Synthesis and antiproliferative activity of pyrrolo[2,3-b]pyridine derivatives bearing the 1,8-naphthyridin-2-one moiety

Article abstract of DOI:10.1016/j.ejmech.2017.11.034

A series of pyrrolo[2,3-b]pyridine derivatives bearing the 1,8-naphthyridin-2-one moiety were synthesized, and evaluated for their antiproliferative activity against four cancer cell lines (HT-29, A549, H460, and U87MG) and six tyrosine kinases (c-Met, Flt-3, PDGFR-β VEGFR-2, EGFR, and c-Kit) inhibitory activities in vitro. Most compounds showed moderate to excellent potency, with the most promising analogue 32 showing Flt-3/c-Met IC₅₀ value of 1.16/1.92 nM. Structure-activity relationship studies indicated that the hydrogen atom served as R₁ group was benefited to the potency, and mono-electron-withdrawing groups (mono-EWGs) on the phenyl ring (such as R₃ = 4-F) showed a higher preference for antiproliferative activity.

Full text of DOI:10.1016/j.ejmech.2017.11.034

Accepted Manuscript
Synthesis and antiproliferative activity of pyrrolo[2,3-b]pyridine derivatives bearing the
1,8-naphthyridin-2-one moiety
Qidong Tang, Yongli Duan, Linxiao Wang, Min Wang, Yiqiang O'Yang, Caolin Wang,
Han Mei, Sheng Tang, Yinhua Xiong, Pengwu Zheng, Ping Gong, Wufu Zhu
PII:
S0223-5234(17)30937-6
10.1016/j.ejmech.2017.11.034
EJMECH 9909
DOI:
Reference:
To appear in: European Journal of Medicinal Chemistry
Received Date: 8 August 2017
Revised Date: 25 October 2017
Accepted Date: 15 November 2017
Please cite this article as: Q. Tang, Y. Duan, L. Wang, M. Wang, Y. O'Yang, C. Wang, H. Mei, S. Tang,
Y. Xiong, P. Zheng, P. Gong, W. Zhu, Synthesis and antiproliferative activity of pyrrolo[2,3-b]pyridine
derivatives bearing the 1,8-naphthyridin-2-one moiety, European Journal of Medicinal Chemistry (2017),
doi: 10.1016/j.ejmech.2017.11.034.
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ACCEPTED MANUSCRIPT
Graphical abstract
A series of pyrrolo[2,3-b]pyridine derivatives bearing 1,8-naphthyridin-2-one moiety (23–54)
were designed, synthesized and evaluated for their activity against four cancer cell lines and six
tyrosine kinases. The most promising compound 32 showed excellent activity in vitro.

ACCEPTED MANUSCRIPT
Synthesis and antiproliferative activity of pyrrolo[2,3-b]pyridine derivatives bearing the
1,8-naphthyridin-2-one moiety
Qidong Tang a,b, ,†, Yongli Duan a,†, Linxiao Wang a, Min Wang a, Yiqiang O’Yanga, Caolin Wanga, Han Mei
a, Sheng Tang a, Yinhua Xiong a, Pengwu Zheng a, Ping Gong b, Wufu Zhu a,*
a Jiangxi Provincial Key Laboratory of Drug Design and Evaluation, School of Pharmacy, Jiangxi Science
& Technology Normal University, Nanchang 330013, PR China
b Key Laboratory of Structure-Based Drug Design and Discovery of Ministry of Education, School of
Pharmaceutical Engineering, Shenyang Pharmaceutical University, Shenyang 110016, PR China
Abstract
A series of pyrrolo[2,3-b]pyridine derivatives bearing the 1,8-naphthyridin-2-one moiety
were synthesized, and evaluated for their antiproliferative activity against four cancer cell
lines (HT-29, A549, H460, and U87MG) and six tyrosine kinases (c-Met, Flt-3, PDGFR-β,
VEGFR-2, EGFR, and c-Kit) inhibitory activities in vitro. Most compounds showed moderate
to excellent potency, with the most promising analogue 32 showing Flt-3/c-Met IC50 value of
1.16/1.92 nM. Structure-activity relationship studies indicated that the hydrogen atom served
as R1 group was benefited to the potency, and mono-electron-withdrawing groups
(mono-EWGs) on the phenyl ring (such as R3 = 4-F) showed a higher preference for
antiproliferative activity.
Keywords:
Synthesis;
pyrrolo[2,3-b]pyridine
derivatives;
1,8-naphthyridin-2-one;
antiproliferative activity; c-Met; Flt-3
1. Introduction
Cancer is the second leading cause of death globally, and was responsible for 8.8 million
deaths in 2015. Globally, nearly 1 in 6 deaths is due to cancer [1]. Despite the efforts to
discover and develop small molecule anticancer drugs in the last decade [2–5], development
of new antitumor agents with improved safety, efficiency, and tumor selectivity remains
desirable.
c-Met inhibitors are a class of small molecules that inhibit the enzymatic activity of the
Corresponding authors. Tel./fax: +86 791 83802393.
E-mail addresses: tangqidongcn@126.com (Q. Tang), zhuwufu-1122@163.com (WF. Zhu).
† These authors contribute equally to this work.
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ACCEPTED MANUSCRIPT
c-Met tyrosine kinase. Recently, a number of c-Met inhibitors with excellent antitumor
activity have been reported. Cabozantinib (1) is a small molecule that inhibits the activity of
multiple tyrosine kinases, including RET, MET, and VEGFR-2, was approved on November
2012 by the U.S. FDA for the treatment of patients with progressive metastatic medullary
thyroid cancer (MTC) [6]. Recently, many derivatives of Cabozantinib were reported, such as
Foretinib (2), BMS777607 (3), MGCD-265 (4), JM800476q-2 (5), BMS-1 (6) listed in Fig. 1
[7-10]. Many structure types of these derivatives were included, such as substitutedquinoline,
thieno[2,3-b]pyridine, 2-amino-3-chloropyridine, and pyrrolo[2,3-b]pyridine series [11-17].
However, the main modification of these different series of derivatives was focused on the
5-atom linker, which has two obvious structural characteristics. One is the ‘5 atoms
regulation’, which means six chemical bonds distance existing between moiety A and moiety
B; the other is the linker containing hydrogen, oxygen, and nitrogen atoms which could form
hydrogen-bond donor or acceptor [18-19].
(Figure 1. should listed here)
In our previous study, we introduced 1,4-dihydrocinnoline and 1,2,3-triazole fragments
into the 5-atom linker based on the “5 atoms regulation”/“hydrogen-bond donor or acceptor”,
and the resulting derivatives 7 and 8 (Fig. 2) showed excellent potency [20-21].
1,8-naphthyridin-2-one fragment was widely used as a building block in the design of
anticancer agents. For example, compounds 9 and 10 (Fig. 2) displayed a multitude of
biological activities [22-23]. In this work, 1,8-naphthyridin-2-one was introduced to the
5-atom linker, because the carbonyl oxygen and two nitrogen atoms in 1,8-naphthyridin-2-one
have
high
ability
to
form
hydrogen-bonding
interactions
with
c-Met.
4-(2-substitutedphenoxy)-1-substituted-1H-pyrrolo[2,3-b]pyridine was used as the moiety A.
Substituted phenyl ring was reserved as the moiety B. Small substituents R1, R2, and R3 were
introduced to investigate their effects on activity of the target compounds. Accordingly, we
designed
a
novel series of pyrrolo[2,3-b]pyridine derivatives bearing the
1,8-naphthyridin-2-one moiety (Fig. 3).
(Figure 2. should listed here)
(Figure 3. should listed here)
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2. Chemistry
2.1. Synthesis of 3-substituted-4-((1-substituted-1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)aniline
The
synthesis
of
the
key
intermediates
14a–d
of
3-substituted-4-((1-substituted-1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)aniline
was
achieved from the commercially available 4-chloro-1H-pyrrolo[2,3-b]pyridine or
4-chloro-1-methyl-1H-pyrrolo[2,3-b]pyridine as shown in Scheme 1, which has been
illustrated in detail in our previous study [21].
(Scheme 1. should be listed here)
2.2.
pyrrolo[2,3-b]pyridine derivatives
The target compounds 23–54 were prepared as illustrated in Scheme 2. Condensation of
Synthesis
of
the
target
compounds
of
1,8-naphthyridin-2-one-based
substituted aniline 16a–h with 2-chloronicotinic acid 15 in AcOH at 100 °C resulted in high
yield of intermediates 17a–h as white solids. 17a–h were reduced by LiAlH4 in THF to afford
intermediates 18a–h as white solids, which were oxidized by pyridinium dichromate to get
intermediates 19a–h. Acylation of the 19a–h with dimethyl malonate in the presence of
piperidine
in
refluxing
ethanol
(EtOH)
yielded
ethyl
2-oxo-1-substituted
phenyl-1,2-dihydro-1,8-naphthyridine-3-carboxylates 20a–h. Simple procedures such as
hydrolysis and acyl chlorination were used to convert ethyl 20a–h to the corresponding acyl
chloride 22a–h; the reactions proceeded with K2CO3 and thionyl chloride, respectively.
Reaction of anilines 14a–d with acyl chloride 22a–h promoted by DIPEA in dichloromethane
at room temperature yielded the target compounds 23–54 [24].
(Scheme 2. should be listed here)
3. Results and Discussion
3.1. In vitro cytotoxic activities and SAR
The cytotoxic activities of the target compounds 23–54 have been evaluated in HT-29
(human colon cancer) and A549 (human lung adenocarcinoma) cell lines using the MTT assay
[24-26]. Some potent compounds were further evaluated against the H460 (human lung
cancer) and U87MG (human glioblastoma) cell lines. Foretinib is structural optimization of
3

