Design and synthesis of chloroquine analogs with anti-breast cancer property

Article abstract of DOI:10.1016/j.ejmech.2010.05.046

A series of chloroquine (CQ) analogs were designed and synthesized in a repositioning approach to develop compounds with high anti-breast cancer property. The compounds were then examined for their antiproliferative effects on two human breast tumor cell lines and a matching non-cancer cell line. Although many of them showed substantial antiproliferative effects on breast cancer cells examined, two compounds, 7-chloro-N-(3-(4-(7-(trifluoromethyl) quinolin-4-yl)piperazin-1-yl)propyl)quinolin-4-amine (14) and {3-[4-(7-chloro-quinolin-4-yl)-piperazin-1-yl]-propyl}-(7-trifluoromethyl- quinolin-4-yl)-amine (26), emerged as the most active among this series. They were particularly potent against MCF7 cells when compared to CQ and cisplatin, a widely prescribed anti-cancer drug. The results suggest that these CQ analogs could serve as bases for the development of a new group of effective cancer chemotherapeutics. A series of chloroquine (CQ) analogs were designed and synthesized by a repositioning approach-based lead optimization concept to improve their anti-breast cancer property.

Full text of DOI:10.1016/j.ejmech.2010.05.046

European Journal of Medicinal Chemistry 45 (2010) 3916e3923
Contents lists available at ScienceDirect
European Journal of Medicinal Chemistry
journal homepage: http://www.elsevier.com/locate/ejmech
Original article
Design and synthesis of chloroquine analogs with anti-breast cancer property
,
,b,c,
V.R. Solomon a b, Changkun Hu a, Hoyun Lee a
*
a Tumour Biology Group, Northeastern Ontario Regional Cancer Program at the Sudbury Regional Hospital, 41 Ramsey Lake Road, Sudbury, Ontario P3E 5J1, Canada
b Department of Biology, Laurentian University, Sudbury, Ontario P3E 2C6, Canada
c Northern Ontario School of Medicine, 935 Ramsey Lake Road, Sudbury, Ontario P3E 2C6, Canada
a r t i c l e i n f o
a b s t r a c t
Article history:
A series of chloroquine (CQ) analogs were designed and synthesized in a repositioning approach to
develop compounds with high anti-breast cancer property. The compounds were then examined for
their antiproliferative effects on two human breast tumor cell lines and a matching non-cancer cell line.
Although many of them showed substantial antiproliferative effects on breast cancer cells examined, two
compounds, 7-chloro-N-(3-(4-(7-(trifluoromethyl)quinolin-4-yl)piperazin-1-yl)propyl)quinolin-4-amine
(14) and {3-[4-(7-chloro-quinolin-4-yl)-piperazin-1-yl]-propyl}-(7-trifluoromethyl-quinolin-4-yl)-amine
(26), emerged as the most active among this series. They were particularly potent against MCF7 cells
when compared to CQ and cisplatin, a widely prescribed anti-cancer drug. The results suggest that these
Received 15 March 2010
Received in revised form
13 April 2010
Accepted 21 May 2010
Available online 31 May 2010
Keywords:
Chloroquine analogs
4-Aminoquinoline
Anti-cancer drugs
Breast cancer
CQ analogs could serve as bases for the development of
chemotherapeutics.
a new group of effective cancer
Ó 2010 Elsevier Masson SAS. All rights reserved.
Repositioning approach
1. Introduction
repurposing approach can be very effective way to develop new
drug, since many existing drugs have been studied for their phar-
macokinetics and safety profiles and often have already been
approved by regulatory agencies for human use. Therefore, a newly
identified use of existing drugs can often be rapidly evaluated in
phase II trials [9,10]. The efficacy and specificity of a known drug
can also be improved by modifications of clinical formulations,
which is termed redirecting [9,10]. An important facet of the repo-
sitioning approach is that the discovery of new targets can be par-
layed directly into the generation of new chemical entities (NCEs)
by structural analog derivatization that can further enhance the
new mechanism or target activity. Therefore, we have applied
a repositioning and lead optimization approach to develop effective
anti-cancer agents using chloroquine (CQ) as a lead compound.
Chloroquine (Fig. 1) is a well-known anti-malarial and -rheu-
matoid agent, possessing a 4-aminoquinoline scaffold [11]. Based on
Breast cancer is one of the most commonly diagnosed cancers
and causes the second leading cancer deaths in women [1,2].
Although overall survival rate of breast cancer patients has
substantially increased during the last decades, this is mainly due
to early tumor detection [3e5]. Unfortunately, the recovery rate of
advanced breast cancer by currently available treatment modalities
is still unacceptably low [6]. Although chemotherapy is the main-
stay of cancer therapy, most of the chemotherapy drugs cause
general toxicity to any proliferating cells, which can severely limit
the therapeutic value of these drugs [7]. In an attempt to overcome
this problem, new anti-cancer agents with unique mechanisms of
action have been developed; however, many of them have not been
therapeutically useful due to low tumor selectivity [7]. This
prompted us to design and synthesize novel compounds with high
efficacy and specificity for the treatment of breast tumors.
repositioning concept, we have previously demonstrated that 10
mM
A study of 68 newly approved drugs estimated that developing
a single effective cancer drug takes an average of 15 years and US
$800 million [8]. One approach to overcome this hurdle may be
developing a new use of existing drugs [9]. This repositioning or
CQ substantially increases cancer cell killing effects when used in
combination with radiation or Akt inhibitors [12,13]. Importantly,
the CQ-mediated enhancement of cell killing by Akt inhibitors is
cancer-specific [13,14]. In continuation of our efforts to develop
effective anti-cancer drugs from CQ, we designed and synthesized
several CQ analogs. In this study, we introduced linear alkyl side
chain and dialkyl substitution on the lateral side chain, and exam-
ined their antiproliferative effects on MDA-MB468 and MCF7 breast
cancer cell lines [15]. We found that some of these compounds
were indeed more effective than CQ. The lysosomotropic CQ is
* Corresponding author. Tumour Biology Group, Northeastern Ontario Regional
Cancer Program at the Sudbury Regional Hospital, 41 Ramsey Lake Road, Sudbury,
Ontario P3E 5J1, Canada. Tel.: þ1 705 522-6237x2703; fax: þ1 705 523 7326.
E-mail address: hlee@hrsrh.on.ca (H. Lee).
0223-5234/$ e see front matter Ó 2010 Elsevier Masson SAS. All rights reserved.
doi:10.1016/j.ejmech.2010.05.046

V.R. Solomon et al. / European Journal of Medicinal Chemistry 45 (2010) 3916e3923
3917
R1
N
N
HN
N
R2
HN
HN
Repositioning
Repositioning
approach
approach based
X
N
Cl
N
Cl
N
lead optimization
Chloroquine
Chloroquine
7-19 X = Cl
20-32
X = CF3
Antimlarial Activity
Anticancer Activity
Fig. 1. Synthesis of CQ analogs to develop effective CQ-derived cancer agents.
accumulated in the lysosomes, raises intra-lysosomal pH, and
interferes with autophagosome degradation in the lysosomes [11].
This unique property of CQ and its analogs may be important for the
enhancement of cell killing/antiproliferative activities by cancer
therapeutic agents in a variety of different tumors [11].
This was followed by O-mesylation in THF at 0 ꢀC for 4 h to furnish
mesylate (5e6) in very good yield. Chemoselectivity in the mesy-
lation of preformed alcohol (1e2) was not a problem in spite of the
presence of a 4-amino (NH) group, which is poorly nucleophilic due
to the conjugation of the lone pair of electrons into the quinoline
nitrogen. The synthesis of N-alkylated 4-aminoquinoline deriva-
tives (7e32) (Scheme 1) employed with various active amino
components and sodium hydride as the base in N,N-dime-
thylformamide (DMF) as the solvent resulting in good yields.
It should be noted that synthesis of compounds 3, 5, 7, 9, 13, and
20 has been reported [17e21]. However, none of these compounds
has been examined for their antiproliferative activities on cancer
cells.
These findings have given impetus to our cancer drug research
by further augmenting the realization that rational choice of inputs
based on known CQ 4-aminoquinoline scaffold could lead to
molecules with desirable anti-breast cancer property. Therefore,
we designed and synthesized new molecules to further optimize
CQ-based anti-cancer agents, in which we selectively modified the
lateral side chain of diethyl amino functionality (Fig. 1, Scheme 1)
with a variety of heterocyclic ring substitutions including piper-
idinyl, pyrrolidinyl, morpholinyl, piperazinyl, substituted piper-
azinyl, and isatin. We took this approach because the heterocyclic
ring substituted CQ analogs have not yet been explored for the anti-
breast cancer activity. We have found that some of them are
promising as they show more effective antiproliferative activities
than CQ in a cancer-specific manner.
2.2. Antiproliferative effects of the compounds on cancer and non-
cancer cells
All of the compounds synthesized were evaluated for their
antiproliferative effects on two breast cancer cell lines, MDA-
MB231 (p53 and pRB mutated, ER negative breast carcinoma cell
line), and MCF7 (p53þ/ꢁ, invasive ductal breast carcinoma)
[22e25]. In addition, the cytotoxicity of all the compounds was also
evaluated using MCF10A, a non-cancer breast epithelial cell line, to
determine if our newly synthesized compounds have differential
effects on cancer and non-cancer cells. The antiproliferative activity
was measured by a sulforhodamine B (SRB) assay as described
previously [14]. The reading of SRB staining is known to accurately
reflect the levels of total cellular macromolecules/cell growth/
proliferation. For each compound, 50% growth inhibition (GI50) was
2. Results and discussion
2.1. Chemistry
The target N-alkylated 4-aminoquinoline compounds were
prepared as outlined in Scheme 1. The amino alcohol components
(3e4) used in the present study were prepared by aromatic
nucleophilic substitution on 4-chloro-7-substituted-quinoline with
excess of propanol amine in triethyl amine as reported earlier [16].
