Synthesis and antitumor activity of ATB-429 derivatives containing a nitric oxide-releasing moiety

Article abstract of DOI:10.1016/j.bmcl.2016.03.012

A series of novel ATB-429 (an anti-inflammatory candidate) derivatives containing a nitric oxide (NO)-releasing moiety were designed, synthesized and evaluated for their in vitro activity against six human cancer cell lines. Our results reveal that phenyl

Full text of DOI:10.1016/j.bmcl.2016.03.012

Bioorganic & Medicinal Chemistry Letters xxx (2016) xxx–xxx
Contents lists available at ScienceDirect
Bioorganic & Medicinal Chemistry Letters
journal homepage: www.elsevier.com/locate/bmcl
Synthesis and antitumor activity of ATB-429 derivatives containing
a nitric oxide-releasing moiety
a
a
Chunlan Wang a,y, Guimin Xia a,y, Xiujun Liu a, , Rui Zhang , Yun Chai , Jun Zhang a,b, Xiaoning Li a,
⇑
Yang Yang a, Juxian Wang a, Mingliang Liu a,
⇑
a Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
b Zhejiang Starry Pharmaceutical Co. Ltd, Xianju 317300, China
a r t i c l e i n f o
a b s t r a c t
Article history:
A series of novel ATB-429 (an anti-inflammatory candidate) derivatives containing a nitric oxide
(NO)-releasing moiety were designed, synthesized and evaluated for their in vitro activity against six
human cancer cell lines. Our results reveal that phenylsulfonylfuroxan-based derivatives have
Received 17 January 2016
Revised 25 February 2016
Accepted 4 March 2016
Available online xxxx
considerable antitumor activity, and compounds 7–9 (IC50s: 0.256–3.024
PANC-1, 8a,b (IC50s: 2.677–3.051 M) against MCF-7 and 8a (IC50: 1.270 M) against DU145 are more
active than Vandetanib (IC50s: 1.925–4.107 M).
lM) against HT-29 and
l
l
l
Keywords:
ATB-429 derivatives
Nitric oxide
Ó 2016 Published by Elsevier Ltd.
Synthesis
Antitumor activity
Nonsteroidal anti-inflammatory drugs (NSAIDs), in general, and
aspirin, in particular, are recognized as the prototypical chemopre-
ventive agents against many forms of cancers1 and may serve as
possible adjunct in cancer treatment.2 However, NSAID-induced
upper gastrointestinal (GI) side effects remain a major problem
that affects a broad segment of the population, due to frequent pre-
scription and over the counter dispensing.3 And this has stimulated
the search for alternative anti-inflammatory drugs that are safe for
long-term use. Hydrogen sulfide (H2S), nitric oxide (NO) and car-
bon monoxide (CO) form parts of a group of biologically active
gases that are termed gasotransmitters or gasomediators.4 It was
reported that NO-releasing NSAIDs are indeed safer to the GI
mucosa than the parent drugs.5 Similarly, H2S-releasing NSAIDs
have been shown to be more effective than the parent drugs in
reducing inflammation, while producing significantly less damage
in the GI tract.6,7 For example, ATB-429 (Fig. 1), a H2S-releasing
derivative of mesalamine (5-aminosalicylicacid, a first-line therapy
for inflammatory bowel disease), exhibits a marked increase in
anti-inflammatory activity and potency in a murine model of coli-
tis and exerts antinociceptive effects in a model of post inflamma-
tory hypersensitivity model of colitis.6,8 On the other hand, many
of NO-releasing aspirins and H2S-releasing aspirins have proved
to possess antitumor activity.9,10 More recently, Kashfi et al.
described a series of new NOSH (NO-, H2S-releasing) aspirins (such
as NOSH-1, Fig. 1) which are extremely effective in inhibiting the
growth of different human cancer cell lines.11 More interesting, dif-
ferent active compounds containing
a novel phenylsulfonyl-
furoxan-based NO releasing moiety (such as hydrids 1 and 2,
Fig. 1) display potent antitumor activity both in vivo and
in vitro.12,13
Receptor tyrosine kinases (RTKs) represent a large family of
membrane-bound enzymes that play key roles in tumor growth,
survival, and metastasis.14 Inhibition of RTK pathways has become
an important approach for the discovery of new anticancer drugs.15
Many RTK inhibitors have been introduced to the market during
the last decade, such as Sorafenib and Linifanib (Fig. 1) having a
diaryl urea motif.16–18
Inspired by the above research results, we decided to make
structural modifications on ATB-429 by introduction of a NO-
releasing moiety and replacement of the amino group with an aryl
urea unit in this study. Our primary object was to identify potent
and novel antitumor compounds so as to lay a foundation for the
further study.
Detailed synthetic pathways to the intermediate 5 and ATB-429
derivatives 7–10, 13 and 14a–f are shown in Schemes 1 and 2,
respectively. Treatment of 5-(4-methoxyphenyl)-3H-1,2-dithiole-
3-thione (ADT-OCH3, 1) with pyridine hydrochloride gave ADT-OH
(2).19 5-Amino-2-hydroxybenzoic acid 3 was protected by reaction
⇑
Corresponding authors.
