Synthesis, antiproliferative and anti-dengue virus evaluations of 2-aroyl-3-arylquinoline derivatives

Article abstract of DOI:10.1016/j.ejmech.2014.03.074

A number of 2-aroyl-3-arylquinoline derivatives was synthesized and evaluated for their anti-Dengue virus activity. Both 2-(hydroxyphenylmethyl)-3- (4-methoxyphenyl)quinoline (13a) and 2-(4-hydroxybenzoyl)-3-(4-hydroxyphenyl) quinoline (17) were found to significantly inhibit the DENV2 RNA expression in Huh-7-DV-Fluc cells with a potency approximately equal to that of ribavirin and the inhibition is in a dose-dependent manner. Compounds 13a and 17 reduced DENV replication in both viral protein and mRNA levels, and no significant cell cytotoxicity was detected, with greater than 50% viability of Huh-7-DV-Fluc cells at a concentration of 100 μM. However, significant cytotoxicity was detected for the positive ribavirin. In addition, we performed infectious assay to further verify the inhibitory activity of 13a and 17 on DENV replication in protein and RNA levels. On the other hand, compounds 19a-19c exhibited IC ₅₀ values ranged from 4.47 to 8.68 μM against A549, H1299, MCF-7, and Huh-7 which were approximately equal potent to the positive topotecan. Structural optimization of lead compounds, 13a and 17, and their detailed molecular mechanism of action are ongoing.

Full text of DOI:10.1016/j.ejmech.2014.03.074

Accepted Manuscript
Synthesis, Antiproliferative and Anti-Dengue Virus Evaluations of 2-Aroyl-3-
arylquinoline Derivatives
Chih-Hua Tseng, Chun-Kuang Lin, Yeh-Long Chen, Chih-Yao Hsu, Huey-Nan Wu,
Chin-Kai Tseng, Jin-Ching Lee
PII:
S0223-5234(14)00288-8
10.1016/j.ejmech.2014.03.074
EJMECH 6858
DOI:
Reference:
To appear in: European Journal of Medicinal Chemistry
Received Date: 16 December 2013
Revised Date: 17 March 2014
Accepted Date: 27 March 2014
Please cite this article as: C.-H. Tseng, C.-K. Lin, Y.-L. Chen, C.-Y. Hsu, H.-N. Wu, C.-K. Tseng, J.-
C. Lee, Synthesis, Antiproliferative and Anti-Dengue Virus Evaluations of 2-Aroyl-3-arylquinoline
Derivatives, European Journal of Medicinal Chemistry (2014), doi: 10.1016/j.ejmech.2014.03.074.
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ACCEPTED MANUSCRIPT
Graphical Abstract
A number of 2-aroyl-3-arylquinoline derivatives were synthesized and evaluated for
their anti-Dengue virus activity. Both 13a and 17 were found to significantly inhibit
the DENV2 RNA expression in Huh-7-DV-Fluc cells.

ACCEPTED MANUSCRIPT
Synthesis, Antiproliferative and Anti-Dengue Virus Evaluations of 2-Aroyl-3-arylquinoline
Derivatives
1
*
2
3
3
4
Chih-Hua Tseng , Chun-Kuang Lin , Yeh-Long Chen , Chih-Yao Hsu , Huey-Nan Wu , Chin-Kai
5
,6
7 *
Tseng , and Jin-Ching Lee
1
School of Pharmacy, College of Pharmacy, Kaohsiung Medical University, Kaohsiung, Taiwan
Doctoral Degree Program in Marine Biotechnology, National Sun Yat-Sen University, Kaohsiung,
2
Taiwan
3
Department of Medicinal and Applied Chemistry, College of Life Science, Kaohsiung Medical
University, Kaohsiung City 807, Taiwan
4
Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan, ROC
5
Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University,
Tainan, Taiwan
6
Center of Infectious Disease and Signaling Research, College of Medicine, National Cheng Kung
University, Tainan, Taiwan
7
Department of Biotechnology, College of Life Science, Kaohsiung Medical University,
Kaohsiung City 807, Taiwan
*
Corresponding author. Tel.: +886 7 3121101 x2163; fax: +886 7 3125339.
E-mail addresses: chihhua@kmu.edu.tw; jclee@kmu.edu.tw
1

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Abstract
A number of 2-aroyl-3-arylquinoline derivatives was synthesized and evaluated for their
anti-Dengue virus activity. Both 2-(hydroxyphenylmethyl)-3-(4-methoxyphenyl)quinoline (13a)
and 2-(4-hydroxybenzoyl)-3-(4-hydroxyphenyl)quinoline (17) were found to significantly inhibit
the DENV2 RNA expression in Huh-7-DV-Fluc cells with a potency approximately equal to that
of ribavirin and the inhibition is in a dose-dependent manner. Compounds 13a and 17 reduced
DENV replication in both viral protein and mRNA levels, and no significant cell cytotoxicity was
detected, with greater than 50% viability of Huh-7-DV-Fluc cells at a concentration of 100 µM.
However, significant cytotoxicity was detected for the positive ribavirin. In addition, we performed
infectious assay to further verify the inhibitory activity of 13a and 17 on DENV replication in
protein and RNA levels. On the other hand, compounds 19a - 19c exhibited IC values ranged
5
0
from 4.47 to 8.68 µM against A549, H1299, MCF-7, and Huh-7 which were approximately equal
potent to the positive topotecan. Structural optimization of lead compounds, 13a and 17, and their
detailed molecular mechanism of action are ongoing.
Keywords
2-Aroyl-3-arylquinoline; Ribavirin; Topotecan; Anti-Dengue virus; Antiproliferative
2

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1. Introduction
Dengue virus (DENV) is a mosquito-borne human pathogen and belongs to the genus
Flavivirus in the Flaviviridae family [1]. DENV has been identified as an etiological agent causing
dengue hemorrhagic fever (DHF), dengue fever (DF), and dengue shock syndrome (DSS) [2]. In
recent years, these members of the genus Flavivirus cause prominent morbidity and mortality, and
DENV has become a serious public health threat worldwide. It is estimated that 40 to 80 million
people are infected by DENV per year, particularly in the tropical Asia, Latin America, and the
Caribbean, and infection with DENV lead to approximately 500,000 severe life-threatening cases
and over 20,000 deaths [3, 4]. Unfortunately, there is no clinical approval vaccine to prevent
DENV infection and effective antiviral therapy against DENV replication [5, 6]. Therefore, the
development of safe and effective therapeutic agent is now urgent needed.
DENV is an enveloped RNA virus containing a positive-sense and single strand genome with
an approximate 11 kilobases (kb) in the length [7]. Upon DENV entry into the target cells, the
RNA genome is translated to a single polyprotein associated with the host endoplasmic reticulum
(ER), on which members of Flavivirus are dependent for translation and replication [8]. The
polyprotein is cleaved by host and viral proteases into three structural proteins (capsid [C],
premembrane [prM], and envelope [E]) and seven non-structure proteins (NS1, NS2A, NS2B, NS3,
NS4A, NS4B and NS5). The structure proteins are important components for consisting of the
functional virion to procceed virus entry, fusion and assembly, and the non-structure proteins are
3

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essential components for virus replication [9]. Recently, a number of small molecule compounds
were found to inhibit DENV replication significantly through different mechanisms, including the
inhibition of virus entry [10], virus replication, or viral RNA dependent RNA polymerase [11].
Quinoline skeleton is one of the key building elements for a large number of natural and
synthetic heterocycles which possess a wide variety of biological effects such as antimicrobial
[
12-16], anticancer [17-24], and antiviral activities [25-27]. Among these known antiviral quinoline
derivatives, 4-[4-(2-chlorobenzyloxy)aniline]-6-ethoxy-2-methylquinoline (1, Figure 1) exhibited
inhibitory activities against a DENV-2 sub-genomic replicon cell line with an IC value of 5 µM
5
0
and against a WNV sub-genomic replicon cell line with an IC50 of 1.9 µM [27] while
3’-nitrophenylaminoquinoline (2) inhibited the growth of Hepatitis C virus with an EC value of
50
7.0 µM [24]. Certain quinoline derivatives are highly cytotoxic. For examples, compound 3 was
active against the growth of H1299 and SKBR-3 with IC values of 1.41 and 0.70 µM respectively
5
0
[
22] while 6-fluoro-2,3-bis{4-[2-(piperidin-1-yl)ethoxy]phenyl}quinoline (4) was more active than
tamoxifene against the growth of Hep 3B, H1299, and MDA-MB-231 with GI values of 0.71,
5
0
1.46, and 0.72 µM respectively [21].
The present study describes the preparation and anti-Dengue virus activities of certain
2-aroyl-3-arylquinoline derivatives whose structures are similar to compounds 1 - 4. Structures of
the target compounds can also be considered as derivatives of compound 3 in which the conjugated
double bond bridge between quinoline and the carbonyl group is removed. Due to the significant
4