O
S
O
Cl
N
HN
N
OH
b
HN
N
O
CH3
a
X
X
X
5
X = Cl
X = CF3
1
X = Cl
X = CF3
3
X = Cl
X = CF3
6
2
4
c
R1
N
HN
R2
X
N
7-19 X = Cl
20-32 X = CF3
Reagent and Conditions: (a) Triethyl amine, Amino propanol, 120-130o C for 6 h (b) Triethylamine, Methane
sulfonyl chloride, THF, RT, 4 h (c) Amino component, NaH, DMF reflux at 65o C, 12 h
Scheme 1. Synthesis of CQ analogs.

3918
V.R. Solomon et al. / European Journal of Medicinal Chemistry 45 (2010) 3916e3923
calculated from Sigmoidal dose-response curves that were gener-
ated with data obtained from two independent experiments
carried out each in triplicate. The resultant data is presented in
Table 1. The data for CQ and cisplatin were included as references.
Among the twenty six CQ analogs synthesized and examined,
the antiproliferative activity on MCF7 cells (GI50 ¼ 21.45
mM). In
contrast, substitutions with alicyclic amino functionality (i.e., the
six-membered heterocyclic ring) namely piperidinyl (9) and mor-
pholinyl (10) resulted in a decrease of antiproliferative activity on
MDA-MB231 cells.
ten compounds showed GI50 in the range of 4.31e19.13
compounds 25.72e49.37 M, and remaining six compounds
showed above 50.24 M on the MDA-MB231 breast cancer cells
(Table 1). As for MCF-7 cells, sixteen compounds showed GI50 in the
range of 4.60e18.77 M, ten compounds at 20.63e46.72 M. The
differences in the GI50 values may be attributable to such factors as
the nature of the lateral side chain N-substitution at the 4-amino-
quinoline ring system and the halogen substitution on the 7th
position of 4-aminoquinoline ring system, and the genetic and
biochemical background of the cell lines.
The structureeactivity relationship (SAR) analysis appeared to
suggest that compounds 7e19 derived from the lateral side chain of
the 7-chloro-4-aminoquinoline ring system (except compound 16)
showed better antiproliferative activity than CQ on MCF7 cells.
Compounds derived from the 7- trifluoromethyl-4-aminoquinoline
lateral side chain substituted series (20e32) showed less anti-
proliferative activity than the corresponding 7-Cl derivatives.
However, they are generally equivalent to or more potent than CQ
on MCF7 cells, with the exception of compound 28. Compounds
11e14 derived from the lateral side chain of the 7-chloro-4-ami-
noquinoline ring system generally showed better antiproliferative
activity than CQ on MDA-MB231 cells.
m
M, ten
In the case of 4-methyl (11) and 4-phenyl (12) piperazinyl
substituted compound, there is an increase in antiproliferative
activity 1e2-fold on MDA-MB231 in comparison to morpholinyl
substituted compound (10). Furthermore, substitution of 4-(7-
chloroquinolin-4-yl)piperazin-1-yl (13) and 4-(7-trifluoromethyl)
quinolin-4-yl)piperazin-1-yl (14) showed an increase in anti-
proliferative activity on both MDA-MB231 and MCF7 cells.
However, compounds substituted with isatin ring (15) showed
a decrease in antiproliferative effects on both MDA-MB231 and
MCF7cells. The compounds derived from the 4-chloro isatin (16)
and 6-bromo isatin (19) ring substitution led to the reduction of
antiproliferation activity for MDA-MB231 and MCF7cells. Intro-
duction of the 4-bromo isatin (17) and 6-chloro isatin (18) ring led
to a 5-fold increase in antiproliferative activity for MCF7 cells in
comparison to CQ. Among the 7-chloro substitution on 4-amino-
quinoline derived analogs, the compound 14 was the most effective
m
m
m
m
as its GI50 values were 6.33 and 5.42
mM on MDA-MB231 and
MCF7cells, respectively. This data demonstrates that the anti-
proliferative effect of 14 on MDA-MB231 and MCF7 cells is 3.5e7.7-
fold, respectively, higher than the original CQ compound (Table 1
and Fig. 2). Furthermore, compound 14 is 3.7-fold (MDA-MB231)
to 5.16-fold (MCF7) more potent than cisplatin, one of the most
widely prescribed anti-cancer agents. Importantly, the compound
14 is 2.03-fold (MDA-MB231) to 2.58-fold (MCF7) more active than
MCF10A, the non-cancer cell control.
Further SAR studies suggest that the introduction of a diethyl
amino (7) group on the lateral side chain of the 7-chloro-4-ami-
noquinoline ring system increases in the antiproliferative activity
on MCF7 cells (GI50 ¼ 17.85
m
M, compared to GI50 38.44
m
M of CQ;
Compounds derived from bioisoteric replacement of 7-chloro
group with 7-trifluoromethyl substitution on the 4-aminoquinoline
ring system having diethyl (20), pyrrolidinyl (21), piperidinyl (22),
Table 1). The substitution of the five-membered heterocyclic ring
system with a piperidinyl group (8) also resulted in an increase of
Table 1
Antiproliferative activity of CQ analogs on human breast cancer cells and non-cancer cells.
Compoundsa
X
NR1R2
GI50 (m
M)b,c
MDA-MB231
MCF7
MCF10A
7
8
9
Cl
Cl
Cl
Cl
Cl
Cl
Cl
Cl
Cl
Cl
Cl
Cl
(CH3CH2)2N
Pyrrolidin-1-yl
Piperidin-1-yl
Morpholinoyl
4-Methylpiperazin-1-yl
4-Phenylpiperazin-1-yl
4-(7-Chloroquinolin-4-yl)piperazin-1-yl
4-(7-Trifluoromethyl)quinolin-4-yl)piperazin-1-yl
Isatin
4-Chloro-isatin
4-Bromo-isatin
6-Chloro-isatin
6-Bromo-isatin
(CH3CH2)2N
Pyrrolidin-1-yl
Piperidin-1-yl
Morpholinoyl
4-Methylpiperazin-1-yl
4-Phenylpiperazin-1-yl
4-(7-Chloroquinolin-4-yl)piperazin-1-yl
4-(7-Trifluoromethyl)quinolin-4-yl)piperazin-1-yl
Isatin
4-Chloro-isatin
4-Bromo-isatin
6-Chloro-isatin
6-Bromo-isatin
27.81 ꢂ 1.17
29.78 ꢂ 1.21
37.95 ꢂ 1.34
40.25 ꢂ 1.45
19.13 ꢂ 0.95
15.88 ꢂ 0.78
7.52 ꢂ 0.32
6.33 ꢂ 0.22
47.57 ꢂ 1.61
55.58 ꢂ 1.83
16.83 ꢂ 0.65
15.81 ꢂ 0.60
35.04 ꢂ 1.23
57.05 ꢂ 1.77
70.39 ꢂ 1.91
38.62 ꢂ 1.33
79.76 ꢂ 1.94
43.29 ꢂ 1.42
9.90 ꢂ 0.32
4.31 ꢂ 0.09
25.72 ꢂ 1.02
54.13 ꢂ 1.53
50.24 ꢂ 1.49
49.37 ꢂ 1.38
17.38 ꢂ 0.76
18.88 ꢂ 0.82
22.52 ꢂ 1.44
23.65 ꢂ 0.23
17.85 ꢂ 0.84
21.45 ꢂ 0.97
17.66 ꢂ 0.78
17.25 ꢂ 0.74
17.10 ꢂ 0.72
12.77 ꢂ 0.64
5.42 ꢂ 0.21
4.99 ꢂ 0.18
23.52 ꢂ 0.99
46.72 ꢂ 1.45
6.57 ꢂ 0.24
7.36 ꢂ 0.32
16.55 ꢂ 0.58
20.63 ꢂ 0.90
36.75 ꢂ 1.21
32.61 ꢂ 1.32
38.75 ꢂ 1.41
30.75 ꢂ 1.32
8.75 ꢂ 0.27
4.60 ꢂ 0.10
17.23 ꢂ 0.85
45.31 ꢂ 1.54
18.78 ꢂ 0.84
34.36 ꢂ 1.01
14.30 ꢂ 0.52
7.98 ꢂ 0.25
38.44 ꢂ 1.20
25.77 ꢂ 0.38
65.26 ꢂ 1.87
45.84 ꢂ 1.25
47.83 ꢂ 1.45
86.46 ꢂ 1.89
16.66 ꢂ 0.23
12.60 ꢂ 0.54
8.72 ꢂ 0.23
12.87 ꢂ 0.44
35.87 ꢂ 0.86
84.76 ꢂ 1.87
20.79 ꢂ 0.75
6.88 ꢂ 0.21
19.90 ꢂ 0.66
45.81 ꢂ 1.23
58.65 ꢂ 1.56
48.84 ꢂ 1.23
26.48 ꢂ 0.88
51.68 ꢂ 1.64
19.78 ꢂ 0.88
8.84 ꢂ 0.21
30.01 ꢂ 0.65
46.79 ꢂ 1.21
20.15 ꢂ 0.77
33.66 ꢂ 1.01
25.17 ꢂ 1.24
14.57 ꢂ 0.78
81.26 ꢂ 1.45
51.51 ꢂ 0.65
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
CQ
Cisplatin
Cl
CF3
CF3
CF3
CF3
CF3
CF3
CF3
CF3
CF3
CF3
CF3
CF3
CF3
a
For chemical structures of these compounds, see Fig. 1 and Scheme 1.