ACCEPTED MANUSCRIPT
the marketed drug cabozantinib. Comparing with other small molecule c-Met kinase
inhibitors reported, foretinib exhibited excellent antiproliferative activity. In our study,
foretinib was used as the positive control, and the results expressed as half-maximal inhibitory
concentration (IC50) values and are presented in Table 1. The values are the average of three
independent experiments.
All the target compounds showed moderate to excellent cytotoxic activity against the
different cancer cells with potencies in the single-digit µM range. Ten of these compounds
were more potent than foretinib against one or more cell lines, which suggest that
1,8-naphthyridin-2-one is a useful framework in the designing of antitumor agents (Table 1).
The IC50 values of the most promising compound 32 were 0.036 µM, 0.062 µM, and 0.087
µM against HT29, A549, and H460 cell lines, respectively; these values indicated that this
compound was 7.2, 5.2, and 3.2 times more active than foretinib (IC50 values: 0.26 µM, 0.32
µM, and 0.28 µM, respectively).
According to the data shown in Table 1, the cell lines data revealed a preference for
activity when R1 group was hydrogen atom. For example, the activity of compound 23 (HT29
IC50 = 0.29 µM; R1 = H, R2 = H, R3 = H) was more potent than compound 39 (HT29 IC50 =
0.62 µM; R1 = CH3, R2 = H, R3 = H), and the same trend was observed in compounds 24/40,
31/47, 32/48, and so on. At the same time, the data showed a preference for activity when the
R2 group was fluorine atom. For example, the IC50 value of compound 31, 32, 47, and 48
were lower than that of 23, 24, 39, and 40, respectively, against HT29 cells.
Further studies were performed to examine the effect of different substituents on the
phenyl ring (moiety B) on potency. The stronger mono-electron-withdrawing groups
(mono-EWGs) introduced to the phenyl ring increased the cytotoxic activity to a higher extent.
For example, compound 31, with no substituent on the phenyl ring, showed a HT29 IC50
value 0.16 µM. Introduction of stronger mono-EDGs to R3 (32, R3 = 4-F, IC50 = 0.036 µM,
increased 4.4-fold) increased the inhibitory efficacy greater than that of weaker mono-EDGs
(33, R3 = 4-Cl, IC50 = 0.082 µM, increased 2.0-fold; 34, R3 = 4-Br, IC50 = 0.12 µM, increased
1.3-fold). However, incorporation of mono-electron-donating groups (mono-EDGs) and
double electron-withdrawing groups (double-EWGs) could decrease the potency of the
compounds. Incorporation of mono-EDGs decreased the cytotoxic activity. The inhibitory
4

ACCEPTED MANUSCRIPT
efficacy of 51 (R3 = 4-OCH3, IC50 = 1.29 µM) and 52 (R3 = 3-Cl-4-F, IC50 = 1.46 µM) are 2.5
times and 2.9 times lower than 47 (R3 = H, IC50 = 0.51 µM), respectively. Therefore, this
could be demonstrated that mono-EWGs (such as R3 = 4-F) had a positive effect on the
cytotoxic activity, especially for the stronger mono-EWGs.
(Table 1. should be listed here)
3.2. In vitro enzymatic assays
The c-Met enzymatic assays of eight pyrrolo[2,3-b]pyridine derivatives were evaluated
using homogeneous time-resolved fluorescence (HTRF) assay [27-29]. The results suggested
that the inhibition of c-Met may be one mechanism of the antitumor effect of these derivatives
(Table 2). Compound 32 showed the most potent activity with an IC50 value of 1.92 nM,
which was comparable to that of the positive control foretinib (IC50 = 1.56 nM), and this
compound should be studied further.
(Table 2. should be listed here)
3.3. Enzymatic selectivity assays
As shown in Table 3, compound 32 was chosen for further evaluation of the selectivity
on c-Met over other tyrosine kinases. Compared with its high potency against c-Met (IC50 =
1.92 nM), 32 also exhibited high inhibitory effects against Flt-3 (IC50 = 1.16 nM) and
PDGFR-β (IC50 = 1.81 nM). While, compound 32 showed inhibitory effects against
VEGFR-2, EGFR, and c-Kit, although the potency was 79.3-, 329.6-, and 356.5-fold lower
than that of c-Met. These data suggested that compound 32 is a promising multitarget kinase
inhibitor.
(Table 3. should be listed here)
4. Binding model analysis
To further elucidate the binding mode of these pyrrolo[2,3-b]pyridine derivatives,
docking analysis was performed. The docking simulation was conducted using
SURFLEX-DOCK module of SYBYL 8.1 package version. The co-crystal structure of
foretinib (GSK1363089) with c-Met kinase were obtained from RCSB Protein Data Bank.
The binding model was exemplified by the interaction of compound 32 with c-Met. As shown
in Fig. 4, the hydrogen atom connected to nitrogen atom of pyrrolidine and the nitrogen atom
5

ACCEPTED MANUSCRIPT
of the pyridine ring in 32 formed two hydrogen bonds with MET1160. In the 5-atom linker,
the oxygen atom of the amide and 1,8-naphthyridin-2-one formed two hydrogen bonds with
LYS1110. Therefore, compound 32 formed four hydrogen-bonding interactions with c-Met.
5. Conclusions
In summary,
a
series of pyrrolo[2,3-b]pyridine derivatives bearing the
1,8-naphthyridin-2-one moiety were designed and synthesized. Four human cancer cell lines
(HT29, A549, H460, and U87MG) and six tyrosine kinases were used to evaluate the potency
of the synthesized compounds. Compared with foretinib, ten of the derivatives were more
potent against one or more cell lines. With a Flt-3/c-Met IC50 value of 1.16/1.92 nM,
compound 32 (a multitarget tyrosine kinase inhibitor) showed the strongest cytotoxic
activities against HT-29, A549, and H460 cell lines, which was 7.2, 5.2, and 3.2 times more
active than foretinib against these three cell lines, respectively. Analysis of SARs indicated
that the hydrogen atom served as R1 group was benefited to the potency, and mono-EWGs on
the phenyl ring (such as R3 = 4-F) showed a higher preference for antiproliferative activity.
6. Experimental
6.1. Chemistry
Unless otherwise noted, all materials were obtained from commercial suppliers and were
used without further purification. Reactions’ time and purity of the products were monitored
by TLC on FLUKA silica gel aluminum cards (0.2 mm thickness) with fluorescent indicator
254 nm. Column chromatography was run on silica gel (200–300 mesh) from Qingdao Ocean
Chemicals (Qingdao, Shandong, China). All melting points were obtained on a Büchi Melting
Point B-540 apparatus (Büchi Labortechnik, Flawil, Switzerland) and were uncorrected. Mass
spectra (MS) were taken in ESI mode on Agilent 1100 LC-MS (Agilent, Palo Alto, CA, USA).
13
1H NMR and C NMR spectra were recorded on Bruker ARX-400, 400MHz spectrometers
(Bruker Bioscience, Billerica, MA, USA) with TMS as an internal standard. Elemental
analysis was determined on a Carlo-Erba 1106 Elemental analysis instrument (Carlo Erba,
Milan, Italy) [29].
6.2. General
procedure
for
3-substituted-4-((1-substituted-1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)aniline (14a–d)
6

ACCEPTED MANUSCRIPT
The preparation of the key intermidiates 14a–d has been illustrated in detail in our
previous work [21], and so the synthesis method would not be listed here.
6.2.1. 4-((1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)aniline (14a)
1
Light yellow solid; Yield: 55%; M.p.: 182–185°C; H NMR (400 MHz, DMSO-d6) δ
11.61 (s, 1H), 8.01 (d, J = 5.3 Hz, 1H), 7.30 (d, J = 2.3 Hz, 1H), 6.88 (d, J = 8.5 Hz, 2H), 6.63
(d, J = 8.5 Hz, 2H), 6.28 (d, J = 5.4 Hz, 1H), 6.21 (s, 1H), 5.08 (s, 2H); MS (ESI) m/z(%):
226.5 [M+H]+.
6.2.2. 3-fluoro-4-((1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)aniline (14b)
1
Light yellow solid; Yield: 49%; M.p.: 184–188°C; H NMR (400 MHz, DMSO-d6) δ
11.67 (s, 1H), 8.03 (d, J = 5.3 Hz, 1H), 7.33 (s, 1H), 7.02 (t, J = 9.0 Hz, 1H), 6.52 (d, J = 13.3
Hz, 1H), 6.44 (d, J = 8.6 Hz, 1H), 6.29 (d, J = 5.5 Hz, 1H), 6.24 (s, 1H), 5.42 (s, 2H); MS
(ESI) m/z(%): 244.2 [M+H]+.
6.2.3. 4-((1-methyl-1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)aniline (14c)
1
Light yellow solid; Yield: 53%; M.p.: 188–191°C; H NMR (400 MHz, DMSO-d6) δ
8.01 (d, J = 5.3 Hz, 1H), 7.31 (d, J = 2.5 Hz, 1H), 6.87 (d, J = 8.6 Hz, 2H), 6.62 (d, J = 8.6 Hz,
2H), 6.26 (d, J = 5.3 Hz, 1H), 6.23 (m, 1H), 5.10 (s, 2H), 3.96 (s, 3H); MS (ESI) m/z(%):
240.8 [M+H]+.
6.2.4. 3-fluoro-4-((1-methyl-1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)aniline (14d)
Light yellow solid; Yield: 56%; M.p.: 192–195°C; 1H NMR (DMSO-d6) 8.02 (m, 1H),
7.32 (s, 1H), 7.01 (t, J = 9.0, 1H), 6.51 (dd, J = 13.2, 1H), 6.43 (dd, J = 8.6, 1H), 6.28 (d, J =
5.4 Hz, 1H), 6.24 (m, 1H), 5.42 (s, 2H), 4.09 (s, 3H); MS (ESI) m/z(%): 258.7 [M+H]+.
6.3. General procedure for the preparation of compounds 23–54
To the mixture of an appropriately substituted phenylamine 16a–h (0.054 mol) and
glacial acetic acid (100 mL), 2-chloronicotinic acid 15 (0.032 mol) was added at room
temperature. Upon the completion of addition, the reaction mixture was stirred at 100 °C for
3–6 h and monitored by thin-layer chromatography (TLC). The reaction mixture was cooled
to room temperature and basified with potassium hydroxide to pH 12, and filtered. The filtrate
was acidified with hydrochloric acid to pH 3, and stirred for 0.5 h. The precipitated was
collected
by
filtration
and
dried
to
give
the
corresponding
2-(substitutedphenylamino)nicotinic acid 17a–h as white solids.
7