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antiproliferative activities exhibited by compound 3, these newly synthesized
2
-aroyl-3-arylquinoline derivatives have also been evaluated for their cytotoxicities. Our aim is to
identify potential anti-Dengue virus drug candidates with no significant cytotoxicity.
Insert Figure 1 here >
<
2. Chemistry
The Pfitzinger reaction of indolin-2,3-dione (isatin, 5) and 4-methoxyphenyacetone (9) under
basic conditions gave 3-(4-methoxyphenyl)-2-methylquinoline-4-carboxylic acid (10a) [22, 28].
Accordingly, compounds 10b – 10e were obtained from the starting materials 5 - 9 respectively
under the same reaction conditions. Thermal decarboxylation of 10a – 10e gave
3-(4-methoxyphenyl)-2-methylquinoline (11a) or its respective analogs 11b – 11e in a yield of 70 –
78%. Oxidation of 11a – 11e with selenium oxide afforded 3-(4-methoxyphenyl)quinoline-
2-carbaldehyde (12a) or its analogs 12b – 12e respectively in a yield of 70 – 87%. Treatment of
12a with phenyl magnesium bromide (Grignard reagent) afforded 2-(hydroxyphenylmethyl)-
3-(4-methoxyphenyl)quinoline (13a) which was then oxidized with MnO2 to gave
2-benzoyl-3-(4-methoxyphenyl)quinoline (14a) as described in Scheme 1. Accordingly, Grignard
reaction of compounds 12b – 12e afforded compounds 13b – 13e respectively which was then
oxidized with MnO to give their respective carbonyl products 14b – 14e under the same reaction
2
conditions.
Treatment of 12a with 4-methoxyphenyl magnesium bromide or 3,4,5-trimethoxyphenyl
5

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magnesium bromide gave 2-(hydroxy-4-methoxyphenylmethyl)-3-(4-methoxyphenyl)quinoline
(
15a) or its analog 15b which was then oxidized with MnO2 to afford
-(4-methoxybenzoyl)-3-(4-methoxyphenyl)quinoline (16a) or its analog 16b respectively as
described in Scheme 2. Demethylation of 16a with 48% HBr gave
-(4-hydroxybenzoyl)-3-(4-hydroxyphenyl)quinoline (17) which was then alkylated with
2
2
N-(2-chloroethyl)pyrrolidine to give a mixture of the monoalkylated product 18a and dialkylated
product 19a in the presence of NaH. The structural assignment of the monoalkylated products 18a
was determined by 2D Nuclear Overhauser Effect (2D NOESY) experiments, as shown in Figure 2.
Compound 18a was assigned as a monoalkylated product at the C-3 phenyl moiety by the
correlation between OCH (δ = 3.93 ppm) / meta-H of 3-phenyl (δ = 6.74 ppm), meta-H of
2
H
H
3
7
1
3
-phenyl (δ = 6.74 ppm) / ortho-H of 3-phenyl (δ = 7.25 ppm), and ortho-H of 3-phenyl (δ =
H H H
.25 ppm) / 4-H (δ = 8.20 ppm) were observed (Figure 2). Accordingly, compounds 18b, c and
H
9b, c were obtained by the alkylation of 17 with N-(2-chloroethyl)piperidine, and
-chloro-N,N-dimethylpropanamine respectively as described in Scheme 3.
<
Insert Scheme 1-3 and Figure 2 here >
3. Biological Results and Discussion
3
.1. Anti-DENV2 and Antiproliferative Activities
The anti-DENV2 and cytotoxicities of 2-aroyl-3-arylquinoline derivatives are
summarized in Table 1. Huh-7-DV-Fluc cells were treated with compounds 13 – 19 or the positive
6

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ribavirin respectively at a concentration of 5 or 20 µM for three days. Cells were then analyzed
through the firefly luciferase activity. Compounds which exhibited >50% inhibition of DENV at a
concentration of 20 µM were considered as active. Results from Table 1 indicated that
2-(hydroxyphenylmethyl)-3-(4-methoxyphenyl)quinoline (13a) was more active than its
fluoro-substituted counterparts, 13c – 13e. The anti-DENV2 activity was also slightly decreased by
the substitution of a methoxy group at C-4 position in which 13a was more active than 13b.
Oxidation of the secondary alcohol resulted in the lost of activity in which compound 14a was
inactive. The same SAR was observed since the secondary alcohol 15a was more active than the
oxo derivative 16a. However, compound 17 was more active than its precursor 16a thus indicating
that the hydrogen bond donor groups are more favorable than that of hydrogen accepting groups.
Among these 2-aroyl-3-arylquinoline derivatives, compounds 13a, 13b, 14b, 15a and 17 exhibited
more than 50% inhibition of DENV replication in the Huh-7-DV-Fluc cells at a concentration of 20
µM. The cell cytotoxicity of was determined by XTT assay in the Huh-7 cells after 3 days
treatment with 20 and 100 µM of 2-aroyl-3-arylquinoline derivatives. Compounds 13a, 14b, and 17
exhibited low cytotoxicity, with greater than 50% viability at a concentration of 100 µM. However,
significant cytotoxicities were detected for compounds 13b, 15a, and the positive ribavirin. The
concentration that inhibited 50% DENV replication (IC ), the concentration that inhibited the
5
0
growth of 50% cells (CC ), and the selective index (SI : CC /IC ) of compounds 13a, 13b, 14b,
5
0
50
50
15a and 17 were determined as shown in Table 2. Results indicated that all the tested compounds
7

ACCEPTED MANUSCRIPT
exhibited comparable anti-DENV2 actitity (IC50 ranged from 12.57 to 18.16 µM) to that of
ribavirin (IC50 = 12.61 µM). However, compounds 13a, 14b, and 17 demonstrated a good
selectivity with SI value of greater than 7.96, 5.76, and 7.60 respectively which was higher than
that of ribavirin (SI = 4.47).
Among these newly synthesized 2-aroyl-3-arylquinoline derivatives, compounds 18a – 18c and
19a – 19c exhibited significant cytotoxicities against Huh-7 cell with less than 20% viability at a
concentration of 100 µM. These compounds were then evaluated for their antiproliferative activities
against A549, H1299, MDA-MB231, MCF-7, and Huh-7 and the IC values are summarized in
5
0
Table 3. Results indicated that diaminoalkoxy-substituted 2-aroyl-3-arylquinoline derivatives, 19a -
9c, were more cytotoxic than their monoaminoalkoxy-substituted counterparts, 18a - 18c.
Compounds 19a - 19c exhibited IC values ranged from 4.47 to 8.68 µM against A549, H1299,
1
5
0
MCF-7, and Huh-7 which were approximatedly equal potent to the positive topotecan. However,
topotecan was more active than compounds 19a - 19c against MDA-MB231.
<
Insert Table 1-3 >
3
.2. Compounds 13a and 17 reduced DENV replication in DENV infected Huh-7 cells
To confirm the results of dose-dependent decease luciferase activity representing the
DENV replication in the Huh-7-DV-Fluc cells, we performed western blotting with anti-NS2B and
anti-GAPDH and RT-qPCR with specific primers to determine the DENV NS2B protein expression
and DENV NS5 mRNA expression. Both results of western blotting and RT-qPCR revealed that
13a and 17 consistently reduced DENV replication in the Huh-7-DV-Fluc cells at the concentration
8

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of 5 and 20 µM after 3 days treatment. Treatment of ribavirin was served as a positive control of
the inhibition on DENV replication and 0.1% DMSO was served as mock control (Figures 3 and 4).
Results from Figure 3 also indicated that compound 13a was more active than 13b which implied
that the methoxy group substituted at C-6 position is unfavorable. Substitution of the methoxy
group at the para-position of C-2 phenylmethyl group resulted in a decreased activity in which
compound 15a was less ative than 13a. The inhibitory activities of compounds 13a and 17 on
DENV2 RNA expression in Huh-7-DV-Fluc cells were approximately equal to that of ribavirin and
the inhibition is in a dose-dependent manner (Figure 4). Furthermore, compounds 13a and 17 were
inoculated with the Huh-7-DV-Fluc cells at various concentrations for 3 days, and then total protein
and RNA were collected and analyzed through western blotting and RT-PCR. Results showed 13a
and 17 reduced DENV replication in the dose dependent manner in both viral protein and mRNA
levels, and no significant cell cytotoxicity in Huh-7-DV cells was detected (Figure 5). In addition,
we performed infectious assay to further verify the inhibitory activity of 13a and 17 on DENV
replication in protein and RNA levels (Figure 6). Results further confirmed that compounds 13a
and 17 were capable of reducing DENV replication in DENV infected Huh-7 cells in a
concentration-dependent manner.
<
Insert Figure 3-6 here >
4. Conclusion
A number of 2-aroyl-3-arylquinoline derivatives were synthesized and evaluated for
9