GI50 values were calculated from Sigmoidal doseeresponse curves (variable slope), which were generated with GraphPad Prism V. 4.02 (GraphPad Software Inc.).
Values are the mean of triplicates of at least two independent experiments.
b
c

V.R. Solomon et al. / European Journal of Medicinal Chemistry 45 (2010) 3916e3923
3919
4. Experimental protocols
1.25
1.00
0.75
0.50
0.25
0.00
-0.25
-0.50
-0.75
Compound 14
Compound 26
CQ
Melting points (mp) were taken in open capillaries on the
Complab melting point apparatus. Elemental analysis was per-
formed on a PerkineElmer 2400 C, H, N analyzer and values were
within the acceptable limit of the calculated values. The 1H spectra
were recorded on a DPX-500 MHz Bruker FT-NMR spectrometer
using CDCl3 and DMSO-d6 as solvent. The chemical shifts were
reported as parts per million (d ppm) tetramethylsilane (TMS) as an
internal standard. Mass spectra were obtained on a JEOL-SX-102
instrument using fast atom bombardment (FAB positive). The
progress of the reaction was monitored on readymade silica gel
plates (Merck) using chloroformemethanol (9:1) as solvent. Iodine
was used as a developing agent or by spraying with the Dra-
gendorff’s reagent. Chromatographic purification was performed
over a silica gel (100e200 mesh). All chemicals and reagents
obtained from Aldrich (USA) were used without further
purification.
-3
-2
-1
0
1
2
3
Log [µM]
Fig. 2. Antiproliferative effects of compounds 14, 26 and CQ on MCF7 breast cancer
cells.
morpholinyl (23), isatin (28), 4-chloro isatin (29), 4-bromo isatin
(30), 6-chloro isatin (31) and 6-bromo isatin (32) were generally
not as effective as those derived from the 7-chloro substitution on
4-aminoquinoline ring system (Table 1). However, 4-(7-chlor-
oquinolin-4-yl)piperazin-1-yl substituted compound (26) emerged
as the most active compound in this series, as its GI50 values were
4.1. Synthesis of 3-(7-substituted-quinolin-4-ylamino)-propanol
(3e4)
A mixture of 4-chloro-7-substituted-quinoline (20.25 mmol),
propanolamine (1.96 ml, 25.75 mmol) and triethylamine (3.6 ml,
25.75 mmol) was heated slowly to 80 ꢀC longer than 1 h while
stirring. The temperature was then increased to 130e140 ꢀC, where
it was kept for 6 h while stirring continuously. The reaction mixture
was cooled to room temperature, and then poured into ice-cold
water and filtered. The precipitate was filtered, washed, and
recrystallized using chloroform:methanol (3:1) mixture to obtain
as cream-white solid.
4.31 mM (MDA-MB231) to 4.60 mM (MCF7). Compound 26 was 1.92-
fold (MCF7) to 2.05-fold (MDA-MB231) more effective on cancer
cells than MCF10A non-cancer cells (Table 1). This differential effect
on cancer and non-cancer cells is similar to that of compound 14.
Thus, compounds 14 and 26 are potentially very promising anti-
breast cancer agents.
Compounds 7e10,13,14,16,17, 22, 24, 25, 26 and 31 showed less
cytotoxicity on MCF10A cells in comparison to cancer cells.
However, most of them may not be useful anti-cancer agents as
their cytotoxic effects are generally too low, except compounds 14
and 26.
4.1.1. 3-(7-Chloroquinolin-4-ylamino)propanol (3)
Yield 80%; mp 140e142 ꢀC; 1H NMR (500 MHz, CDCl3):
d 1.90 (br
It may be important to note that the substitution of the 4-(7-
(trifluoromethyl)quinolin-4-yl)piperazin-1-yl ring system on
4-aminoquinoline lateral side chain is very effective in differential
antiproliferation on cancer cells when the 7th position of the ring is
a eCl group (14), but not eCF3 group (27). Conversely, the substi-
tution of the 4-(7-chloroquine 4-yl)piperazin-1-yl ring system on
4-aminoquinoline lateral side chain showed higher differential
antiproliferation effects on cancer cells when the 7th position of
the ring is a eCF3 group (26) than a eCl group (13). Compounds
derived from the 7-chloro-4-aminoquinoline ring system with
either 4-methylpiperazin-1-yl (compound 11), 4-phenylpiperazin-
1-yl (12), or 4-(7-chloroqunolin-4-yl)piperazin-1-yl (13) showed
an increase in cytotoxic activity on non-cancer cells; thus, they may
not be ideal anti-cancer agents.
s, 1H, OH), 2.06e2.10 (m, 2H, CH2), 3.32e3.38 (m, 2H, CH2),
3.65e3.67 (m, 2H, CH2), 6.34e6.35 (d, J ¼ 5.0 Hz, 1H, Ar-H), 6.96 (br
s, 1H, NH), 7.24e7.27 (dd, J ¼ 10.0 Hz, 1H, Ar-H), 7.78 (s, 1H, Ar-H),
8.00e8.02 (d, J ¼ 10.0 Hz, 1H, Ar-H), 8.35e8.36 (d,J ¼ 5.0 Hz, 1H, Ar-
H); 13C NMR (500 MHz, CDCl3):
d 30.95, 40.75, 59.85, 98.62, 117.73,
123.40, 124.40, 127.92, 128.31, 134.20, 149.26, 150.59, 152.00; ES-MS
m/z 237 [M þ H]þ; Anal. Calcd for C12H13ClN2O: C, 60.89; H, 5.54; N,
11.84: found: C, 60.92; H, 5.51; N, 11.87.
4.1.2. 3-(7-Trifluoromethyl-quinolin-4-ylamino)-propan-1-ol (4)
Yield 79%; mp 122e124 ꢀC; 1H NMR (500 MHz, CDCl3):
d 1.90 (br
s, 1H, OH), 2.07e2.11 (m, 2H, CH2), 3.47e3.51 (m, 2H, CH2),
3.98e4.02 (m, 2H, CH2), 6.16 (br s, 1H, NH D2O exchangeable),
6.44e6.45 (d,J ¼ 5.0 Hz, 1H, Ar-H), 8.39e8.41 (m, 2H, Ar-H), 8.49
(s,1H, Ar-H), 8.57e8.58 (d, J ¼ 5.0 Hz,1H, Ar-H); 13C NMR (500 MHz,
3. Conclusion
CDCl3): d 30.14, 39.77, 58.51, 98.81, 118.31, 120.35, 122.40, 122.62,
126.72, 128.31, 146.89, 149.68, 151.45; ES-MS m/z 271 [M þ H]þ;
Anal. Calcd for C13H13F3N2O: C, 57.78; H, 4.85; N, 10.37; found: C,
57.82; H, 4.88; N, 10.32.
We here report the design, synthesis, and examination of CQ
analogs in an attempt to develop effective and safe anti-breast
cancer agents. At least 10 of the 26 CQ-derived compounds
exhibited improved anti-cancer activity against human breast
cancer cells, compared to CQ. In particular, 7-chloro-N-(3-(4-(7-
(trifluoromethyl)quinolin-4-yl)piperazin-1-yl)propyl)quinolin-4-
amine (14) and {3-[4-(7-chloro-quinolin-4-yl)-piperazin-1-yl]-
propyl}-(7-trifluoromethyl-quinolin-4-yl)-amine (26) emerged as
the most active compounds in this series. These two compounds
are particularly promising, since they are not only much more
active than CQ, but also their toxicities are at least twice more
effective on cancer cells than the MCF10A non-cancer control. Our
data thus demonstrates that CQ is an excellent base compound for
repositioning toward breast cancer treatment.
4.2. Synthesis of 3-(7-substituted-quinolin-4-ylamino)-propyl
methanesulfonate (5e6)
A solution of compound 3-(7-Substituted-quinolin-4-ylamino)-
propanol (12.70 mmol) in anhydrous THF (25 ml) under a nitrogen
atmosphere was added triethylamine (15.25 mmol). The mixture
was cooled to below 0 ꢀC. Methanesulfonyl chloride (0.9 ml,
12.70 mmol) was added slowly, while maintaining the temperature
below 5 ꢀC, and the mixture was stirred in an ice bath 1 h. After
dilution with saturated NaHCO3 solution (50 ml, 2ꢃ) the reaction
was extracted with ether. The organic extracts were dried over

3920
V.R. Solomon et al. / European Journal of Medicinal Chemistry 45 (2010) 3916e3923
Na2SO4, filtered, and evaporated to leave compounds 3 and 4 as
C16H20ClN3: C, 66.31; H, 6.96; N, 14.50; found: C, 66.29; H, 6.92;
a white solid.
N, 14.53.