E-mail addresses: liuxiujun2000@163.com (X. Liu), lmllyx@126.com (M. Liu).
y
These authors contributed equally to this work.
http://dx.doi.org/10.1016/j.bmcl.2016.03.012
0960-894X/Ó 2016 Published by Elsevier Ltd.
Please cite this article in press as: Wang, C.; et al. Bioorg. Med. Chem. Lett. (2016), http://dx.doi.org/10.1016/j.bmcl.2016.03.012

2
C. Wang et al. / Bioorg. Med. Chem. Lett. xxx (2016) xxx–xxx
S
S
S
S
O
S
S
O
O
H2N
O
O
O
ONO2
NOSH-1
OH
ATB-429
SO2Ph
O
N
O
O
N
O
O
N
CH3
O
O
N
N
N
O
O
S
SO2Ph
O
1
2
F
H
N
H
N
H
H
N
NH2
N
CF3
Cl
N
HN
N
O
H3CHN
O
O
CH3
O
Sorafenib
Linifanib
Figure 1. Structures of selected compounds.
S
S
S
S
HO
H3CO
a
S
S
S
S
2
1
Boc
HN
S
O
c
Boc
HN
O
O
O
H2N
b
OH
OH
OH
OH
OH
5
3
4
Scheme 1. Synthesis of Boc-protected ATB-429 (5). Reagents and conditions: (a) C5H5NꢀHCl, 215 °C, 2 h, 80%; (b) Boc2O, NaOH, dioxane/H2O, rt, 4 h, 93%; (c) DCC/DMAP,
CH2Cl2, 0 °C-rt, 8 h, 62%.
with di-tert-butyl dicarbonate (Boc2O) produced compound 4.20
Esterification of ADT-OH and the acid 4 in the presence of dicyclo-
inhibition against HT-29 or A549, and >90% inhibition against the
other four cells at the concentration of 30 M were subjected to
l
hexylcarbodiimide
yielded Boc-protected ATB-429 (5) (Scheme 1).
(DCC)/4-dimethylaminopyridine
(DMAP)
IC50s (50% inhibition concentrations) determination. Six target
compounds 7–10 containing a phenylsulfonylfuroxan-based NO
releasing moiety meeting this criterion (Table 1) were further eval-
uated for their in vitro antitumor activity in the above six cell lines
by standard MTT assay.21 The IC50 values were compared with
those of Vandetanib, a multi-targeted receptor TK inhibitor22
(Table 2).
The Boc-protected ATB-429 (5) was treated with 2-bro-
moethan-1-ol, 3-bromopropan-1-ol or 2-(2-chloroethoxy)ethan-
1-ol to provide the intermediates 6a–c. Condensation of 6a,b with
3,4-diphenylsulfonyl-1,2,5-oxadiazole 2-oxide in the presence of
1,8-diazabicyclo[5.4.0]undec-7-ene(DBU) yielded compounds 7a,
b. The Boc-protecting group of 7a,b was removed by pumping
hydrogen chloride gas in CH2Cl2 to afford ATB-429 derivatives 8a,
b. The target compound 10 was obtained from 6c in a similar man-
ner as for the preparation of 8a,b (Scheme 2).23
Esterification of the phenol 5 and 4-bromobutyric acid in the
presence of DCC/DMAP yielded compound 11. The bromo moiety
in the bromide 11 was then substituted with nitrate using AgNO3
to give compound 12, on which the Boc-protecting group was
removed by pumping hydrogen chloride gas in CH2Cl2 to afford
amine 13. Ureas 14a–f were obtained by condensation of 13 with
commercially available various phenyl isocyanates (Scheme 2).
For preliminary screening of antitumor candidates, all the
newly synthesized ATB-429 derivatives 7–10, 13 and 14a–f were
first investigated for cytotoxic activity in vitro against HT-29 (colon
adenocarcinoma), PANC-1 (pancreatic carcinoma), MCF-7 (breast
cancer), A549 (lung adenocarcinoma), DU-145 (prostate cancer)
and HL60 (human leukemia), and the compounds having >100%
The selected ATB-429 derivatives 7–10 have potent in vitro
antitumor activity against the tested cancer cell lines. Among
them, compounds 7–9 (IC50s: 0.256–3.024
and PANC-1, 8a,b (IC50s: 2.677–3.051 M) against MCF-7 and 8a
(IC50: 1.270 M) against DU145 are more active than Vandetanib
lM) against HT-29
l
l
(IC50s: 1.925, 4.107, 3.536 and 1.974
lM against the four cell lines,
respectively) (Table 2).
According to the biological evaluation results showed in Tables
1 and 2, antitumor activity of the ATB-429 derivatives 7–10, 13 and
14a–f depends mainly on the NO-releasing moiety. In general, the
contribution of the phenylsulfonylfuroxan moiety to the antitumor
activity is significantly greater than the corresponding nitrate one
(AONO2) (8a,b, 10 vs 13) (Table 1). Compound 13 and its deriva-
tives 14a–f having an aryl urea motif, contrary to expectation, have
virtually no activity at 30 lM against the tested cell lines (Table 1).
On the other hand, the antitumor activity of phenylsulfonyl-
furoxan-based ATB-429 derivatives is closely related to the linkers.