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anti-Dengue virus activity against of DENV2. Among them, 2-(hydroxyphenylmethyl)-3-(4-
methoxyphenyl)quinoline (13a) and 2-(4-hydroxybenzoyl)-3-(4-hydroxyphenyl)quinoline (17)
were found to significantly inhibit the DENV2 RNA expression in Huh-7-DV-Fluc cells with a
potency approximately equal to that of ribavirin and the inhibition is in a dose-dependent manner.
Compounds 13a and 17 reduced DENV replication in both viral protein and mRNA levels, and no
significant cell cytotoxicity was detected, with greater than 50% viability of Huh-7-DV-Fluc cells
at a concentration of 100 µM. Both compounds were identified as novel type of structures for
further development of anti-DENV agents.
5
5
. Experimental
.1. General
Melting points were determined on a Electrothermal IA9100 melting point apparatus and are
1
13
uncorrected. Nuclear magnetic resonance ( H and C) spectra were recorded on a Varian Gemini
200 spectrometer or Varian-Unity-400 spectrometer. Chemical shifts were expressed in parts per
million (δ) with tetramethylsilane (TMS) as an internal standard. Thin-layer chromatography was
performed on silica gel 60 F-254 plates purchased from E. Merck and Co.. Mass spectra were
recorded on Bruker APEX II (ESI) mass spectrometer. The elemental analyses were performed in
the Instrument Center of National Science Council at National Cheng-Kung University and
National Taiwan University using Heraeus CHN-O Rapid EA, and all values are within ± 0.4% of
the theoretical compositions.
1
0

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5.2. General procedure for the preparation of 3-aryl-2-methylquinoline-4-carboxylic acids 10
[22]. A mixture of isatin 5, 6, or 7 (40 mmol), phenylacetone 8 or 9 (48 mmol) and KOH (6.74 g,
o
1
20 mmol) in EtOH was heated at 80 C for 48 h (TLC monitoring). After cooling, the solvent was
removed in vacuo and the residue dissolved in H O (50 mL), and the aqueous solution was washed
2
twice with Et O (30 mL). The ice-cold aqueous phase was acidified to pH 1 with 37% HCl, and the
2
precipitate was collected by suction filtration, washed with H O and recrystallized with EtOH to
2
give 3-aryl-2-methylquinoline-4-carboxylic acids 10.
5.2.1. 6-Fluoro-3-(4-methoxyphenyl)-2-methylquinoline-4-carboxylic acid (10b). Yield: 93% as
o
1
a white solid. Mp. 269 C (dec). H NMR (DMSO-d ): 2.45 (s, 3H, 2-Me), 3.83 (s, 3H, OMe),
6
7
1
5
.05-7.08 (m, 2H, Ar-H), 7.29-7.32 (m, 2H, Ar-H), 7. 45 (dd, 1H, J = 9.6, 2.8 Hz, 5-H), 7.73 (ddd,
1
3
H, J = 9.2, 8.4, 2.8 Hz, 7-H), 8.12 (dd, 1H, J = 9.2, 5.6 Hz, 8-H). C NMR (DMSO-d ): 24.43,
6
5.15, 108.07 (J = 23.5 Hz), 113.82 (2C), 119.78 (J = 25.7 Hz), 122.49 (J = 9.9 Hz), 128.17, 130.49
(2C), 131.27, 131.59 (J = 9.1 Hz), 139.65 143.39, 157.60 (J = 2.3 Hz), 159.03, 159.92 (J = 244 Hz),
1
67.79. Anal. calcd for C H FNO : C 69.45, H 4.53, N 4.50; found C 69.45, H 4.59, N 4.57.
18 14 3
5.2.2. 6-Methoxy-3-(4-methoxyphenyl)-2-methylquinoline-4-carboxylic acid (10c). Yield: 84%
o
1
as a white solid. Mp. 279 C (dec). H NMR (DMSO-d ): 2.72 (s, 3H, 2-Me), 3.82 (s, 3H, OMe),
6
3
0
1
.87 (s, 3H, 6-OMe), 7.03-7.06 (m, 3H, Ar- & 5-H), 7.27-7.29 (m, 2H, Ar-H), 7.45 (dd, 1H, J = 8.4,
1
3
.8 Hz, 7-H), 7.95 (d, 1H, J = 8.4 Hz, 8-H). C NMR (DMSO-d ): 24.16, 55.19, 55.51, 102.71,
6
13.81 (2C), 121.98, 122.80, 129.21, 130.22, 130.60 (2C), 139.38, 142.29, 155.06, 157.53, 158.95,
1
1

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1
4
5
68.38. Anal. calcd for C H NO ·0.25 H O: C 69.60, H 5.39, N 4.27; found C 69.78, H 5.44, N
19
17
4
2
.16.
.2.3. (4-Fluorophenyl)-2-methylquinoline-4-carboxylic acid (10d). Yield: 88% as a white solid.
o
1
Mp. 348 C (dec). H NMR (DMSO-d ): 2.43 (s, 3H, 2-Me), 7.31-7.44 (m, 4H, Ar-H), 7.63--7.83 (m,
6
1
3
3
H, Ar-H), 8.04 (d, 1H, J = 8.4 Hz, 8-H). C NMR (DMSO-d ): 24.51, 115.28 (2C, J = 21.3 Hz),
6
121.64, 124.89, 127.09, 128.56, 129.43, 130.01, 131.53 (2C, J = 8.3 Hz), 133.19, 143.30, 157.46,
1
61.88 (J = 243.3 Hz), 168.01. Anal. calcd for C H FNO ·0.2 H O: C 71.67, H 4.39, N 4.92;
17
12
2
2
found C 71.80, H 4.46, N 4.88.
5.2.4. 6-Fluoro-3-(4-fluorophenyl)-2-methylquinoline-4-carboxylic acid (10e). Yield: 88% as a
o
1
white solid. Mp. 279 C (dec). H NMR (DMSO-d ): 2.44 (s, 3H, 2-Me), 7.32-7.50 (m, 5H, Ar- &
6
1
3
5
-H), 7.74 (ddd, 1H, J = 9.2, 9.2, 2.8 Hz, 7-H), 7.13 (dd, 1H, J = 9.2, 5.6 Hz, 8-H). C NMR
(
DMSO-d ): 24.42, 108.21 (J = 23.5 Hz), 115.39 (2C, J = 22.0 Hz), 120.10 (J = 25.8 Hz), 122.40 (J
6
=
9.9 Hz), 130.07, 131.46 (2C, J = 8.4 Hz), 131.66 (J = 9.1 Hz), 133.04 (J = 3.8 Hz), 139.68 (J =
.3 Hz), 143.61, 157.18, 160.02 (J = 244.7 Hz), 162.00 (J = 243.3 Hz), 167.65. Anal. calcd for
C H NO ·0.25 H O: C 69.60, H 5.39, N 4.27; found C 69.78, H 5.44, N 4.16.
5
19
17
4
2
5.3. General procedure for the decarboxylation of acids 10 [22]. The suspension of
o
quinoline-4-carboxylic acid 10 (5.0 mmol) in 10 mL dowtherm was heated to 280 C for 4 h (TLC
monitoring). After cooling, the reaction mixture was added n-hexane (50 mL) and the formed solid
was collected by filtration, washed with n-hexane. The crude product was purified by flash
1
2

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chromatography on silica gel (hexane/CH Cl 1/1) and recrystallized from EtOH to give
2
2
compounds 11.
5
8
7
7
1
.3.1. 6-Fluoro-3-(4-methoxyphenyl)-2-methylquinoline (11b). Yield: 73% as a brown solid. Mp.
o
1
8-89 C. H NMR (CDCl ): 2.66 (s, 3H, 2-Me), 3.89 (s, 3H, OMe), 6.99-7.03 (m, 2H, Ar-H),
3
.31-7.34 (m, 2H, Ar-H), 7.39 (dd, 1H, J = 9.2, 2.8 Hz, 5-H), 7.44 (ddd, 1H, J = 9.2, 8.8, 2.8 Hz,
1
3
-H), 7.88 (s, 1H, 4-H), 8.05 (dd, 1H, J = 9.2, 5.2 Hz, 8-H). C NMR (CDCl ): 24.48, 55.34,
3
10.29 (J = 21.2 Hz), 113.92 (2C), 119.23 (J = 25.8 Hz), 127.47 (J = 9.8 Hz), 130.28 (2C), 130.80
(J = 9.1 Hz), 131.81, 135.33 (J = 5.3 Hz), 136.20, 143.95, 157.04 (J = 3.1 Hz), 159.28, 160.18 (J =
2
44.8 Hz). Anal. calcd for C H FNO: C 76.39, H 5.28, N 5.24; found: C 76.25, H 5.38, N 5.18.
17 14
5.3.2. 6-Methoxy-3-(4-methoxyphenyl)-2-methylquinoline (11c). Yield: 70% as a brown solid.
o
1
Mp. 209-210 C. H NMR (CDCl ): 2.69 (s, 3H, 2-Me), 3.88 (s, 3H, OMe), 3.92 (s, 3H, 6-OMe),
3
6
4
1
.98-7.02 (m, 2H, Ar-H), 7.04 (d, 1H, J = 2.8 Hz, 5-H), 7.31-7.35 (m, 3H, Ar- & 7-H), 7.84 (s, 1H,
1
3
-H), 7.95 (d, 1H, J = 9.2 Hz, 8-H). C NMR (CDCl ): 24.22, 55.32, 55.48, 104.94, 113.81 (2C),
3
21.72, 127.77, 129.78, 130.31 (2C), 132.38, 135.02, 135.60, 142.95, 154.92, 157.38, 159.08. Anal.
calcd for C H NO ·0.3 H O: C 75.91, H 6.24, N 4.91; found C 75.63, H 6.21, N 4.82.
1
8
17
2
2
1
5
.3.3. 3-(4-Fluorophenyl)-2-methylquinoline (11d). Yield: 75% as a brown oil. Mp. H NMR
(
CDCl ): 2.61 (s, 3H, 2-Me), 7.08-7.12 (m, 2H, Ar-H), 7.27-7.30 (m, 2H, Ar-H), 7.41-7.45 (m, 1H,
3
6-H), 7.61-7.64 (m, 1H, 7-H), 7.69 (dd, 1H, J = 8.4, 1.2 Hz, 5-H), 7.85 (s, 1H, 4-H), 8.05 (d, 1H, J
1
3
=
8.4 Hz, 8-H). C NMR (CDCl ): 24.27, 115.21 (2C, J = 21.3 Hz), 125.95, 126.57, 127.23, 128.16,
3
1
3