4.2.1. 3-(7-Chloroquinolin-4-ylamino)propyl methanesulfonate (5)
Yield 75%; mp 124e126 ꢀC; 1H NMR (500 MHz, DMSO-
4.3.3. 7-Chloro-N-(3-(piperidin-1-yl)propyl)quinolin-4-amine (9)
Yield 56%; 1H NMR (500 MHz, CDCl3):
d 1.38e1.42 (m, 2H, CH2
d6 þ CDCl3):
d
2.09e2.13 (m, 2H, CH2), 3.08 (s, 3H, SO2CH3),
piperidinyl), 1.68e1.72 (m, 4H, CH2 piperidinyl), 1.89e1.92 (m, 2H,
CH2), 2.33e2.39 (m, 4H, CH2 piperidinyl), 2.51e2.54 (m, 2H, CH2),
3.29e3.32 (m, 2H, CH2), 6.26e6.27 (d, J ¼ 5.0 Hz, 1H, Ar-H),
7.29e7.31 (dd, J ¼ 5.0 Hz, J ¼ 10.0 Hz, 1H, Ar-H), 7.81 (br s, 1H, NH
D2O exchangeable), 7.83e7.85 (d, J ¼ 10.0 Hz, 1H, Ar-H), 8.41 (s, 1H,
3.38e3.42 (m, 2H, CH2), 4.32e4.34 (m, 2H, CH2), 6.38e6.39 (d,
J ¼ 5.0 Hz, 1H, Ar-H), 7.13 (br s, 1H, NH), 7.30e7.31 (d, J ¼ 5.0 Hz, 1H,
Ar-H), 7.74 (s, 1H, Ar-H), 8.15e8.17 (d, J ¼ 10.0 Hz, 1H, Ar-H),
8.37e8.38 (d, J ¼ 5.0 Hz, 1H, Ar-H); 13C NMR (DMSO-d6 þ CDCl3):
d
27.90, 37.17, 38.64, 68.34, 98.81, 117.86, 123.96, 124.50, 127.84,
Ar-H), 8.44e8.45 (d, J ¼ 5.0 Hz, 1H, Ar-H); 13C NMR (CDCl3):
d 23.99,
134.26, 149.24, 150.52, 151.93; ES-MS m/z 315 [M þ H]þ; Anal. Calcd
for C13H15ClN2O3S; C, 49.60; H, 4.80; N, 8.90; found: C, 49.56; H,
4.85; N, 8.92.
24.32, 26.10 (2C), 44.46, 54.92 (2C), 59.43, 98.34, 117.59, 122.53,
124.44, 128.77, 134.54, 149.06, 150.71, 152.07; ES-MS m/z 305
[M þ H]þ; Anal. Calcd for C17H22ClN3: C, 67.20; H, 7.30; N, 13.83;
found: C, 67.22; H, 7.35; N, 13.87.
4.2.2. Methanesulfonic acid 3-(7-trifluoromethyl-quinolin-4-
ylamino)-propyl ester (6)
4.3.4. 7-Chloro-N-(3-morpholinopropyl)quinolin-4-amine (10)
Yield 67%; mp 118e120 ꢀC; 1H NMR (500 MHz, CDCl3):
d 1.93e1.97 (m, 2H, CH2), 2.59 (s, 4H, N(CH2CH2)2O), 2.63e2.66 (m,
Yield 73%; mp 82e84 ꢀC; 1H NMR (500 MHz, DMSO-d6 þ CDCl3):
d
2.11e2.16 (m, 2H, CH2), 3.01 (s, 3H, SO2CH3), 3.42e3.45 (m, 2H,
CH2), 4.32e4.35 (m, 2H, CH2), 6.48e6.49 (d, J ¼ 5.0 Hz, 1H, Ar-H),
7.29 (br s, 1H, NH D2O exchangeable), 7.50e7.52 (d, J ¼ 10.0 Hz,
1H, Ar-H), 8.05 (s, 1H, Ar-H), 8.34e8.36 (d, J ¼ 10.0 Hz, 1H, Ar-H),
8.46e8.47 (d, J ¼ 5.0 Hz, 1H, Ar-H); 13C NMR (DMSO-d6 þ CDCl3):
2H, CH2), 3.40e3.43 (m, 2H, CH2), 3.87 (s, 4H, N(CH2CH2)2O),
6.36e6.37 (d, J ¼ 5.0 Hz, 1H, Ar-H), 7.20 (br s, 1H, NH D2O
exchangeable), 7.38e7.41 (dd, J ¼ 5.0 Hz, J ¼ 10.0 Hz, 1H, Ar-H),
7.82e7.84 (d, J ¼ 10.0 Hz, 1H, Ar-H), 7.97 (s, 1H, Ar-H), 8.53e8.54 (d,
d
32.55, 41.94, 44.34, 72.99, 104.51, 124.11, 125.92, 127.89, 128.44,
J ¼ 5.0 Hz, 1H, Ar-H); 13C NMR (CDCl3):
d 23.36, 44.12, 54.04 (2C),
131.15,135.14,152.11,155.30,156.63; ES-MS m/z 350 [M þ H]þ; Anal.
Calcd for C14H15F3N2O3S: C, 48.27; H, 4.34; N, 8.04; found: C, 48.22;
H, 4.37; N, 8.07.
59.01, 68.17 (2C), 98.64, 117.47, 121.78, 124.90, 128.81, 134.75, 149.17,
150.40, 152.21; ES-MS m/z 307 [M
C16H20ClN3O: C, 62.84; H, 6.59; N, 13.74; found: C, 62.79; H, 6.62;
N, 13.70.
þ
H]þ; Anal. Calcd for
4.3. General synthetic procedure for 7-substituted-N-(3-(alkyl/
heteroalkyl/aryl)propyl) quinolin-4-amine
4.3.5. 7-Chloro-N-(3-(4-methylpiperazin-1-yl)propyl)quinolin-4-
amine (11)
To a mixture of 3-(7-substituted-quinolin-4-ylamino)-propyl
methanesulfonate (3.81 mmol), active amine compound
(3.81 mmol) and triethylamine (0.4 ml, 3.81 mmol) in 20 ml of
anhydrous DMF were stirred at 50e60 ꢀC for 72 h. The reaction
mixture was cooled to room temperature and the solvent evapo-
rated under reduced pressure. The residue was taken up in
dichloromethane. The organic layer was washed with 5% aq.
NaHCO3, followed by brine wash. The organic layer was dried over
anhydrous Na2SO4 and solvent was removed under reduced pres-
sure. The crude product was chromatographed on silica gel, eluting
with chloroformemethanol.
Yield 59%; 1H NMR (500 MHz, CDCl3):
d 1.48e1.52 (m, 2H, CH2),
2.29e2.35 (m, 2H, CH2), 2.38e2.44 (m, 2H, CH2), 2.53 (s, 3H, N-
CH3), 4.37e4.40 (s, 8H, N(CH2CH2)2N), 6.12e6.14 (d, J ¼ 5.0 Hz, 1H,
Ar-H), 7.27 (br s, 1H, NH D2O exchangeable), 7.29 (s, 1H, Ar-H),
7.82e7.83 (d, J ¼ 5.0 Hz, 1H, Ar-H), 7.95 (s, 1H, Ar-H), 8.47e8.48 (d,
J ¼ 5.0 Hz, 1H, Ar-H); 13C NMR (CDCl3):
d 29.37, 34.19, 44.24, 45.79,
54.25 (4C), 101.01, 117.93, 125.52, 125.63, 128.75, 134.65, 150.84,
151.94, 153.10; ES-MS m/z 319 [M þ H]þ; Anal. Calcd for C17H23ClN4:
C, 64.04; H, 7.27; N, 17.57; found: C, 64.09; H, 7.30; N, 17.52.
4.3.6. 7-Chloro-N-(3-(4-phenylpiperazin-1-yl)propyl)quinolin-4-
amine (12)
4.3.1. 7-Chloro-N-(3-(diethylamino)propyl)quinolin-4-amine (7)
Yield 53%; mp 110e112 ꢀC; 1H NMR (500 MHz, CDCl3):
Yield 65%; 1H NMR (500 MHz, CDCl3):
d
1.06e1.09 (m, 6H, N
d 2.01e2.07 (m, 2H, CH2), 2.65e2.70 (m, 2H, CH2), 2.71 (s, 4H, N
(CH2CH3)2),1.87e1.91 (m, 2H, CH2), 2.60e2.64 (m, 4H, N(CH2CH3)2),
2.65e2.67 (m, 2H, CH2), 3.72e3.75 (m, 2H, CH2), 6.25e6.26
(d, J ¼ 5.0 Hz,1H, Ar-H), 7.29e7.31 (dd, J ¼ 5.0 Hz, J ¼ 10.0 Hz,1H, Ar-
H), 7.68e7.69 (d, J ¼ 5.0 Hz, 1H, Ar-H), 7.91 (s, 1H, Ar-H), 8.16 (br s,
(CH2CH2)2N-Ar), 3.27e3.36 (m, 2H, CH2), 3.41 (s, 4H, N(CH2CH2)2N-
Ar), 6.33 (br s, 1H, NH D2O exchangeable), 6.35e6.36 (d, J ¼ 5.0 Hz,
1H, Ar-H), 6.94e6.97 (m, 2H, Ar-H), 7.00e7.01 (d, J ¼ 5.0 Hz, 1H, Ar-
H), 7.21e7.22 (d, J ¼ 5.0 Hz, 1H, Ar-H), 7.33e7.38 (m, 2H, Ar-H),
7.81e7.83 (d, J ¼ 10.0 Hz, 1H, Ar-H), 7.95 (s, 1H, Ar-H), 8.52e8.53 (d,
1H, NH D2O exchangeable), 8.53e8.54 (d, J ¼ 5.0 Hz, 1H, Ar-H); 13
C
NMR (CDCl3):
d
11.55, 24.23 (2C), 47.03 (2C), 53.55, 68.14, 98.21,
J ¼ 5.0 Hz, 1H, Ar-H); 13C NMR (CDCl3):
d 23.65, 37.44, 44.25 (2C),
122.16, 125.38, 128.50, 132.44, 134.58, 150.70, 151.86, 152.01; ES-MS
m/z 293 [M þ H]þ; Anal. Calcd for C16H22ClN3: C, 65.85; H, 7.60; N,
14.40; found: C, 65.80; H, 7.55; N, 14.37.