ACCEPTED MANUSCRIPT
Lithium aluminum hydride (LiAlH4, 0.119 mol) was add to tetrahydrofuran (THF, 40 mL)
under an atmosphere of nitrogen at
0
°C, and stirred for 10 min.
2-(substitutedphenylamino)nicotinic acid 17a–h (0.027 mol) dissolved in THF was added to
the reaction mixture, and stirred for 3.5 h at room temperature. Ethyl acetate was added to the
mixture, and basified with potassium hydroxide to pH 12, and filtered. The filtrate was
concentrated in a vacuum and the residue was stirred in petroleum ether. The precipitated was
collected
by
filtration
and
dried
to
give
the
corresponding
(2-(substitutedphenylamino)pyridin-3-yl)methanol 18a–h as white solids.
(2-(substitutedphenylamino)pyridin-3-yl)methanol 18a–h (0.018 mol) and pyridinium
dichromate (0.031 mol) were added to CH2Cl2 (75 mL) at room temperature. The reaction
mixture was stirred at room temperature for 5–7 h and monitored by thin-layer
chromatography (TLC). The solvent was concentrated in vacuum and the residue was stirred
in water (50 mL) for 0.5 h. The precipitated was collected by filtration and dried to give the
corresponding 2-(substitutedphenylamino)nicotinaldehyde (19a–h) as light yellow solids.
To the mixture of an appropriately 2-(substitutedphenylamino)nicotinaldehyde 19a–h
(0.011 mol) and EtOH (75 mL), diethyl malonate (0.022 mol) and piperidine (0.009 mol) was
added at room temperature. Upon completion of the addition, the reaction mixture was heated
at reflux for 30–35 h. The solvent was concentrated in vacuum and the residue was stirred in
H2O (70 mL) for 0.5 h at room temperature. The precipitated was collected by filtration and
dried
to
give
the
corresponding
2-oxo-1-substitutedphenyl-1,2-dihydro-1,8-naphthyridine-3-carboxylate (20a–h) as light
yellow solids.
To
the
mixture
of
dioxane
(40
mL)
and
water
(40
mL),
2-oxo-1-substitutedphenyl-1,2-dihydro-1,8-naphthyridine-3-carboxylate 20a–h (8 mmol) and
potassium carbonate (30 mmol) was added at room temperature. The reaction mixture was
heated at 80 °C for 4–5 h. Water (150 mL) was added to the mixture, and acidified with
hydrochloric acid to pH 6 at 0 °C. The precipitated was collected by filtration and dried to
give
the
corresponding
ethyl
2-oxo-1-substitutedphenyl-1,2-dihydro-1,8-naphthyridine-3-carboxylic acid 21a–h as light
yellow solids.
8

ACCEPTED MANUSCRIPT
An
appropriate
ethyl
2-oxo-1-substitutedphenyl-1,2-dihydro-1,8-naphthyridine-3-carboxylic acid 21a–h (2 mmol)
was added to thionyl chloride (10 mL) and refluxed for 6 h. The reaction mixture was
evaporated
to
yield
the
corresponding
2-oxo-1-substitutedphenyl-1,2-dihydro-1,8-naphthyridine-3-carbonyl chlorides 22a–h, which
were used for the next step immediately without further purification.
To a solution of an appropriate aniline 14a–d (1 mmol) and N,N-diisopropylethylamine
(3 mmol) in dichloromethane (30 mL), an appropriate carbonyl chloride 22a–h in the
previous step dissolved in dried dichloromethane (20 mL) was added drop-wise in an ice bath.
Upon completion of the addition, the reaction was removed to room temperature for 5–8 h
and monitored by TLC. The mixture was washed with 10% K2CO3 (20 mL × 3) followed by
brine (20 mL × 1), and the organic phase was separated, dried, and concentrated in vacuum.
The crude product was purified by chromatography on silica gel using MeOH/CH2Cl2 to
afford the target compounds 23–54 as white solids.
6.3.1. N-(4-((1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)phenyl)-2-oxo-1-phenyl-1,2-dihydro-1,8-na
phthyridine-3-carboxamide (23)
1
Yield: 56%; M.p.: 329.9–330.8 °C; H NMR (400 MHz, DMSO-d6) δ 11.91 (s, 1H),
11.85 (s, 1H), 9.16 (s, 1H), 8.59 (d, J = 6.8 Hz, 2H), 8.09 - 8.00 (m, 2H), 7.56 (d, J = 7.1 Hz,
3H), 7.53 - 7.43 (m, 3H), 7.39 (t, J = 8.6 Hz, 4H), 6.41 (d, J = 5.5 Hz, 1H), 6.25 (s, 1H); 13C
NMR (100 MHz, DMSO-d6) δ 160.33, 156.86, 152.16, 150.33, 143.35, 143.20, 138.87,
136.38, 135.97, 128.68 (2C), 128.47 (2C), 127.82, 124.72, 124.59, 123.30 (2C), 122.00,
119.28 (2C), 116.13, 114.12, 113.63, 109.17, 108.17, 100.46, 96.39; ESI-MS m/z: 473.15;
Anal. calcd. for C28H19N5O3 (%): C, 61.78; H, 4.04; N, 14.79; Found (%): C, 61.79; H, 4.05;
N, 14.80.
6.3.2. N-(4-((1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)phenyl)-1-(4-fluorophenyl)-2-oxo-1,2-dihyd
ro-1,8-naphthyridine-3-carboxamide (24)
Yield: 71%; M.p.: 253.3-254.1°C; 1H NMR (400 MHz, DMSO-d6) δ 11.89 (s, 1H), 11.78
(s, 1H), 9.16 (s, 1H), 8.61 (s, 2H), 8.04 (d, J = 15.3 Hz, 2H), 7.56 (s, 1H), 7.43 (s, 3H), 7.39 (s,
5H), 6.39 (s, 1H), 6.23 (s, 1H); ESI-MS m/z: 492.14; 13C NMR (100 MHz, DMSO-d6) δ
163.46, 161.02, 157.74, 153.01, 151.32, 144.68, 144.15, 139.85, 135.47, 133.54, 131.67,
9

