 615-626.
[2] S. Minucci, P. G. Pelicci, Histone deacetylase inhibitors and the promise of epigenetic (and more)
treatments for cancer. Nat. Rev. Cancer 6 (2006) 38-51.
[3] P. A. Marks, Discovery and development of SAHA as an anticancer agent. Oncogene 26 (2007)
1351-1356.
[4] L. Barbarotta, K. Hurley, Romidepsin for the treatment of peripheral T-cell lymphoma. J. Adv.
Pract. Oncol. 6 (2015) 22-36.
[5] X. Qian, G. Ara, E. Mills, W. J. LaRochelle, H. S. Lichenstein, M. Jeffers, Activity of the histone
deacetylase inhibitor belinostat (PXD101) in preclinical models of prostate cancer. Int. J. Cancer
122 (2008) 1400-1410.
[6] J. P. Laubach, P. Moreau, J. F. San-Miguel, P. G. Richardson, Panobinostat for the treatment of
multiple myeloma. Clin. Cancer Res. 21 (2015) 4767-4773.
[7] M. Paris, M. Porcelloni, M. Binaschi, D. Fattori, Histone deacetylase inhibitors: from bench to
clinic. J. Med. Chem. 51 (2008) 1505-1529.
[8] M. J. Lai, H. L. Huang, S. L. Pan, Y. M. Liu, C. Y. Peng, H. Y. Lee, T. K. Yeh, P. H. Huang, C.
M. Teng, C. S. Chen, H. Y. Chuang, J. P. Liou, Synthesis and biological evaluation of
1-arylsulfonyl-5-(N-hydroxyacrylamide)indoles as potent histone deacetylase inhibitors with
antitumor activity in vivo. J. Med. Chem. 55 (2012) 3777-3791.
[9] H. Y. Lee, C. R. Yang, M. J. Lai, H. L. Huang, Y. L. Hsieh, Y. M. Liu, T. K. Yeh, Y. H. Li, S.
Mehndiratta, C. M. Teng, J. P. Liou, 1-Arylsulfonyl-5-(N-hydroxyacrylamide)indolines histone
deacetylase inhibitors are potent cytokine release suppressors. Chembiochem. 14 (2013)
1248-1254.
[10] H. L. Huang, H. Y. Lee, A. C. Tsai, C. Y. Peng, L M. J. ai, J. C. Wang, S. L. Pan, C. M. Teng, J.
P. Liou, Anticancer activity of MPT0E028, a novel potent histone deacetylase inhibitor, in
human colorectal cancer HCT116 cells in vitro and in vivo. PLoSOne 7 (2012) e43645.
[11] H. Y. Lee, A. C. Tsai, M. C. Chen, P. J. Shen, Y. C. Cheng, K C. C. uo, S. L. Pan, Y. M. Liu, J.
F. Liu, T. K. Yeh, J. C. Wang, C. Y. Chang, J. Y. Chang, J. P. Liou, Azaindolylsulfonamides,
with a more selective inhibitory effect on histone deacetylase 6 activity, exhibit antitumor
activity in colorectal cancer HCT116 cells. J. Med. Chem. 57 (2014) 4009-4022.
[12] Y. M. Liu, H. Y. Lee, C. H. Chen, C. H. Lee, L. T. Wang, S. L. Pan, M. J. Lai, T. K. Yeh, J. P.
Liou, 1-Arylsulfonyl-5-(N-hydroxyacrylamide)tetrahydroquinolines as potent histone deacetylase
inhibitors suppressing the growth of prostate cancer cells. Eur. J. Med. Chem. 89 (2015) 320-330.
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Table 1
Antiproliferative Activity (GI50) of Compounds 8a-k, 18a-b, and 23.