Please cite this article in press as: Wang, C.; et al. Bioorg. Med. Chem. Lett. (2016), http://dx.doi.org/10.1016/j.bmcl.2016.03.012

C. Wang et al. / Bioorg. Med. Chem. Lett. xxx (2016) xxx–xxx
3
S
S
S
S
S
S
S
S
Boc
HN
O
O
S
Boc
HN
O
O
O
O
O
H2N
ii
O
O
O
iii
N
O
O
N
N
O
N
O
O
O
OH
O
O
SO2Ph
SO2Ph
9
6c
10
iv
O
S
S
S
S
S
S
S
S
S
O
O
Boc
HN
O
S
H2N
S
Boc
HN
S
Boc
HN
O
O
O
iii
ii
N
N
O
N
O
N
( )n
( )n
i
O
O
O
O
O
PhO2S SO2Ph
O
O
( )n
N
N
O
6b
OH
O
O
OH
PhO2S
8a,b
PhO2S
7a,b
6a (n=2)
(n=3)
5
v
S
S
S
S
S
S
R
S
S
S
S
Boc
HN
S
O
Boc
HN
S
O
O
O
O
H
iii
vi
vii
HN
N
H2N
O
O
O
O
CNO
O
R
O
O
O
O
ONO2
ONO2
ONO2
Br
O
O
O
14d: R=3-CF3
14e: R=3-Cl
14a: R=4-OCH3
14b: R=4-F
11
12
13
14f
14c
: R=3-CH3
: R=2,4-di-F
Scheme 2. Synthesis of ATB-429 derivatives 7–10, 13 and 14a–f. Reagents and conditions: (i) Br(CH2)nOH, K2CO3, DMF, reflux, 3 h, 44–50%; (ii) DBU, CH2Cl2, 0 °C-rt, 12 h, 35–
38%; (iii) HCl (g), CH2Cl2, rt, 1 h, 50–90%; (iv) Cl(CH2)O(CH2)2OH, K2CO3, DMF, reflux, 5 h, 42%; (v) Br(CH2)3CO2H, DCC/DMAP, CH2Cl2, 0 °C-rt, 8 h, 69%; (vi) AgNO3, CH3CN,
70 °C, 3 h, 38%; (vii) Et3N, C6H5CH3, reflux, 4 h, 30–40%.
Table 1
Table 2
In vitro activity of compounds 7–10, 13 and 14a–f against six cell lines (at 30 lM)
In vitro activity of selected compounds 7–10 against six cell lines
Cell lines
Compd
% inhibition
MCF-7 A549
88.45
Cell lines
Compd
IC50
(
l
M)
HT-29
PANC1
DU145
HL60
HT-29
PANC1
MCF-7
A549
DU145
HL60
7a
7b
8a
8b
9
10
13
14a
14b
14c
14d
14e
14f
102.87
102.63
101.92
102.63
102.95
100.64
ꢁ13.27
12.11
97.12
97.40
96.64
97.45
97.88
83.12
25.19
90.13
92.12
63.09
90.03
ꢁ5.55
15.97
19.06
ꢁ6.87
ꢁ6.78
6.10
61.60
67.91
93.81
94.81
54.74
63.20
ꢁ7.67
ꢁ6.39
15.30
ꢁ7.47
ꢁ14.25
5.49
84.62
83.98
92.33
87.32
84.45
84.39
8.73
8.30
8.68
0.43
7a
7b
8a
8b
9
10
0.256
0.926
0.769
0.559
0.536
5.437
1.925
1.448
3.024
1.858
0.971
2.797
8.002
4.107
—
—
—
—
4.171
3.275
—
—
—
1.270
2.236
—
—
—
1.877
—
—
ꢁ23.80
100.42
100.47
18.73
2.677
3.051
—
11.894
3.536
97.12
62.75
—
2.630
—
1.974
—
1.492
ꢁ10.51
ꢁ18.38
Vandetanib
2.19
3.19
6.92
ꢁ12.95
ꢁ14.80
ꢁ5.71
ꢁ17.26
ꢁ14.25
ꢁ27.18
ꢁ28.03
ꢁ22.11
ꢁ23.29
ꢁ19.77
ꢁ6.41
In summary, a series of novel ATB-429 derivatives containing a
NO-releasing moiety were designed, synthesized and evaluated for
their antitumor activity. Our results reveal that phenylsulfonyl-
furoxan-based derivatives have potent antitumor activity, and
13.15
14.06
10.90
7.34
21.53
9.56
13.89
ꢁ19.32
compounds 7–9 (IC50s: 0.256–3.024
PANC-1, 8a,b (IC50s: 2.677–3.051 M) against MCF-7 and 8a
(IC50: 1.270 M) against DU145 are more active than Vandetanib
lM) against HT-29 and
l
For example, compounds with an alkyl (ethyl or propyl) linker
show much better activity for HT-29, PANC-1 and MCF-7 than
the analogs containing an ethoxyethyl one (IC50s: 0.559–
l
(IC50s: 1.925–4.107 lM).