ACCEPTED MANUSCRIPT
131.57, 131.48, 125.22, 123.19 (2C), 121.97 (2C), 121.44, 120.32 (2C), 116.67, 116.45,
115.21 (2C), 102.92, 102.62, 97.60; Anal. calcd. for C28H18FN5O3: (%): C, 68.43; H, 3.69; N,
14.25; Found (%): C, 68.42; H, 3.70; N, 14.35.
6.3.3. N-(4-((1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)phenyl)-1-(4-chlorophenyl)-2-oxo-1,2-dihyd
ro-1,8-naphthyridine-3-carboxamide (25)
1
Yield: 63%; M.p.: 233.3-234.1 °C; H NMR (400 MHz, DMSO-d6) δ 12.69 - 12.69 (m,
1H), 11.66 (s, 2H), 9.08 (s, 1H), 8.52 (d, J = 8.0 Hz, 2H), 8.00 (d, J = 5.4 Hz, 1H), 7.77 (s,
1H), 7.74 (s, 1H), 7.57 (d, J = 8.4 Hz, 2H), 7.39 (t, J = 9.4 Hz, 3H), 7.27 (s, 1H), 7.13 (d, J =
8.7 Hz, 2H), 6.35 (d, J = 5.4 Hz, 1H), 6.12 (s, 1H); 13C NMR (100 MHz, DMSO-d6) δ 160.78,
157.62, 152.95, 151.61, 151.15, 144.65, 144.14, 139.83, 136.31 (2C), 135.39, 131.67, 133.51,
131.48, 129.72 (2C), 125.13, 123.25, 121.92 (2C), 121.37, 120.32 (2C), 116.54, 115.20,
110.62, 102.68, 97.54; ESI-MS m/z: 507.93; Anal. Calcd. for C28H18ClN5O3(%): C, 66.21; H,
3.57; N, 13.79; Found (%): C, 66.22; H, 3.67; N, 13.78.
6.3.4. N-(4-((1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)phenyl)-1-(4-bromophenyl)-2-oxo-1,2-dihyd
ro-1,8-naphthyridine-3-carboxamide (26)
Yield: 57%; M.p.: 264–265 °C; 1H NMR (400 MHz, DMSO-d6) δ 12.05 (s, 1H), 11.86 (s,
1H), 9.15 (s, 1H), 8.60 (d, J = 6.6 Hz, 2H), 8.13 (d, J = 5.6 Hz, 1H), 8.05 (d, J = 12.8 Hz, 1H),
7.78 (d, J = 8.3 Hz, 2H), 7.58 (d, J = 7.9 Hz, 1H), 7.50 - 7.35 (m, 6H), 6.48 (d, J = 5.4 Hz,
1H), 6.31 (s, 1H); ESI-MS m/z: 552.39; Anal. calcd. for C28H18BrN5O3(%): C, 60.88; H, 3.28;
N, 12.68; Found (%): C, 60.89; H, 3.38; N, 12.67.
6.3.5. N-(4-((1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)phenyl)-1-(4-methoxyphenyl)-2-oxo-1,2-dih
ydro-1,8-naphthyridine-3-carboxamide (27)
1
Yield: 59%; M.p.: 299.5–301.2°C; H NMR (400 MHz, DMSO-d6) δ 11.95 (s, 1H),
11.81 (s, 1H), 9.14 (s, 1H), 8.59 (t, J = 5.8 Hz, 2H), 8.08 - 8.00 (m, 2H), 7.56 (d, J = 8.7 Hz,
1H), 7.48 - 7.44 (m, 1H), 7.38 (d, J = 6.5 Hz, 2H), 7.28 (d, J = 8.7 Hz, 2H), 7.10 (d, J = 8.7
Hz, 2H), 6.39 (d, J = 5.4 Hz, 1H), 6.24 (s, 1H), 3.84 (s, 1H); ESI-MS m/z: 473.15; Anal. calcd.
for C29H21N5O4 (%): C, 69.18; H, 4.20; N, 13.91; Found (%): C, 69.19; H, 4.21; N, 13.92.
6.3.6. N-(4-((1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)phenyl)-1-(3-chloro-4-fluorophenyl)-2-oxo-
1,2-dihydro-1,8-naphthyridine-3-carboxamide (28)
Yield: 59%; M.p.: 234.8–235.6 °C; 1H NMR (400 MHz, DMSO-d6) δ 11.81 (s, 2H), 9.17
10

ACCEPTED MANUSCRIPT
(s, 1H), 8.61 (d, J = 8.9 Hz, 2H), 8.09 - 8.01 (m, 2H), 7.80 (d, J = 4.6 Hz, 1H), 7.65 (t, J = 8.9
Hz, 1H), 7.58 (d, J = 8.8 Hz, 1H), 7.52 - 7.46 (m, 2H), 7.43 - 7.32 (m, 2H), 6.40 (d, J = 5.5 Hz,
1H), 6.25 (s, 1H); ESI-MS m/z: 525.92; Anal. calcd. for C28H17FClN5O3(%): C, 63.95 H, 3.26;
N, 13.32; Found (%): C, 63.94; H, 3.27; N, 13.31.
6.3.7. N-(4-((1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)phenyl)-1-(4-bromo-2-fluorophenyl)-2-oxo-
1,2-dihydro-1,8-naphthyridine-3-carboxamide (29)
Yield: 55%; M.p.: 275–277 °C; 1H NMR (400 MHz, DMSO-d6) δ 11.71 (s, 1H), 11.55 (s,
1H), 9.12 (s, 1H), 8.56 (d, J = 5.4 Hz, 2H), 7.98 (dd, J = 20.3, 6.2 Hz, 2H), 7.82 (d, J = 9.6 Hz,
1H), 7.60 (d, J = 8.9 Hz, 1H), 7.54 - 7.41 (m, 4H), 7.36 - 7.26 (m, 2H), 6.33 (d, J = 4.5 Hz,
1H), 6.17 (s, 1H); ESI-MS m/z: 569.04; Anal. calcd. for C28H17BrFN5O3(%): C, 58.96; H,
3.00; N, 12.28; Found (%): C, 58.95; H, 2.96; N, 12.23.
6.3.8. N-(4-((1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)phenyl)-1-(2-chloro-4-(trifluoromethyl)phen
yl)-2-oxo-1,2-dihydro-1,8-naphthyridine-3-carboxamide (30)
1
Yield: 61%; M.p.: 243.3-244.1 °C; H NMR (400 MHz, DMSO-d6) δ 11.73 - 11.45 (m,
2H), 9.10 (s, 1H), 8.54 (d, J = 6.7 Hz, 2H), 8.00 (d, J = 10.4 Hz, 2H), 7.91 (d, J = 8.4 Hz, 1H),
7.79 (dd, J = 23.9, 9.8 Hz, 3H), 7.40 (dd, J = 17.5, 9.9 Hz, 1H), 7.26 (s, 1H), 7.12 (d, J = 8.7
Hz, 2H), 6.35 (d, J = 5.1 Hz, 1H), 6.11 (s, 1H); ESI-MS m/z: 529.95; Anal. calcd. for
C29H17F3ClN5O3(%): C, 60.98; H, 2.98; N, 12.16; Found (%): C, 60.97; H, 2.97; N, 12.18.
6.3.9. N-(4-((1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)-3-fluorophenyl)-2-oxo-1-phenyl-1,2-dihydr
o-1,8-naphthyridine-3-carboxamide (31)
1
Yield: 54%; M.p.: 255.4–256.1 °C; H NMR (400 MHz, DMSO-d6) δ 11.91 (s, 1H),
11.80 (s, 1H), 9.16 (s, 1H), 8.62 - 8.56 (m, 2H), 8.09 - 8.00 (m, 2H), 7.57 (t, J = 7.5 Hz, 3H),
7.52 - 7.43 (m, 2H), 7.42 - 7.35 (m, 4H), 6.39 (d, J = 5.5 Hz, 1H), 6.24 (s, 1H); ESI-MS m/z:
491.14; Anal. calcd. for C28H18FN5O3(%): C 68.43; H, 3.69; N, 14.25; Found (%): C, 68.53;
H, 3.70; N, 14.35.
6.3.10. N-(4-((1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)-3-fluorophenyl)-1-(4-fluorophenyl)-2-oxo-
1,2-dihydro-1,8-naphthyridine-3-carboxamide (32)
Yield: 65%; M.p.: 263.3-264.1 °C; 1H NMR(400 MHz, DMSO-d6) δ11.88 (br, 2H), 9.15
(s, 1H), 8.60 (s, 3H), 8.05 (dd, J = 16.3, 8.7 Hz, 2H), 7.56 (d, J = 8.2 Hz, 1H), 7.46 (s, 3H),
7.42 (s, 1H), 7.38 (s, 2H), 6.39 (d, J = 4.6 Hz, 1H), 6.25 (s, 1H); 13C NMR (100 MHz,
11

ACCEPTED MANUSCRIPT
DMSO-d6) δ 162.99, 162.61, 160.78, 160.55, 157.00, 152.64, 152.35, 151.10, 150.86, 144.19,
143.89, 139.41, 136.45, 132.98, 131.16, 131.08, 124.89, 123.80, 122.50, 119.83, 116.63,
116.17, 115.94, 114.69, 109.41, 108.66, 100.86, 96.70; ESI-MS m/z: 509.15; Anal. calcd. for
C28H17F2N5O3;(%): C, 66.01; H, 3.36; N, 13.75; Found (%): C, 66.11; H, 3.37; N, 13.76.
6.3.11. N-(4-((1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)-3-fluorophenyl)-1-(4-chlorophenyl)-2-oxo-
1,2-dihydro-1,8-naphthyridine-3-carboxamide (33)
1
Yield: 59%; M.p.: 243.3-244.1°C; H NMR(400 MHz, DMSO-d6) δ 11.75 (d, J = 27.1
Hz, 2H), 9.10 (s, 1H), 8.53 (d, J = 5.0 Hz, 2H), 8.02 - 7.93 (m, 2H), 7.58 (d, J = 8.5 Hz, 2H),
7.49 (d, J = 8.8 Hz, 2H), 7.38 (d, J = 8.4 Hz, 2H), 7.31 (d, J = 8.2 Hz, 2H), 6.31 (d, J = 5.3 Hz,
1H), 6.17 (s, 1H); 13C NMR (100 MHz, DMSO-d6) δ 162.97, 161.20, 157.51, 153.14, 151.57,
151.20, 144.70, 144.48, 139.94, 136.93 (2C), 136.27, 133.58, 131.49, 129.77 (2C), 128.23，
125.38, 124.35, 120.39, 117.10, 115.19, 109.87, 109.35, 109.12, 102.00, 101.28, 97.22;
ESI-MS m/z: 525.15; Anal. calcd. for C28H17FClN5O3(%): C, 63.95; H, 3.28; N, 13.32; Found
(%): C, 63.97; H, 3.27; N, 13.31.
6.3.12. N-(4-((1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)-3-fluorophenyl)-1-(4-bromophenyl)-2-oxo-
1,2-dihydro-1,8-naphthyridine-3-carboxamide (34)
1
Yield: 59%; M.p.: 288.4–289.1 °C; H NMR (400 MHz, DMSO-d6) δ 12.05 (s, 1H),
11.86 (s, 1H), 9.15 (s, 1H), 8.60 (d, J = 6.6 Hz, 2H), 8.13 (d, J = 5.6 Hz, 1H), 8.05 (d, J = 12.8
Hz, 1H), 7.78 (d, J = 8.3 Hz, 2H), 7.58 (d, J = 7.9 Hz, 1H), 7.50 - 7.35 (m, 6H), 6.48 (d, J =
5.4 Hz, 1H), 6.31 (s, 1H); ESI-MS m/z: 570.38; Anal. Calcd. for C28H16BrF2N5O3(%): C,
58.96; H, 3.00; N, 12.28; Found (%): C, 58.97; H, 3.01; N, 12.38.
6.3.13. N-(4-((1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)-3-fluorophenyl)-1-(4-methoxyphenyl)-2-ox
o-1,2-dihydro-1,8-naphthyridine-3-carboxamide (35)
1
Yield: 59%; M.p.: 320.5-321.8 °C; H NMR (400 MHz, DMSO-d6) δ 11.80 (s, 1H),
11.78 (s, 1H), 9.16 (s, 1H), 8.60 (d, J = 8.7 Hz, 2H), 8.09 - 8.00 (m, 2H), 7.79 (d, J = 6.7 Hz,
1H), 7.64 (t, J = 8.9 Hz, 1H), 7.57 (d, J = 8.5 Hz, 1H), 7.49 (d, J = 4.8 Hz, 2H), 7.43 - 7.34 (m,
2H), 6.38 (d, J = 5.2 Hz,1H), 6.24 (s,1H); ESI-MS m/z: 521.15; Anal. Calcd. for
C29H20FN5O4(%): C, 66.79; H, 3.83; N, 13.43; Found (%): C, 66.78; H, 3.84; N, 13.53.
6.3.14. N-(4-((1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)-3-fluorophenyl)-1-(3-chloro-4-fluorophenyl
)-2-oxo-1,2-dihydro-1,8-naphthyridine-3-carboxamide (36)
12