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1
2
5
2
7
1
29.29, 130.65 (2C, J = 7.6 Hz), 134.46, 135.58 (J = 3.0 Hz), 135.99, 146.81, 156.99, 162.16 (J =
45.5 Hz),. Anal. calcd for C H FN: C 80.99, H 5.09, N 5.90; found C 80.69, H 5.23, N 5.82.
1
6
12
.3.4. 6-Fluoro-3-(4-fluorophenyl)-2-methylquinoline (11e). Yield: 78% as a brown solid. Mp.
o
1
09-210 C. H NMR (CDCl ): 2.63 (s, 3H, 2-Me), 7.14-7.20 (m, 2H, Ar-H), 7.34-7.49 (m, 4H,5-,
3
13
-, and Ar-H), 7.88 (s, 1H, 4-H), 8.04 (dd, 1H, J = 8.8, 5.6 Hz, 8-H). C NMR (CDCl ): 24.40,
3
10.35 (J = 21.3 Hz), 115.50 (2C, J = 21.3 Hz), 119.58 (J = 25.0 Hz), 127.29 (J = 9.9 Hz), 130.78
(2C, J = 7.6 Hz), 130.93, 135.45, 135.48, 135.53, 144.15, 156.60, 160.23 (J = 245.5 Hz), 162.46 (J
=
245.5 Hz). Anal. calcd for C H NO ·0.3 H O: C 75.91, H 6.24, N 4.91; found C 75.63, H 6.21,
18 17 2 2
N 4.82.
5.4. General procedure for the preparation of quinoline-2-carbaldehydes 12 [22]. A mixture 11
o
(
3.0 mmol) and selenium dioxide (0.66 g, 6.0 mmol) in 1,4-dioxane (50 mL) was heated to 100 C
for 2 h (TLC monitoring). The mixture was diluted with saturated aqueous NaHCO and extracted
3
with CH Cl The combined organic layers were washed with H O followed by brine, dried with
2
2.
2
MgSO4 and evaporated. The crude product was recrystallized with EtOH to give
quinoline-2-carbaldehydes 12.
5.4.1. 6-Fluoro-3-(4-methoxyphenyl)quinoline-2-carbaldehyde (12b). Yield: 73% as a yellow
o
1
solid. Mp. 116-117 C. H NMR (CDCl ): 3.89 (s, 3H, OMe), 7.01-7.05 (m, 2H, Ar-H), 7.34-7.38
3
(m, 2H, Ar-H), 7.49 (dd, 1H, J = 8.4, 2.8 Hz, 5-H), 7.58 (ddd, 1H, J = 9.2, 8.4, 2.8 Hz, 7-H), 8.13 (s,
13
1
H, 4-H), 8.33 (dd, 1H, J = 9.2, 5.6 Hz, 8-H), 10.24 (s, 1H, CHO). C NMR (CDCl ): 55.37,
3
1
4

ACCEPTED MANUSCRIPT
1
1
1
5
10.43 (J = 22.0 Hz), 114.08 (2C), 121.02 (J = 26.5 Hz), 128.65, 129.94 (J = 10.6 Hz), 130.78 (2C),
33.33 (J = 9.8 Hz), 136.32, 137.72 (J = 6.1 Hz), 144.06, 149.43, 159.88, 162.23 (J = 251.6 Hz),
92.23. Anal. calcd for C H FNO : C 72.59, H 4.30, N 4.98; found C 72.82, H 4.45, N 4.76.
1
7
12
2
.4.2. 6-Methoxy-3-(4-methoxyphenyl)quinoline-2-carbaldehyde (12c). Yield 70% as a yellow
o
1
solid. Mp. 100-102 C. H NMR (CDCl ): 3.89 (s, 3H, OMe), 3.97 (s, 3H, 6-OMe), 7.01-7.05 (m,
3
2H, Ar-H), 7.10 (d, 1H, J = 2.8 Hz, 5-H), 7.35-7.39 (m, 2H, Ar-H), 7.45 (dd, 1H, J = 9.2, 2.8 Hz,
1
3
7
-H), 8.05 (s, 1H, 4-H), 8.20 (d, 1H, J = 9.2 Hz, 8-H), 10.22 (s, 1H, CHO). C NMR (CDCl ):
3
55.35, 55.70, 104.30, 113.93 (2C), 123.81, 129.28, 130.57, 130.77 (2C), 132.09, 136.25, 136.86,
1
43.23, 147.59, 159.66, 160.12, 192.37. Anal. calcd for C H NO : C 73.69, H 5.16, N 4.91; found
1
8
15
3
C 73.63, H 4.91, N 4.70.
5
1
7
8
1
1
4
5
.4.3. 3-(4-Fluorophenyl)quinoline-2-carbaldehyde (12d). Yield 87% as a yellow solid. Mp.
o
1
55-156 C. H NMR (400 MHz, CDCl ): 7.15-7.20 (m, 2H, Ar-H), 7.37-7.41 (m, 2H, Ar-H),
3
.68-7.85 (m, 2H, 6-, and 7-H), 7.88 (d, 1H, J = 8.4 Hz, 5-H), 8.17 (s, 1H, 4-H), 8.36 (d, 1H, J =
1
3
.4 Hz, 8-H), 10.26 (s, 1H, CHO). C NMR (100 MHz, CDCl ): 115.43 (2C, J = 22.0 Hz), 127.58,
3
28.80, 129.64, 130.39, 130.60, 131.10 (2C, J = 8.4 Hz), 133.17 (J = 3.0 Hz), 134.38, 138.74,
47.06, 149.75, 162.76 (J = 246.4 Hz), 192.64. Anal. calcd for C H FNO·0.2 H O: C 75.40, H
1
6
10
2
.11, N 5.50; found: C 75.65, H 4.03, N 5.46.
.4.4. 3-(4-Fluorophenyl)-6-floroquinoline-2-carbaldehyde (12e). Yield 81% as a yellow solid.
o
1
Mp. 154-156 C. H NMR (400 MHz, CDCl ): 7.16-7.21 (m, 2H, Ar-H), 7.37-7.40 (m, 2H, Ar-H),
3
1
5

ACCEPTED MANUSCRIPT
7.51 (dd, 1H, J = 8.4, 2.8 Hz), 7.60 (ddd, 1H, J = 9.2, 8.4, 2.8 Hz, 7-H), 8.11 (s, 1H, 4-H), 8.33 (dd,
1
3
1
H, J = 9.2, 5.2 Hz, 8-H), 10.23 (s, 1H, CHO). C NMR (100 MHz, CDCl ): 110.56 (J = 21.2 Hz),
3
115.43 (2C, J = 22.0 Hz), 121.28 (J = 26.5 Hz), 129.78 (J = 10.6 Hz), 131.06 (2C, J = 8.3 Hz),
1
1
7
5
33.23 (J = 9.8 Hz), 132.77 (J = 3.0 Hz), 135.12, 137.96, 138.02, 144.20, 162.36 (J = 252.3 Hz),
62.86 (J = 247.1 Hz), 192.26. Anal. calcd for C H F NO: C 71.37, H 3.37, N 5.20; found: C
16
9 2
1.39, H 7.70, N 5.17.
.5. General procedure for the preparation of 2-(hydroxyphenylmethyl)-3-phenylquinoline
compounds 13a-e, 15a and 15b. A mixture of 3-phenylquinoline-2-carbaldehyde 12a (0.23 g, 1.0
mmol), phenyl magnesium bromide (3 mmol, 3 mL of a 1 M solution in THF), and THF (30 mL)
o
was stirded at 0 C for 12 h (TLC monitoring). The reaction was quenched by addition of water (3
mL) and partitioned between H O (50 mL) and CH Cl (50 mL). The organic layer was washed
2
2
2
with brine and dried over MgSO and removal of the volatiles in vacuo provided a residue, which
4
was purified by flash chromatography on silica gel (n-hexane : CH Cl = 3/2) and recrystallized
2
2
from EtOH to give compounds 13a. Accordingly, compounds 13b-e, 15a, and 15b were obtained in
this manner.
5.5.1. 2-(Hydroxyphenylmethyl)-3-(4-methoxyphenyl)quinoline (13a). Yield 58% as a white
o
1
solid. Mp. 113-114 C. H NMR (400 MHz, CDCl ): 3.86 (s, 3H, OCH ), 5.98 (d, 1H, J = 6.0 Hz,
3
3
CH), 6.31 (d, 1H, J = 6.0 Hz, OH), 6.78-6.81 (m, 2H, Ar-H), 6.84-6.86 (m, 2H, Ar-H), 6.93- 6.96
m, 2H, Ar-H) 7.03-7.11 (m, 3H, Ar-H), 7.56-7.60 (m, 1H, 6-H), 7.75-7.83 (m, 2H, 7- and 5-H),
(
1
6