3.051
lM for 8a,b vs 5.437–11.894 lM for 10) (Table 2), although
Acknowledgments
all of the three have similar rates of growth inhibitions at 30
lM
(Table 1). Moreover, the sizes of the alkyl linkers seem to have
no significantly impact on the activity (8a vs 8b) (Tables 1 and
2). Finally, some ATB-429 derivatives with a Boc moiety on the
amino group at the C-5 position, by comparison, were found to
be more active against some cell lines (7a vs 8a, 9 vs 10), which
suggests that a carbamate moiety is permitted at the C-5 position
of these phenylsulfonylfuroxan-basedATB-429 derivatives and
would be more beneficial to the increase of the antitumor activity
that could lay a solid foundation for the further study.
This work was supported by the National S&T Major Special
Project on Major New Drug Innovations (2014ZX09507009-003,
2015ZX09102007) and NSFC 81373267-003, 21502237.
Supplementary data
Supplementary data associated with this article can be found, in
the online version, at http://dx.doi.org/10.1016/j.bmcl.2016.03.
Please cite this article in press as: Wang, C.; et al. Bioorg. Med. Chem. Lett. (2016), http://dx.doi.org/10.1016/j.bmcl.2016.03.012

4
C. Wang et al. / Bioorg. Med. Chem. Lett. xxx (2016) xxx–xxx
3 mmol) in toluene (8 mL) was stirred for 4 h under refluxing and then filtered.
The solid was purified by column chromatography (silica gel) eluting with
CH2Cl2/MeOH (100:1, v/v) to get target compounds 14a–f (30–40%) as orange
solids.
012. These data include MOL files and InChiKeys of the most
important compounds described in this article.
Compound 7a (24.5%, from 5), mp 155–156 °C. 1H NMR (500 MHz, DMSO-d6) d
9.74 (1H, s, –NH), 8.20 (1H, d, J = 2.5 Hz, Ar-H), 7.97 (1H, dd, J = 8.5, 2.5 Hz, Ar-
H), 7.81–7.72 (5H, m, Ar-H), 7.69 (1H, s, @CH), 7.62–7.59 (2H, m, Ar-H), 7.24
(1H, d, J = 8.5 Hz, Ar-H), 6.84–6.80 (2H, m, Ar-H), 4.48 (2H, t, J = 5.0 Hz, AOCH2),
4.37 (2H, t, J = 5.0 Hz, AOCH2), 1.49 (9H, s, AC(CH3)3). MS-ESI (m/z): 730.2 (M
+H)+. Compound 7b (20%, from 5), mp 170–172 °C. 1H NMR (500 MHz, DMSO-
d6) d 9.72 (1H, s, ANH), 8.16 (d, J = 2.5 Hz, 1H), 7.99–7.95 (2H, m, Ar-H), 7.87
(1H, dd, J = 8.5, 2.5 Hz, Ar-H), 7.82–7.78 (2H, m, Ar-H), 7.73–7.71 (3H, m, Ar-H),
7.69 (1H, s, @CH), 7.20 (1H, d, J = 8.5 Hz, Ar-H), 6.89 (2H, m, Ar-H), 4.23 (2H, t,
J = 6.0 Hz, AOCH2), 4.19 (2H, t, J = 6.0 Hz, ACH2OH), 2.05–1.94 (2H, m, ACH2A),
1.49 (9H, s, AC(CH3)3). MS-ESI (m/z): 744.2 (M+H)+. Compound 9 (25%, from 5),
mp 175–177 °C. 1H NMR (500 MHz, DMSO-d6) d 9.71 (1H, s, ANH), 8.17 (1H, d,
J = 2.0 Hz, Ar-H), 8.00–7.97 (2H, m, Ar-H), 7.88–7.86 (2H, m, Ar-H), 7.85 (1H,
dd, J = 8.0, 2.0 Hz, Ar-H), 7.74 (1H, s, @CH), 7.74–7.68 (3H, m, Ar-H), 7.20 (1H, d,
J = 8.0 Hz, Ar-H), 6.95–6.91 (2H, m, Ar-H), 4.43 (2H, t, J = 5.0 Hz, ACH2A), 4.25
(2H, t, J = 5.0 Hz, ACH2A), 3.70 (2H, t, J = 5.0 Hz, ACH2A), 3.59 (2H, t, J = 5.0 Hz,
ACH2A), 1.48 (9H, s, AC(CH3)3). MS-ESI (m/z): 774.1 (M+H)+.
References and notes
1. Kashfi, K. Adv. Pharmacol. 2009, 57, 31.
2. Hinz, B.; Brune, K. J. Pharmacol. Exp. Ther. 2002, 300, 367.
3. Wallace, J. L. Baillieres Best Pract. Res. Clin. Gastroenterol. 2000, 14, 147.
4. Li, L.; Hsu, A.; Moore, P. K. Pharmacol. Ther. 2009, 123, 386.
5. Fiorucci, S.; Santucci, L.; Gresele, P.; Faccino, R. M.; Del Soldato, P.; Morelli, A.
Gastroenterology 2003, 124, 600.
6. Fiorucci, S.; Orlandi, S.; Mencarelli, A.; Caliendo, G.; Santagada, V.; Distrutti, E.;
Santucci, L.; Cirino, G.; Wallace, J. L. Br. J. Pharmacol. 2007, 150, 996.
7. Wallace, J. L.; Caliendo, G.; Santagada, V.; Cirino, G. Br. J. Pharmacol. 2010, 159,
1236.