49.42 (2C), 53.64, 58.59, 98.56, 116.24, 117.44, 120.25, 122.08,
124.84, 127.56, 128.63, 129.95, 134.73, 149.06, 150.52, 151.12, 152.13;
ES-MS m/z 382 [M þ H]þ; Anal. Calcd for C22H25ClN4: C, 69.37; H,
6.62; N, 14.71; found: C, 69.41; H, 6.66; N, 14.75.
4.3.2. 7-Chloro-N-(3-(pyrrolidin-1-yl)propyl)quinolin-4-amine (8)
Yield 66%; mp 86e88 ꢀC; 1H NMR (500 MHz, CDCl3):
4.3.7. 7-Chloro-N-(3-(4-(7-chloroquinolin-4-yl)piperazin-1-yl)
d
1.83e1.94 (m, 2H, CH2), 2.59e2.64 (m, 4H, CH2), 2.73e2.77 (m,
propyl)quinolin-4-amine (13)
2H, CH2), 3.39e3.44 (m, 4H, CH2), 2.51e2.54 (m, 2H, CH2),
6.23e6.24 (d, J ¼ 5.0 Hz, 1H, Ar-H), 7.25e7.27 (d, J ¼ 5.0 Hz, 1H,
Ar-H), 7.57e7.60 (dd, J ¼ 5.0 Hz, J ¼ 10.0 Hz, 1H, Ar-H), 7.89 (s, 1H,
Ar-H), 8.23 (br s, 1H, NH D2O exchangeable), 8.42e8.43 (d,
Yield 61%; 1H NMR (500 MHz, CDCl3):
d 2.01e2.03 (m, 2H, CH2),
2.69e2.74 (m, 2H, CH2), 2.94 (s, 4H, N(CH2CH2)2N-Ar), 3.42 (s, 4H, N
(CH2CH2)2N-Ar), 3.43e3.46 (m, 2H, CH2), 6.36e6.37 (d, J ¼ 5.0 Hz,
1H, Ar-H), 6.88e6.89 (d, J ¼ 5.0 Hz, 1H, Ar-H), 7.08 (br s, 1H, NH),
7.25e7.26 (d, J ¼ 5.0 Hz, 1H, Ar-H), 7.29 (s, 1H, Ar-H), 7.42e7.44 (d,
J ¼ 10.0 Hz, 1H, Ar-H), 7.71e7.72 (d, J ¼ 5.0 Hz, 1H, Ar-H), 7.78e7.80
(d, J ¼ 10.0 Hz, 1H, Ar-H), 7.93e7.95 (d, J ¼ 10.0 Hz, 1H, Ar-H),
J ¼ 5.0 Hz, 1H, Ar-H); 13C NMR (CDCl3):
d 23.74 (2C), 25.30, 44.22,
54.14 (2C), 55.98, 98.38, 117.66, 121.93, 124.88, 128.10, 134.68,
148.32, 150.95, 151.80; ES-MS m/z 291 [M þ H]þ; Anal. Calcd for

V.R. Solomon et al. / European Journal of Medicinal Chemistry 45 (2010) 3916e3923
3921
8.50e8.51 (d, J ¼ 5.0 Hz, 1H, Ar-H), 8.78e8.79 (d, J ¼ 5.0 Hz, 1H, Ar-
H); 13C NMR (CDCl3):
30.36, 43.83, 46.07, 52.23 (2C), 53.42 (2C),
98.70, 108.87, 117.40, 121.86, 124.78, 126.32, 128.67, 128.96, 130.89,
132.45, 134.74, 135.01, 149.01, 150.39, 152.05, 152.08, 156.70, 167.77;
ES-MS m/z 467 [M þ H]þ; Anal. Calcd for C25H25Cl2N5: C, 64.38; H,
5.40; N, 15.02; found: C, 64.35; H, 5.37; N, 14.99.
(d, J ¼ 5.0 Hz,1H, Ar-H), 7.12e7.13 (d, J ¼ 5.0 Hz,1H, Ar-H), 7.36e7.37
(d, J ¼ 5.0 Hz, 1H, Ar-H), 7.54e7.62 (m, 2H, Ar-H), 7.71e7.72 (d,
J ¼ 5.0 Hz, 1H, Ar-H), 7.90e7.92 (d, J ¼ 10.0 Hz, 1H, Ar-H), 8.49e8.50
d
(d, J ¼ 5.0 Hz, 1H, Ar-H); 13C NMR (CDCl3):
d 25.61, 34.26, 48.71,
93.86, 111.22, 112.59, 116.79, 119.77, 120.87, 121.99, 124.05, 126.16,
127.69, 130.39, 140.39, 144.63, 146.99, 154.44, 163.05, 176.59; ES-MS
m/z 401 [M þ H]þ; Anal. Calcd for C20H15Cl2N3O2: C, 60.01; H, 3.78;
N, 10.50; found: C, 59.98; H, 3.75; N, 10.47.
4.3.8. 7-Chloro-N-(3-(4-(7-(trifluoromethyl)quinolin-4-yl)
piperazin-1-yl)propyl)quinolin-4-amine (14)
Yield 61%; mp 121e123 ꢀC; 1H NMR (500 MHz, CDCl3):
4.3.13. 6-Bromo-(3-(7-chloroquinolin-4-ylamino)propyl)isatin (19)
Yield 60%; mp 76e78 ꢀC; IR (KBr, cmꢁ1): 1732, 1632; 1H NMR
d
2.05e2.07 (m, 2H, CH2), 2.79e2.81 (m, 2H, CH2), 2.95 (s, 4H, N
(CH2CH2)2N-Ar), 3.41 (s, 4H, N(CH2CH2)2N-Ar), 3.46e3.49 (m, 2H,
CH2), 6.40e6.41 (d, J ¼ 5.0 Hz, 1H, Ar-H), 7.01 (br s, 1H, NH D2O
exchangeable), 7.02e7.03 (d, J ¼ 5.0 Hz, 1H, Ar-H), 7.30e7.32 (d,
J ¼ 10.0 Hz, 1H, Ar-H), 7.68e7.70 (d, J ¼ 10.0 Hz, 1H, Ar-H),
7.82e7.83 (d, J ¼ 5.0 Hz, 1H, Ar-H), 7.97e7.98 (d, J ¼ 5.0 Hz, 1H, Ar-
H), 8.16e8.17 (d, J ¼ 5.0 Hz, 1H, Ar-H), 8.41 (s, 1H, Ar-H), 8.55e8.56
(d, J ¼ 5.0 Hz, 1H, Ar-H), 8.91e8.92 (d, J ¼ 5.0 Hz, 1H, Ar-H); 13C
(500 MHz, DMSO-d6 þ CDCl3):
d 2.07e2.11 (m, 2H, CH2), 3.35e3.39
(m, 2H, CH2), 3.82e3.85 (m, 2H, CH2), 6.39e6.40 (d, J ¼ 5.0 Hz, 1H,
Ar-H), 6.99e7.01 (d, J ¼ 10.0 Hz, 1H, Ar-H), 7.28 (br s, 1H, NH),
7.30e7.32 (d, J ¼ 10.0 Hz,1H, Ar-H), 7.44e7.46 (d, J ¼ 10.0 Hz,1H, Ar-
H), 7.70 (s, 1H, Ar-H), 8.11e8.13 (d, J ¼ 10.0 Hz, 1H, Ar-H), 8.35 (s, 1H,
Ar-H),8.49e8.50 (d, J ¼ 5.0 Hz, 1H, Ar-H); ES-MS m/z 401 [M þ H]þ;
Anal. Calcd for C20H15BrClN3O2: C, 54.02; H, 3.40; N, 9.45; found: C,
54.08; H, 3.44; N, 9.49.
NMR (CDCl3):
d 23.95, 43.90, 52.25 (2C), 53.44 (2C), 58.30, 98.76,
110.15, 117.41, 121.06, 121.68, 124.85, 124.91 (2C), 125.16, 127.96,
128.88, 134.78, 148.81, 149.14, 150.32, 152.21, 152.32 (2C), 156.31;
ES-MS m/z 501 [M þ H]þ; Anal. Calcd for C26H25ClF3N5: C, 62.46; H,
5.04; N, 14.01; found: C, 62.49; H, 5.07; N, 14.06.