ACCEPTED MANUSCRIPT
1
Yield: 55%; M.p.: 267.8–269.5 °C; H NMR (400 MHz, DMSO-d6) δ 11.80 (s, 1H),
11.78 (s, 1H), 9.16 (s, 1H), 8.60 (d, J = 8.7 Hz, 2H), 8.09 - 8.00 (m, 2H), 7.79 (d, J = 6.7 Hz,
1H), 7.64 (t, J = 8.9 Hz, 1H), 7.57 (d, J = 8.5 Hz, 1H), 7.49 (d, J = 4.8 Hz, 2H), 7.43 - 7.34 (m,
2H), 6.38 (d, J = 5.2Hz, 1H), 6.24 (s, 1H); ESI-MS m/z: 543.91; Anal. Calcd. for
C28H16FClN5O3(%): C, 61.83; H, 2.97; N, 12.28; Found (%): C, 61.84; H, 2.98; N, 12.38.
6.3.15. N-(4-((1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)-3-fluorophenyl)-1-(4-bromo-2-fluorophenyl
)-2-oxo-1,2-dihydro-1,8-naphthyridine-3-carboxamide (37)
1
Yield: 54%; M.p.: 262.2–263.9 °C; H NMR (400 MHz, DMSO-d6) δ 11.78 (s, 1H),
11.61 (s, 1H), 9.18 (s, 1H), 8.63 (s, 2H), 8.06 (d, J = 5.3 Hz, 1H), 8.02 (d, J = 13.1 Hz, 1H),
7.88 (d, J = 9.2 Hz, 1H), 7.67 (d, J = 8.7 Hz, 1H), 7.57 (d, J = 8.0 Hz, 2H), 7.51 (s, 1H), 7.41
- 7.37 (m, 2H), 6.39 (s, 1H), 6.23 (s, 1H); 13C NMR (100 MHz, DMSO-d6) δ 162.22, 161.00,
159.27, 157.53, 156.75, 155.27, 153.40, 152.83, 151.51, 150.38, 144.89, 144.66, 140.21,
133.28, 128.94, 125.40, 124.28, 123.21, 120.91, 120.43, 120.21, 117.22, 115.14, 109.93,
109.47, 109.24, 101.42, 97.24; ESI-MS m/z: 588.37; Anal. calcd. for C28H16BrF2N5O3(%): C,
57.16; H, 2.74; N, 11.90; Found (%): C, 57.26; H, 2.75; N, 11.91.
6.3.16. N-(4-((1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)-3-fluorophenyl)-1-(2-chloro-4-(trifluorome
thyl)phenyl)-2-oxo-1,2-dihydro-1,8-naphthyridine-3-carboxamide (38)
1
Yield: 62%; M.p.: 288.3–289.1°C; H NMR (400 MHz, DMSO-d6) δ 11.76 (d, J = 6.1
Hz, 2H), 9.17 (s, 1H), 8.60 (s, 2H), 8.10 - 8.03 (m, 2H), 8.02 - 7.95 (m, 1H), 7.90 (s, 1H),
7.83 (s, 1H), 7.57 (d, J = 8.5 Hz, 1H), 7.48 (s, 1H), 7.36 (s, 2H), 6.38 (d, J = 5.5 Hz, 1H), 6.23
(s, 1H); ESI-MS m/z: 593.09; Anal. calcd. for C29H16F4ClN5O3(%): C, 58.65; H, 2.72; N,
11.78; Found (%): C, 58.64; H, 2.73; N, 11.68.
6.3.17. N-(4-((1-methyl-1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)phenyl)-2-oxo-1-phenyl-1,2-dihyd
ro-1,8-naphthyridine-3-carboxamide (39)
Yield: 59%; M.p.: 258.3–259.1 °C; 1H NMR (400 MHz, DMSO-d6) δ 11.94 (s, 1H), 9.18
(s, 1H), 8.61 (s, 2H), 8.13 (d, J = 5.4 Hz, 1H), 8.05 (d, J = 14.1 Hz, 1H), 7.58 (d, J = 7.3 Hz,
3H), 7.54 - 7.50 (m, 1H), 7.47 (dd, J = 12.8, 5.1 Hz, 2H), 7.45 (d, J = 3.3 Hz, 1H), 7.40 (d, J =
7.4 Hz, 3H), 6.44 (d, J = 5.2 Hz, 1H), 6.26 (d, J = 3.4 Hz, 1H), 3.82 (s, 3H); ESI-MS m/z:
487.16; Anal. calcd. for C29H21N5O3(%): C, 71.45; H, 4.34; N, 14.37; Found (%): C, 71.44; H,
4.43; N, 14.38.
13

ACCEPTED MANUSCRIPT
6.3.18. 1-(4-fluorophenyl)-N-(4-((1-methyl-1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)phenyl)-2-oxo-
1,2-dihydro-1,8-naphthyridine-3-carboxamide (40)
Yield: 61%; M.p.: 298.3–299.1 °C; 1H NMR (400 MHz, DMSO-d6) δ 11.88 (s, 1H), 9.19
(s, 1H), 8.63 (d, J = 9.1 Hz, 2H), 8.19 (d, J = 5.2 Hz, 1H), 8.07 (d, J = 12.9 Hz, 1H), 7.60 (d, J
= 8.6 Hz, 1H), 7.54 - 7.47 (m, 4H), 7.46 (s, 2H), 7.44 - 7.36 (m, 2H), 6.50 (d, J = 5.1 Hz, 1H),
6.29 (d, J = 2.9 Hz, 1H), 3.87 (s, 3H); 13C NMR (100 MHz, DMSO-d6) δ 163.24, 161.40,
161.18, 157.73, 155.39, 153.26, 151.50, 150.66, 144.72, 144.52, 140.03, 133.60, 131.78,
131.70, 129.49, 124.35, 123.14 (2C), 120.45, 117.28, 116.78, 116.55, 115.31 (2C), 110.26,
109.54, 101.72, 96.40, 31.77; ESI-MS m/z: 505.16; Anal. calcd. for C29H20FN5O3(%): C,
68.90; H, 3.99; N, 13.85; Found (%): C, 68.91; H, 3.40; N, 13.86.
6.3.19. N-(4-((1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)-3-fluorophenyl)-1-(4-chlorophenyl)-2-oxo-
1,2-dihydro-1,8-naphthyridine-3-carboxamide (41)
Yield: 57%; M.p.: 273.3–274.1°C; 1H NMR (400 MHz, DMSO-d6) δ 11.67 (s, 1H), 9.08
(s, 1H), 8.54 - 8.50 (d, 2H), 8.05 (d, J = 5.4 Hz, 1H), 7.75 (d, J = 8.9 Hz, 2H), 7.57 (d, J = 8.6
Hz, 2H), 7.39 (d, J = 9.4 Hz, 2H), 7.33 (d, J = 3.4 Hz, 2H), 7.12 (d, J = 8.8 Hz, 2H), 6.40 (d, J
= 5.4 Hz, 1H), 6.12 (d, J = 3.4 Hz, 1H), 3.73 (s, 3H); 13C NMR (100 MHz, DMSO-d6) δ
163.05, 160.79, 157.81, 152.99, 151.15, 150.43, 144.50, 144.17, 139.85, 136.33 (2C), 135.49
(2C), 133.54, 131.50, 129.76 (2C), 129.18, 123.21, 121.93 (2C), 121.39, 120.35 (2C), 115.21,
110.86, 102.83, 96.66, 31.65; ESI-MS m/z: 521.13; Anal. Calcd. for C29H20ClN5O3(%): C,
66.73; H, 3.86; N, 13.42; Found (%): C, 66.74; H, 3.87; N,13.52.
6.3.20. 1-(4-bromophenyl)-N-(4-((1-methyl-1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)phenyl)-2-oxo-
1,2-dihydro-1,8-naphthyridine-3-carboxamide (42)
Yield: 54%; M.p.: 248.4–249.1 °C; 1H NMR (400 MHz, DMSO-d6) δ 11.73 (s, 1H), 9.14
(s, 1H), 8.59 (d, J = 6.0 Hz, 2H), 8.13 (d, J = 5.4 Hz, 1H), 7.82 (d, J = 8.8 Hz, 2H), 7.78 (d, J
= 8.4 Hz, 2H), 7.46 (s, 1H), 7.40 (d, J = 3.2 Hz, 2H), 7.37 (s, 1H), 7.21 (s, 1H), 7.18 (s, 1H),
6.47 (d, J = 5.3 Hz, 1H), 6.19 (d, J = 3.3 Hz, 1H), 3.80 (s, 3H); 13C NMR (100 MHz,
DMSO-d6) δ163.12, 161.45, 157.81, 155.48, 153.33, 153.04, 151.37, 150.75, 144.81, 144.65,
140.13, 136.94, 132.93 (2C), 132.05, 129.58, 124.46 (2C), 123.25, 122.28, 120.61, 117.34,
115.41, 110.34, 109.61, 109.38, 101.81, 96.49, 31.86; ESI-MS m/z: 566.41; Anal. Calcd. for
C29H20BrN5O3(%): C, 61.50; H, 3.53; N, 12.46; Found (%): C, 61.51; H, 3.54; N, 12.47.
14