ACCEPTED MANUSCRIPT
1
3
7
.91 (s, 1H, 4-H), 8.20 (dd, 1H, J = 8.4, 1.2 Hz, 8-H). C NMR (100 MHz, CDCl ): 55.37, 72.86,
3
113.75 (2C), 126.86, 127.26, 127.45, 127.60 (2C), 127.95 (2C), 128.66, 129.68, 130.15,
1
30.51(2C), 133.95, 137.54, 142.35, 145.11, 159.10, 159.35. Anal. calcd for C H NO ·0.1 H O:
23
19
2
2
C 80.49, H 5.64, N 4.08; found: C 80.21, H 5.59, N 4.00.
5.5.2. 2-(Hydroxyphenylmethyl)-3-(4-methoxyphenyl)-6-methoxyquinoline (13b). Yield 51%
o
1
as a white solid. Mp. 170-171 C. H NMR (400 MHz, CDCl ): 3.86 (s, 3H, OCH ), 3.93 (s, 3H,
3
3
OCH ), 5.94 (s, 1H, CH), 6.22 (br s, 1H, OH), 6.78-6.80 (m, 2H, Ar-H), 6.84-6.86 (m, 2H, Ar-H),
3
6.93-6.95 (m, 2H, Ar-H), 7.03-7.10 (m, 4H, 5- and Ar-H), 7.42 (dd, 1H, J = 9.2, 2.8 Hz, 7-H), 7.81
13
(
s, 1H, 4-H), 8.09 (d, 1H, J = 9.2 Hz, 8-H). C NMR (100 MHz, CDCl ): 55.35, 55.59, 72.69,
3
104.96, 113.72 (2C), 122.31, 127.17, 127.55 (2C), 127.92 (2C), 128.56, 130.07, 130.34, 130.47
(
2C), 134.19, 136.43, 141.16, 142.67, 156.48, 158.11, 159.30. Anal. calcd for C H NO ·0.2 H O:
24
21
3
2
C 76.86, H 5.75, N 3.73; found: C 76.53, H 5.65, N 3.68.
5.5.3. 6-Fluoro-2-(hydroxyphenylmethyl)-3-(4-methoxyphenyl)quinoline (13c). Yield 53% as a
o
1
white solid. Mp. 124-125 C. H NMR (400 MHz, CDCl ): 3.86 (s, 3H, OCH ), 5.97(s, H, CH), 6.16
3
3
(br s, 1H, OH), 6.77-6.80 (m, 2H, Ar-H), 6.84-6.87 (m, 2H, Ar-H), 6.92-6.96 (m, 2H, Ar-H),
7
7
7
1
.04-7.12 (m, 3H, Ar-H), 7.43 (dd, 1H, J = 8.8, 2.8 Hz, 5-H), 7.53 (ddd, 1H, J = 9.2, 8.4, 2.8 Hz,
1
3
-H), 7.86 (s, 1H, 4-H), 8.20 (dd, 1H, J = 9.2, 5.2 Hz, 8-H). C NMR (100 MHz, CDCl ): 55.37,
3
2.84, 110.51 (J = 21.3 Hz), 113.82 (2C), 119.87 (J = 25.8 Hz), 127.36, 127.55 (2C), 128.01 (2C),
28.23 (J = 9.9 Hz), 129.72, 130.43 (2C), 131.06 (J = 9.1 Hz), 134.82, 136.96, 142.14, 142.18,
1
7

ACCEPTED MANUSCRIPT
1
58.62 (J = 3.0 Hz), 159.50, 160.73 (J = 247.2 Hz). Anal. calcd for C H FNO ·0.5 H O: C 75.40,
2
3
16
2
2
H 4.68, N 3.82; found: C 75.72, H 4.94, N 3.81.
5.5.4. 3-(4-Fluorophenyl)-2-(hydroxyphenylmethyl)quinoline (13d). Yield 60% as a white solid.
o
1
Mp.: 145-146 C. H NMR (400 MHz, CDCl ): 5.91 (s, 1H, CH), 6.33 (br s, 1H, OH), 6.75-6.78 (m,
3
2
1
2
H, 2-H), 6.93-7.12 (m, 7H, Ar-H), 7.57-7.62 (m, 1H, 6-H), 7.77-7.84 (m, 2H, 7- and 5-H), 7.91 (s,
1
3
H, 4-H), 8.22 (dd, 1H, J = 8.4, 1.2 Hz, 8-H). C NMR (100 MHz, CDCl ): 73.00, 115.26 (2C, J =
3
1.2 Hz), 127.07, 127.42, 127.48, 127.66 (2C), 128.06 (2C), 128.68, 130.01, 131.03 (2C, J = 7.6
Hz), 133.20, 133.75 (J = 3.8 Hz), 137.65, 142.04, 145.16, 158.63, 162.49 (J = 246.3 Hz). Anal.
calcd for C H FNO· 0.1 H O: C 79.79, H 4.93, N 4.23; found: C 79.60, H 4.79, N 4.21.
2
2
16
2
5.5.5. 6-Fluoro-2-(hydroxyphenylmethyl)-3-(4-fluorophenyl)quinoline (13e). Yield 52% as a
o
1
white solid. Mp.: 154-155 C. H NMR (400 MHz, CDCl ): 5.90 (s, 1H, CH), 6.18 (br s, 1H, OH),
3
6
1
.74-6.77 (m, 2H, ArH), 6.93-7.13 (m, 7H, Ar-H), 7.44 (dd, 1H, J = 8.8, 2.8 Hz, 5-H), 7.56 (ddd,
1
3
H, J = 9.2, 8.4, 2.8 Hz, 7-H), 7.87 (s, 1H, 4-H), 8.22 (dd, 1H, J = 9.2, 5.2 Hz, 8-H). C NMR (100
MHz, CDCl ): 72.97, 110.58 (J = 22.0 Hz), 115.35 (2C, J = 22.0 Hz), 120.18 (J = 25.7 Hz), 127.57
3
(J = 9.1 Hz), 127.61 (2C), 128.13 (2C), 130.95 (2C, J = 8.3 Hz), 131.16 (J = 9.0 Hz), 133.39 (J =
3
1
7
5
.8 Hz), 134.06, 136.99, 137.05, 141.88, 142.29, 158.16 (J = 3.1 Hz), 160.81 (J = 247.8 Hz),
62.59 (J = 246.3 Hz). Anal. calcd for C H F NO·0.1 H O: C 75.68, H 4.39, N 4.01; found: C
2
2
15
2
2
5.63, H 4.20, N 4.05.
.5.6. 2-(hydroxy-4-methoxyphenylmethyl)-3-(4-methoxyphenyl)quinoline (15a). Yield 54% a
1
8