4.3.14. N,N-diethyl-N0-(7-trifluoromethyl-quinolin-4-yl)-propane-
1,3-diamine (20)
Yield 51%; 1H NMR (500 MHz, CDCl3):
d 0.99e1.13 (m, 6H, N
(CH2CH3)2), 1.92e1.96 (m, 2H, CH2), 2.64e2.67 (m, 2H, CH2),
2.69e2.72 (m, 4H, N(CH2CH3)2), 3.39e3.42 (m, 2H, CH2), 6.37e6.38
(d, J ¼ 5.0 Hz,1H, Ar-H), 7.54e7.56 (dd, J ¼ 5.0 Hz, J ¼ 10.0 Hz,1H, Ar-
H), 7.87e7.89 (d, J ¼ 10.0 Hz, 1H, Ar-H), 8.30 (s, 1H, Ar-H), 8.35 (br s,
4.3.9. (3-(7-Chloroquinolin-4-ylamino)propyl)isatin (15)
Yield 61%; mp 87e89 ꢀC; 1H NMR (500 MHz, DMSO-
d6 þ CDCl3):
d 2.09e2.11 (m, 2H, CH2), 3.33e3.39 (m, 2H, CH2),
3.82e3.85 (m, 2H, CH2), 6.34e6.35 (d, J ¼ 5.0 Hz, 1H, Ar-H), 6.97 (br
s, 1H, NH), 7.02e7.05 (m, 2H, Ar-H), 7.25e7.27 (d, J ¼ 10.0 Hz, 1H,
Ar-H), 7.45e7.49 (m, 2H, Ar-H), 7.63e7.65 (d, J ¼ 10.0 Hz, 1H, Ar-H),
8.06e8.08 (d, J ¼ 10.0 Hz, 1H, Ar-H), 8.34e8.35 (d, J ¼ 5.0 Hz, 1H,
1H, NH D2O exchangeable), 8.59e8.61 (d, J ¼ 5.0 Hz, 1H, Ar-H); 13
C
NMR (CDCl3):
d 11.58 (2C), 24.17, 44.84, 47.10 (2C), 53.70, 99.19,
121.00 (2C), 121.93, 125.23, 127.42, 127.46, 147.78, 150.48, 152.42;
ES-MS m/z 326 [M þ H]þ; Anal. Calcd for C17H22F3N3: C, 62.75; H,
6.82; N, 12.91; found: C, 62.78; H, 6.79; N, 12.95.
Ar-H); 13C NMR (DMSO-d6 þ CDCl3):
d 25.81, 38.09, 40.65, 98.86,
110.65, 117.69, 117.83, 123.64, 123.69 (2C), 124.48, 124.97, 127.91,
134.24, 138.38, 150.37, 150.79, 151.94, 158.62, 183.51; ES-MS m/z
366 [M þ H]þ; Anal. Calcd for C20H16ClN3O2: C, 65.67; H, 4.41; N,
11.49; found: C, 65.71; H, 4.39; N, 11.52.
4.3.15. (3-Pyrrolidin-1-yl-propyl)-(7-trifluoromethyl-quinolin-4-
yl)-amine (21)
Yield 55%; 1H NMR (500 MHz, CDCl3):
d 1.81e1.87 (m, 6H, CH2),
2.59e2.64 (m, 4H, CH2), 2.77e2.79 (m, 2H, CH2), 3.36e3.39 (m, 2H,
CH2), 6.35e6.36 (d, J ¼ 5.0 Hz, 1H, Ar-H), 7.51e7.53 (d, J ¼ 10.0 Hz,
1H, Ar-H), 7.76e7.78 (dd, J ¼ 5.0 Hz, J ¼ 10.0 Hz, 1H, Ar-H), 8.23 (s,
1H, Ar-H), 8.41 (br s, 1H, NH D2O exchangeable), 8.56e8.57 (d,
J ¼ 5.0 Hz, 1H, Ar-H); ES-MS m/z 324 [M þ H]þ; Anal. Calcd for
C17H20F3N3: C, 63.14; H, 6.23; N, 13.00; found: C, 63.11; H, 6.25;
N, 13.02.
4.3.10. 4-Chloro-(3-(7-chloroquinolin-4-ylamino)propyl)isatin (16)
Yield 59%; mp 227e229 ꢀC; IR (KBr, cmꢁ1): 1725, 1625; 1H NMR
(500 MHz, DMSO-d6 þ CDCl3):
d 1.58e1.62 (m, 2H, CH2), 2.18e2.25
(m, 2H, CH2), 3.31e3.40 (m, 2H, CH2), 6.35 (br s, 1H, NH), 6.37e6.38
(d, J ¼ 5.0 Hz, 1H, Ar-H), 7.11e7.12 (d, J ¼ 5.0 Hz, 1H, Ar-H), 7.31e7.32
(d, J ¼ 5.0 Hz, 1H, Ar-H), 7.45e7.49 (m, 2H, Ar-H), 7.69e7.70 (d,
J ¼ 5.0 Hz, 1H, Ar-H), 7.79e7.81 (d, J ¼ 10.0 Hz, 1H, Ar-H), 8.45e8.46
(d, J ¼ 5.0 Hz, 1H, Ar-H); ES-MS m/z 401 [M þ H]þ; Anal. Calcd for
C20H15Cl2N3O2: C, 60.01; H, 3.78; N, 10.50; found: C, 60.03; H, 3.75;
N, 10.44.
4.3.16. (3-Piperidin-1-yl-propyl)-(7-trifluoromethyl-quinolin-4-yl)-
amine (22)
Yield 56%; mp 118e120 ꢀC; 1H NMR (500 MHz, CDCl3):
d
1.58e1.62 (m, 2H, CH2 piperidinyl), 1.70e1.78 (m, 4H, CH2 piper-
4.3.11. 4-Bromo-(3-(7-chloroquinolin-4-ylamino)propyl)isatin (17)
Yield 58%; mp 86e88 ꢀC; IR (KBr, cmꢁ1): 1722, 1621; 1H NMR
idinyl), 1.94e1.97 (m, 2H, CH2), 2.49e2.52 (m, 4H, CH2 piperidinyl),
2.58e2.62 (m, 2H, CH2), 3.37e3.40 (m, 2H, CH2), 6.39e6.40 (d,
J ¼ 5.0 Hz, 1H, Ar-H), 7.56e7.58 (d, J ¼ 10.0 Hz, 1H, Ar-H), 8.06e8.08
(d, J ¼ 10.0 Hz, 1H, Ar-H), 8.12 (br s, 1H, NH D2O exchangeable), 8.29
(s, 1H, Ar-H), 8.59e8.60 (d, J ¼ 5.0 Hz, 1H, Ar-H); 13C NMR (CDCl3):
(500 MHz, DMSO-d6 þ CDCl3):
d 2.09e2.11 (m, 2H, CH2), 3.42e3.46
(m, 2H, CH2), 3.83e3.91 (m, 2H, CH2), 6.35e6.36 (d, J ¼ 5.0 Hz, 1H,
Ar-H), 7.11e7.12 (d, J ¼ 5.0 Hz, 1H, Ar-H), 7.32e7.39 (m, 2H, Ar-H),
7.75e7.76 (d, J ¼ 5.0 Hz, 1H, Ar-H), 7.90e7.92 (d, J ¼ 10.0 Hz, 1H, Ar-
H), 8.04e8.05 (d, J ¼ 5.0 Hz, 1H, Ar-H), 8.35e8.36 (d, J ¼ 5.0 Hz, 1H,
d
23.27, 24.34, 26.00 (2C), 44.77, 55.02 (2C), 59.65, 100.10, 119.30,
120.95, 121.22, 121.50, 122.30, 127.43, 148.74, 150.57, 152.44; ES-MS
m/z 338 [M þ H]þ; Anal. Calcd for C18H22F3N3: C, 64.08; H, 6.57; N,
12.45; found: C, 64.12; H, 6.60; N, 12.49.
Ar-H); 13C NMR (CDCl3):
d 25.72, 38.29, 40.64, 98.92, 109.74, 116.41,
120.50, 123.76, 124.41 (2C), 127.84 (2C), 127.93, 134.16, 138.50,
150.33, 151.98, 152.53, 157.86, 181.00; ES-MS m/z 446 [M þ H]þ;
Anal. Calcd for C20H15BrClN3O2: C, 54.02; H, 3.40; N, 9.45; found: C,
54.06; H, 3.44; N, 9.49.
4.3.17. (3-Morpholin-4-yl-propyl)-(7-trifluoromethyl-quinolin-4-
yl)-amine (23)
Yield 62%; mp 120e122 ꢀC; 1H NMR (500 MHz, CDCl3):
4.3.12. 6-Chloro-(3-(7-chloroquinolin-4-ylamino)propyl)isatin (18)
Yield 57%; mp 119e121 ꢀC; IR (KBr, cmꢁ1): 1727, 1628; 1H NMR
d 1.97e2.02 (m, 2H, CH2), 2.61 (s, 4H, N(CH2CH2)2O), 2.65e2.68 (m,
2H, CH2), 3.42e3.45 (m, 2H, CH2), 3.85 (s, 4H, N(CH2CH2)2O),
6.44e6.45 (d, J ¼ 5.0 Hz, 1H, Ar-H), 7.43 (br s, 1H, NH D2O
exchangeable), 7.62e7.63 (d, J ¼ 10.0 Hz, 1H, Ar-H), 8.01e8.03
(500 MHz, DMSO-d6 þ CDCl3):
d 1.63e1.69 (m, 2H, CH2), 2.08e2.15
(m, 2H, CH2), 3.36e3.44 (m, 2H, CH2), 6.08 (br s, 1H, NH), 6.39e6.40

3922
V.R. Solomon et al. / European Journal of Medicinal Chemistry 45 (2010) 3916e3923
(d, J ¼ 10.0 Hz, 1H, Ar-H), 8.28 (s, 1H, Ar-H), 8.62e8.63 (d, J ¼ 5.0 Hz,
1H, Ar-H); 13C NMR (CDCl3):
23.23, 44.27, 54.06 (2C), 59.08, 67.02
(2C), 99.62, 119.65, 119.68, 120.78, 121.64, 127.73, 127.76, 147.75,
150.23, 152.48; ES-MS m/z 340 [M
H]þ; Anal. Calcd for
C17H20F3N3O: C, 60.17; H, 5.94; N, 12.38; found: C, 60.12; H, 5.91;
N, 2.40.