8. Distrutti, E.; Sediari, L.; Mencarelli, A.; Renga, B.; Orlandi, S.; Russo, G.;
Caliendo, G.; Santagada, V.; Cirino, G.; Wallace, J. L.; Fiorucci, S. J. Pharmacol.
Exp. Ther. 2006, 319, 447.
9. Chattopadhyay, M.; Kodela, R.; Nath, N.; Barsegian, A.; Boring, D.; Kashfi, K.
Biochem. Pharmacol. 2012, 83, 723.
Compound 8a (75.5%), mp 95–96 °C. 1H NMR (500 MHz, DMSO-d6) d 7.98–7.95
(2H, m, Ar-H), 7.83–7.80 (1H, m, Ar-H), 7.72–7.70 (2H, m, Ar-H), 7.67 (1H, s,
@CH), 7.64–7.61 (2H, m, Ar-H), 7.21 (1H, d, J = 2.5 Hz, Ar-H), 6.98 (1H, d,
J = 8.5 Hz, Ar-H), 6.91 (1H, dd, J = 8.5, 2.5 Hz, Ar-H), 6.79–6.77 (2H, m, Ar-H),
5.53 (2H, s, ANH2), 4.43 (2H, dd, J = 5.0, 3.0 Hz, AOCH2), 4.31 (2H, dd, J = 5.0,
10. Hulsman, N.; Medema, J. P.; Bos, C.; Jongejan, A.; Leurs, R.; Smit, M. J.; de Esch, I.
J.; Richel, D.; Wijtmans, M. J. Med. Chem. 2007, 50, 2424.
11. Kodela, R.; Chattopadhyay, M.; Kashfi, K. ACS Med. Chem. Lett. 2012, 3, 257.
12. Han, C.; Huang, Z.; Zheng, C.; Wan, L.; Zhang, L.; Peng, S.; Ding, K.; Ji, H.; Tian, J.;
Zhang, Y. J. Med. Chem. 2013, 56, 4738.
3.0 Hz, AOCH2). 13C NMR (500 MHz, DMSO-d6)
d 214.65, 173.04, 164.52,
13. Liu, M. M.; Chen, X. Y.; Huang, Y. Q.; Feng, P.; Guo, Y. L.; Yang, G.; Chen, Y. J.
Med. Chem. 2014, 57, 9343.
162.67, 158.15, 146.68, 142.10, 136.97, 135.95, 134.10, 129.78, 128.61, 128.17,
124.21, 124.07, 123.40, 119.35, 115.90, 115.44, 109.99, 68.89, 61.84. MS-ESI
(m/z): 630.0 (M+H)+. HRMS-ESI (m/z): Calcd. for C26H19N3O8S4 (M+H)+:
630.0055; Found: 630.0100. Compound 8b (80%), mp 103–105 °C. 1H NMR
(500 MHz, DMSO-d6) d 7.99–7.97 (2H, m, Ar-H), 7.90–7.87 (1H, m, Ar-H), 7.79–
7.77 (2H, m, Ar-H), 7.74–7.71 (2H, m, Ar-H), 7.68 (1H, s, @CH), 7.17 (1H, d,
J = 2.0 Hz, Ar-H), 6.94 (1H, d, J = 8.0 Hz, Ar-H), 6.87 (1H, dd, J = 8.0, 2.0 Hz, Ar-
H), 6.86–6.83 (2H, m, Ar-H), 5.49 (2H, s, ANH2), 4.19 (2H, t, J = 6.0 Hz, AOCH2),
4.15 (2H, t, J = 6.0 Hz, AOCH2), 1.95 (2H, m, ACH2A). 13C NMR (500 MHz,
DMSO-d6) d 214.81, 173.35, 164.95, 162.87, 158.53, 146.80, 142.16, 137.15,
136.16, 134.34, 130.04, 129.00, 128.30, 124.39, 124.25, 123.83, 119.32, 116.12,
115.50, 110.29, 67.77, 60.76, 27.26. MS-ESI (m/z): 644.1 (M+H)+. HRMS-ESI (m/
z): Calcd. for C27H21N3O8S4 (M+H)+: 644.0211; Found: 644.0256. Compound 10
(50%), mp 118–120 °C. 1H NMR (500 MHz, DMSO-d6) d 7.98–7.96 (2H, m, Ar-
H), 7.85–7.83 (1H, m, Ar-H), 7.71 (1H, s, @CH), 7.70–7.67 (2H, m, Ar-H), 7.12
(1H, d, J = 2.0 Hz, Ar-H), 6.93 (1H, d, J = 8.0 Hz, Ar-H), 6.88–6.86 (2H, m, Ar-H),
6.84 (1H, dd, J = 8.0, 2.0 Hz, Ar-H), 5.45 (2H, s, ANH2), 4.41 (2H, t, J = 5.0 Hz,
ACH2A), 4.19 (2H, t, J = 5.0 Hz, ACH2A), 3.66 (2H, t, J = 5.0 Hz, ACH2A), 3.54
(2H, t, J = 5.0 Hz, ACH2A). 13C NMR (500 MHz, DMSO-d6) d 214.85, 173.55,