ACCEPTED MANUSCRIPT
o
1
yellow solid. Mp. 129-130 C. H NMR (400 MHz, CDCl ): 3.71 (s, 3H, OMe), 3.86 (s, 3H, OMe),
3
5
6
8
1
.95 (s, 1H, CH), 6.60-6.62 (m, 2H, Ar-H), 6.73-6.75 (m, 2H, Ar-H), 6.86-6.88 (m, 2H, Ar-H),
.95-6.97 (m, 2H, Ar-H), 7.57-7.62 (m, 1H, 6-H), 7.77-7.86 (m, 2H, 5- and 7-H), 7.95 (s, 1H, 4-H),
1
3
.27 (d, 1H, J = 8.4 Hz, 8-H). C NMR (100 MHz, CDCl ): 55.17, 55.37, 72.42, 113.45 (2C),
3
13.74 (2C), 127.05, 127.46, 127.53 (2C), 128.14, 128.85 (2C), 129.80, 129.91, 130.00, 130.51
(
2C), 134.00, 138.08, 158.83, 159.36, 159.45. Anal. calcd for C H NO : C 77.61, H 5.70, N 3.77;
24 21 3
found: C 77.65, H 5.81, N 3.56.
5.5.7. 2-(Hydroxy-3,4,5-trimethoxyphenylmethyl)-3-(4-methoxyphenyl)quinoline (15b). Yield
o
1
5
4% a yellow solid. Mp. 143-144 C. H NMR (400 MHz, CDCl ): 3.61 (s, 6H, OMe), 3.74 (s, 3H,
3
OMe), 3.78 (s, 3H, OMe), 5.95 (s, 1H, CH), 6.04 (s, 2H, Ar-H), 6.88-6.89 (m, 2H, Ar-H), 6.99-7.03
(m, 2H, Ar-H), 7.60-7.64 (m, 1H, 6-H), 7.79-7.87 (m, 2H, 5- and 7-H), 7.98 (s, 1H, 4-H), 8.30 (d,
1
3
1
1
1
3
5
H, J = 8.4 Hz, 8-H). C NMR (100 MHz, CDCl ): 55.31, 55.77 (2C), 60.69, 73.21, 104.53 (2C),
3
13.82 (2C), 114.19, 127.25, 127.54 (2C), 127.58, 128.04, 129.96, 130.20, 130.63 (2C), 133.92,
37.17, 137.43, 138.37, 152.82, 158.99, 159.39. Anal. calcd for C H NO : C 72.37, H 5.84, N
2
6
25
5
.25; found: C 72.24, H 5.90, N 3.14.
.6. General procedure for preparation of 2-benzoyl-3-phenylquinoline derivatives: 14a-e, 16a
and 16b. A mixture of 13a (0.34 g, 1 mmol) and MnO (0.87 g, 10 mmol) in CH Cl (20 mL) was
2
2
2
stirred at room temperature for 12 h (TLC monitoring). The reaction mixture was partitioned
between H O (50 mL) and CH Cl (50 mL). The organic layer was washed with brine and dried
2
2
2
1
9

ACCEPTED MANUSCRIPT
over MgSO and removal of the volatiles in vacuo provided a residue, which was crystallized from
4
MeOH to give compounds 14a. Accordingly, compounds 14b-e, 16a, and 16b were obtained in this
manner.
o
5
.6.1. 2-Benzoyl-3-(4-methoxyphenyl)quinoline (14a). Yield 93% a white solid. Mp. 124-125 C.
1
H NMR (400 MHz, CDCl ): 3.78 (s, 3H, OCH ), 6.83-6.87 (m, 2H, Ar-H), 7.30-7.34 (m, 2H,
3
3
Ar-H) 7.38-7.42 (m, 2H, Ar-H), 7.52-7.56 (m, 1H, Ar-H), 7.62-7.66 (m, 1H, 6-H), 7.74-7.78 (m,
H, 7-H), 7.85-7.88 (m, 2H, Ar-H), 7.91 (dd, 1H, J = 8.0, 1.2 Hz, 5-H), 8.16 (dd, 1H, J = 8.4, 0.8
1
1
3
Hz, 8-H), 8.24 (s, 1H, 4-H). C NMR (100 MHz, CDCl ): 55.21, 114.13 (2C), 127.64, 127.86,
3
1
1
4
5
1
2
7
28.16, 128.41 (2C), 129.61, 129.87, 129.98, 130.21 (2C), 130.43 (2C), 133.53, 133.57, 136.13,
36.77, 145.87, 156.44, 159.40, 195.35. Anal. calcd for C H NO ·0.2 H O: C 80.54, H 5.11, N
2
3
17
2
2
.08; found: C 80.83, H 5.02, N 4.06.
.6.2. 2-Benzoyl-6-methoxy-3-(4-methoxyphenyl)quinoline (14b). Yield 89% a white solid. Mp:
o
1
22-123 C. H NMR (400 MHz, CDCl ): 3.77 (s, 3H, OCH ), 3.97 (s, 3H, OCH ), 6.82-6.86 (m,
3
3
3
H, Ar-H), 7.14 (d, 1H, J = 2.8 Hz, 5-H), 7.29-7.32 (m, 2H, Ar-H) 7.37-7.41 (m, 3H, 7- and Ar-H),
.51-7.55 (m, 1H, Ar-H), 7.86-7.88 (m, 2H, Ar-H), 8.04 (d, 1H, J = 9.2 Hz, 8-H), 8.11 (s, 1H, 4-H).
1
3
C NMR (100 MHz, CDCl ): 55.19, 55.62, 104.78, 114.07 (2C), 122.85, 128.34 (2C), 129.41,
3
1
1
5
30.12 (2C), 130.24, 130.46 (2C), 131.07, 133.37, 134.01, 135.51, 136.35, 141.93, 153.81, 158.89,
59.32, 195.42. Anal. calcd for C H NO ·0.2 H O: C 77.28, H 5.24, N 3.75; found: C 77.09, H
2
4
19
3
2
.19, N 3.70.
2
0

ACCEPTED MANUSCRIPT
5.6.3. 2-Benzoyl-6-fluoro-3-(4-methoxyphenyl)quinoline (14c). Yield 90% a white solid. Mp.
o
1
1
57-158 C. H NMR (400 MHz, CDCl ): 3.77 (s, 3H, OCH ), 6.83-6.87 (m, 2H, Ar-H), 7.29-7.32
3 3
(m, 2H, Ar-H), 7.38-7.42 (m, 2H, Ar-H), 7.49-7.57 (m, 3H, 5-, 7-, and Ar-H), 7.84-7.87 (m, 2H,
1
3
Ar-H), 8.15 (dd, 1H, J = 9.6, 5.2 Hz, 8-H), 8.17 (s, 1H, 4-H). C NMR (100 MHz, CDCl ): 55.21,
3
1
10.55 (J = 21.9 Hz), 114.18 (2C), 120.22 (J = 25.7 Hz), 128.44 (2C), 128.94 (J = 9.9 Hz), 129.56,
30.16 (2C), 130.38 (2C), 132.20 (J = 9.1 Hz), 133.61, 134.39, 136..03, 136.08, 142.89, 155.79 (J
1
=
3.0 Hz), 159.54, 161.31 (J = 248.6 Hz), 195.35. Anal. calcd for C H FNO ·0.2 H O: C 76.53,
23 16 2 2
H 4.58, N 3.88; found: C 76.51, H 4.49, N 3.82.
o
5
.6.4. 2-Benzoyl-3-(4-fluorophenyl)quinoline (14d). Yield 91% a white solid. Mp. 103-104 C.
1
H NMR (400 MHz, CDCl ): 6.95-7.01 (m, 2H, Ar-H), 7.31-7.40 (m, 4H, Ar-H), 7.50-7.54 (m, 1H,
3
Ar-H), 7.60-7.64 (m, 1-H, 6-H), 7.72-7.77 (m, 1H, 7-H), 7.84-7.90 (m, 3H, 5- and Ar-H), 8.16 (d,
1
3
1
1
1
1
4
5
1
7
H, J = 8.8 Hz, 8-H), 8.21 (s, 1H, 4-H). C NMR (100 MHz, CDCl ): 115.54 (2C, J = 22.0 Hz),
3
27.63, 127.90, 128.02, 128.41 (2C), 129.51, 130.16, 130.32 (2C), 130.64 (2C, J = 8.3 Hz),
32.83, 133.61, 133.66 (J = 3.0 Hz), 135.95, 137.08, 145.93, 156.02, 162.45 (J = 245.6 Hz),
94.96. Anal. calcd for C H FNO·0.2 H O: C 79.84, H 4.38, N 4.23; found: C 79.83, H 4.46, N
22
14
2
.11.
.6.5. 2-Benzoyl-6-fluoro-3-(4-fluorophenyl)quinoline (14e). Yield 91% a white solid. Mp.
o
1
18-119 C. H NMR (400 MHz, CDCl ): 6.99-7.04 (m, 2H, Ar-H), 7.32-7.37 (m, 2H, Ar-H)
3
.39-7.44 (m, 2H, Ar-H), 7.51-7.58 (m, 3H, 5-, 7-, and Ar-H), 7.84-7.87 (m, 2H, Ar-H), 8.16-8.19
2
1