GI50 ± SDa (μM)
Compd
HL-60
HCT116
PC-3
A549
8a
8b
>10
>10
>10
>10
>10
>10
>10
>10
8c
1.14±0.20
0.83±0.21
1.17±0.15
1.39±0.06
0.24±0.02
0.31±0.02
1.35±0.17 4.75±0.25
1.01±0.12 1.51±0.16
0.79±0.22 1.32±0.02
8d
8e
8f
0.29±0.06 0.08±0.001 0.15±0.01 0.27±0.02
8g
0.80±0.10
0.72±0.10
1.33±0.07
0.72±0.10
2.64±0.95
1.23±0.03
1.15±0.25
1.98±0.64
1.74±0.21
1.09±0.20
0.31±0.02
0.24±0.01
0.92±0.15
0.44±0.11
1.31±0.31
0.35±0.03
0.36±0.04
1.48±0.26
0.15±0.03
0.13±0.01
0.49±0.05 0.88±0.02
0.28±0.02 0.35±0.03
0.76±0.05 1.01±0.05
0.32±0.04 0.64±0.04
1.35±0.29 1.42±0.13
0.47±0.08 0.84±0.02
0.56±0.04 1.13±0.05
2.65±0.52 1.71±0.10
0.73±0.05 1.02±0.15
0.39±0.07 0.78±0.07
8h
8i
8j
8k
18a
18b
23
SAHA
PXD101
aSD: standard deviation, all experiments were independently performed at least three times.
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Table 2
Activities of 8f, 8j, PXD101, and SAHA against HDAC Isoforms 1,2, 6, and 8
IC50 ± SD (nM))
Compd
HDAC1
HDAC2
HDAC6
HDAC8
8f
8j
14
5.74
48
11.48
15
15
130
200
200
>300
5.89
50
PXD101
SAHA
49
120
110
110
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Caption
Figure 1. FDA-approved HDAC inhibitors.
Figure 2. Design of 2-(phenylsulfonyl)quinoline N-hydroxyacrylamides.
Figure 3. Effect of α-tubulin acetylation and histone H3 acetylation in cultured human
colorectal HCT-116 cancer and prostate PC-3 cancer cells using Western blot analysis.
Quantitative analysis of Western blot was done with ImageQuant (Molecular
Dynamics, U.S.).
Figure 4. Inhibition of human HCT-116 cancer xenograft growth in nude mice (n =
4-5).
Scheme 1. Reagents and conditions: (a) i. 4-methoxybenzenethiol or
o
o
3-bromobenzenethiol, K2CO3, DMF, 100 C; ii. mCPBA, DCM, 0 C to rt; (b)
tert-butyl acrylate, Pd2(dba)3, [P(t-Bu)3]HBF4,Cy2NMe, DMF, 100 oC; (c) TFA, DCM,
rt; (d) i. NH2OTHP, EDC∙HCl, DMAP, DCM, rt; ii. 1 N HCl(aq), MeOH, 0 oC to rt.
Scheme 2. Reagents and conditions: (a) i. (3-(diethoxymethyl)phenyl)magnesium
o
bromide or (4-(dimethoxymethyl)phenyl)magnesium bromide, THF, 0 C to rt; ii.
PDC, MS, DCM, rt; (b) 2 N HCl, THF, 0 oC to rt; (c) methyl
(triphenylphosphoranyl)acetate, DCM, rt; (d) 1 N LiOH, THF, rt; (e) i. NH2OTHP,
EDC HCl, DMAP, DCM, rt; ii. 1 N HCl, MeOH, rt.
Scheme 3. Reagents and conditions: (a) i. 3-bromobenzenethiol, K2CO3, DMF, 100
oC; ii. mCPBA, DCM, 0 oC to rt; (b) tert-butyl acrylate, Pd2(dba)3,
o
[P(t-Bu)3]HBF4,Cy2NMe, DMF, 100 C; (c) TFA, DCM, rt; (d) i. NH2OTHP,
EDC∙HCl, DMAP, DCM, rt; ii. 1 N HCl(aq.), MeOH, 0 oC to rt.
3