164.77, 162.97, 158.82, 146.72, 142.28, 137.18, 136.10, 134.37, 129.97, 129.01,
128.29, 124.33, 124.24, 123.90, 119.21, 116.29, 115.35, 110.47, 70.76, 68.31,
67.71, 63.95. MS-ESI (m/z): 674.1 (M+H)+. Compound 11, mp 199–201 °C. 1H
NMR (500 MHz, DMSO-d6) d 9.73 (1H, s, ANH), 8.38 (1H, d, J = 2.5 Hz, Ar-H),
8.06–8.03 (2H, m, Ar-H), 7.86 (1H, s, @CH), 7.76 (1H, dd, J = 8.8, 2.5 Hz, Ar-H),
7.44–7.40 (2H, m, Ar-H), 7.27 (1H, d, J = 8.8 Hz, Ar-H), 3.58 (2H, t, J = 6.5 Hz,
ACH2Br), 2.71 (2H, t, J = 7.5 Hz, ACOCH2), 2.16–2.10 (2H, m, ACH2A), 1.50 (9H,
s, AC(CH3)3). MS-ESI (m/z): 612.1 (M+H)+. Compound 12, 1H NMR (500 MHz,
DMSO-d6) d 9.73 (1H, s, ANH), 8.38 (1H, d, J = 2.5 Hz, Ar-H), 8.06–8.01 (2H, m,
Ar-H), 7.86 (1H, s, @CH), 7.76 (1H, dd, J = 8.8, 2.5 Hz, Ar-H), 7.44–7.38 (2H, m,
Ar-H), 7.26 (1H, d, J = 8.8 Hz, Ar-H), 4.56 (2H, t, J = 6.5 Hz, AONO2CH2), 2.70
(2H, t, J = 7.0 Hz, ACOCH2), 1.98–2.03 (2H, m, ACH2A), 1.50 (9H, s, AC(CH3)3).
MS-ESI (m/z): 593.1 (M+H)+. Compound 13, mp 160–162 °C. 1H NMR
(500 MHz, DMSO-d6) d 8.02–8.00 (2H, m, Ar-H), 7.85 (1H, s, @CH), 7.41–7.37
(2H, m, Ar-H), 7.36 (1H, d, J = 2.7 Hz, Ar-H), 6.98 (1H, d, J = 8.7 Hz, Ar-H), 6.91
(1H, dd, J = 8.7, 2.8 Hz, Ar-H), 5.50 (2H, s, ANH2), 4.55 (2H, t, J = 6.5 Hz,
AONO2CH2), 2.64 (2H, t, J = 7.0 Hz, ACOCH2), 2.01–1.96 (2H, m, ACH2A). MS-
ESI (m/z): 493.0 (M+H)+. Compound 14a (38.5%), mp 187–188 °C. 1H NMR
(500 MHz, DMSO-d6) d 9.01 (1H, s, ANH), 8.58 (1H, s, ANH), 8.35 (1H, d,
J = 2.7 Hz, Ar-H), 8.05–8.02 (2H, m, Ar-H), 7.87 (1H, s, @CH), 7.77 (1H, dd,
J = 8.8, 2.7 Hz, Ar-H), 7.45–7.42 (2H, m, Ar-H), 7.38–7.35 (2H, m, Ar-H), 7.27
(1H, d, J = 8.8 Hz, Ar-H), 6.90–6.86 (2H, m, Ar-H), 4.56 (2H, t, J = 6.5 Hz,
AONO2CH2), 3.72 (3H, s, AOCH3), 2.70 (2H, t, J = 7.0 Hz, ACOCH2), 2.02–1.97
(2H, m, ACH2A). 13C NMR (500 MHz, DMSO-d6) d 215.74, 172.87, 171.56,
162.44, 154.87, 153.32, 152.95, 144.66, 138.40, 136.12, 132.53, 129.42, 129.07,
124.71, 123.37, 121.75, 120.83, 120.60, 114.16, 72.77, 55.36, 29.82, 21.62. MS-
ESI (m/z): 642.0 (M+H)+. HRMS-ESI (m/z): Calcd. for C28H23N3O9S3 (M+H)+:
642.0596; Found: 642.0686. Compound 14b (35.5%), mp 189–191 °C. 1H NMR
(500 MHz, DMSO-d6) d 9.10 (1H, s, ANH), 8.83 (1H, s, ANH), 8.36 (1H, d,
J = 2.4 Hz, Ar-H), 8.03–8.05 (2H, m, Ar-H), 7.87 (1H, s, @CH), 7.78 (1H, dd,
J = 8.8, 2.5 Hz, Ar-H), 7.49 (2H, m, Ar-H), 7.42–7.44 (2H, m, Ar-H), 7.28 (1H, d,
J = 8.8 Hz, Ar-H), 7.14 (2H, t, J = 8.8 Hz, Ar-H), 4.56 (2H, t, J = 6.5 Hz, AONO2-
CH2), 2.70 (2H, t, J = 7.0 Hz, ACOCH2), 2.08–1.96 (2H, m, ACH2A). 13C NMR
(500 MHz, DMSO-d6) d 215.99, 173.13, 171.82, 162.68, 158.93, 157.03, 153.58,
153.15, 145.11, 138.45, 136.39, 136.17, 129.69, 129.34, 125.09, 123.63, 122.06,
121.29, 120.83, 115.77, 73.04, 30.10, 21.89. MS-ESI (m/z): 630.0 (M+H)+.