ACCEPTED MANUSCRIPT
1
3
(
m, 2H, 4-H and 8-H). C NMR (100 MHz, CDCl ): 110.54 (J = 21.2 Hz), 115.72 (2C, J = 22.0
3
Hz), 120.61 (J = 25.7 Hz), 128.51 (2C), 128.80 (J = 9.9 Hz), 130.40 (2C), 130.69 (2C, J = 8.4 Hz),
32.31 (J = 9.1 Hz), 133.39 (J = 3.1 Hz), 133.75, 135.94, 136.41, 136.47, 143.10, 155.51 (J = 2.2
Hz), 161.43 (J = 248.6 Hz), 162.67 (J = 246.2 Hz), 194.74. Anal. calcd for C H F2NO: C 76.51,
1
2
2
13
H 3.79, N 4.06; found: C 76.37, H 3.67, N 4.05.
.6.6. 2-(4-Methoxybenzoyl)-3-(4-methoxyphenyl)quinoline (16a). Yield 89% a yellow solid.
5
o
1
Mp. 135-137 C. H NMR (400 MHz, CDCl ): 3.78 (s, 3H, OMe), 3.84 (s, 3H, OMe), 6.84-6.88 (m,
3
4H, Ar-H), 7.32-7.35 (m, 2H, Ar-H), 7.60-7.65 (m, 1H, 6-H), 7.73-7.77 (m, 1H, 7-H), , 7.82-7.86
1
3
(
m, 2H, Ar-H), 7.89 (d, 1H, J = 8.4 Hz, 5-H), 8.15 (d, 1H, J = 8.4 Hz, 8-H), 8.23 (s, 1H, 4-H). C
NMR (100 MHz, CDCl ): 55.19, 55.46, 113.74 (2C), 114.08 (2C), 127.61, 127.72, 129.08, 129.22,
3
1
1
5
29.53, 129.79, 130.07, 130.14 (2C), 132.82 (2C), 133.45, 136.71, 145.84, 156.79, 159.34, 163.90,
94.04. Anal. calcd for C H NO : C 78.03, H 5.18, N 3.79; found: C 77.64, H 5.27, N 3.66.
2
4
19
3
.6.7. 2-(3,4,5-Trimethoxybenzoyl)-3-(4-methoxyphenyl)quinoline (16b). Yield 82% as a yellow
o
1
solid. Mp. 161-1623 C. H NMR (400 MHz, CDCl ): 3.79 (s, 6H, OMe), 3.80(s, 3H, OMe), 3.92 (s,
3
3H, OMe), 6.88-6.90 (m, 2H, Ar-H), 7.17 (s, 2H, Ar-H), 7.32-7.36 (m, 2H, Ar-H), 7.64-7.68 (m,
1H, 6-H), 7.75-7.79 (m, 1H, 7-H ) 7.93 (d, 1H, J = 8.4 Hz, 5-H), 8.18 (d, 1H, J = 8.4 Hz, 8-H), 8.26
1
3
(
s, 1H, 4-H). C NMR (100 MHz, CDCl ): 55.23, 56.23 (2C), 60.92, 108.06 (2C), 114.22 (2C),
3
1
27.66 (2C), 127.94, 128.16, 129.55, 129.96, 130.03, 130.09 (2C), 130.78, 131.10, 133.66, 136.84,
45.79, 152.92, 156.24, 159.45, 194.09. Anal. calcd for C H NO : C 71.09, H 6.71, N 10.36;
1
2
6
23
5
2
2

ACCEPTED MANUSCRIPT
found: C 71.09, H 6.76, N 10.41.
.7. 2-(4-Hydroxybenzoyl)-3-(4-hydroxyphenyl)quinoline (17). A solution of 16a (0.37 g, 1.0
5
mmol) in 48% HBr (5 mL) was heated at reflux for 48 h. The mixture was cooled and evaporated in
vacuo to give a residue which was treated with H O (50 mL). The crude product was collected and
2
o
1
crystallized from MeOH to give 17 (0.31 g, 90%) as a green solid. Mp. 173-174 C. H NMR (400
MHz, DMSO-d ): 6.73-6.76 (m, 2H, Ar-H), 6.82-6.84 (m, 2H, Ar-H), 7.22-7.24 (m, 2H, Ar-H),
6
7
.61-7.63 (m, 2H, Ar-H), 7.69-7.73 (m, 1H, 6-H), 7.80-7.83 (m, 1H, 7-H), 8.05 (d, 1H, J = 8.4 Hz,
-H), 8.11 (d, 1H, J = 8.4 Hz, 8-H), 8.48 (s, 1H, 4-H), 9.64 (br s, 1H, OH), 10.58 (br s, 1H, OH).
5
1
3
C-NMR (100 MHz, DMSO-d ): 115.46 (2C), 115.52 (2C), 127.48, 127.70, 127.78, 127.96,
6
1
1
3
5
28.12, 128.61, 130.04 (2C), 132.59 (2C), 132.81, 136.53, 145.01, 156.83, 157.31, 162.74 (2C),
93.25. Anal. calcd for C H NO ·1.3 H O: C 72.44, H 4.86, N 3.84; found: C 72.49, H 4.75, N
22
15
3
2
.84.
.8. General procedure for preparation of aminoalkylated derivatives and disubstituted
derivatives: 18a-19c. To a stirred solution of 17 (1.0 mmol) in dry DMF (20 mL) was added NaH
o
(
60% in oil, 0.50 g) at 0 C for 1 h. An appropriate tertiary-aminoalkyl halide (3 mmol) was added
and stirred at room temperature for 4 h (TLC monitoring). The organic phase was washed with
brine, dried over MgSO , filtered and concentrated under vacuo. Crude product was purified by
4
flash chromatography on silica gel, using a gradient of MeOH/CH Cl (1/30 to 1/10) to give the
2
2
18a-19c.
2
3

ACCEPTED MANUSCRIPT
5.8.1. 2-(4-hydroxybenzoyl)-3-{4-[3-(dimethylamino)propoxyl]phenyl}quinoline (18a) and
2-{4-[3-(dimethylamino)propoxy]benzoyl}-3-{4-[3-(dimethylamino)propoxyl]phenyl}quinolin
1
e (19a). Compound 18c was obtained in 26 % yield (0.11 g) as a green liquid. H-NMR (400 MHz,
CDCl ): 1.89-1.96 (m, 2H, OCH CH CH N), 2.35 (s, 6H, NMe ), 2.56-2.60 (m, 2H,
3
2
2
2
2
OCH CH CH N), 3.93 (t, 2H, J = 5.6 Hz, OCH CH CH N), 6.23-6.28 (m, 4H, Ar-H ), 7.57-7.62
2
2
2
2
2
2
(m, 3H, 6- and Ar-H), 7.72 (m, 1H, 7-H), 7.89 (d, 1H, J = 8.0 Hz, 5-H), 8.14 (d, 1H, J = 8.4Hz,
1
3
8
-H), 8.22 (s, 1H, 4-H). C NMR (100 MHz, CDCl ): 26.36, 44.68 (2C), 56.01, 65.68, 114.75
3
(2C), 155.93 (2C), 127.68, 127.71, 127.86, 128.10, 129.24, 129.93, 130.19, 130.28 (2C), 132.97
+
(
2C), 133.37, 136.68, 145.84, 157.18, 158.31, 163.03, 194.31. ESIMS [M+H] : 427.2.
1
Compound 19a was obtained in 43% yield (0.22 g) as a green liquid. H-NMR (400 MHz, CDCl ):
3
2
.00-2.07 (m, 4H, OCH CH CH N), 2.34 and 2.38 (two s, 12H, NMe ), 2.56-2.65 (m, 4H,
2 2 2 2
OCH CH CH N), 3.99 and 4.07 (two t, 4H, J = 5.6 Hz, OCH CH CH N), 6.82-6.88 (m, 4H, Ar-H ),
2
2
2
2
2
2
7
1
2
1
1
5
2
.27-7.33 (m, 2H, Ar-H), 7.63 (m, 1H, 6-H), 7.75 (m, 1H, 7-H), 7.80-7.83 (m, 2H, Ar-H), 7.92 (d,
1
3
H, J = 8.0 Hz, 5-H), 8.16 (d, 1H, J = 8.4 Hz, 8-H), 8.22 (s, 1H, 4-H). C NMR (100 MHz, CDCl ):
3
6.65, 26.72, 44.72 (2C), 44.91 (2C), 55.95, 56.07, 65.77, 66.17, 114.20 (2C), 114.61 (2C), 127.62,
27.73, 128.09, 129.23, 129.54, 129.71, 129.82, 130.16 (2C), 132.81 (2C), 133.43, 136.70, 145.88,
+
56.81, 158.63, 163.26, 194.03. ESIMS [M+H] : 512.3.
.8.2. 2-(4-Hydroxybenzoyl)-3-{4-[2-(piperidin-1-yl)ethoxy]phenyl}quinoline (18b) and
-{4-[2-(piperidin-1-yl)ethoxy]benzoyl}-3-{4-[2-(piperidin-1-yl)ethoxy]phenyl}quinoline
2
4