52.18 (2C), 53.32 (2C), 58.03, 99.44, 99.71, 121.70, 122.04, 122.87,.
122.92, 125.12, 127.47, 127.76, 127.79, 128.76, 147.47, 147.63, 148.01,
148.72, 150.19, 151.89, 152.22, 152.35, 156.51; ES-MS m/z 535
[M þ H]þ; Anal. Calcd for C27H25F6N5: C, 60.78; H, 4.72; N, 13.13;
found: C, 60.72; H, 4.69; N, 13.09.
d
þ
4.3.22. (3-(7-Trifluoromethyl-quinolin-4-ylamino)propyl)isatin
(28)
4.3.18. [3-(4-Methyl-piperazin-1-yl)-propyl]-(7-trifluoromethyl-
quinolin-4-yl)-amine (24)
Yield 72%; mp 138e140 ꢀC; IR (KBr, cmꢁ1): 1738, 1619; 1H NMR
Yield 62%; 1H NMR (500 MHz, CDCl3):
d
1.94e1.99 (m, 2H, CH2),
(500 MHz, DMSO-d6 þ CDCl3):
d 2.07e2.10 (m, 2H, CH2), 3.45e3.49
2.38 (s, 3H, N-CH3), 2.65 (s, 8H, N(CH2CH2)2N), 2.67e2.72 (m, 2H,
CH2), 3.37e3.40 (m, 2H, CH2), 6.39e6.40 (d, J ¼ 5.0 Hz, 1H, Ar-H),
7.53e7.55 (d, J ¼ 10.0 Hz, 1H, Ar-H), 7.70 (br s, 1H, NH D2O
exchangeable), 8.06e8.07 (d, J ¼ 5.0 Hz,1H, Ar-H), 8.25 (s,1H, Ar-H),
(m, 2H, CH2), 3.87e3.90 (m, 2H, CH2), 6.25 (br s, 1H, NH D2O
exchangeable), 6.49e6.50 (d, J ¼ 5.0 Hz, 1H, Ar-H), 6.92e6.93 (d,
J ¼ 5.0 Hz, 1H, Ar-H), 7.16e1.79 (dd, J ¼ 5.0, 10.0 Hz, 1H, Ar-H),
7.53e7.64 (m, 4H, Ar-H), 8.11e8.13 (d, J ¼ 10.0 Hz, 1H, Ar-H), 8.22 (s,
8.58e8.59 (d, J ¼ 5.0 Hz, 1H, Ar-H); 13C NMR (CDCl3):
d
23.30, 44.52,
1H, Ar-H); 13C NMR (DMSO-d6 þ CDCl3):
d 25.60, 37.21, 38.89, 99.58,
46.34, 53.57 (2C), 55.28 (2C), 58.73, 99.46, 119.34, 120.80, 122.30,
123.02, 125.18, 127.47, 147.68, 150.41, 152.44; ES-MS m/z 353
[M þ H]þ; Anal. Calcd for C18H23F3N4: C, 61.35; H, 6.58; N, 15.90;
found: C, 61.32; H, 6.54; N, 15.86.
110.04, 117.73, 120.36, 121.44, 124.33, 125.83, 127.26, 127.46, 128.79,
138.60, 147.89, 149.16, 150.09, 152.12, 159.13, 167.79, 182.83; ES-MS
m/z 400 [M þ H]þ; Anal. Calcd for C21H16F3N3O2: C, 63.16; H, 4.04;
N, 10.52; found: C, 63.20; H, 4.07; N, 10.54.
4.3.19. [3-(4-Phenyl-piperazin-1-yl)-propyl]-(7-trifluoromethyl-
quinolin-4-yl)-amine (25)
4.3.23. 4-Chloro-(3-(7-trifluoromethyl-quinolin-4-ylamino)-
propyl)isatin (29)
Yield 60%; mp 127e129 ꢀC; 1H NMR (500 MHz, CDCl3):
Yield 69%; mp 135e137 ꢀC; IR (KBr, cmꢁ1): 1725, 1625; 1H NMR
d
1.98e2.02 (m, 2H, CH2), 2.59e2.63 (m, 2H, CH2), 2.71 (s, 4H, N
(500 MHz, DMSO-d6 þ CDCl3):
d 2.10e2.13 (m, 2H, CH2), 3.37e3.41
(CH2CH2)2N-Ar), 3.43 (s, 4H, N(CH2CH2)2N-Ar), 3.39e3.42 (m, 2H,
CH2), 6.33 (br s, 1H, NH D2O exchangeable), 6.44e6.45 (d, J ¼ 5.0 Hz,
1H, Ar-H), 6.96e6.97 (d, J ¼ 5.0 Hz, 1H, Ar-H), 7.00e7.02 (d,
J ¼ 10.0 Hz, 1H, Ar-H), 7.43e7.45 (d, J ¼ 10.0 Hz, 1H, Ar-H), 7.49 (s,
1H, Ar-H), 7.53e7.55 (dd, J ¼ 5.0, 10.0 Hz, 1H, Ar-H), 7.72e7.73 (d,
J ¼ 5.0 Hz, 1H, Ar-H), 7.99e8.01 (d, J ¼ 10.0 Hz, 1H, Ar-H), 8.26 (s, 1H,
(m, 2H, CH2), 4.32e4.35 (m, 2H, CH2), 6.41e6.42 (d, J ¼ 5.0 Hz, 1H,
Ar-H), 6.94e6.95 (d, J ¼ 5.0 Hz, 1H, Ar-H), 7.05 (br s, 1H, NH D2O
exchangeable), 7.31e7.34 (dd, J ¼ 5.0, 10.0 Hz, 1H, Ar-H), 7.43e7.45
(d, J ¼ 10.0 Hz, 1H, Ar-H), 8.04 (s, 1H, Ar-H), 7.56e7.58 (d,
J ¼ 10.0 Hz, 1H, Ar-H), 8.20e8.22 (d, J ¼ 10.0 Hz, 1H, Ar-H),
8.46e8.47 (d, J ¼ 5.0 Hz, 1H, Ar-H); 13C NMR (DMSO-d6 þ CDCl3):
Ar-H), 8.61e8.62 (d, J ¼ 5.0 Hz, 1H, Ar-H); 13C NMR (CDCl3):
d
23.77,
d 25.88, 37.21, 68.22, 109.11, 114.70, 119.20, 121.17, 123.15, 123.35,
44.33, 49.44 (2C), 53.65 (2C), 58.58, 99.57, 116.24 (2C), 119.63,
119.65, 120.27, 120.77, 121.91, 128.81 (2C), 132.47, 147.67, 150.33,
151.09, 152.41, 167.78; ES-MS m/z 415 [M þ H]þ; Anal. Calcd for
C23H25F3N4: C, 66.65; H, 6.08; N, 13.52; found: C, 66.61; H, 6.05;
N, 13.49.
124.84, 125.31, 126.71, 126.74, 132.78, 138.97, 147.70, 150.17, 152.20,
152.26, 157.91, 180.43; ES-MS m/z 435 [M þ H]þ; Anal. Calcd for
C21H15ClF3N3O2: C, 58.14; H, 3.49; N, 9.69; found: C, 58.11; H, 3.52;
N, 9.72.
4.3.24. 4-Bromo-(3-(7-trifluoromethyl-quinolin-4-ylamino)-
propyl)isatin (30)
4.3.20. {3-[4-(7-Chloro-quinolin-4-yl)-piperazin-1-yl]-propyl}-(7-
trifluoromethyl-quinolin-4-yl)-amine (26)
Yield 57%; mp 88e90 ꢀC; IR (KBr, cmꢁ1): 1737, 1615; 1H NMR
Yield 56%; 1H NMR (500 MHz, CDCl3):
d
2.07e2.09 (m, 2H, CH2),
(500 MHz, DMSO-d6 þ CDCl3):
d 1.87e1.91 (m, 2H, CH2), 3.17e3.20
2.80e2.82 (m, 2H, CH2), 2.90 (s, 4H, N(CH2CH2)2N-Ar), 3.40 (s, 4H, N
(CH2CH2)2N-Ar), 3.49e3.53 (m, 2H, CH2), 6.49e6.50 (d, J ¼ 5.0 Hz,
1H, Ar-H), 6.93e6.94 (d, J ¼ 5.0 Hz, 1H, Ar-H), 7.13 (br s, 1H, NH D2O
exchangeable), 7.48e7.49 (d, J ¼ 5.0 Hz, 1H, Ar-H), 7.52e7.54 (d,
J ¼ 10.0 Hz, 1H, Ar-H), 7.98e8.00 (d, J ¼ 10.0 Hz, 1H, Ar-H),
8.00e8.02 (d, J ¼ 10.0 Hz, 1H, Ar-H), 8.10 (s, 1H, Ar-H), 8.26 (s, 1H,
Ar-H), 8.64e8.65 (d, J ¼ 5.0 Hz, 1H, Ar-H), 8.82e8.83 (d, J ¼ 5.0 Hz,
(m, 2H, CH2), 3.62e3.65 (m, 2H, CH2), 6.18e6.19 (d, J ¼ 5.0 Hz, 1H,
Ar-H), 6.53 (br s, 1H, NH D2O exchangeable), 6.60e6.61 (d,
J ¼ 5.0 Hz, 1H, Ar-H), 6.87e6.88 (d, J ¼ 5.0 Hz, 1H, Ar-H), 6.98e6.99
(d, J ¼ 5.0 Hz, 1H, Ar-H), 7.24e7.26 (d, J ¼ 10.0 Hz, 1H, Ar-H), 7.85 (s,
1H, Ar-H), 7.90e7.92 (d, J ¼ 10.0 Hz, 1H, Ar-H), 8.25e8.26 (d,
J ¼ 5.0 Hz, 1H, Ar-H); 13C NMR (DMSO-d6 þ CDCl3):
d 25.12, 37.94,
39.38, 99.49, 109.38, 116.14, 119.22 (2C), 120.83 (2C), 120.99 (2C),
122.54,126.72 (2C),128.05,138.16,149.68,151.97,157.76,180.51; ES-
MS m/z 479 [M þ H]þ; Anal. Calcd for C21H15BrF3N3O2: C, 52.74; H,
3.16; N, 8.79; found: C, 52.69; H, 3.12; N, 8.77.