ACCEPTED MANUSCRIPT
6.3.21. 1-(4-methoxyphenyl)-N-(4-((1-methyl-1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)phenyl)-2-ox
o-1,2-dihydro-1,8-naphthyridine-3-carboxamide (43)
1
Yield: 61%; M.p.: 320.8.4–321.5 °C; H NMR (400 MHz, DMSO-d6) δ 11.83 (s, 1H),
9.13 (s, 1H), 8.58 (t, J = 5.6 Hz, 2H), 8.12 (d, J = 5.3 Hz, 1H), 7.82 (d, J = 8.7 Hz, 2H), 7.48 -
7.37 (m, 2H), 7.27 (d, J = 8.6 Hz, 2H), 7.19 (d, J = 8.6Hz, 2H), 7.10 (d, J = 8.7 Hz, 2H), 6.47
(d, J = 5.2 Hz, 1H), 6.19 (d, J = 3.2 Hz, 1H), 3.84 (s, 3H), 3.80 (s, 3H); 13C NMR (100 MHz,
DMSO-d6) δ 162.37, 159.98, 158.58, 156.79, 152.04, 150.53, 150.33, 149.58, 143.61, 142.97,
138.78 (2C), 134.52, 129.45, 128.83, 128.19, 122.21, 121.00, 120.37, 119.32, 119.21, 114.16
(2C), 113.98, 101.95, 95.68, 54.94, 30.65; ESI-MS m/z: 517.18; Anal. Calcd. for
C28H17N5O3(%): C, 58.96; H, 3.00; N, 12.28; Found (%): C, 58.97; H, 3.02; N, 12.38.
6.3.22. 1-(3-chloro-4-fluorophenyl)-N-(4-((1-methyl-1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)pheny
l)-2-oxo-1,2-dihydro-1,8-naphthyridine-3-carboxamide (44)
Yield: 54%; M.p.: 281.4–283.0 °C; 1H NMR (400 MHz, DMSO-d6) δ 11.70 (s, 1H), 9.16
(s, 1H), 8.61 (d, J = 8.5 Hz, 2H), 8.14 (d, J = 5.4 Hz, 1H), 7.84 (d, J = 8.8 Hz, 2H), 7.82 -
7.79 (m, 1H), 7.64 (d, J = 9.0 Hz, 1H), 7.52 - 7.47 (m, 2H), 7.41 (d, J = 3.4 Hz, 1H), 7.20 (d,
13
J = 8.8 Hz, 2H), 6.48 (d, J = 5.4 Hz, 1H), 6.20 (d, J = 3.4 Hz, 1H), 3.81 (s, 3H); C NMR
(100 MHz, DMSO-d6) δ 163.20, 161.34, 159.05, 157.81, 156.59, 155.47, 153.35, 153.02,
151.41, 150.74, 144.79, 140.16, 134.46, 132.11, 130.86, 129.57, 124.42, 123.16, 120.67,
118.21, 117.99, 117.35, 115.41, 110.36, 109.62, 109.40, 101.80, 96.50, 31.85; ESI-MS m/z:
537.95; Anal. Calcd. for C29H19ClFN5O3(%): C, 64.51; H, 3.51; N, 12.97; Found (%): C,
64.52; H, 3.52; N, 12.98.
6.3.23. 1-(4-bromo-2-fluorophenyl)-N-(4-((1-methyl-1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)pheny
l)-2-oxo-1,2-dihydro-1,8-naphthyridine-3-carboxamide (45)
1
Yield: 60%; M.p.: 321.8–323.4 °C ; H NMR (400 MHz, DMSO-d6) δ 11.44 (s, 1H),
9.11 (s, 1H), 8.55 (d, J = 5.2Hz, 2H), 8.06 (d, J = 5.0 Hz, 1H), 7.81 (d, J = 9.6 Hz, 1H), 7.76
(d, J = 7.2 Hz, 2H), 7.60 (d, J = 8.5Hz, 1H), 7.53 - 7.42 (m, 2H), 7.33 (s, 1H), 7.13 (d, J = 7.4
Hz, 2H), 6.41 (d, J = 5.2 Hz, 1H), 6.12 (s, 1H), 3.73 (s, 3H); 13C NMR (100 MHz, DMSO-d6)
δ 162.34, 160.55, 159.28, 157.74, 156.77, 153.27, 151.33, 150.55, 150.35, 144.67, 140.14,
135.40, 133.30, 129.13, 124.25, 124.11, 123.38, 122.97, 122.88 (2C), 122.02, 121.34 (2C),
120.86, 115.18, 110.84, 102.87, 96.64, 31.62; ESI-MS m/z: 584.2; Anal. calcd. for
15

ACCEPTED MANUSCRIPT
C29H19BrFN5O3(%): C, 59.60; H, 3.28; N, 11.98; Found (%): C, 59.61; H, 3.38; N, 11.99.
6.3.24. 1-(2-chloro-4-(trifluoromethyl)phenyl)-N-(4-((1-methyl-1H-pyrrolo[2,3-b]pyridin-4-yl
)oxy)phenyl)-2-oxo-1,2-dihydro-1,8-naphthyridine-3-carboxamide (46)
Yield: 66%; M.p.: 293.4–292.0 °C; 1H NMR (400 MHz, DMSO-d6) δ 11.58 (s, 1H), 9.10
(s, 1H), 8.53 (s, 2H), 8.08 - 8.00 (m, 2H), 7.91 (d, J = 8.1 Hz, 1H), 7.76 (d, J = 7.4 Hz, 3H),
7.41 (s, 1H), 7.33 (s, 1H), 7.12 (d, J = 8.0 Hz, 2H), 6.40 (s, 1H), 6.12 (s, 1H), 3.72 (s, 3H);
ESI-MS m/z: 607.1; Anal. calcd. for C30H18F4ClN5O3(%): C, 59.27; H, 2.98; N, 11.52; Found
(%): C, 59.37; H, 2.99; N, 11.53.
6.3.25. N-(3-fluoro-4-((1-methyl-1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)phenyl)-2-oxo-1-phenyl-1
,2-dihydro-1,8-naphthyridine-3-carboxamide (47)
Yield: 64%; M.p.:299.4–297.2 °C; 1H NMR (400 MHz, DMSO-d6) δ 12.03 (s, 1H), 9.27
(s, 1H), 8.70 (d, J = 4.8 Hz, 2H), 8.23 (d, J = 5.3 Hz, 1H), 8.13 (s, 1H), 7.67 (d, J = 7.7 Hz,
3H), 7.60 (d, J = 6.7 Hz, 1H), 7.54 (d, J = 3.5 Hz, 1H), 7.49 (d, J = 6.9 Hz, 2H), 6.53 (d, J =
5.4 Hz, 1H), 6.35 (d, J = 3.6 Hz, 1H), 5.85 (s, 3H), 3.91 (s, 3H); ESI-MS m/z: 505.51; Anal.
Calcd. for C29H20BrFN5O3(%): C, 68.90; H, 3.99; N, 13.85; Found(%): C, 68.89; H, 3.97; N,
13.89.
6.3.26. N-(3-fluoro-4-((1-methyl-1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)phenyl)-1-(4-fluoropheny
l)-2-oxo-1,2-dihydro-1,8-naphthyridine-3-carboxamide (48)
1
Yield: 61%; M.p.:309.4–307.2°C; H NMR (400 MHz, DMSO-d6) δ 11.88 (s, 1H), 9.16
(s, 1H), 8.61 (d, J = 2.3 Hz, 1H), 8.59 (d, J = 4.0 Hz, 1H), 8.14 (d, J = 5.4 Hz, 1H), 8.04 (dd, J
= 12.8, 2.1 Hz, 1H), 7.57 (d, J = 8.7 Hz, 1H), 7.50 - 7.34 (m, 7H), 6.45 (d, J = 5.4 Hz, 1H),
6.26 (d, J = 3.4 Hz, 1H), 3.82 (s, 3H); 13C NMR (101 MHz, DMSO-d6) δ 163.49, 163.11,
161.31, 161.05, 157.89, 155.24, 153.15, 151.38, 150.01, 144.41, 144.18, 139.92, 133.46,
131.66, 131.57, 129.58, 124.27, 123.01, 120.34, 117.17, 116.66, 116.44, 115.19, 110.31,
109.42, 109.19, 101.62, 96.45, 31.80;; ESI-MS m/z: 523.15; Anal. Calcd. for
C29H19BrF2N5O3(%): C, 66.54; H, 3.55; N, 13.38; Found(%): C, 66.51; H, 3.52; N, 13.39.
6.3.27. 1-(4-chlorophenyl)-N-(4-((1-methyl-1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)phenyl)-2-oxo-
1,2-dihydro-1,8-naphthyridine-3-carboxamide (49)
1
Yield: 66%; M.p.: 299.4–297.0 °C; H NMR (400 MHz, DMS-d6) δ 11.79 (s, 1H), 9.14
(s, 1H), 8.58 (d, J = 7.4 Hz, 2H), 8.13 (d, J = 5.3 Hz, 1H), 8.01 (d, J = 12.7 Hz, 1H), 7.78 (d, J
16