ACCEPTED MANUSCRIPT
1
(
19b). Compound 18b was obtained in 24 % yield (0.11 g) as a yellow liquid. H-NMR (400 MHz,
CDCl ): 1.57-1.59 (m, 2H, piperidinyl-H), 1.81-1.84 (m, 4H, piperidinyl-H), 2.86-2.88 (m, 4H,
3
piperidinyl-H), 3.05(t, 2H, J = 5.6 Hz, OCH CH N), 4.24 (t, 2H, J = 5.6 Hz, OCH CH N),
2
2
2
2
6
7
.72-6.77 (m, 4H, Ar-H), 7.26-7.28 (m, 2H, Ar-H), 7.60-7.65 (m, 3H, Ar-H and 6-H), 7.75 (m, 1H,
1
3
-H), 7.91 (d, 1H, J = 8.0 Hz, 5-H), 8.17 (d, 1H, J = 8.4 Hz, 8-H), 8.21 (s, 1H, 4-H). C NMR
(
100 MHz, CDCl ): 23.35, 25.05 (2C), 54.22 (2C), 57.02, 65.08, 114.16 (2C), 115.08 (2C), 127.22
3
(2C), 127.44 (2C), 128.52 (2C), 129.43, 129.58 (2C), 132.28 (2C), 132.50, 136.18, 145.06, 156.41,
1
57.93, 162.54, 193.04. Anal. calcd for C H N O ·0.4 H O·0.5 HCl: C 72.85, H 6.19, N 5.86;
29 28 2 3 2
found: C 72.91, H 6.23, N 5.58.
1
Compound 19b was obtained in 53 % yield (0.30 g) as a yellow liquid. H-NMR (400 MHz,
CDCl ): 1.44-1.46 (m, 4H, piperidinyl-H), 1.60-1.68 (m, 8H, piperidinyl-H), 2.53-2.57 (m, 8H,
3
piperidinyl-H), 2.79-2.83 (m, 4H, OCH CH N), 4.10-4.18 (m, 4H, OCH CH N), 6.83-6.88 (m, 4H,
2
2
2
2
Ar-H), 7.30-7.32 (m, 2H, Ar-H), 7.63 (m, 1H, 6-H), 7.75 (m, 1H, 7-H), 7.80-7.83 (m, 2H, Ar-H),
1
3
7
.92 (d, 1H, J = 8.0 Hz, 5-H), 8.16 (d, 1H, J = 8.4Hz, 8-H), 8.22 (s, 1H, 4-H). C NMR (100 MHz,
CDCl ): 23.90, 23.98, 25.54 (2C), 25.69 (2C), 54.90 (2C), 54.99 (2C), 57.57, 57.67, 65.54, 66.30,
3
1
1
0
5
14.30 (2C), 114.73 (2C), 127.62, 127.72, 128.09, 129.27, 129.56, 129.80, 130.15 (2C), 130.25,
32.80 (2C), 133.43, 136.70, 145.88, 156.79, 158.46, 163.10, 194.02. Anal. calcd for C H N O ·
3
6
41
3
3
.6 H O: C 75.25, H 7.40, N 7.31; found: C 75.04, H 7.52, N 7.23.
2
.8.3. 2-(4-Hydroxybenzoyl)-3-{4-[2-(pyrrolidin-1-yl)ethoxy]phenyl}quinoline (18c) and
2
5

ACCEPTED MANUSCRIPT
2-{4-[2-(pyrrolidin-1-yl)ethoxy]benzoyl-3-{4-[2-(pyrrolidin-1-yl)ethoxy]phenyl}quinoline
1
(
19c). Compound 18c was obtained in 29% yield (0.13 g) as a yellow liquid. H NMR (400 MHz,
CDCl ): 1.82-1.84 (m, 4H, pyrrolidinyl-H), 2.87-2.89 (m, 4H, pyrrolidinyl-H), 2.99 (t, 2H, J = 5.6
3
Hz, OCH CH N), 4.07 (t, 2H, J = 5.6 Hz, OCH CH N), 6.65-6.74 (m, 4H, Ar-H), 7.23-7.28 (m, 2H,
2
2
2
2
Ar-H), 7.56-7.72 (m, 4H, 6-, 7-, and Ar-H), 7.85 (d, 1H, J = 8.0 Hz, 5-H),8.12 (d, 1H, J = 8.4 Hz,
1
3
8
-H), 8.17 (s, 1H, 4-H). C NMR(100MHz, CDCl ): 23.17 (2C), 54.38 (2C), 54.66, 65.58, 114.58
3
(2C), 115.87 (2C), 127.61, 127.69, 128.05, 129.18, 129.90, 130.18 (2C), 130.44, 133.10 (2C),
1
7
33.30, 136.82, 145.71, 157.10, 158.09, 163.36, 194.06. Anal. calcd for C H N O ·2.25 H O: C
28 26 2 3 2
0.19, H 6.43, N 5.85; found: C 70.54, H 6.83, N 5.53.
1
Compound 19c was obtained in 57 % yield (0.31 g) as a yellow liquid. H NMR (400 MHz, CDCl ):
3
1.89-1.95 (m, 8H, pyrrolidinyl-H), 2.82-2.92 (m, 8H, pyrrolidinyl-H), 3.06 and 3.11 (two t, 4H, J =
5
.6 Hz, OCH CH N), 4.22-4.27 (m, 4H, OCH CH N), 6.84-6.89 (m, 4H, Ar-H), 7.30-7.34 (m, 2H,
2
2
2
2
Ar-H), 7.62 (m, 1H, 6-H), 7.75 (m, 1H, 7-H), 7.80-7.84 (m, 2H, Ar-H), 7.91 (d, 1H, J = 8.0 Hz,
1
3
5
2
1
1
5
5
-H),8.15 (d, 1H, J = 8.4Hz, 8-H), 8.22 (s, 1H, 4-H). C-NMR (100 MHz, CDCl ): 23.36 (2C),
3
3.40 (2C), 54.52 (2C), 54.62 (2C), 65.62, 66.37, 77.21 (2C), 114.32 (2C), 114.76 (2C), 127.65,
27.77, 128.08, 129.50, 129.55, 129.87, 130.23 (2C), 130.61, 132.81 (2C), 133.32, 136.76, 145.91,
+
56.71, 158.06, 162.77, 193.98. ESIMS [M+H] : 536.3.
.9. Cytotoxicity and antiviral activity assays
.9.1. Compounds
2
6

ACCEPTED MANUSCRIPT
Compounds were dissolved in DMSO at 10 mM and then diluted in culture medium.
5.9.2. Cells and virus
Cancer cells (A549, H1299, MCF-7, MDA-MB-231 and Huh-7) were purchased from Bioresources
Collection and Research Center, Taiwan. Huh-7-DV-Fluc cells and C6/36 cells were kindly
provided by Dr Huey Nan Wu, Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan,
ROC. The DENV-2 strain 16681 was isolated from a patient with dengue hemorrhage fever (DHF)
from Thailand [29], and was amplified in C6/36 mosquito cells.
5.9.3. Cytotoxicity assays
3
For cytotoxicity tests, run in parallel with antiviral assays, plates at an initial density of (5 x 10
cells/well), in maintenance medium, with or without serial dilutions of test compounds. Cell
o
viability was determined after 72 h at 37 C in a humidified CO (5%) atmosphere by the (2,3-bis
2
[
2-methyloxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide) (XTT) method [30].
.9.4. Analysis of luciferase activity
5
4
Huh-7-DV-Fluc cells were seeded in 24-well plates at a density of 2 × 10 cells per well, and
treated with the 2-aroyl-3-arylquinoline compounds at two concentrations (5 and 20 µM) or 0.1%
DMSO as control. After 72 h of incubation, the luciferase activity assay was performed using the
Bright-Glo Luciferase assay system (Promega) according to the manufacturer’s instructions.
5.9.5. Immunoblot analysis
The standard procedure was followed to perform western blotting as described previously [31]. The
2
7

ACCEPTED MANUSCRIPT
membranes were incubated overnight with rabbit polyclonal antibodies against NS2B (1：3000,
Genetex, Irvine, CA, USA) and GAPDH (1：10000, Genetex, Irvine, CA, USA) serving as loading
control.
5.9.6. Quantification of DENV RNA
Total cellular RNA was extracted after 3 days compounds treatment through Total RNA Miniprep
Purification Kit (GMbiolab, Taiwan) according to the manufacturer’s instructions. The expression
of DENV NS5 mRNA level was determine through quantification real-time RT-PCR (RT-PCR)
with specific primers corresponding to the DENV NS5 gene：Forward primer, 5-AAG GTG AGA
AGC AAT GCA GC-3；reverse primer, 5-CCA CTC AGG GAG TTC TCT CT-3. The copy number
of NS5 in each sample was normalized to cellular endogenous reference gene
glyceraldehydes-3-phosphate dehydrogenase (gapdh)；Forward primer: 5-GTC TTC ACC ACC
ATG GAG AA-3 and Reverse primer: 5-ATG GCA TGG ACT GTG GTC AT-3. The CT value of
each sample was determined by the ABI Step One Real-Time PCR-System (ABI Warrington, UK).
5.9.7. DENV infection assay
4
Huh-7 cells were seeded at the density of 4 X 10 cells/well in the 24 well culture plate for 16-20
hours and then infected with DENV-2 (16681 strain) at an MOI of 0.1 for 2 hours at 37 ℃. Cells
were washed with PBS once and then re-filled with DMEM-2% FBS medium containing various
indicating concentration of 13a and 17.
5.9.8. Statistical analysis
The results were expressed as means±S.D. Differences in mean values between groups were
2
8