14. Khanwelkar, R. R.; Chen, G. S.; Wang, H. C.; Yu, C. W.; Huang, C. H.; Lee, O.;
Chen, C. H.; Hwang, C. S.; Ko, C. H.; Chou, N. T.; Lin, M. W.; Wang, L. M.; Chen, Y.
C.; Hseu, T. H.; Chang, C. N.; Hsu, H. C.; Lin, H. C.; Shih, Y. C.; Chou, S. H.; Tseng,
H. W.; Liu, C. P.; Tu, C. M.; Hu, T. L.; Tsai, Y. J.; Chern, J. W. Bioorg. Med. Chem.
2010, 18, 4674.
15. Gschwind, A.; Fisher, O. M.; Ullrich, A. Nat. Rev. Cancer. 2004, 4, 361.
16. Ng, R.; Chen, E. X. Curr. Clin. Pharmacol. 2006, 1, 223.
17. Dai, Y.; Hartandi, K.; Ji, Z.; Ahmed, A. A.; Albert, D. H.; Bauch, J. L.; Bouska, J. J.;
Bousquet, P. F.; Cunha, G. A.; Glaser, K. B.; Harris, C. M.; Hickman, D.; Guo, J.; Li,
J.; Marcotte, P. A.; Marsh, K. C.; Moskey, M. D.; Martin, R. L.; Olson, A. M.;
Osterling, D. J.; Pease, L. J.; Soni, N. B.; Stewart, K. D.; Stoll, V. S.; Tapang, P.;
Reuter, D. R.; Davidsen, S. K.; Michaelides, M. R. J. Med. Chem. 2007, 50, 1584.
18. Albert, D. H.; Tapang, P.; Magoc, T. J.; Pease, L. J.; Reuter, D. R.; Wei, R. Q.; Li, J.;
Guo, J.; Bousquet, P. F.; Ghoreishi-Haack, N. S.; Wang, B.; Bukofzer, G. T.; Wang,
Y. C.; Stavropoulos, J. A.; Hartandi, K.; Niquette, A. L.; Soni, N.; Johnson, E. F.;
McCall, J. O.; Bouska, J. J.; Luo, Y.; Donawho, C. K.; Dai, Y.; Marcotte, P. A.;
Glaser, K. B.; Michaelides, M. R.; Davidsen, S. K. Mol. Cancer Ther. 2006, 5, 995.
19. Chen, P.; Luo, Y.; Hai, L.; Qian, S.; Wu, Y. Eur. J. Med. Chem. 2010, 45, 3005.
20. Wang, C.; Shi, W.; Cai, L.; Lu, L.; Wang, Q.; Zhang, T.; Li, J.; Zhang, Z.; Wang, K.;
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21. Green, L. M.; Reade, J. L.; Ware, C. F. J. Immunol. Methods 1984, 70, 257.
22. Commander, H.; Whiteside, G.; Perry, C. Drugs 2011, 71, 1355.
23. A mixture of 219 (2.3 g, 10 mmol), 420 (3.1 g, 12 mmol), DCC (2.5 g, 12 mmol)
and DMAP (0.61 g, 5 mmol) in CH2Cl2 (150 mL) was stirred for 8 h at room
temperature under nitrogen atmosphere and then filtered. The filtrate was
washed with saturated brine (100 mL) and concentrated under reduced
pressure. The residue was recrystallized from MeOH to get compound
5
(2.9 g, 62.8%) as a yellow solid, mp 162–164 °C.
A mixture of 5 (462 mg, 1 mmol), 2-bromoethanol/3-bromopropanol/2-(2-
chloroethoxy)ethanol (1.2 mmol), K2CO3 (276 mg, 2 mmol), NaI (14.9 mg,
0.1 mmol) in anhydrous DMF (8 mL) was stirred for 3 h under refluxing, and
poured into ice water and then extracted with EtOAc (5 mL ꢂ 3). The combined
extracts were dried over anhydrous Na2SO4 and concentrated under reduced
pressure to afford crude compounds 6a–c.
A mixture of the above crude compounds 6a–c, 3,4-diphenylsulfonyl-1,2,5-
oxadiazole 2-Oxide (1.2 mmol), DBU (2 mmol) and CH2Cl2 (8 mL) was stirred
for 12 h at room temperature, washed with water (10 mL ꢂ 3) and then
concentrated under reduced pressure. The residue was purified by column
chromatography (silica gel) eluting withCH2Cl2/MeOH (200:1, v/v) to get 7a,b
and 9 (20–25%, for two steps) as orange solids.
To a solution of 7a,b or 9 (1 mmol) in CH2Cl2 (10 mL) was pumped dried
hydrochloride gas for 1 h at room temperature. The precipitate was collected
by suction, washed with CH2Cl2, and dried under vacuum to give 8a,b or 10
(50–80%) as orange solids.
A mixture of 5 (3.0 g, 6 mmol), 4-bromobutyric acid (1.3 g, 8 mmol), DCC (1.6 g,
8 mmol) and DMAP (0.4 g, 3 mmol) in CH2Cl2 (150 mL) was stirred for 8 h at
room temperature under nitrogen atmosphere and then filtered. The filtrate
was washed with saturated brine (100 mL) and concentrated under reduced
pressure. The residue was recrystallized from a ether to afford 11 (2.7 g, 68.7%)
as a yellow solid.