1H, Ar-H); 13C NMR (CDCl3):
d 23.88, 44.03, 52.27 (2C), 53.51 (2C),
58.35, 99.76, 108.91, 119.61, 120.72, 121.53, 121.90, 124.58, 125.08,
126.37, 127.80, 127.84, 129.09, 135.06, 147.78, 150.14, 150.27, 152.09,
152.50, 156.64; ES-MS m/z 501 [M
C26H25ClF3N5: C, 62.46; H, 5.04; N, 14.01; found: C, 62.40; H, 5.07;
N, 13.98.
þ
H]þ; Anal. Calcd for
4.3.25. 6-Chloro-(3-(7-trifluoromethyl-quinolin-4-ylamino)-
propyl)isatin (31)
Yield 58%; mp 116e118 ꢀC; IR (KBr, cmꢁ1): 1735, 1633; 1H NMR
4.3.21. (7-Trifluoromethyl-quinolin-4-yl)-{3-[4-(7-trifluoromethyl-
quinolin-4-yl)-piperazin-1-yl]-propyl}-amine (27)
(500 MHz, DMSO-d6 þ CDCl3):
d 2.10e2.14 (m, 2H, CH2), 3.38e3.41
(m, 2H, CH2), 3.81e3.85 (m, 2H, CH2), 6.43e6.44 (d, J ¼ 5.0 Hz, 1H,
Ar-H), 6.94e6.95 (d, J ¼ 5.0 Hz, 1H, Ar-H), 6.96 (br s, 1H, NH D2O
exchangeable), 7.03e7.05 (d, J ¼ 10.0 Hz, 1H, Ar-H), 7.52e7.55 (dd,
J ¼ 5.0, 10.0 Hz, 1H, Ar-H), 7.56e7.58 (d, J ¼ 10.0 Hz, 1H, Ar-H), 8.04
(s, 1H, Ar-H), 8.22e8.24 (d, J ¼ 10.0 Hz, 1H, Ar-H), 8.44e8.45 (d,
Yield 62%; mp 125e127 ꢀC; 1H NMR (500 MHz, CDCl3):
d
2.00e2.05 (m, 2H, CH2), 2.73e2.76 (m, 2H, CH2), 2.84 (s, 4H, N
(CH2CH2)2N-Ar), 3.40 (s, 4H, N(CH2CH2)2N-Ar), 3.41e3.46 (m, 2H,
CH2), 6.41e6.42 (d, J ¼ 5.0 Hz, 1H, Ar-H), 6.94e6.95 (d, J ¼ 5.0 Hz,
1H, Ar-H), 7.14 (br s, 1H, NH D2O exchangeable), 7.44e7.45 (d,
J ¼ 5.0 Hz, 1H, Ar-H), 7.62e7.64 (d, J ¼ 10.0 Hz, 1H, Ar-H), 7.94e7.96
(d, J ¼ 10.0 Hz,1H, Ar-H), 8.09e8.11 (d, J ¼ 10.0 Hz,1H, Ar-H), 8.36 (s,
1H, Ar-H), 8.50 (s, 1H, Ar-H), 8.56e8.57 (d, J ¼ 5.0 Hz, 1H, Ar-H),
J ¼ 5.0 Hz, 1H, Ar-H); 13C NMR (DMSO-d6 þ CDCl3):
d 25.64, 38.38,
39.60, 99.91, 11.45, 116.21, 119.20, 121.21 (2C), 123.38 (2C), 123.62,
126.06, 126.75, 144.09, 147.78, 150.18, 151.87, 152.25, 158.69, 182.07;
ES-MS m/z 435 [M þ H]þ; Anal. Calcd for C21H15ClF3N3O2: C, 58.14;
H, 3.49; N, 9.69; found: C, 58.18; H, 3.44; N, 9.72.
8.83e8.84 (d, J ¼ 5.0 Hz, 1H, Ar-H); 13C NMR (CDCl3):
d 23.93, 43.72,

V.R. Solomon et al. / European Journal of Medicinal Chemistry 45 (2010) 3916e3923
3923
4.3.26. 6-Bromo-(3-(7-trifluoromethyl-quinolin-4-ylamino)-
propyl)isatin (32)
Unbound SRB was removed by five washes with tap water, followed
by air-drying. The cells “stained” with SRB were solubilized with
10 mM trizma base, and the absorbance was read on an automated
plate reader at a wavelength of 515e564 nm. The relative growth
rate (%) was calculated for each of the compound concentrations
according to the following formula:
Yield 59%; mp 116e118 ꢀC; IR (KBr, cmꢁ1): 1729, 1628; 1H NMR
(500 MHz, DMSO-d6 þ CDCl3):
d 2.10e2.13 (m, 2H, CH2), 3.45e3.48
(m, 2H, CH2), 3.86e3.89 (m, 2H, CH2), 6.13 (br s, 1H, NH D2O
exchangeable), 6.49e6.50 (d, J ¼ 5.0 Hz, 1H, Ar-H), 7.29e7.32 (dd,
J ¼ 5.0, 10.0 Hz, 1H, Ar-H), 7.42e7.43 (d, J ¼ 5.0 Hz, 1H, Ar-H),
7.59e7.61 (d, J ¼ 10.0 Hz,1H, Ar-H), 8.07e8.09 (d, J ¼ 10.0 Hz,1H, Ar-
H), 8.21 (s, 1H, Ar-H), 8.69e8.70 (d, J ¼ 5.0 Hz, 1H, Ar-H); 13C NMR
ðTi ꢁ TzÞ=ðC ꢁ TzÞ ꢃ 100
In the formula, time zero (Tz), control growth (C), and OD for
different concentration of tested compounds (Ti). The GI50 for each
compound was obtained from a non-linear Sigmoidal dose-
response (variable slope) curve which is fitted by GraphPad Prism
v.4.03 software. Values were calculated for each of these parame-
ters if the level of activity was reached. However, if the effect was
not reached or was exceeded, the value for that parameter was
expressed as greater or less than the maximum or minimum
concentration tested.
(DMSO-d6 þ CDCl3):
d 24.99, 36.29, 39.01, 99.69, 113.75, 115.83,
120.42, 120.68, 121.32, 122.89, 127.59 (2C), 128.79 (2C), 133.93,
149.10, 150.90, 151.26, 152.11, 159.13, 191.56; ES-MS m/z 479
[M þ H]þ; Anal. Calcd for C21H15BrF3N3O2: C, 52.74; H, 3.16; N, 8.79;
found: C, 52.70; H, 3.12; N, 8.73.
4.4. Cell lines
The human MDA-MB231 and MCF-7 breast cancer cell lines
were maintained in RPMI 1640 medium supplemented with 10%
fetal bovine serum (Hyclone, Logan UT) and 2 mM L-glutamine.
Acknowledgements
MCF10A immortalized breast cells were maintained in mammary
epithelial basal medium supplemented with an MEGM mammary
epithelial singlequot kit (Cambrex). Cells were grown at 37 ꢀC with
5% CO2, 95% air under the humidified conditions.
The authors wish to thank G. Ulibarri (Laurentian University) for
letting us using his laboratory equipment in the process of
synthesizing compounds. This work was supported by funds from
the Natural Sciences and Engineering Council of Canada (NSERC)
and the Northern Cancer Research Foundation to H.L. V. R. S. is
a recipient of a postdoctoral fellowship from the Ontario Ministry of
Research and Innovation.
4.5. Reagents
Chloroquine diphosphate and cisplatin were purchased from
SigmaeAldrich Canada Ltd. (Oakaville, ON, Canada). All the
compounds were dissolved in 10e20 mM dimethyl sulfoxide
(DMSO) and stored at ꢁ20 ꢀC until use. The stock solution was
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Antiproliferative effects were determined by a Sulphorhod-
amine B (SRB)-based protocol [22e25]. For a typical screening
experiment, 5000e10,000 cells were inoculated into 100
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for 60 min at 4 ꢀC. The supernatant was discarded, and the plate
was washed five times with tap water, followed by air-dry. 50 ml of
SRB solution at 0.4% (w/v) in 1% acetic acid was added to each well,
and the plate was incubated for >30 min at room temperature.
[25] V. Vichai, K. Kirtikara, Nat. Protoc. 1 (2006) 1112e1116.