ACCEPTED MANUSCRIPT
= 8.3 Hz, 2H), 7.54 (d, J = 8.6 Hz, 1H), 7.46 (dd, J = 7.2, 5.0 Hz, 1H), 7.43 - 7.33 (m, 4H),
6.45 (d, J = 5.2 Hz, 1H), 6.24 (d, J = 3.1 Hz, 1H), 3.82 (s, 3H); 13C NMR (100 MHz,
DMSO-d6) δ 163.04, 161.36, 157.72, 153.24, 151.29, 150.65, 144.71, 144.57, 140.05, 136.86
(2C), 133.68, 132.84 (2C), 131.96, 129.50 (2C), 124.38, 123.16, 122.19, 120.52, 117.25,
115.33, 110.25, 109.52, 109.29, 101.70, 96.40, 31.78; ESI-MS m/z: 539.15; Anal. calcd. for
C29H19FClN5O3(%): C, 64.51; H, 3.55; N, 12.97; Found (%): C, 64.39; H, 3.4; N, 12.93.
6.3.28. 1-(4-bromophenyl)-N-(3-fluoro-4-((1-methyl-1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)pheny
l)-2-oxo-1,2-dihydro-1,8-naphthyridine-3-carboxamide (50)
Yield: 56%; M.p.: 250.4–252.3 °C; 1H NMR (400 MHz, DMSO-d6) δ 11.81 (s, 1H), 9.17
(s, 1H), 8.61 (d, J = 8.5 Hz, 2H), 8.12 (d, J = 5.1 Hz, 1H), 8.04 (d, J = 12.8 Hz, 1H), 7.79 (d, J
= 6.9 Hz, 1H), 7.65 (t, J = 9.0 Hz, 1H), 7.57 (d, J = 8.2 Hz, 1H), 7.49 (d, J = 4.8 Hz, 2H), 7.44
- 7.34 (m, 2H), 6.43 (d, J = 5.1 Hz, 1H), 6.24 (d, J = 3.2 Hz,1H), 3.80 (s, 3H); ESI-MS m/z:
565.07; Anal. Calcd. for C29H20BrF2N5O3(%): C, 61.49; H, 3.51; N, 12.36; Found(%); C,
61.51; H, 3.52; N, 12.34.
6.3.29. N-(3-fluoro-4-((1-methyl-1H-pyrrolo[2,3-b]pyridin-4-yl)oxy)phenyl)-1-(4-methoxyphe
nyl)-2-oxo-1,2-dihydro-1,8-naphthyridine-3-carboxamide (51)
Yield: 69%; M.p.: 278.4–277.0 °C; 1H NMR (400 MHz, DMSO-d6) δ 11.96 (s, 1H), 9.13
(s, 1H), 8.58 (t, J = 6.0 Hz, 2H), 8.11 (d, J = 5.3 Hz, 1H), 8.03 (d, J = 12.9 Hz, 1H), 7.55 (d, J
= 9.1 Hz, 1H), 7.47 - 7.33 (m, 3H), 7.27 (d, J = 8.7 Hz, 2H), 7.10 (d, J = 8.8 Hz, 2H), 6.41 (d,
J = 5.3 Hz, 1H), 6.24 (d, J = 3.4 Hz, 1H), 3.81 (d, J = 15.0 Hz, 6H); ESI-MS m/z: 535.17;
Anal. Calcd. for C30H22FN5O4(%): C, 67.28; H, 4.14; N, 13.08; Found (%): C, 67.38; H, 4.15;
N, 13.19.
6.3.30. 1-(3-chloro-4-fluorophenyl)-N-(3-fluoro-4-((1-methyl-1H-pyrrolo[2,3-b]pyridin-4-yl)o
xy)phenyl)-2-oxo-1,2-dihydro-1,8-naphthyridine-3-carboxamide (52)
Yield: 63%; M.p.: 281.4–283.0 °C; 1H NMR(400 MHz, DMSO-d6) δ 11.81 (s, 1H), 9.17
(s, 1H), 8.61 (d, J = 8.5 Hz, 2H), 8.12 (d, J = 5.1 Hz, 1H), 8.04 (d, J = 12.8 Hz, 1H), 7.79 (d, J
= 6.9 Hz, 1H), 7.65 (t, J = 9.0 Hz, 1H), 7.57 (d, J = 8.2 Hz, 1H), 7.49 (d, J = 4.8 Hz, 2H), 7.44
- 7.34 (m, 2H), 6.43 (d, J = 5.1 Hz, 1H), 6.24 (d, J = 3.2 Hz, 1H), 3.80 (s, 3H); ESI-MS m/z:
557.15; Anal. Calcd. for C29H18F2ClN5O3(%): C, 62.43; H, 3.25; N, 12.55; Found (%): C,
62.43; H, 3.26; N, 12.54.
17

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6.3.31. 1-(3-chloro-4-fluorophenyl)-N-(3-fluoro-4-((1-methyl-1H-pyrrolo[2,3-b]pyridin-4-yl)o
xy)phenyl)-2-oxo-1,2-dihydro-1,8-naphthyridine-3-carboxamide (53)
Yield: 56%; M.p.: 240.4–241.0 °C; 1H NMR (400 MHz, DMSO-d6) δ 11.55 (s, 1H), 9.11
(s, 1H), 8.56 (d, J = 5.7 Hz, 2H), 8.05 (d, J = 5.3 Hz, 1H), 7.96 (d, J = 13.0 Hz, 1H), 7.81 (d, J
= 9.1 Hz, 1H), 7.60 (d, J = 8.0 Hz, 1H), 7.53 - 7.42 (m, 3H), 7.33 (dd, J = 18.2, 6.2 Hz, 2H),
6.36 (d, J = 5.3 Hz, 1H), 6.17 (d, J = 3.5 Hz, 1H), 3.74 (s, 3H); ESI-MS m/z: 601.06; Anal.
calcd. for C29H18BrF2N5O3(%): C, 57.82; H, 3.01; N, 11.63; Found (%); C, 57.83; H, 3.21; N,
11.64.
6.3.32. 1-(2-chloro-4-(trifluoromethyl)phenyl)-N-(3-fluoro-4-((1-methyl-1H-pyrrolo[2,3-b]pyr
idin-4-yl)oxy)phenyl)-2-oxo-1,2-dihydro-1,8-naphthyridine-3-carboxamide (54)
Yield: 63%; M.p.: 293.4–292.0 °C; 1H NMR (400 MHz, DMSO-d6) δ 11.58 (s, 1H), 9.10
(s, 1H), 8.53 (s, 2H), 8.08 - 8.00 (m, 2H), 7.91 (d, J = 8.1 Hz, 1H), 7.76 (d, J = 7.4 Hz, 3H),
7.41 (s, 1H), 7.33 (s, 1H), 7.12 (d, J = 8.0 Hz, 2H), 6.40 (s, 1H), 6.12 (s, 1H), 3.72 (s, 3H);
13C NMR (100 MHz, DMSO-d6) δ 161.96, 160.17, 156.63, 154.25, 152.16, 150.12, 149.52,
143.62, 143.69, 139.05, 136.75, 135.92, 134.79, 132.23, 130.39, 130.02, 128.60, 128.41,
123.29, 122.06, 119.58, 116.19, 114.33, 109.14, 109.08, 108.45, 108.21, 100.59, 95.29, 30.68;
ESI-MS m/z: 589.11; Anal. calcd. for C30H19F3ClN5O3(%): C, 61.08; H, 3.25; N, 11.87;
Found (%): C, 61.09; H, 3.26; N, 11.88.
6.4. Pharmacology
6.4.1. MTT assay in vitro
The anti-proliferative activities of compounds 23–54 were evaluated against HT-29,
H460, A549, and U87MG cell lines using the standard MTT assay in vitro, with foretinib as
the positive control, as previously reported protocol. The cancer cell lines were cultured in
minimum essential medium (MEM) supplemented with 10% fetal bovine serum (FBS).
Approximate 4 × 103 cells, suspended in MEM medium, were plated onto each well of a
96-well plate and incubated in 5% CO2 at 37 °C for 24 h. The compounds tested at the
indicated final concentrations were added to the culture medium and the cell cultures were
continued for 72 h. Fresh MTT was added to each well at a terminal concentration of 5 µg/mL,
and incubated with cells at 37 °C for 4 h. The formazan crystals were dissolved in 100 mL of
18