A mixture of 11 (1.4 g, 2 mmol), AgNO3 (1.0 g, 6 mmol) in anhydrous CH3CN
was stirred for 3 h under refluxing in the dark, cooled to room temperature and
then filtered. The filtrate was concentrated under reduced pressure and the
residue was purified by column chromatography (silica gel) eluting with
EtOAc/petroleum ether (1:5, v/v) to afford 12 (0.5 g, 38%) as an red oil.
Compound 13 was obtained from 12 in a similar manner as for the preparation
of 8a,b (1.4 g, 90%) as an orange solid.
HRMS-ESI (m/z): Calcd. for
C
27H20FN3O8S3 (M+H)+: 630.0397; Found:
630.0498. Compound 14c (32.5%), mp 181–183 °C. 1H NMR (500 MHz,
DMSO-d6) d 9.41 (1H, s, ANH), 8.58 (1H, s, ANH), 8.36 (1H, d, J = 2.6 Hz, Ar-
H), 8.03 (3H, m, Ar-H), 7.87 (1H, s, @CH), 7.77 (1H, dd, J = 8.8, 2.6 Hz, Ar-H),
A solution of 13 (530 mg, 1 mmol), isocyanates (2 mmol) and Et3N (0.5 mL,
Please cite this article in press as: Wang, C.; et al. Bioorg. Med. Chem. Lett. (2016), http://dx.doi.org/10.1016/j.bmcl.2016.03.012

C. Wang et al. / Bioorg. Med. Chem. Lett. xxx (2016) xxx–xxx
5
7.44 (2H, m, Ar-H), 7.29 (2H d, J = 8.8 Hz, Ar-H), 7.06 (1H, t, J = 9.0 Hz, Ar-H),
4.56 (2H, t, J = 6.5 Hz, AONO2CH2), 2.71 (2H, t, J = 7.0 Hz, ACOCH2), 2.03–1.98
(2H, m, ACH2A). MS-ESI (m/z): 648.0 (M+H)+. Compound 14d (34.5%), mp 170–
172 °C. 1H NMR (500 MHz, DMSO-d6) d 9.24 (1H, s, ANH), 9.18 (1H, s, ANH),
8.37 (1H, d, J = 2.7 Hz, Ar-H), 8.05–8.01 (3H, m, Ar-H), 7.87 (1H, s, @CH), 7.82
(1H, dd, J = 8.8, 2.7 Hz, Ar-H), 7.63 (1H, d, J = 8.9 Hz, Ar-H), 7.53 (1H, t,
J = 8.0 Hz, Ar-H), 7.45–7.42 (2H, m, Ar-H), 7.34 (1H, d, J = 7.7 Hz, Ar-H), 7.30
(1H, d, J = 8.8 Hz, Ar-H), 4.56 (2H, t, J = 6.5 Hz, AONO2CH2), 2.71 (2H, t,
J = 7.0 Hz, ACOCH2), 2.03–1.98 (2H, m, ACH2A). MS-ESI (m/z): 680.0 (M+H)+.
Compound 14e (31.5%), mp 168–170 °C. 1H NMR (500 MHz, DMSO-d6) d 9.23
(1H, s, ANH), 9.06 (1H, s, ANH), 8.37 (1H, d, J = 2.7 Hz, Ar-H), 8.04 (2H, d,
J = 8.7 Hz, Ar-H), 7.87 (1H, s, @CH), 7.79 (1H, dd, J = 8.8, 2.7 Hz, Ar-H), 7.72 (1H,
s, Ar-H), 7.46–7.42 (2H, m, Ar-H), 7.28–7.32 (3H, m, Ar-H), 7.05–7.02 (1H, m,
Ar-H), 4.56 (2H, t, J = 6.5 Hz, AONO2CH2), 2.71 (2H, t, J = 7.0 Hz, ACOCH2), 2.03–
1.98 (2H, m, ACH2A). MS-ESI (m/z): 646.0 (M+H)+. Compound 14f (31.5%), mp
178–180 °C. 1H NMR (500 MHz, DMSO-d6) d 9.08 (1H, s, ANH), 8.70 (1H, s,
ANH), 8.37 (1H, d, J = 2.7 Hz, Ar-H), 8.05–8.02 (2H, m, Ar-H), 7.87 (1H, s, @CH),
7.77 (1H, dd, J = 8.8, 2.7 Hz, Ar-H), 7.46–7.42 (2H, m, Ar-H), 7.33 (1H, s, Ar-H),
7.28 (1H, d, J = 8.8 Hz, Ar-H), 7.24 (1H, d, J = 7.7 Hz, Ar-H), 7.17 (1H, t, J = 7.8 Hz,
Ar-H), 6.81 (1H, d, J = 7.4 Hz, Ar-H), 4.56 (2H, t, J = 6.5 Hz, AONO2CH2), 2.70
(2H, t, J = 7.0 Hz, ACOCH2), 2.28 (3H, s, ACH3), 2.04–1.97 (2H, m, ACH2A). MS-
ESI (m/z): 626.1 (M+H)+.
Please cite this article in press as: Wang, C.; et al. Bioorg. Med. Chem. Lett. (2016), http://dx.doi.org/10.1016/j.bmcl.2016.03.012