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DMSO each well, and the absorbency at 492 and 630 nm (for the reference wavelength) was
measured with an ELISA reader. All of the compounds were tested three times in each cell
line. The results expressed as IC50 (inhibitory concentration 50%) were the averages of three
determinations and calculated by using the Bacus Laboratories Incorporated Slide Scanner
(Bliss) software [25-26].
6.4.2. Tyrosine kinases assay
The tyrosine kinases activities were evaluated using homogeneous time-resolved
fluorescence (HTRF) assays, as previously reported protocol. Briefly, 20 µg/mL poly (Glu,
Tyr) 4:1 (Sigma) was preloaded as a substrate in 384-well plates. Then 50 µL of 10 mM ATP
(Invitrogen) solution diluted in kinase reaction buffer (50 mM HEPES, pH 7.0, 1 M DTT, 1 M
MgCl2, 1 M MnCl2, and 0.1% NaN3) was added to each well. Various concentrations of
compounds diluted in 10 µL of 1% DMSO (v/v) were used as the negative control. The kinase
reaction was initiated by the addition of purified tyrosine kinase proteins diluted in 39 µL of
kinase reaction buffer solution. The incubation time for the reactions was 30 min at 25 °C,
and the reactions were stopped by the addition of 5 µL of Streptavidin-XL665 and 5 µL Tk
Antibody Cryptate working solution to all of wells. The plates were read using Envision
(PerkinElmer) at 320 nm and 615 nm. The inhibition rate (%) was calculated using the
following equation: % inhibition = 100 - [(Activity of enzyme with tested compounds - Min)/
(Max - Min)] × 100 (Max: the observed enzyme activity measured in the presence of enzyme,
substrates, and cofactors; Min: the observed enzyme activity in the presence of substrates,
cofactors and in the absence of enzyme). IC50 values were calculated from the inhibition
curves [27-29].
7. Acknowledgements
We gratefully acknowledge the generous support provided by National Natural Science
Foundation of China (NSFC No. 81660572; NSFC No. 81660692), Natural Science
Foundation of Jiangxi Province (20171BAB215071), Science and Technology Project
Founded by the Education Department of Jiangxi Province (GJJ150797), Top-notch talent
project of Jiangxi Science & Technology Normal University (2016QNBJRC002), Research
Fund for the Doctoral Program of Jiangxi Science & Technology Normal University (No.
19

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3000990351), and Jiangxi Provincial Key Laboratory of Drug Design and Evaluation
(20171BCD40015).
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Legends
Fig. 1. The representative small-molecule c-Met kinase inhibitors.
Fig. 2. Our previous work on antiproliferative agents bearing pyrrolo[2,3-b]pyridine scaffolds
(7 and 8) and potent drugs bearing 1,8-naphthyridin-2-one (9 and 10).
Fig. 3. Design strategy for the pyrrolo[2,3-b]pyridine derivatives bearing the
1,8-naphthyridin-2-one moiety.
Fig. 4. Binding poses of compound 32 with c-Met. The proteins were displayed by silver
ribbon. Compound 32 were displayed by multicolor sticks. H-bonding interactions between
the 32 and c-Met were indicated with dashed lines in black.
Scheme 1. Reagents and conditions: (i) Diphenyl Ether, 190 °C, 51–55%; (ii) FeCl3,
21

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N2H4·H2O, Activated Carbon, 80 °C, 78–81%.
Scheme 2. Reagents and conditions: (i) AcOH, 100 °C, 3–6 h; (ii) LiAlH4, N2, THF, r.t. 3.5 h;
(iii) Pyridinium dichromate, CH2Cl2, r.t. 5–7 h; (iv) Ethyl acetylacetate, piperidine, EtOH,
reflux, 30–35 h; (v) K2CO3, 1,4-dioxane/H2O, 80 °C, 4–5 h (vi) SOCl2, reflux, 6 h; (vii)
Appropriate aniline, carbonyl chloride, DIPEA, CH2Cl2, 0 °C, 1 h, r.t., 5–8 h.
22

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Table 1
Cytotoxic activities of compounds 23–54 against HT-29, A549, H460, and U87MG cancer cell lines in vitro.
IC50 (µM) ± SD
Compd.
R1
R2
R3
HT29
A549
H460
0.38 ± 0.04
0.19 ± 0.02
0.29 ± 0.03
ND b
U87MG
1.58 ± 0.09
1.36 ± 0.12
3.37 ± 0.10
ND
H
H
H
H
H
H
H
H
H
F
H
0.29 ± 0.01
0.16 ± 0.01 a
0.28 ± 0.04
0.27 ± 0.03
1.26 ± 0.08
0.56 ± 0.08
2.36 ± 0.08
2.16 ± 0.11
0.16 ± 0.03
0.036 ± 0.003
0.082 ± 0.004
0.12 ± 0.002
0.54 ± 0.05
0.31 ± 0.03
0.82 ± 0.09
1.36 ± 0.03
0.62 ± 0.02
0.25 ± 0.03
0.73 ± 0.05
0.69 ± 0.04
2.05 ± 0.11
1.21 ± 0.03
2.58 ± 0.13
6.05 ± 0.09
0.51 ± 0.05
0.16 ± 0.03
0.22 ± 0.05
0.33 ± 0.04
1.29 ± 0.10
2.46 ± 0.11
3.29 ± 0.10
5.83 ± 0.16
0.26 ± 0.01
0.36 ± 0.03
0.21 ± 0.02
0.29 ± 0.03
0.28 ± 0.02
0.93 ± 0.05
0.68 ± 0.05
1.57 ± 0.15
3.23 ± 0.09
0.19 ± 0.005
0.062 ± 0.003
0.11 ± 0.02
0.21 ± 0.03
0.61 ± 0.06
0.63 ± 0.05
0.46 ± 0.06
1.02 ± 0.07
0. 85 ± 0.03
0. 21 ± 0.01
0.63 ± 0.03
0.68 ± 0.05
3.46 ± 0.08
0.82 ± 0.09
1.63 ± 0.08
8.25 ± 0.10
0. 43 ± 0.03
0.28 ± 0.03
0.35 ± 0.06
0.39 ± 0.06
2.75 ± 0.12
3.56 ± 0.09
2.69 ± 0.15
3.53 ± 0.10
0.32 ± 0.03
23
H
4-F
24
H
4-Cl
25
H
4-Br
26
H
4-OCH3
3-Cl-4-F
2-F-4-Br
2-Cl-4-CF3
H
0.96 ± 0.05
ND
2.35 ± 0.14
ND
27
H
28
H
ND
ND
29
H
1.95 ± 0.06
0.18 ± 0.04
0.087 ± 0.002
ND
6.03 ± 0.18
1.26 ± 0.15
0.62 ± 0.03
ND
30
H
31
H
F
4-F
32
H
F
4-Cl
33
H
F
4-Br
1.51 ± 0.06
ND
34
0.26 ± 0.02
ND
H
F
4-OCH3
3-Cl-4-F
2-F-4-Br
2-Cl-4-CF3
H
35
H
F
1.05 ± 0.08
ND
5.23 ± 0.12
ND
36
H
F
37
H
F
ND
ND
38
CH3
CH3
CH3
CH3
CH3
CH3
CH3
CH3
CH3
CH3
CH3
CH3
CH3
CH3
CH3
CH3
H
H
H
H
H
H
H
H
F
0.56 ± 0.04
0.26 ± 0.04
ND
5.03 ± 0.11
2.12 ± 0.06
ND
39
4-F
40
4-Cl
41
4-Br
ND
ND
42
4-OCH3
3-Cl-4-F
2-F-4-Br
2-Cl-4-CF3
H
1.92 ± 0.07
1.21 ± 0.05
ND
5.15 ± 0.16
2.35 ± 0.11
ND
43
44
45
6.95 ± 0.07
0.55 ± 0.06
0.25 ± 0.05
ND
12.55 ± 0.11
3.59 ± 0.12
1.32 ± 0.06
ND
46
47
F
4-F
48
F
4-Cl
49
F
4-Br
0.42 ± 0.05
ND
2.58 ± 0.09
ND
50
F
4-OCH3
3-Cl-4-F
2-F-4-Br
2-Cl-4-CF3
51
F
ND
ND
52
F
3.15 ± 0.08
6.01 ± 0.09
0.28 ± 0.02
6.47 ± 0.11
10.15 ± 0.11
0.91 ± 0.06
53
F
54
Foretinib c
a Bold values show the IC50 values of the target compounds lower than the values of the positive control.
b ND: Not determined.
c Used as the positive control.

ACCEPTED MANUSCRIPT
Table 2
c-Met kinase activity of selected compounds 24, 25, 31, 32, 33, 40, 48, 49, and foretinib in vitro.
Compd.
IC50 on c-Met (nM)
24
25
8.53
9.25
31
3.59
32
1.92
33
2.23
40
21.76
32.51
16.83
1.56
48
49
Foretinib

ACCEPTED MANUSCRIPT
Table 3
Inhibition of tyrosine kinases by compound 32.
Kinase
Flt-3
Enzyme IC50 (nM)
1.16
1.81
PDGFR-β
VEGFR-2
EGFR
152.3
632.8
684.5
c-Kit

ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT