New phenylaniline derivatives as modulators of amyloid protein precursor metabolism

Article abstract of DOI:10.1016/j.bmc.2018.03.016

The chloroquinoline scaffold is characteristic of anti-malarial drugs such as chloroquine (CQ) or amodiaquine (AQ). These drugs are also described for their potential effectiveness against prion disease, HCV, EBV, Ebola virus, cancer, Parkinson or Alzheimer diseases. Amyloid precursor protein (APP) metabolism is deregulated in Alzheimer's disease. Indeed, CQ modifies amyloid precursor protein (APP) metabolism by precluding the release of amyloid-beta peptides (Aβ), which accumulate in the brain of Alzheimer patients to form the so-called amyloid plaques. We showed that AQ and analogs have similar effects although having a higher cytotoxicity. Herein, two new series of compounds were synthesized by replacing 7-chloroquinolin-4-amine moiety of AQ by 2-aminomethylaniline and 2-aminomethylphenyle moieties. Their structure activity relationship was based on their ability to modulate APP metabolism, Aβ release, and their cytotoxicity similarly to CQ. Two compounds 15a, 16a showed interesting and potent effect on the redirection of APP metabolism toward a decrease of Aβ peptide release (in the same range compared to AQ), and a 3–10-fold increased stability of APP carboxy terminal fragments (CTFα and AICD) without obvious cellular toxicity at 100 μM.

Full text of DOI:10.1016/j.bmc.2018.03.016

Bioorganic & Medicinal Chemistry xxx (2018) xxx–xxx
Contents lists available at ScienceDirect
Bioorganic & Medicinal Chemistry
journal homepage: www.elsevier.com/locate/bmc
New phenylaniline derivatives as modulators of amyloid protein
precursor metabolism
a
b
a
Marion Gay a, Pascal Carato a, , Mathilde Coevoet , Nicolas Renault , Paul-Emmanuel Larchanché ,
⇑
Amélie Barczyk b, Saïd Yous a, Luc Buée a, Nicolas Sergeant a, Patricia Melnyk a,
⇑
a Univ. Lille, Inserm, CHU Lille, UMR-S 1172 – JPArc – Centre de Recherche Jean-Pierre AUBERT Neurosciences et Cancer, F-59000 Lille, France
b Univ. Lille, Inserm, CHU Lille, U995 – LIRIC – Lille Inflammation Research International Center, F-59000 Lille, France
a r t i c l e i n f o
a b s t r a c t
Article history:
The chloroquinoline scaffold is characteristic of anti-malarial drugs such as chloroquine (CQ) or amodi-
aquine (AQ). These drugs are also described for their potential effectiveness against prion disease,
HCV, EBV, Ebola virus, cancer, Parkinson or Alzheimer diseases. Amyloid precursor protein (APP) metabo-
lism is deregulated in Alzheimer’s disease. Indeed, CQ modifies amyloid precursor protein (APP) metabo-
lism by precluding the release of amyloid-beta peptides (Ab), which accumulate in the brain of Alzheimer
patients to form the so-called amyloid plaques. We showed that AQ and analogs have similar effects
although having a higher cytotoxicity. Herein, two new series of compounds were synthesized by replac-
ing 7-chloroquinolin-4-amine moiety of AQ by 2-aminomethylaniline and 2-aminomethylphenyle moi-
eties. Their structure activity relationship was based on their ability to modulate APP metabolism, Ab
release, and their cytotoxicity similarly to CQ. Two compounds 15a, 16a showed interesting and potent
effect on the redirection of APP metabolism toward a decrease of Ab peptide release (in the same range
Received 22 December 2017
Revised 8 March 2018
Accepted 10 March 2018
Available online xxxx
Keywords:
Amyloid
Polyamines
Phenylanilines
Abeta peptides
compared to AQ), and a 3–10-fold increased stability of APP carboxy terminal fragments (CTFa and AICD)
without obvious cellular toxicity at 100 mM.
Ó 2018 Published by Elsevier Ltd.
1. Introduction
(anthrax18) activity or even cancer.19,20 The AQ major drawback
is its weak metabolic stability leading to hepatotoxic derivatives
with cases of agranulocytosis, neutropenia and hepatitis. The 4-
hydroxyanilino moiety of AQ explained its toxicity.21–23 Thus, a
great number of AQ analogs without this 4-hydroxyaniline sub-
structure have been synthesized to circumvent this drawback.
Others and we succeeded in designing compounds with nanomolar
activities on CQ-resistant strains of P. falciparum, the parasite
responsible for malaria.24–33 Isoquine derivatives are the most
advanced compounds.
Considering Alzheimer’s disease (AD), we previously reported
indirect modulatory effect of CQ on APP metabolism.34 The meta-
bolism of this type transmembrane protein is central to AD patho-
physiology. This complex metabolism leads to the production and
release of amyloid-beta peptides (Ab) of 35–43 amino acids among
which Ab42 form neurotoxic oligomers and abnormally accumu-
lates as parenchymal amyloid deposits in Alzheimer patient’s
brains. As illustrated in Fig. 2, Ab42 is an intermediate proteolytic
4-Aminoquinoline moiety is present in many biologically active
compounds. Compounds bearing this sub-structure are described
with anti-tuberculosis,1 anti-leishmania2 or anti-inflammatory,3
or antiviral (Ebola4) activity or against Parkinson’s disease5
although an anti-malarial therapeutic indication is most well-
known. The most used compounds of this family are chloroquine
(CQ) and amodiaquine (AQ) (Fig. 1). For decades, CQ has been
one of the two most widely used antimalarial drugs with moderate
acute toxicity. Following a repositioning strategy, CQ and CQ-
derived compounds have already been evaluated in several medi-
cal indications such as prion disease,6–9 HCV10,11 and even
cancer.12,13 CQ-derived compounds such as hydroxychloroquine
are administered, for instance, for the treatment of systemic lupus
erythematosus14 or rheumatoid polyarthritis.15 AQ proved to be
effective against CQ-resistant malarial strains,16 and was also
described with antiviral (Ebola,4 dengue,17
) and antibacterial
product arising from the carboxy-peptidase activity of
c-secre-
tase.35 The ratio of Ab42/Ab40 is increased in AD suggesting that
the carboxy-peptidase activity is defective. Part of the Ab peptides
are produced in acidic cellular compartments in which beta- and
⇑
Corresponding authors at: Univ Poitiers, CIC INSERM 1402, F-86073 Poitiers,
France (P. Carato).
E-mail address: patricia.melnyk@univ-lille2.fr (P. Melnyk).
https://doi.org/10.1016/j.bmc.2018.03.016
0968-0896/Ó 2018 Published by Elsevier Ltd.
Please cite this article in press as: Gay M., et al. Bioorg. Med. Chem. (2018), https://doi.org/10.1016/j.bmc.2018.03.016

2
M. Gay et al. / Bioorganic & Medicinal Chemistry xxx (2018) xxx–xxx
1-dimethylamine-2-methylaminoethyl is possible (4, 5, 6 and 7),
5) very small modifications could improve cytotoxicity (6 and 7)
and 6) symmetric substitution with amino side chain is possible
(8 and 9). Nevertheless, these compounds, though interesting hits,
provided relatively high cytotoxicity in comparison with their
activity.
Considering the challenge to provide new drugs for the treat-
ment of neurodegenerative diseases, such as AD, we designed
two original series of compounds (16a–d, 22a–d) starting from
compounds 6 and 9 with general structure I (Fig. 3). We aimed
to evaluate the replacement of the 7-chloroquinolin-4-amine scaf-
fold by 2-aminomethylaniline moiety for the first series of com-
pounds 16a–d and by 2-aminomethylphenyle for the other series
of compounds 22a–d. Previous results underlined the potential
interest of amide compounds (2, 6 and 7). Thus the dicarboxamide
intermediate derivatives 15a–d, 21a–d were also considered and
allowed us to determine the importance of the dicarboxamide
groups (piperidinoethyl carboxamide moieties) when compared
to their analogs 16a–d, 22a–d, with diamine groups (piperidi-
noethyl aminomethyl moieties). The amino groups (CH2NR2) intro-
Fig. 1. Structures of anti-malarial 4-aminoquinolines, Chloroquine, Amodiaquine,
and Isoquine.
duced
were
piperidine,
morpholine,
piperazine
and
dimethylamine. Compounds 16a–d, 22a–d and their dicarboxam-
ide analogs 15a–d, 21a–d were tested toward the modulation of
APP metabolism and their cytotoxicity was also evaluated.
2. Chemistry
Fig. 2. Amyloid protein precursor (APP) metabolism.
For the synthesis of compounds 16a–d, aminomethylaniline
intermediate 12a–d were prepared in two steps (Scheme 1). For
the first reaction, various attempts were engaged with piperidine
as reagent. With NaBH(OAc)3,29,51 no reaction was observed and
starting material was recovered. With NaBH4 or NaBH3CN a mix-
ture of derivatives was observed as compounds 11a (27–47%), 2-
nitrophenylmethanol (34–46%), resulting from the reduction of
the aldehyde function, and with or without starting material (0–
20%). Then, reduction with NaBH3CN and ZnCl2 gave only com-
pound 11a with 85% yields.52,53 The other derivatives were synthe-
sized in the same conditions with 77–83%. The nitro group of
compounds 11a–d was reduced in ethanol with Pd/C and ammo-
nium formate,54 the resulting unstable aniline derivatives 12a–d
were then immediately introduced in the Buchwald reaction.
For the synthesis of compounds 16a-d two ways were
attempted in 3 or 4 steps (Scheme 2).
gamma-secretase have both optimal activity.36–42 CQ is known to
repress Ab peptides production through its lysomotropic activity.
Considering the lack of curative therapeutic option, current strate-
gies propose repositioning compounds or multifunctional mole-
cules. For example, numerous works described the synthesis of
multi-target compounds, exhibited significant ability to inhibit b-
amyloid (Ab) aggregation but also displayed antioxidant activity,
biometal chelating ability43 or cholinesterase inhibition.44–46
Our laboratory described N,N0-disubstituted piperazine deriva-
tives of CQ and their ability to reduce the release of Ab species
and increase the amount of APP metabolites (carboxy terminal
fragments CTF
a
and AICD).47–50 We also demonstrated that it
was possible to replace 7-chloroquinoline by other heterocycles
or benzyl group. AQ and related anti-malarial analogs have also
been evaluated and showed an improved ability to inhibit the
The first way was realized starting from 5-bromoisophthalic
acid (13) with 1-piperidineethanamine, 1-ethyl-3-(3-dimethy-
laminopropyl) carbodiimide (EDC), hydroxybenzotriazole (HOBt)
in DMF afforded dicarboxamide derivative 14 with a good yield
of 89%.51,55 A Buchwald reaction with the previously and freshly
prepared aniline derivatives 12a–d gave compounds 15a–d. Best
yields (30–88%) were in dioxane with Cs2CO3, Xantphos, and Pd2-
dba3. All attempts of reduction of the amide group in derivatives
15a–d in THF with LiAlH4 gave degradation of the reaction media.
Then a second way was attempted in 4 steps. Starting from 5-bro-
moisophthalic acid (13), the Weinreb amide derivative 17 was pre-
pared in a solution of DCM/ACN with EDC, hydroxyl benzotriazole
(HOBt), N,O-dimethylhydroxylamine, N-methylmorpholine with
good yield (89%). A Buchwald reaction, in the same optimized con-
ditions, allowed to furnish derivatives 18a–d (yields 26–92%),
which were reduced in THF with LiAlH4 and afforded derivatives
19a–d. The last reaction was a reductive amination in DCE with
the corresponding amine and NaBH(OAc)3, to furnish compounds
16a–d.51,55
release of Ab species although both CTF
a and AICD levels were
reduced for AQ when compared to CQ effect (respectively 0.5 and
0.4) (Table 1).50 Compounds 1, 3–4 and 8 showed similar activities
when compared to CQ or AQ for the inhibition of the secretion of
Ab species reaching 50% at 3.1–10 mM and 7.1–13.8 mM respec-
tively for Ab1–40 and Ab1–42. Derivatives 2, 5–7 and 9 showed better
activities than CQ and AQ with 1.5–2.5 mM and 1.9–4.9 mM respec-
tively. Increase amounts of CTFa were also achieved for com-
pounds 2, 5–7 and 9, with a range of 1.2–2.1 when compared to
CQ at 3 mM. Consequently, these compounds 2, 5–7 and 9 also pre-
sented upsurge of AICD with a range of 0.9–3.4 when compared to
CQ at 3 mM. These five compounds had better profile toward the
reduction of both Ab40 and Ab42 production and increase of CTF
AICD when compared to CQ. Especially, derivative 6 displayed an
a,
excellent profile for the APP metabolism with high CTF
sus to CQ, respectively 2.1 and 3.4.
a, AICD ver-
Structure-activity relationships of CQ, AQ, and compounds 1–9
have shown (Table 1) that: 1) AQ seems more efficient than CQ to
decrease Ab secretion, 2) phenol function is not necessary (1), 3)
addition of an amino side chain could improve of activity (2 for
instance, 4) modulation of diethylamino group to morpholine or
For the synthesis of compounds 22a–d, two ways were also
evaluated in 4 or 5 steps (Scheme 3). Same intermediates 14 and
17 were used.
Please cite this article in press as: Gay M., et al. Bioorg. Med. Chem. (2018), https://doi.org/10.1016/j.bmc.2018.03.016

M. Gay et al. / Bioorganic & Medicinal Chemistry xxx (2018) xxx–xxx
3
Table 1
In vitro evaluation of anti-malarial drugs CQ, AQ and AQ analogs (1–9) on APP metabolism (SY5Y cells).
Cpda
Structure
Cytotoxicity CC50 (mM)b
Ab1–40 IC50 (mM)c,d
Ab1–42 IC50 (mM)c,d
CTF
a
vs CQ (3mM)d,e
AICD vs CQ (3mM)d,f
CQ
AQ
1
–
–
30
10
12
7.0
4.0
4.5
12.8
5.4
10.4
1
0.5
0.6
1
0.4
0.5
HN
N
N
N
N
Cl
Cl
Cl
Cl
Cl
Cl
2
3
4
5
6
7
8
4
1.5
2.8
1.6
0.5
0.7
1.2
2.1
1.7
0.5
0.9
0.4
0.5
1.2
3.4
2.3
0.6
O
N
N
N
N
N
N
HN
HN
HN
HN
HN
HN
HN
N
15
10
10
4
10
13.8
HN
N
3.1
2.5
1.7
2.0
5.1
7.1
O
HN
N
N
O
4.9
HN
N
N
O
2.9
O
HN
N
N
N
15
2.1
O
HN
N
HN
N
Cl
Cl
30
11.2
N
OH
HN
N
N
(continued on next page)
Please cite this article in press as: Gay M., et al. Bioorg. Med. Chem. (2018), https://doi.org/10.1016/j.bmc.2018.03.016

4
M. Gay et al. / Bioorganic & Medicinal Chemistry xxx (2018) xxx–xxx
Table 1 (continued)
Cpda
Structure
Cytotoxicity CC50 (mM)b
Ab1–40 IC50 (mM)c,d
Ab1–42 IC50 (mM)c,d
CTF
1.4
a
vs CQ (3mM)d,e
AICD vs CQ (3mM)d,f
9
>15
2.3
1.9
1.1
N
N
HN
N
N
N
Cl
a
b
c
d
e
f
Compounds are described in Refs. 29–33.
Compound concentration causing 50% of SY5Y cell death after 24 h treatment, done in duplicate.
Compound concentration inhibiting 50% of Ab peptide secretion.
Mean values calculated on the basis of at least three independent experiments with less than 10% deviation.
CTF
a increase compared to chloroquine ([CTF]compound/[CTF]CQ) at 3 mM.
AICD increase compared to chloroquine ([AICD]compound/ [AICD]CQ) at 3 mM.
Fig. 3. Structure of general structure I and target compounds 16a–d and 22a–d.
to afford the corresponding compound 20 with 43–44% yield.
The best conditions were found with Pd(OAc)2, and P(o-tol)3
with 62% yield. We observed degradation of compound 20 dur-
ing the purification step on silica gel. Thus reductive amination
was engaged with crude aldehyde 20 in DCE with the corre-
sponding commercial amine and NaBH(OAc)3, to furnish com-
pounds 21a–d.56 The last step was the reduction of the amide
group, two reactions were attempted.57,58 No conversion could
be observed in a first reaction in THF with BH3-THF as reductive
agent. A second reaction in THF with lithium aluminium hydride
afforded degradation of the reaction. The second route was
engaged starting from derivative 17 in a Suzuki coupling reac-
tion with Pd(OAc)2, and P(o-tol)3 in DMF and afforded derivative
21 (87% yield). During this reaction we observed the formation
of the debrominated compound as N1,N3-dimethoxy-N1,N3-
dimethylbenzene-1,3-dicarboxamide. The next reaction was a
Scheme 1. Synthesis of intermediate compounds 12a–d. Reagents and conditions:
(a) (i): Secondary amine, ZnCl2, DCE, rt, 3 h (ii): NaBH3CN, rt, 18 h, 77–84% (b) Pd/C
10%, ammonium formate, EtOH, rt, 30–60 min.
By the first route, various attempts were considered for the
Suzuki coupling reaction by varying catalyst with Pd(PPh3)4, Pd
(OAc)2, Pd(dba)3 and a ligand PPh3
P(o-tol)3 when necessary,
or
Please cite this article in press as: Gay M., et al. Bioorg. Med. Chem. (2018), https://doi.org/10.1016/j.bmc.2018.03.016

M. Gay et al. / Bioorganic & Medicinal Chemistry xxx (2018) xxx–xxx
5
Scheme 2. Synthesis of phenylaniline target compounds 16a–d. Reagents and conditions: (a) 1-piperidineethanamine, EDCꢀHCl, HOBt-H2O, DMF, rt, 16 h, 89%; (b) 2-(amine-
1-ylmethyl)aniline 12a–d, Cs2CO3, Xantphos, Pd2dba3, dioxane, reflux, 16 h, 26–92%; (c) LiAlH4, THF; (d) N,O-dimethylhydroxylamine, EDCꢀHCl, HOBt-H2O, N-
methylmorpholine, ACN, DCM, rt, 16 h, 89%; (e) LiAlH4, THF, 0 °C, 1 h, (f) (i): 1-piperidineethanamine, toluene, reflux, 1 h, (ii): NaBH(OAc)3, AcOH, DCE, rt, 15 h, 8–26%.
Scheme 3. Synthesis of aminomethyldiphenyl compounds 22a–d. Reagents and conditions: (a) 2-formylphenylboronic acid, K2CO3, P(o-tol)3, Pd(OAc)2, toluene, EtOH, reflux,
18 h; (b) (i): Commercial amine (R1H), DCE, rt, 5 h (ii): NaBH(OAc)3, AcOH, rt, 24 h, 26–67%; (c) BH3-THF, THF, reflux, 2 h; (d) LiAlH4, THF, rt, 4 h; (e) (i): Commercially amine
(R1H), toluene, reflux, 1 h (ii): NaBH(OAc)3, AcOH, DCE, rt, 15 h, 42–67%; (f) LiAlH4, dry THF, 0 °C, 1 h, 50–92%.; (g) (i): 1-piperidineethanamine, toluene, reflux, 1 h (ii): NaBH
(OAc)3, AcOH, DCE, rt, 15 h, 4–54%.
reductive amination, in the same conditions as previously
described for the first route, with the corresponding commer-
cially amine and NaBH(OAc)3, to obtain compounds 24a–d. The
amide Weinreb derivatives 24a–d were reduced in dry THF with
lithium aluminium hydride to give compounds 25a–d with 50%
yields. The derivative 25c was directly engaged in the next step,
without further purification, indeed we observed degradation
during the purification on silica gel. The last step, to obtain com-
pounds 22a–d, was a reductive amination in toluene with 1-
piperidine ethanamine to give the imine intermediate derivatives
and then NaBH(OAc)3 in DCE to afford the desired compounds
22a–d with yields not higher than 54%.
Please cite this article in press as: Gay M., et al. Bioorg. Med. Chem. (2018), https://doi.org/10.1016/j.bmc.2018.03.016

6
M. Gay et al. / Bioorganic & Medicinal Chemistry xxx (2018) xxx–xxx
metabolism of APP is expressed as the intensity of the western-blot
3. Results and discussion
band corresponding to the APP-CTFs resulting from the secretase
cleavages. The effect of the compounds on APP metabolism were
measured at various concentrations (1, 3, 10 mM, Fig. 4) and com-
pared to those of CQ at 3 mM (Table 2).
Considering Ab release, the IC50 of compounds 15b–d, 16c–d,
21b–d and 22a–d were high compared to CQ or AQ. Best results
were obtained for derivatives 15a, 15d, 16a–b, and 21a with range
The compounds were tested for modulating APP metabolism in
SY5Y human neuroblastoma cell line stably expressing the neu-
ronal isoform of human wild-type APP695 (SY5Y-APPwt). This cell
line is a well-established cellular model for the study of APP
metabolism.
Cytotoxicity, APP carboxy-terminal fragments (CTFa and AICD)
from 4.1 to 6.6 mM and 4.7–9.4 mM respectively for Ab40 and Ab42
.
and Ab levels (Ab1–40 and Ab1–42) were defined as outcome param-
eters and compared to CQ and AQ. We have also evaluated the
capability of the synthesized compounds to cross the blood brain
barrier (LogD at pH = 7.4), and the polar surface area. Compounds
15,16a–d and 21,22a–d were charged at physiological pH, so it was
important to calculate the LogD at pH = 7.4 instead of LogP.
Cytotoxicity is expressed as the compound concentration caus-
ing 50% of cell death (CC50). IC50 indicates the concentration of a
compound effective for inhibiting the yield of Ab secretion by
50%. Ab peptides of 1–40 or 1–42 amino acids were considered.
Only compounds that inhibit Ab secretion with an IC50 lower than
10 mM were evaluated on APP metabolism through a western blot
analysis of APP-CTFs. In Table 2, the effect of the compounds on the
Among these compounds, 15a and 16a have IC50 similar to those of
AQ, whereas the others are closer to CQ. It is important to empha-
size that the quantity of CTF
a and AICD were higher for 15a and
16a with 3.2–10 more than AQ. These compounds 15a, 15d, 16a–
b, and 21a showed suitable LogD from ꢁ0.12 to 1.34. Their polar
surface area were all inferior to 90. They could cross the blood
brain barrier as expected.
The effect of the target compounds on APP metabolism was
studied toward the production of CTF
a (Fig. 4A) and AICD (Fig.
4B) by Western blot analysis. Only five derivatives (15a, 15d,
16a, 16b, 21a), with significant results toward Ab40 and Ab42, were
evaluated at three concentrations 1, 3 and 10 mM and compared to
Table 2
In vitro evaluation of compounds 15,16a–d and 21,22a–d on APP metabolism (SY5Y cells).
Cpd
R
Cytotoxicity CC50 (mM)a
Ab40 IC50 (mM)b,c
Ab42 IC50 (mM)b,c
CTFa
vs CQ (3mM)c,d
AICD vs CQ (3mM)c,e
LogDf pH = 7.4
PSAf Å2
CQ
AQ
15a
30
10
>100
7.0
4.0
4.1
12.8
5.4
4.7
1
0.5
2.8
1
0.4
2.3
–
–
0.43
80
89
83
80
15b
15c
15d
>100
>100
>100
ꢂ10
ꢂ10
8.2
ꢂ10
ꢂ10
ꢂ10
–
–
0.72
–
–
0.47
1.0
3.0
ꢁ0.03
16a
16b
16c
16d
>100
77
4.6
6.0
2.6
0.9
–
4.0
1.3
–
ꢁ0.12
0.21
46
55
49
46
6.6
7.9
>100
>100
ꢂ10
ꢂ10
ꢂ10
ꢂ10
ꢁ0.07
ꢁ0.56
–
–
21a
21b
21c
21d
>100
>100
>100
>100
6.2
9.4
1.4
–
1.9
–
1.34
1.10
0.86
0.88
68
77
71
68
ꢂ10
ꢂ10
ꢂ10
ꢂ10
ꢂ10
ꢂ10
–
–
–
–
22a
22b
22c
22d
>100
>100
>100
>100
ꢂ10
ꢂ10
ꢂ10
ꢂ10
ꢂ10
ꢂ10
ꢂ10
ꢂ10
–
–
–
–
–
–
–
–
1.04
0.78
0.38
0.41
34
43
37
34
a
b
c
d
e
f
Compound concentration causing 50% of SY5Y cell death after 24 h treatment, done in duplicate.
Compound concentration inhibiting 50% of Ab peptide secretion.
Mean values calculated on the basis of at least three independent experiments with less than 10% deviation.
CTF increase compared to chloroquine ([CTF]compound/[CTF]CQ) at 3 mM.
a
AICD increase compared to chloroquine ([AICD]compound/[AICD]CQ) at 3 mM.
LogD and polar surface area PSA were calculated using ACD/ADME Suite 4.95 soft.
Please cite this article in press as: Gay M., et al. Bioorg. Med. Chem. (2018), https://doi.org/10.1016/j.bmc.2018.03.016

M. Gay et al. / Bioorganic & Medicinal Chemistry xxx (2018) xxx–xxx
7
Fig. 4. Effect of target compounds on APP metabolism (A: APP CTFa, B: AICD).
control CQ and AQ. Dose-dependent profiles on the quantification
of CTF and AICD were obtained for all compounds and all showed
modulations considering their moderate ability to modulate the
APP metabolism.
a
higher efficiency than AQ (Fig. 4).
In a longer term, these non-toxic compounds could also be
tested on other models of pathologies where CQ and AQ proved
efficient, especially towards antimalarial properties.
In Fig. 4A, compound 15a with the best IC50 for Ab40 and Ab42
release had similar effect at 3 mM than all derivatives 15d, 16a,
16b, 21a at 3 or 10 mM concentrations. At 10 mM, the release of
CTF
a for compound 15a was 1.5 times better than all compounds
5. Experimental section
evaluated and 3 times better than CQ and AQ. At 3 mM, deriva-
tives 15a, 16a and 21a gave better release of CTF
AQ at 10 mM.
a compared to
5.1. Chemistry
In Fig. 4B, the best result was obtained for compound 16a
and had similar effect at 10 mM compared to derivative 16b
and a little bit higher than 15a and 21a. At the concentration
of 3 mM, AICD was 3-fold and 10-fold times higher than with
CQ and AQ respectively. At 3 mM, compounds 15d and 16a gave
much more AICD releasing compared to AQ evaluated at 3 or
10 mM concentrations.
All together, aminomethylaniline series seemed more efficient
than aminomethylphenyle series. Considering the substituent R,
the piperidine induced the best profile: lower Ab release IC50 and
Chemicals and solvents were purchased from various suppliers
(Sigma-Aldrich, Alfa Aesar, Fisher, VWR) and used without purifi-
cation. The reaction monitoring was performed by thin layer chro-
matography (TLC) on Macherey-Nagel AlugramÒ Sil 60/UV254
(thickness 0.2 mm). TLC were revealed by UV (k = 254 nm) and/
or the appropriate stain. Purification of the compounds was carried
out by column chromatography (flash or manual). Manual chro-
matography was performed using Macherey-Nagel silica gel
(0.04–0.063 mm of particle size), while flash chromatography
was performed on a RevelerisÒ Flash Chromatography System
using Macherey-Nagel Chromabond flash RS columns. NMR spec-
tra were recorded on a Bruker DRX 300 spectrometer (operating
at 300 MHz for 1H and 75 MHz for 13C). Chemical shifts are
expressed in ppm relative to tetramethylsilane (TMS) or to residual
proton signal in deuterated solvents. Chemical shifts are reported
as position (d in ppm), multiplicity (s = singulet, d = doublet, t = tri-
plet, q = quartet, m = multiplet, br = broad and M = massif), cou-
pling constant (J in Hz), relative integral and assignment. The
attributions of protons and carbons were achieved by analysis of
1D and 2D experiments (1H, 13C, COSY, HQC and HMBC). LC–MS
were performed on a Varian triple quadrupole 1200 W mass spec-
trometer equipped with a non-polar C18 TSK-gel Super ODS (4.6 ꢃ
50 mm) column, using electrospray ionisation and a UV detector
(diode array). Elution was performed at a flow rate of 2 mL/min
with water-formic acid (pH = 3.8) as eluent A and ACN-formic acid
(pH = 3.8) as eluent B, employing a 0.25 min plateau with 0% B and
a linear gradient from 0% B to 98% B in 3.25 min, followed by a 0.5
min plateau with 98% B. Then, column re-equilibration was per-
formed for 1 min. The injection duty cycle was 5 min, taking into
account the column equilibration time. HRMS were recorded on
a Hight Resolution Mass Spectrometer (HRMS) Thermo ScientificTM
ExactiveTM. Analysed compounds were dissolved in methanol and
directly introduced in the ionisation source ESI, in positive or neg-
ative mode according to the analysed compound, and recorded for
1 min. The Xcalibur software was used to determine the elementar
composition of main pics of the spectrum. The purity of final com-
pounds was determined by high pressure liquid chromatography
(HPLC) using to columns: C18 Interchrom UPTISPHERE and C4 Inter-
chrom UPTISPHERE. The HPLC analysis was carried out on a Shi-
madzu LC-2010AHT system equipped with a UV detector set at
higher increase in APP-CTFs (APP-CTFa and AICD). On the contrary,
in all cases, N-methylpiperazine substitution leads to non-efficient
compounds (Ab release IC50 ꢂ 10 mM).
All the compounds, except compound 16b with a CC50 of 77 mM,
showed no cytotoxicity at the concentration of 100 mM, underlin-
ing the interest of aminomethylaniline and aminomethylphenyle
series compared to reference compounds CQ, AQ and 1–9.
The two compounds 15a, 16a showed the best profiles as there
were able to inhibit both Ab40 and Ab42 at the micromolar range
(4.1–6.0 mM), at the same range of AQ and CQ. They also increased
the quantity of neurotrophic APP-CTFs: CTF
a (2.8 and 2.6-times
more) and AICD (2.3 and 4.0-times more) versus CQ but also versus
AQ with respectively 5.6–5.75 more for CTF
AICD.
a and 3.2–10 more for
4. Conclusion
Two series of compounds 15a–d, 16a–d and 21a–d, 22a–d bear-
ing aminomethylaniline and aminomethylphenyle scaffold, in
replacement of the 7-chloroquinolin-4-amine found in CQ, AQ
and derivatives 1–9 previously tested in our laboratory, were
designed and synthesized. These compounds were evaluated for
their inhibition of the secretion of Ab peptides (50%) by determin-
ing their IC50 and their activity on APP metabolism in SY5Y-APP695
human neuroblastoma cell line. Two compounds 15a, 16a showed
interesting profiles as they were able to inhibit both Ab40 and Ab42
at the micromolar range (4.1–6.0 mM) and increase the quantity
APP-CTF: CTFa and AICD versus AQ (range: 3.2–10). Furthermore,
no cytotoxicity could be observed for concentrations up to 100
mM. Their structures were engaged in further chemistry
Please cite this article in press as: Gay M., et al. Bioorg. Med. Chem. (2018), https://doi.org/10.1016/j.bmc.2018.03.016

8
M. Gay et al. / Bioorganic & Medicinal Chemistry xxx (2018) xxx–xxx
254 and 215 nm. The compounds were dissolved in 100 mL of buf-
fer B and 900 mL of buffer A. The eluent system used was: buffer A
(H2O/TFA, 100:0.1) and buffer B (ACN/H2O/TFA, 80:20:0.1). Reten-
tion times (tr) were obtained at a flow rate of 0.2 mL/min for 37
min using a gradient form 100% of buffer A over 1 min, to 100%
buffer B over the next 30 min, to 100% of buffer A over 1 min and
100% of buffer A over 1 min. The melting point analyses were per-
formed on Barnstead Electrothermal Melting Point Series IA9200.
All final compounds were transformed into their hydrochloride
salts following this procedure: the compound was dissolved in
MeOH and HClaq 2 M was added dropwise until pH1. The solvent
was evaporated and the compound was freeze-dried.
5.1.1.5.
5-Bromo-N1,N3-bis[2-(piperidin-1-yl)ethyl]benzene-1,3-
dicarboxamide 14. To a solution of 5-bromoisophthalic acid 1
(200 mg, 0.82 mmol) and 1-piperidineethanamine (240 mL, 1.17
mmol) in DMF (2.5 mL) was added EDCꢀHCl (330 mg, 1.73 mmol)
and HOBt-H2O (25.2 mg, 0.165 mmol). The reaction mixture was
stirred for 16 h at room temperature. 10 mL of saturated NaHCO3
solution was added. The aqueous layer was extracted with DCM
(3 ꢃ 10 mL). The combined organic layer was dried over MgSO4
and evaporated. The residue was purified by flash chromatography
(DCM/MeOH(NH3), 10:0 to 9.7:0.3 (v/v)). The title compound 14
(340 mg, 0.73 mmol, 89%) was obtained as a white solid. Mp:
127.3 °C. 1H NMR (300 MHz), d (ppm, CDCl3): 8.23 (t, J = 1.5 Hz,
1H); 8.04 (d, J = 1.5 Hz, 2H); 7.46 (t, J = 4.7 Hz, 2H); 3.48 (td, J =
5.9 Hz, J = 5.5 Hz, 4H); 2.50 (t, J = 6.1 Hz, 4H); 2.38 (m, 8H); 1.54
(m, 8H); 1.40 (m, 4H). 13C NMR (75 MHz), d (ppm, CDCl3): 165.3;
136.3; 133.2; 123.7; 123.0; 57.4; 54.3; 36.6; 25.7; 24.2. LC–MS
(ESI) m/z Calculated: 465.2–467.2, Found: 465.0–466.9, 233.1–
234.0 [(M+2H)/2]+.
5.1.1. General procedure for the synthesis of compounds 11a–d
2-Nitrobenzaldehyde 10 (1.00 g, 6.62 mmol) was dissolved in
DCE (95 mL). The appropriate commercially amine (9.93 mmol),
and ZnCl2 (0.90 g, 6.62 mmol) were added. After 3 h of stirring at
room temperature, NaBH3CN (624 mg, 9.93 mmol) was added.
After 18 h of stirring at room temperature, a saturated NaHCO3
solution (40 mL) was added. The reaction mixture was stirred for
1 h at room temperature. DCM (100 mL) was added and the layers
were separated. The organic layer was washed twice with satu-
rated NaHCO3 solution (30 mL). The organic layer was dried over
MgSO4 and evaporated. The residue was purified by column or
flash chromatography.
5.1.1.6. 5-Bromo-N1,N3-dimethoxy-N1,N3-dimethyl benzene-1,3-
dicarboxamide 17. To a stirred solution of 5-bromoisophthalic acid
(4.00 g, 16.3 mmol) in ACN (32 mL) and DCM (32 mL) was added
EDCꢀHCl (8.14 g, 42.40 mmol), HOBt-H2O (5.74 g, 42.40 mmol), N-
méthylmorpholine (23.3 mL, 212.00 mmol) and N,O-dimethylhy-
droxylamineꢀHCl (6.69 g, 68.60 mmol). The mixture was stirred at
room temperature for 16 h. The mixture was washed with a satu-
rated solution of NaHCO3 (2 ꢃ 50 mL), a 1 M solution of HCl (2 ꢃ
50 mL) and 50 mL of brine. The organic layer was dried over
MgSO4, filtered and evaporated. The compound was used without
further purification in the next step. The title compound (4.80 g,
14.49 mmol, 89%) was obtained as a yellow oil. 1H NMR (300
MHz), d (ppm, CDCl3): 7.94 (t, J = 1.4 Hz, 1H); 7.91 (d, J = 1.4 Hz,
2H); 3.54 (s, 6H); 3.35 (s, 6H). 13C NMR (75 MHz), d (ppm, CDCl3):
167.4; 135.5; 133.3; 126.8; 121.7; 61.3; 33.5. LC–MS (ESI) m/z Cal-
culated: 331.0–333.0, Found: 331.0–333.0 [M+H]+.
5.1.1.1. 1-[(2-Nitrophenyl)methyl]piperidine 11a. The residue was
purified by flash chromatography (PE/EtOAc, 10:0 to 7:3 (v/v)).
The compound 11a was obtained as a yellow oil (yield: 84%). 1H
NMR (300 MHz), d (ppm, CDCl3): 7.77 (dd, J = 8.0 Hz, J = 1.2 Hz,
1H); 7.62 (dd, J = 7.7 Hz, J = 0.4 Hz, 1H); 7.50 (td, J = 7.4 Hz, J =
1.1 Hz, 1H); 7.34 (ddd, J = 7.9 Hz, J = 7.5 Hz, J = 1.5 Hz, 1H); 3.71
(s, 2H); 2.34 (m, 4H); 1.52 (m, 4H); 1.40 (m, 2H). 13C NMR (75
MHz), d (ppm, CDCl3): 149.8; 134.6; 132.3; 130.8; 127.6; 124.2;
59.7; 54.6; 26.0; 24.2. LC–MS (ESI) m/z Calculated: 221.1, Found:
221.0 [M+H]+.
5.1.1.7. General procedure for the synthesis of compounds 15a–d,
18a–d. To a solution of 4-[(2-nitrophenyl)methyl]amine 11a–d
(2.25 mmol) in EtOH (45 mL) was added ammonium formate
(0.99 g, 15.75 mmol) and Pd/C 10% (177 mg, 0.17 mmol). The mix-
ture was stirred for 1 h at room temperature. The reaction mixture
was filtered through a Celite pad and the filtrate was evaporated.
The residue was dissolved in DCM (30 mL) and washed with water
(30 mL). The organic layer was dried over MgSO4, filtered and
evaporated. Because of the high instability of the compounds
12a–d, they were used directly without further purification in
the next step.
5.1.1.2. 4-[(2-Nitrophenyl)methyl]morpholine 11b. The residue was
purified by flash chromatography (PE/EtOAc, 10:0 to 7:3 (v/v)).
The compound 11b was obtained as an orange oil (yield: 83%).
1H NMR (300 MHz), d (ppm, CDCl3): 7.81 (dd, J = 8.0 Hz, J = 1.2
Hz, 1H); 7.59 (dd, J = 5.9 Hz, J = 1.7 Hz, 1H); 7.54 (ddd, J = 7.7 Hz,
J = 7.2 Hz, J = 1.3 Hz, 1H); 7.40 (td, J = 8.0 Hz, J = 1.8 Hz, 1H); 3.79
(s, 2H); 3.66 (m, 4H); 2.44 (m, 4H). 13C NMR (75 MHz), d (ppm,
CDCl3): 149.9; 133.4; 132.3; 131.0; 128.1; 124.4; 67.0; 59.5;
53.6. LC–MS (ESI) m/z Calculated: 223.1, Found: 223.0 [M+H]+.
5-Bromo-N1,N3-bis[2-(piperidin-1-yl)ethyl]benzene-1,3-dicar-
boxamide 14 (303 mg, 0.65 mmol) or 5-Bromo-N1,N3-dimethoxy-
N1,N3-dimethylbenzene-1,3-dicarboxamide 17 (215 mg, 0.65
mmol) was dissolved in dioxane (2 mL) and Cs2CO3 (297 mg,
0.91 mmol) were added. The reaction was stirred for 30 min and
deoxygenated by passing a stream of N2 through it. Xantphos
(57 mg, 0.10 mmol), Pd2dba3 (30 mg, 0.03 mmol) and the previ-
ously prepared amine 12a–d dissolved in dioxane (1 mL) were
added. The reaction mixture was stirred for 15 h at reflux. The
reaction mixture was filtered through a Celite pad and the filtrate
was evaporated. The residues were purified by column or flash
chromatography (DCM/MeOH(NH3), 10:0 to 9.5:0.5 (v/v)) to give
compounds 15a–d.
5.1.1.3. 1-Methyl-4-[(2-nitrophenyl)methyl] piperazine 11c. The resi-
due was purified by flash chromatography (DCM/MeOH(NH3), 10:0
to 9.8:0.2 (v/v)). The compound 11c was obtained as a yellow oil
(yield: 77%). 1H NMR (300 MHz), d (ppm, CDCl3): 7.81 (d, J = 8.0
Hz, 1H); 7.56–7.41 (M, 3H); 3.89 (s, 2H); 3.14 (m, 2H); 2.80 (m,
4H); 2.72 (s, 3H); 2.56 (m, 2H). 13C NMR (75 MHz), d (ppm, CDCl3):
149.7; 132.6; 132.3; 131.0; 128.7; 124.6; 58.4; 58.2; 48.8; 47.0.
LC–MS (ESI) m/z Calculated: 236.1, Found: 236.0 [M+H]+.
5.1.1.4. Dimethyl[(2-nitrophenyl)methyl]amine 11d. The residue was
purified by flash chromatography (PE/EtOAc, 10:0 to 7:3 (v/v)). The
compound 11d was obtained as a yellow oil (yield: 79%). 1H NMR
(300 MHz), d (ppm, CDCl3): 7.82 (dd, J = 8.1 Hz, J = 1.3 Hz, 1H); 7.63
(dd, J = 7.6 Hz, J = 1.0 Hz, 1H); 7.55 (ddd, J = 7.7 Hz, J = 7.4 Hz, J =
1.3 Hz, 1H); 7.40 (td, J = 8.0 Hz, J = 1.6 Hz, 1H); 3.72 (s, 2H); 2.24
(s, 6H). 13C NMR (75 MHz), d (ppm, CDCl3): 149.7; 134.4; 132.5;
131.0; 127.8; 124.3; 60.3; 45.6. LC–MS (ESI) m/z Calculated:
181.1, Found: 181.0 [M+H]+, 135.8 [MꢁN(CH3)2+H]+.
5.1.1.8.
N1,N3-bis[2-(piperidin-1-yl)ethyl]-5-([2-(piperidin-1-
ylmethyl)phenyl]amino) benzene-1,3-dicarboxamide 15a. The resi-
due was purified by flash chromatography (DCM/MeOH(NH3),
10:0 to 9.5:0.5 (v/v)) to give compound 15a as a colourless oil
(yield: 88%). 1H NMR (300 MHz), d (ppm, CDCl3): 9.25 (s, 1H);
Please cite this article in press as: Gay M., et al. Bioorg. Med. Chem. (2018), https://doi.org/10.1016/j.bmc.2018.03.016

M. Gay et al. / Bioorganic & Medicinal Chemistry xxx (2018) xxx–xxx
9
7.68 (t, J = 1.5 Hz, 1H); 7.62 (d, J = 1.4 Hz, 2H); 7.40 (dd, J = 8.1 Hz, J
= 1.0 Hz, 1H); 7.20 (ddd, J = 8.0 Hz, J = 7.5 Hz, J = 1.6 Hz, 1H); 7.11
(dd, J = 7.5 Hz, J = 1.4 Hz, 1H); 7.05 (br t, J = 5.0 Hz, 2H); 6.84 (td,
J = 7.4 Hz, J = 1.1 Hz, 1H); 3.57–3.51 (M, 6H); 2.56 (t, J = 6.2 Hz,
4H); 2.46–2.37 (M, 12H); 1.67–1.55 (M, 12H); 1.49–1.41 (M, 6H).
13C NMR (75 MHz), d (ppm, CDCl3): 166.9; 144.3; 142.6; 136.2;
130.8; 128.1; 126.0; 120.3; 118.0; 116.1; 115.5; 62.9; 57.1; 54.3;
54.0; 36.5; 26.3; 25.9; 24.4; 24.3. LC–MS (ESI) m/z Calculated:
575.4, Found: 575.4 [M+H]+, 288.2 [(M+2H)/2]+. HR-MS: m/z Calcu-
lated: 575.40680, Found: 575.40367 [M+H]+ = C34H51N6O2. Purity:
C4 column: tr = 17.5 min, purity = 94%; C18 column: tr = 19.4 min,
purity = 95%.
(v/v)) to give compound 18a as a yellow oil (yield: 75%). 1H NMR
(300 MHz), d (ppm, CDCl3): 9.25 (br s, 1H); 7.43 (d, J = 1.4 Hz,
2H); 7.41 (t, J = 1.3 Hz, 1H); 7.36 (dd, J = 8.1 Hz, J = 1.0 Hz, 1H);
7.18 (td, J = 8.0 Hz, J = 1.6 Hz, 1H); 7.08 (dd, J = 7.4 Hz, J = 1.5 Hz,
1H); 6.82 (td, J = 7.4 Hz, J = 1.1 Hz, 1H); 3.61 (s, 6H); 3.51 (s, 2H);
3.35 (s, 6H); 2.39 (br s, 4H); 1.60 (m, 4H); 1.50 (m, 2H). 13C NMR
(75 MHz), d (ppm, CDCl3): 169.3; 141.3; 142.8; 135.0; 130.7;
128.1; 125.6; 120.0; 118.8; 118.6; 115.0; 62.9; 61.2; 53.9; 33.8;
26.3; 24.4. LC–MS (ESI) m/z Calculated: 441.3, Found: 441.2 [M
+H]+, 356.2 [Mꢁpiperidine+H]+.
5.1.1.13.
N1,N3-Dimethoxy-N1,N3-dimethyl-5-([2-(morpholin-4-
ylmethyl)phenyl]amino) benzene-1,3-dicarboxamide 18b. The resi-
due was purified by flash chromatography (PE/EtOAc, 10:0 to
0:10 (v/v)) to give compound 18b as a yellow oil (yield: 65%). 1H
NMR (300 MHz), d (ppm, CDCl3): 8.72 (br s, 1H); 7.44 (s, 3H);
7.36 (dd, J = 8.1 Hz, J = 1.0 Hz, 1H); 7.21 (td, J = 7.4 Hz, J = 1.6 Hz,
1H); 7.12 (dd, J = 7.5 Hz, J = 1.4 Hz, 1H); 6.85 (td, J = 7.4 Hz, J =
1.1 Hz, 1H); 3.74 (t, J = 4.5 Hz, 4H); 3.61 (s, 6H); 3.56 (s, 2H);
3.36 (s, 6H); 2.46 (t, J = 4.1 Hz, 4H). 13C NMR (75 MHz), d (ppm,
CDCl3): 169.2; 143.1; 142.5; 135.0; 131.1; 128.5; 124.6; 120.4;
119.2; 118.8; 115.4; 67.2; 62.4; 61.2; 53.0; 33.8. LC–MS (ESI) m/z
Calculated: 443.2, Found: 443.2 [M+H]+, 441.1 [MꢁH]ꢁ.
5.1.1.9.
5-([2-(Morpholin-4-ylmethyl)phenyl]amino)-N1,N3-bis[2-
(piperidin-1-yl)ethyl] benzene-1,3-dicarboxamide 15b. The residue
was purified by flash chromatography (DCM/MeOH(NH3), 10:0 to
9.5:0.5 (v/v)) to give compound 15b as a colourless oil (yield:
48%). 1H NMR (300 MHz), d (ppm, CDCl3): 8.69 (s, 1H); 7.77 (s,
1H); 7.67 (s, 2H); 7.40 (d, J = 8.0 Hz, 1H); 7.25–7.13 (M, 4H); 6.88
(td, J = 7.4 Hz, J = 1.0 Hz, 1H); 3.77 (t, J = 4.3 Hz, 4H); 3.61–3.57
(M, 6H); 2.63 (t, J = 5.7 Hz, 4H), 2.51–2.45 (M, 12H); 1.64 (m,
8H); 1.50 (m, 4H). 13C NMR (75 MHz), d (ppm, CDCl3): 166.9;
144.1; 142.4; 136.0; 131.1; 128.6; 125.1; 120.7; 118.3; 116.3;
116.1; 67.2; 62.4; 57.2; 54.3; 53.1; 36.4; 25.7; 24.2. LC–MS (ESI)
m/z Calculated: 577.4, Found: 577.3 [M+H]+, 289.2 [(M+2H)/2]+.
HR-MS: m/z Calculated: 577.38607, Found: 577.38232 [M+H]+ =
5.1.1.14. N1,N3-Dimethoxy-N1,N3-dimethyl-5-((2-[(4-methylpiper-
azin-1-yl)methyl]phenyl)amino) benzene-1,3-dicarboxamide 18c.
The residue was purified by flash chromatography (PE/EtOAc,
10:0 to 9.8:0.2 (v/v)) to give compound 18c as a yellow oil (yield:
92%). 1H NMR (300 MHz), d (ppm, CDCl3): 8.84 (br s, 1H); 7.45 (s,
3H); 7.37 (dd, J = 8.1 Hz, J = 1.0 Hz, 1H); 7.21 (td, J = 7.6 Hz, J =
1.6 Hz, 1H); 7.13 (dd, J = 7.4 Hz, J = 1.5 Hz, 1H); 6.86 (td, J = 7.4
Hz, J = 1.2 Hz, 1H); 3.63 (s, 6H); 3.58 (s, 2H); 3.38 (s, 6H); 2.60–
2.43 (M, 8H); 2.34 (s, 3H). 13C NMR (75 MHz), d (ppm, CDCl3):
169.3; 143.2; 142.6; 135.0; 130.9; 128.3; 125.3; 120.3; 119.0;
118.7; 115.5; 62.0; 61.2; 55.4; 52.5; 46.0; 33.9. LC–MS (ESI) m/z
Calculated: 456.3, Found: 456.2 [M+H]+, 454.1 [MꢁH]ꢁ.
C33H49N6O3. Purity: C4 column: tr = 16.7 min, purity = 90%; C18 col-
umn: tr = 18.7 min, purity = 92%.
5.1.1.10. 5-((2-[(4-Methylpiperazin-1-yl)methyl] phenyl)amino)-N1,
N3-bis[2-(piperidin-1-yl)ethyl] benzene-1,3-dicarboxamide 15c. The
residue was purified by flash chromatography (DCM/MeOH(NH3),
10:0 to 9.5:0.5 (v/v)) to give compound 15c as a colourless oil
(yield: 35%). 1H NMR (300 MHz), d (ppm, CDCl3): 8.83 (s, 1H);
7.74 (t, J = 1.4 Hz, 1H); 7.67 (d, J = 1.4 Hz, 2H); 7.40 (dd, J = 8.0
Hz, J = 0.8 Hz, 1H); 7.23 (td, J = 7.8 Hz, J = 1.6 Hz, 1H); 7.16 (dd, J
= 7.5 Hz, J = 1.6 Hz, 1H); 7.10 (br t, J = 5.1 Hz, 2H); 6.89 (td, J =
7.4 Hz, J = 1.1 Hz, 1H); 3.60–3.54 (M, 6H); 2.61–2.43 (M, 20H);
2.34 (s, 3H); 1.62 (m, 8H); 1.49 (m, 4H). 13C NMR (75 MHz), d
(ppm, CDCl3): 166.9; 144.3; 142.4; 136.1; 131.0; 128.4; 125.8;
120.6; 118.0; 116.1; 116.1; 62.0; 57.1; 55.4; 54.3; 52.7; 46.0;
36.5; 25.9; 24.3. LC–MS (ESI) m/z Calculated: 590.4, Found: 590.4
[M+H]+, 295.7 [(M+2H)/2]+. HR-MS: m/z Calculated: 590.41770,
Found: 590.41328 [M+H]+ = C34H52N7O2. Purity: C4 column: tr =
16.1 min, purity = 95%; C18 column: tr = 18.7 min, purity = 97%.
5.1.1.15.
5-((2-[(Dimethylamino)methyl]phenyl)
amino)-N1,N3-
dimethoxy-N1,N3-dimethylbenzene-1,3-dicarboxamide
18d. The
residue was purified by flash chromatography (PE/EtOAc, 10:0 to
9.8:0.2 (v/v)) to give compound 18d as a yellow oil (yield: 26%).
1H NMR (300 MHz), d (ppm, CDCl3): 7.41 (s, 2H); 7.37 (s, 1H);
7.33 (dd, J = 8.1 Hz, J = 1.1 Hz, 1H); 7.15 (td, J = 7.5 Hz, J = 1.6 Hz,
1H); 7.06 (dd, J = 7.4 Hz, J = 1.5 Hz, 1H); 6.80 (td, J = 7.4 Hz, J =
1.1 Hz, 1H); 3.57 (s, 6H); 3.43 (s, 2H); 3.31 (s, 6H); 2.20 (s, 6H).
13C NMR (75 MHz), d (ppm, CDCl3): 169.3; 143.3; 142.6; 134.9;
130.6; 128.3; 126.3; 120.3; 118.8; 118.7; 115.5; 63.4; 61.2; 44.8;
33.9. LC–MS (ESI) m/z Calculated: 401.2, Found: 401.1 [M+H]+.
5.1.1.11. 5-((2-[(Dimethylamino)methyl]phenyl) amino)-N1,N3-bis[2-
(piperidin-yl)ethyl] benzene-1,3-dicarboxamide 15d. The residue
was purified by flash chromatography (DCM/MeOH(NH3), 10:0 to
9.5:0.5 (v/v)) to give compound 15d as a red oil (yield: 30%). 1H
NMR (300 MHz), d (ppm, CDCl3): 8.92 (s, 1H); 7.69 (t, J = 1.4 Hz,
1H); 7.65 (d, J = 1.4 Hz, 2H); 7.39 (d, J = 7.9 Hz, 1H); 7.20 (td, J =
8.1 Hz, J = 1.4 Hz, 1H); 7.11 (dd, J = 7.7 Hz, J = 1.1 Hz, 1H); 7.06
(br t, J = 4.2 Hz, 2H); 6.85 (td, J = 7.5 Hz, J = 0.9 Hz, 1H); 3.54 (q, J
= 5.5 Hz, 4H); 3.46 (s, 2H); 2.55 (t, J = 6.0 Hz, 4H); 2.43 (br s, 8H);
2.24 (s, 6H); 1.59 (m, 8H); 1.46 (m, 4H). 13C NMR (75 MHz), d
(ppm, CDCl3): 166.9; 144.2; 142.6; 136.1; 130.6; 128.3; 126.5;
120.4; 118.2; 116.0; 115.6; 63.9; 57.1; 54.3; 44.9; 36.5; 25.9;
24.3. LC–MS (ESI) m/z Calculated: 535.4, Found: 535.3 [M+H]+.
HR-MS: m/z Calculated: 535.37550, Found: 535.37152 [M+H]+ =
5.1.1.16. General procedure for the synthesis of compounds 16a–d. To
a solution of the appropriate Weinreb amide derivatives 18a–d
(0.70 mmol) in THF (5 mL) was added LiAlH4 in THF (1 M, 1.3 mL,
1.33 mmol) dropwise, under N2 atmosphere at 0 °C. The mixture
was stirred at 0 °C for 1 h. Saturated KHSO4 solution (3 mL) was
added dropwise. After evaporation of the THF, the residue was dis-
solved in DCM (30 mL) and washed twice with saturated NaHCO3
solution (20 mL), twice with HCl (1 M, 10 mL) and once with brine
(20 mL). The organic layer was dried over MgSO4, filtered and
evaporated. The unstable products 19a–d were used without fur-
ther purification in the next step.
C31H47N6O2. Purity: C4 column: tr = 16.6 min, purity = 90%; C18 col-
The desired dicarbaldehyde derivative 19a–d (0.23 mmol) was
umn: tr = 17.8 min, purity = 92%.
dissolved in toluene (5 mL). 1-Piperidineethanamine (94 lL, 0.65
mmol) was added. After 1–2 h of reflux with a Dean Stark appara-
5.1.1.12.
N1,N3-Dimethoxy-N1,N3-dimethyl-5-([2-(piperidin-1-
tus, the solvent was evaporated and the residue was dissolved in
ylmethyl)phenyl]amino) benzene-1,3-dicarboxamide 18a. The resi-
due was purified by flash chromatography (PE/EtOAc, 10:0 to 1:9
DCE (3 mL). Acetic acid (37
(138 mg, 0.65 mmol) were added. After 15 h of stirring at room
lL, 0.65 mmol) and NaBH(OAc)3
Please cite this article in press as: Gay M., et al. Bioorg. Med. Chem. (2018), https://doi.org/10.1016/j.bmc.2018.03.016

10
M. Gay et al. / Bioorganic & Medicinal Chemistry xxx (2018) xxx–xxx
temperature, a volume of saturated NaHCO3 solution (20 mL) was
added. The reaction mixture was stirred for 1 h at room tempera-
ture. DCM (20 mL) was added and the layers were separated. The
organic layer was washed twice with saturated NaHCO3 solution.
The organic layer was dried over MgSO4 and evaporated. The
residue was purified flash chromatography to afford compounds
16a–d.
[M+H]+ = C31H51N6. Purity: C4 column: tr = 14.3 min, purity = 91%;
C18 column: tr = 16.5 min, purity = 90%.
5.1.1.21. General procedure for the synthesis of compounds 21a–d. 2-
Formylbenzeneboronic acid (350 mg, 2.32 mmol) was dissolved in
a mixture of toluene (45 mL) and EtOH (15 mL). Potassium carbon-
ate (350 mg, 2.51 mmol) and 5-bromo-N1,N3-bis[2-(piperidin-1-
yl)ethyl]benzene-1,3-dicarboxamide 14 (900 mg, 1.93 mmol) were
added and the reaction was stirred for 30 min and deoxygenated
by passing a stream of N2 through it. Pd(OAc)2 (10 mg, 0.04 mmol)
and P(o-tol)3 (120 mg, 0.39 mmol) were added and the mixture
was refluxed for 18 h. After cooling, the mixture was poured into
water, extracted with ethyl acetate. The combined organic layer
was dried over MgSO4 and evaporated. The derivative 20 was used
without further purification in the next step.
5.1.1.17.
3,5-Bis(([2-(piperidin-1-yl)ethyl]amino)
methyl)-N-[2-
(piperidin-1-ylmethyl) phenyl]aniline 16a. The residue was purified
by column chromatography (DCM/MeOH(NH3) 9.5:0.5 to 9.3:0.7
(v/v)) to give compound 16a as a colourless oil (yield: 26%). 1H
NMR (300 MHz), d (ppm, CDCl3): 8.89 (br s, 1H); 7.35 (dd, J = 8.1
Hz, J = 1.0 Hz, 1H); 7.17 (td, J = 7.6 Hz, J = 1.6 Hz, 1H); 7.09 (dd, J
= 7.4 Hz, J = 1.4 Hz, 1H); 6.94 (d, J = 1.2 Hz, 2H); 6.83–6.76 (M,
2H); 3.78 (s, 4H); 3.51 (s, 2H); 2.76 (t, J = 6.4 Hz, 4H); 2.52–2.35
(M, 16H); 1.66–1.43 (M, 18H). 13C NMR (75 MHz), d (ppm, CDCl3):
143.8; 143.5; 141.4; 130.6; 128.0; 125.2; 119.9; 119.0; 116.2;
114.8; 63.0; 58.3; 54.6; 53.9; 45.7; 26.3; 25.9; 24.5; 24.4. HR-MS:
m/z Calculated: 547.44827, Found: 547.44425 [M+H]+ = C34H55N6.
Purity: C4 column: tr = 14.7 min, purity = 97%; C18 column: tr =
17.3 min, purity = 96%.
The obtained aldehyde derivative 20 (2.90 mmol) was dissolved
in DCE and the desired commercially amine (2.90 mmol) was
added. After 5 h of stirring at room temperature, NaBH(OAc)3
(614 mg, 2.90 mmol), acetic acid (166 lL, 2.90 mmol) were added.
After 24 h of stirring at room temperature, a volume of saturated
NaHCO3 solution was added (20 mL). The reaction mixture was
stirred for 1 h at room temperature. DCM (30 mL) was added and
the layers were separated. The organic layer was washed twice
with saturated NaHCO3 solution (20 mL). The organic layer was
dried over MgSO4 and evaporated. The residue was purified by col-
umn chromatography (PE/EtOAc/MeOH(NH3), 4:5/5/0.5 (v/v/v)).
5.1.1.18. N-[2-(Morpholin-4-ylmethyl)phenyl]-3,5-bis(([2-(piperidin-
1-yl)ethyl]amino)methyl) aniline 16b. The residue was purified by
column chromatography (DCM/MeOH(NH3) 10:0 to 9:1 (v/v)) to
give compound 16b as a colourless oil (yield: 14%). 1H NMR (300
MHz), d (ppm, CDCl3): 8.38 (br s, 1H); 7.35 (d, J = 7.6 Hz, 1H);
7.20 (td, J = 6.7 Hz, J = 1.4 Hz, 1H); 7.11 (dd, J = 7.4 Hz, J = 1.1 Hz,
1H); 6.94 (d, J = 0.9 Hz, 2H); 6.85–6.78 (M, 2H); 3.80–3.74 (M,
8H); 3.57 (s, 2H); 2.75 (t, J = 6.4 Hz, 4H); 2.52–2.45 (M, 8H); 2.38
(br s, 8H); 2.21 (br s, 2H); 1.57 (m, 8H); 1.44 (m, 4H). 13C NMR
(75 MHz), d (ppm, CDCl3): 143.7; 143.2; 141.8; 131.0; 128.4;
124.1; 120.2; 119.3; 116.3; 115.1; 67.2; 62.5; 58.5; 54.7; 54.0;
53.1; 46.0; 26.0; 24.4. HR-MS: m/z Calculated: 549.42754, Found:
549.42489 [M+H]+ = C33H53N6O. Purity: C4 column: tr = 14.4 min,
purity = 96%; C18 column: tr = 16.7 min, purity = 97%.
5.1.1.22.
N1,N3-bis[2-(Piperidin-1-yl)ethyl]-5-[2-(piperidin-1-
ylmethyl)phenyl] benzene-1,3-dicarboxamide 21a. The compound
21a was obtained as a colourless oil (yield: 62%). 1H NMR (300
MHz), d (ppm, CDCl3): 8.34 (t, J = 1.6 Hz, 1H); 8.09 (d, J = 1.7 Hz,
2H); 7.50 (m, 1H); 7.39–7.29 (M, 3H); 7.21 (t, J = 5.1 Hz, 2H);
3.61 (td, J = 5.8 Hz, J = 5.6 Hz, 4H); 3.30 (s, 2H); 2.62 (t, J = 6.1 Hz,
4H); 2.49 (m, 8H); 2.25 (m, 4H); 1.63 (m, 8H); 1.54–1.36 (M,
10H). 13C NMR (75 MHz), d (ppm, CDCl3): 166.7; 142.5; 141.2;
136.3; 134.3; 131.3; 130.5; 130.1; 127.6; 126.9; 123.8; 60.9;
57.4; 54.4; 54.2; 36.5; 26.1; 25.7; 24.4; 24.2. LC–MS (ESI) m/z Cal-
culated: 560.4, Found: 560.4 [M+H]+, 558.3 [MꢁH]ꢁ. HR-MS: m/z
Calculated: 560.39590, Found: 560.39511 [M+H]+ = C34H50N5O2.
Purity: C4 column: tr = 18.8 min, purity = 98%; C18 column: tr =
18.4 min, purity = 98%.
5.1.1.19. N-(2-[(4-Methylpiperazin-1-yl)methyl]phenyl)-3,5-bis(([2-
(piperidin-1-yl)ethyl] amino)methyl)aniline 16c. The residue was
purified by column chromatography (DCM/MeOH(NH3) 10:0 to
9:1 (v/v)) to give compound 16c as a colourless oil (yield: 10%).
1H NMR (300 MHz), d (ppm, CDCl3): 8.56 (br s, 1H); 7.34 (dd, J =
7.9 Hz, J = 0.8 Hz, 1H); 7.19 (td, J = 7.5 Hz, J = 1.5 Hz, 1H); 7.11
(dd, J = 7.4 Hz, J = 1.5 Hz, 1H); 6.97 (d, J = 1.2 Hz, 2H); 6.93 (t, J =
1.1 Hz, 1H); 6.82 (td, J = 7.3 Hz, J = 1.0 Hz, 1H); 3.82 (s, 4H); 3.68
(br s, 2H); 3.56 (s, 2H); 2.87 (t, J = 6.4 Hz, 4H); 2.68–2.48 (M,
20H); 2.40 (s, 3H); 1.65 (m, 8H); 1.47 (m, 4H). 13C NMR (75
MHz), d (ppm, CDCl3): 143.6; 143.3; 140.3; 130.9; 128.3; 124.8;
120.1; 119.6; 116.4; 115.2; 62.0; 57.4; 55.3; 54.4; 53.4; 52.3;
45.8; 44.9; 25.2; 23.9. HR-MS: m/z Calculated: 562.45917, Found:
562.45673 [M+H]+ = C34H56N7. Purity: C4 column: tr = 14.4 min,
purity = 94%; C18 column: tr = 16.9 min, purity = 95%.
5.1.1.23. 5-[2-(Morpholine-4-ylmethyl)phenyl]-N1,N3-bis[2-(piperi-
din-1-yl)ethyl]benzene-1,3-dicarboxamide 21b. The compound 21b
was obtained as a colourless oil (yield: 29%). 1H NMR (300 MHz),
d (ppm, CDCl3): 8.34 (t, J = 1.7 Hz, 1H); 8.09 (d, J = 1.6 Hz, 2H);
7.48 (m, 1H); 7.37–7.29 (M, 5H); 3.65–3.58 (M, 8H); 3.35 (s, 2H);
2.61 (t, J = 6.0 Hz, 4H); 2.48 (m, 8H); 2.35 (m, 4H); 1.63 (m, 8H);
1.49 (m, 4H). 13C NMR (75 MHz), d (ppm, CDCl3): 166.6; 142.4;
141.4; 135.2; 134.3; 131.5; 130.5; 130.3; 127.6; 127.3; 123.6;
67.1; 60.6; 57.5; 54.4; 53.2; 36.5; 25.7; 24.2. LC–MS (ESI) m/z Cal-
culated: 562.4, Found: 562.4 [M+H]+, 560.4 [MꢁH]ꢁ. HR-MS: m/z
Calculated: 562.37517, Found: 562.37540 [M+H]+ = C33H48N5O3.
Purity: C4 column: tr = 18.2 min, purity = 99%; C18 column: tr =
17.9 min, purity = 99%.
5.1.1.20. N-(2-[(Dimethylamino)methyl]phenyl)-3,5-bis(([2-(piperi-
din-1-yl)ethyl]amino) methyl) aniline 16d. The residue was purified
by column chromatography (DCM/MeOH(NH3) 10:0 to 9:1 (v/v)) to
give compound 16d as a colourless oil (yield: 8%). 1H NMR (300
MHz), d (ppm, CDCl3): 8.49 (br s, 1H); 7.35 (d, J = 8.0 Hz, 1H);
7.18 (td, J = 7.4 Hz, J = 1.5 Hz, 1H); 7.11 (dd, J = 7.4 Hz, J = 1.3 Hz,
1H); 6.97 (d, J = 1.1 Hz, 2H); 6.85–6.78 (M, 2H); 3.78 (s, 4H); 3.45
(s, 2H); 2.77 (t, J = 6.4 Hz, 4H); 2.51 (t, J = 6.1 Hz, 4H); 2.40 (br s,
8H); 2.30–2.25 (M, 8H); 1.58 (m, 8H); 1.44 (m, 4H). 13C NMR (75
MHz), d (ppm, CDCl3): 143.7; 143.5; 141.4; 130.5; 128.1; 125.9;
120.0; 119.2; 116.2; 115.2; 63.6; 58.3; 54.6; 53.9; 45.7; 44.9;
25.8; 24.3. HR-MS: m/z Calculated: 507.41697, Found: 507.41539
5.1.1.24. 5-(2-[(4-Methylpiperazin-1-yl)methyl] phenyl)-N1,N3-bis[2-
(piperidin-1-yl)ethyl] benzene-1,3-dicarboxamide 21c. The com-
pound 21c was obtained as a colourless oil (yield: 26%). 1H NMR
(300 MHz), d (ppm, CDCl3): 8.28 (t, J = 1.5 Hz, 1H); 8.05 (d, J = 1.5
Hz, 2H); 7.45 (m, 1H); 7.36–7.24 (M, 3H); 7.18 (br t, J = 4.9 Hz,
2H); 3.55 (td, J = 5.8 Hz, J = 5.6 Hz, 4H); 3.33 (s, 2H); 2.56 (t, J =
6.0 Hz, 4H); 2.50–2.25 (M, 16H); 2.22 (s, 3H); 1.58 (m, 8H); 1.44
(m, 4H). 13C NMR (75 MHz), d (ppm, CDCl3): 166.7; 142.3; 141.2;
135.6; 134.4; 131.2; 130.5; 130.1; 127.6; 127.2; 123.7; 60.1;
57.4; 55.2; 54.3; 52.7; 46.0; 36.6; 25.8; 24.2. LC–MS (ESI) m/z
Please cite this article in press as: Gay M., et al. Bioorg. Med. Chem. (2018), https://doi.org/10.1016/j.bmc.2018.03.016

M. Gay et al. / Bioorganic & Medicinal Chemistry xxx (2018) xxx–xxx
11
Calculated: 575.4, Found: 575.4 [M+H]+, 573.4 [MꢁH]ꢁ. HR-MS: m/
z Calculated: 575.40680, Found: 575.40717 [M+H]+ = C34H51N6O2.
Purity: C4 column: tr = 19.3 min, purity = 98%; C18 column: tr =
18.0 min, purity = 98%.
[(M+2H)/2]+. HR-MS: m/z Calculated: 532.43737, Found:
532.43743 [M+H]+ = C34H54N5. Purity: C4 column: tr = 15.0 min,
purity = 95%; C18 column: tr = 17.9 min, purity = 95%.
5.1.1.29. ((3-[2-(Morpholine-4-ylmethyl)phenyl]-5-(([2-(piperidin-1-
yl)ethyl]amino)methyl)phenyl) methyl)[2-(piperidin-1-yl)ethyl]amine
22b. The compound 22b was obtained as a colourless oil (yield:
23%). 1H NMR (300 MHz), d (ppm, MeOD): 7.55 (m, 1H); 7.37–
7.25 (M, 6H); 3.85 (s, 4H); 3.64 (t, J = 4.6 Hz, 4H); 3.46 (s, 2H);
2.76 (t, J = 6.7 Hz, 4H); 2.52 (t, J = 6.1 Hz, 4H); 2.43 (m, 8H); 2.34
(m, 4H); 1.59 (m, 8H); 1.48 (m, 4H). 13C NMR (75 MHz), d (ppm,
MeOD): 142.7; 141.9; 139.3; 134.7; 129.9; 129.7; 128.2; 126.9;
126.7; 66.6; 59.9; 57.7; 54.4; 53.2; 52.9; 44.8; 25.3; 23.8. LC–MS
(ESI) m/z Calculated: 534.4, Found: 534.4 [M+H]+, 267.8 [(M
+2H)/2]+. HR-MS: m/z Calculated: 534.41664, Found: 534.41658
[M+H]+ = C33H52N5O. Purity: C4 column: tr = 14.7 min, purity =
98%; C18 column: tr = 17.4 min, purity = 98%.
5.1.1.25. 5-(2-[(Dimethylamino)methyl] phenyl)-N1,N3-bis[2-(piper-
idin-1-yl)ethyl]benzene-1,3-dicarboxamide 21d. The compound 21d
was obtained as a colourless oil (yield: 55%). 1H NMR (300 MHz), d
(ppm, CDCl3): 8.33 (t, J = 1.6 Hz, 1H); 8.07 (d, J = 1.7 Hz, 2H); 7.45
(m, 1H); 7.35–7.22 (M, 5H); 3.53 (td, J = 5.8 Hz, J = 5.6 Hz, 4H);
3.24 (s, 2H); 2.52 (t, J = 6.1 Hz, 4H); 2.39 (m, 8H); 2.13 (s, 6H);
1.55 (m, 8H); 1.42 (m, 4H). 13C NMR (75 MHz), d (ppm, CDCl3):
166.6; 142.1; 141.0; 136.2; 134.3; 131.3; 130.5; 130.0; 127.7;
127.1; 123.9; 61.2; 57.5; 54.3; 45.7; 36.6; 25.8; 24.2. LC–MS (ESI)
m/z Calculated: 520.4, Found: 520.4 [M+H]+. HR-MS: m/z Calcu-
lated: 520.36460, Found: 520.36475 [M+H]+ = C31H46N5O2. Purity:
C4 column: tr = 18.1 min, purity = 96%; C18 column: tr = 17.9 min,
purity = 96%.
5.1.1.30. [(3-(2-[(4-Methylpiperazin-1-yl)methyl] phenyl)-5-(([2-
(piperidin-1-yl)ethyl]amino)methyl) phenyl)methyl] [2-(piperidin-1-
yl)ethyl]amine 22c. The compound 22c was obtained as a colour-
less oil (yield: 4%). 1H NMR (300 MHz), d (ppm, MeOD): 7.50 (m,
1H); 7.39–7.25 (M, 6H); 3.85 (s, 4H); 3.46 (s, 2H); 2.77 (t, J = 6.6
Hz, 4H); 2.53 (t, J = 6.9 Hz, 4H); 2.36 (m, 16H); 2.26 (s, 3H); 1.60
(m, 8H); 1.47 (m, 4H). 13C NMR (75 MHz), d (ppm, MeOD): 142.6;
141.9; 139.2; 134.9; 129.9; 129.8; 128.2; 126.9; 126.8; 59.4;
57.7; 54.6; 54.3; 52.9; 51.9; 44.8; 25.3; 23.8. LC–MS (ESI) m/z Cal-
culated: 547.5, Found: 547.4 [M+H]+, 274.2 [(M+2H)/2]+. HR-MS:
m/z Calculated: 547.44827, Found: 547.44699 [M+H]+ = C34H55N6.
5.1.1.26. 5-(2-Formylphenyl)-N1,N3-dimethoxy-N1,N3-dimethylben-
zene-1,3-dicarboxamide 23. 2-Formylbenzeneboronic acid (151
mg, 1.01 mmol) was dissolved in a mixture of toluene (20 mL)
and EtOH (5 mL). Potassium carbonate (150 mg, 1.10 mmol) and
5-bromo-N1,N3-bis[2-(piperidin-1-yl)ethyl]benzene-1,3-dicarbox-
amide 17 (280 mg, 0.84 mmol) were added and the reaction was
stirred for 30 min and deoxygenated by passing a stream of N2
through it. Pd(OAc)2 (4 mg, 0.02 mmol) and P(o-tol)3 (52 mg,
0.17 mmol) were added and the mixture was refluxed for 18 h.
After cooling, the mixture was poured into water, extracted with
ethyl acetate. The combined organic layer was dried over MgSO4
and evaporated. The residue was purified by flash chromatography
(PE/EtOAc, 10:0 to 3.5:6.5 (v/v)). The compound 23 was obtained as
a red oil (yield: 87%). 1H NMR (300 MHz), d (ppm, CDCl3): 10.00 (s,
1H), 8.11 (t, J = 1.4 Hz, 1H); 8.06 (dd, J = 7.8 Hz, J = 1.3 Hz, 1H); 7.83
(d, J = 1.5 Hz, 2H); 7.68 (td, J = 7.5 Hz, J = 1.4 Hz, 1H); 7.56 (m, 1H);
7.47 (dd, J = 7.7 Hz, J = 1.1 Hz, 1H); 3.61 (s, 6H); 3.41 (s, 6H). 13C
NMR (75 MHz), d (ppm, CDCl3): 191.5; 168.4; 144.0; 137.7;
134.2; 133.8; 133.7; 131.8; 130.9; 128.5; 128.2; 127.9; 61.3;
33.5. LC–MS (ESI) m/z Calculated: 357.2, Found: 357.1 [M+H]+.
5.1.1.31. [(3-(2-[(Dimethylamino)methyl]phenyl)-5-(([2-(piperidin-1-
yl)ethyl]amino)methyl) phenyl) methyl] [2-(piperidin-1-yl)ethyl]
amine 22d. The compound 22d was obtained as a colourless oil
(yield: 9%). 1H NMR (300 MHz), d (ppm, MeOD): 7.55 (m, 1H);
7.42–7.24 (M, 6H); 3.85 (s, 4H); 3.48 (s, 2H); 2.76 (t, J = 6.5 Hz,
4H); 2.52 (t, J = 7.0 Hz, 4H); 2.12 (s, 6H); 1.59 (m, 8H); 1.46 (m,
4H). 13C NMR (75 MHz), d (ppm, MeOD): 142.5; 141.8; 139.4;
135.1; 129.7; 128.8; 128.2; 127.1; 126.9; 126.7; 60.1; 57.7; 54.4;
52.8; 44.8; 44.1; 25.2; 23.8. LC–MS (ESI) m/z Calculated: 492.4,
Found: 492.4 [M+H]+, 246.7 [(M+2H)/2]+. HR-MS: m/z Calculated:
492.40607, Found: 492.40654 [M+H]+ = C31H50N5. Purity: C4 col-
umn: tr = 14.7 min, purity = 95%; C18 column: tr = 17.4 min, pur-
ity = 90%.
5.1.1.27. General procedure for the synthesis of compounds 22a–d,
24a–d. 5-(2-Formylphenyl)-N1,N3-dimethoxy-N1,N3-dimethyl-
benzene-1,3-dicarboxamide 23 (400 mg, 1.12 mmol) or compound
25a–d (1.12 mmol) was dissolved in toluene (15 mL). The appro-
priate commercially amine (1.68 mmol) was added. After 1 h of
reflux with a Dean Stark apparatus, the solvent was evaporated
5.1.1.32.
N1,N3-Dimethoxy-N1,N3-dimethyl-5-[2-(piperidin-1-
ylmethyl)phenyl]benzene-1,3-dicarboxamide 24a. The compound
24a was obtained as a red oil (yield: 61%). 1H NMR (300 MHz), d
(ppm, CDCl3): 7.96 (t, J = 1.6 Hz, 1H); 7.89 (d, J = 1.6 Hz, 2H); 7.51
(m, 1H); 7.38–7.25 (M, 3H); 3.60 (s, 6H); 3.39 (s, 6H); 3.34 (s,
2H); 2.28 (m, 4H); 1.50 (m, 4H); 1.38 (m, 2H). 13C NMR (75
MHz), d (ppm, CDCl3): 169.2; 141.3; 141.0; 136.2; 133.6; 131.5;
130.5; 130.1; 127.6; 126.9; 126.5; 61.2; 60.8; 54.2; 33.8; 26.0;
24.4. LC–MS (ESI) m/z Calculated: 426.2, Found: 426.2 [M+H]+.
and the residue was dissolved in DCE (15 mL). Acetic acid (97 lL,
1.68 mmol) and NaBH(OAc)3 (357 mg, 1.68 mmol) were added.
After 15 h of stirring at room temperature, saturated solution of
NaHCO3 (20 mL) was added. The reaction mixture was stirred for
1 h at room temperature. DCM (30 mL) was added and the layers
were separated. The organic layer was washed twice with satu-
rated NaHCO3 solution. The organic layer was dried over MgSO4
and evaporated. The products were purified by flash chromatogra-
phy (DCM/MeOH(NH3) 10:0 to 9.6:0.4 (v/v)).
5.1.1.33.
N1,N3-Dimethoxy-N1,N3-dimethyl-5-[2-(morpholine-4-
ylmethyl)phenyl]benzene-1,3-dicarboxamide 24b. The compound
24b was obtained as a brown oil (yield: 67%). 1H NMR (300
MHz), d (ppm, CDCl3): 7.98 (s, 1H); 7.93 (s, 2H); 7.47 (m, 1H);
7.37–7.33 (M, 3H); 3.65 (m, 4H); 3.60 (s, 6H); 3.39 (s, 6H); 3.38
(s, 2H); 2.38 (m, 4H). 13C NMR (75 MHz), d (ppm, CDCl3): 169.1;
141.2; 135.2; 133.7; 131.5; 130.6; 130.3; 127.4; 126.5; 126.5;
67.0; 61.2; 60.6; 53.2; 33.7. LC–MS (ESI) m/z Calculated: 428.2,
Found: 428.2 [M+H]+.
5.1.1.28.
[2-(Piperidin-1-yl)ethyl](([3-(([2-(piperidin-1-yl)ethyl]
amino)methyl)-5-[2-(piperidin-1-ylmethyl) phenyl]phenyl]methyl))
amine 22a. The compound 22a was obtained as a colourless oil
(yield: 54%). 1H NMR (300 MHz), d (ppm, MeOD): 7.54 (dd, J =
6.9 Hz, J = 2.0 Hz, 1H); 7.37–7.21 (M, 6H); 3.83 (s, 4H); 3.43 (s,
2H); 2.74 (t, J = 6.6 Hz, 4H); 2.49 (t, J = 7.0 Hz, 4H); 2.40 (m, 8H);
2.26 (m, 4H); 1.61–1.39 (M, 18H). 13C NMR (75 MHz), d (ppm,
MeOD): 142.6; 142.0; 139.3; 135.1; 129.9; 129.6; 128.3; 126.9;
126.8; 126.6; 60.1; 57.7; 54.4; 54.0; 52.9; 44.7; 25.4; 25.3; 23.8.
LC–MS (ESI) m/z Calculated: 532.4, Found: 532.4 [M+H]+, 266.8
5.1.1.34.
N1,N3-Dimethoxy-N1,N3-dimethyl-5-(2-[(4-methylpiper-
azin-1-yl)methyl]phenyl) benzene-1,3-dicarboxamide 24c. The com-
Please cite this article in press as: Gay M., et al. Bioorg. Med. Chem. (2018), https://doi.org/10.1016/j.bmc.2018.03.016

12
M. Gay et al. / Bioorganic & Medicinal Chemistry xxx (2018) xxx–xxx
pound 24c was obtained as a brown oil (yield: 42%). 1H NMR (300
MHz), d (ppm, CDCl3): 7.94 (t, J = 1.6 Hz, 1H); 7.88 (d, J = 1.6 Hz,
2H); 7.47 (m, 1H); 7.36–7.25 (M, 3H); 3.57 (s, 6H); 3.36 (s, 8H);
2.40 (br s, 8H); 2.24 (s, 3H). 13C NMR (75 MHz), d (ppm, CDCl3):
169.1; 141.2; 141.1; 135.7; 133.6; 131.5; 130.5; 130.2; 127.6;
127.2; 126.4; 61.2; 60.0; 55.1; 52.6; 46.0; 33.7. LC–MS (ESI) m/z
Calculated: 441.3, Found: 441.2 [M+H]+.
129.2; 128.4; 127.7; 61.2; 44.8. LC–MS (ESI) m/z Calculated:
268.13, Found: 268.10 [M+H]+.
5.2. In vitro testing
5.2.1. Cell culture and treatment
The human neuroblastoma cell line SKNSH-SYSY (SY5Y) was
cultured in Dulbecco’s modified Eagle medium supplemented with
10% fetal calf serum (PAA), 2 mM L-glutamine (Invitrogen), 1 mM
5.1.1.35.
5-(2-[(Dimethylamino)methyl]phenyl)-N1,N3-dimethoxy-
N1,N3-dimethylbenzene-1,3-dicarboxamide 24d. The compound
24d was obtained as a red oil (yield: 56%). 1H NMR (300 MHz), d
(ppm, CDCl3): 7.99 (t, J = 1.6 Hz, 1H); 7.82 (d, J = 1.6 Hz,2H); 7.56
(m, 1H); 7.42–7.26 (M, 3H); 3.60 (s, 6H); 3.39 (s, 8H); 2.16 (s,
6H). 13C NMR (75 MHz), d (ppm, CDCl3): 169.0; 141.1; 140.8;
135.9; 133.7; 131.5; 130.3; 130.0; 127.9; 127.1; 126.7; 61.2;
60.9; 45.1; 33.7. LC–MS (ESI) m/z Calculated: 386.2, Found: 386.2
[M+H]+.
non-essential amino-acids and penicillin/streptomycin (Invitro-
gen), in a 5% CO2 humidified incubator at 37 °C. The human
APP695 cDNA was subcloned into eukaryotic expression vector
pcDNA3.1 (Invitrogen), allowing for G418 antibiotic selection of
stable clones. This APP cDNA was transfected into SY5Y cells using
the ethyleneimine polymer ExGen 500 (Euromedex) according to
the manufacturer’s instructions. SY5Y cells stably expressing the
APP695 were selected with Geneticin G418 (Invitrogen) and one
clone named SY5Y-APPwt was used here.
5.1.1.36. General procedure for the synthesis of compounds 25a–d. To
a solution of the appropriate Weinreb amide derivatives 24a–d
(0.70 mmol) in THF (5 mL) was added LiAlH4 in THF (1 M, 1.3 mL,
1.33 mmol) dropwise, under N2 atmosphere at 0 °C. The mixture
was stirred at 0 °C for 1 h. Saturated KHSO4 solution (3 mL) was
added dropwise. After evaporation of the THF, the residue was dis-
solved in DCM (30 mL) and washed twice with saturated NaHCO3
solution (20 mL), twice with HCl (1 M, 10 mL) and once with brine
(20 mL). The organic layer was dried over MgSO4, filtered and
evaporated.
For treatment, SY5Y-APPwt cells were plated onto 12-well plates
(Falcon) 24 h before drug exposure, and cultured in Dulbecco’s
modified Eagle medium (Invitrogen) supplemented with 10% fetal
calf serum (PAA), 2 mM L-glutamine (Invitrogen), 1 mM non-essen-
tial amino acids (Invitrogen), 50 units/mL penicillin/streptomycin
(Invitrogen), and 200 mg Geneticin G418 (Invitrogen), under 5%
CO2 at 37 °C. Cells were exposed to drugs at the indicated concen-
trations for 24 h. After treatment, the conditioned medium was
collected, spun at 200ꢃg to eliminate the cell debris and frozen
at ꢁ80 °C for Ab1–42 and Ab1–40 quantification. Treated SY5Y-APPwt
cells were collected in 50 mL of Laemmli lysis buffer containing pro-
tease inhibitors (Complete Mini, Roche Molecular Biochemicals,
Meylan, France), sonicated for 5 min and stored at ꢁ80 °C until
use. Total protein quantification of extracted samples was per-
formed by BCATM Protein Assay Kit (Thermo Scientific) according
to the manufacturer’s protocol.
5.1.1.37. 5-[2-(Piperidin-1-ylmethyl)phenyl]benzene-1,3-dicarbalde-
hyde 25a. The residue was purified by flash chromatography (PE/
EtOAc 10:0 to 6.5:3.5 (v/v)) to give compound 25a as a colourless
oil (yield: 50%). 1H NMR (300 MHz), d (ppm, CDCl3): 10.16 (s,
2H); 8.39–8.36 (M, 3H); 7.42–7.27 (M, 4H); 3.26 (s, 2H); 2.29 (m,
4H); 1.50 (m, 4H); 1.41 (m, 2H). 13C NMR (75 MHz), d (ppm, CDCl3):
191.3; 143.8; 140.2; 136.6; 136.2; 131.3; 130.1; 129.1; 128.0;
127.5; 61.3; 54.0; 26.0; 24.4. LC–MS (ESI) m/z Calculated: 308.2,
Found: 308.1 [M+H]+.
5.2.2. Western blot analysis
5.1.1.38.
5-[2-(Morpholine-4-ylmethyl)phenyl]benzene-1,3-dicar-
Samples were heated at 85 °C for 2 min with Reducing Agent
(Life TechnologiesTM) and equal quantities of total proteins (20 mg/
lane) were resolved in NuPAGEÒ NovexÒ 16% Tris-Tricine precast
gels (Life TechnologiesTM). After electrophoresis, the proteins were
transferred onto 0.2 mM PVDF membranes (Life TechnologiesTM)
for 1 h at 20 °C using the liquid transfer system (Life Technolo-
giesTM). Membranes were blocked with 5% skimmed milk in TNT
(15 mM Tris buffer pH 8.4, 140 mM NaCl, 0.05% Tween-20) for 1
h at 20 °C. After washing three times, the membrane were incu-
bated with APPCter-C17 rabbit antiserum diluted 1:4000 in TNT
overnight at 4 °C. APP-Cter-C17 was raised against the last 17
amino acids of the human APP sequence.59 To develop the
immunoreaction, the blots were incubated with peroxidase-conju-
gated purified mouse monoclonal anti-goat/sheep IgG (Sigma A
9452, MAb clone GT-34), 1:10,000 in TNT-M, for 1 h at 20 °C, and
developed with SuperSignal West Pico Chemiluminescent Sub-
strate (Thermo Scientific). Membranes were scanned with LAS-
baldehyde 25b. The residue was purified by flash chromatography
(PE/EtOAc 10:0 to 6.5:3.5 (v/v)) to give compound 25b as a colour-
less oil (yield: 50%). 1H NMR (300 MHz), d (ppm, CDCl3): 10.18 (s,
2H); 8.40–8.37 (M, 3H); 7.42–7.27 (M, 4H); 3.65 (m, 4H); 3.32 (s,
2H); 2.37 (m, 4H). 13C NMR (75 MHz), d (ppm, CDCl3): 191.1;
143.6; 140.3; 136.7; 135.0; 131.3; 130.3; 129.7; 128.1; 127.8;
67.0; 61.0; 53.1. LC–MS (ESI) m/z Calculated: 310.1, Found: 310.1
[M+H]+.
5.1.1.39. 5-(2-[(4-Methylpiperazin-1-yl)methyl] phenyl)benzene-1,3-
dicarbaldehyde 25c. The compound 25c was obtained as a colour-
less oil (yield: 92%) and used without further purification in the
next step (degradation). 1H NMR (300 MHz), d (ppm, CDCl3):
10.17 (s, 2H); 8.40–8.37 (M, 3H); 7.42–7.30 (M, 4H); 3.32 (s, 2H);
2.46 (br s, 8H); 2.33 (s, 3H). 13C NMR (75 MHz), d (ppm, CDCl3):
191.2; 143.7; 140.3; 136.6; 136.0; 131.4; 130.2; 129.6; 128.1;
127.8; 60.5; 55.0; 52.1; 45.8. LC–MS (ESI) m/z Calculated: 323.2,
Found: 323.1 [M+H]+.
4000 Mini Image System. CTF
a (12 kDa) was detected. Images
were obtained with a time exposure from 10 to 320 s. Each image
was opened with Adobe Photo Shop CS2 (version 9.0.2) computer
program, a compose containing all WB bands was created for anal-
ysis. Bands quantification was performed by using Image J 1.37v
computer program. Each band was transformed in a plot and the
area under the curve was calculated. Results were expressed as
arbitrary units of optical density. Membranes were then rinsed
for 30 min at 20 °C and reprobed with a goat polyclonal antibody
against H3 (1:1000; Santa Cruz Biotechnology).
5.1.1.40. 5-(2-[(Dimethylamino)methyl]phenyl) benzene-1,3-dicar-
baldehyde 25d. The compound 25d was obtained as a colourless
oil (yield: 50%) and used without further purification in the next
step (degradation). 1H NMR (300 MHz), d (ppm, CDCl3): 10.17 (s,
2H); 8.38 (m, 1H); 8.30 (m, 2H); 7.52 (m, 1H); 7.46–7.37 (M,
2H); 7.30 (m, 1H); 3.32 (s, 2H); 2.18 (s, 6H). 13C NMR (75 MHz), d
(ppm, CDCl3): 191.2; 143.6; 139.6; 136.8; 135.9; 131.0; 130.1;
Please cite this article in press as: Gay M., et al. Bioorg. Med. Chem. (2018), https://doi.org/10.1016/j.bmc.2018.03.016

M. Gay et al. / Bioorganic & Medicinal Chemistry xxx (2018) xxx–xxx
13
12. Vasquez-Martin A, Lopez-Bonetc E, Cuti S, et al. Repositioning chloroquine and
metformin to eliminate cancer stem cell traits in pre-malignant lesions. Drug
Resist Update. 2011;14:212–223.
13. Mahoney E, Maddocks K, Flynn J, et al. Identification of endoplasmic reticulum
stress-inducing agents by antagonizing autophagy: a new potential strategy for
identification of anti-cancer therapeutics in B-cell malignancies. Leuk
Lymphoma. 2013;54:2685–2692.
14. Costedoat-Chalumeau N, Leroux G, Piette JP, Amoura Z. Why all systemic lupus
erythematosus patients should be given hydroxychloroquine treatment? Joint
Bone Spine. 2010;77:4–5.
15. Suarez-Almazor ME, Belseck E, Shea B, Homik J, Wells G, Tugwell P.
Antimalarials for treating rheumatoid arthritis. Cochrane Database Syst Rev.
2010;4:CD000959.
5.2.3. Secreted Ab1–40, and Ab1–42 quantification
Conditioned medium was used to determine the secreted Ab1–40
and Ab1-42 concentrations, using the Human Ab1–40 Assay Kits (IBL)
and the INNOTESTTM Ab1-42 ELISA Kit (Innogenetics). Each sample
was loaded in duplicate onto a 96 well plate. Experiments were
done in triplicate. Results expressed in ng/ml were compared to
control conditions arbitrarily given an average value of 100%.
Results are presented as IC50, the concentration able to decrease
to 50% the basal quantity of secreted Ab1–40 and Ab1–42
.
16. Olliaro P, Nevill C, LeBras J, et al. Systematic review of amodiaquine treatment
in uncomplicated malaria. Lancet. 1996;348:1196–1201.
17. Boonyasuppayakorn S, Reichert ED, Manzano M, Nagarajan K, Padmanabhan R.
Amodiaquine, an antimalarial drug, inhibits dengue virus type 2 replication and
infectivity. Antiviral Res. 2014;106:125–134.
5.2.4. Cytotoxicity assay
The human neuroblastoma cell line (SY5Y) was cultured in
DMEM (Dulbecco’s Modified Eagle Medium) (Gibco) supplemented
with 2 mM L-glutamine, 100 mg/ml streptomycin, 100 IU/mL peni-
18. Zilbermintz L, Leonardi W, Jeong SY, et al. Identification of agents effective
against multiple toxins and viruses by host-oriented cell targeting. Sci Rep.
2015;27:13476.
19. Qiao S, Tao S, Rojo de la Vega M, et al. The antimalarial amodiaquine causes
autophagic-lysosomal and proliferative blockade sensitizing human melanoma
cells to starvation- and chemotherapy-induced cell death. Autophagy.
2013;9:2087–2102.
20. Gonzalbez R, Mozulén S, Carbajo R, Melnyk P, Pineda-Lucena A. Hit
identification of novel heparanase inhibitors by structure- and ligand-based
approaches. Bioorg Med Chem. 2013;21:1944–1951.
21. Clarke JB, Maggs JL, Kitteringham NR, Park BK. Immunogenicity of amodiaquine
in the rat. Int Arch Allergy Immunol. 1990;335–342.
cillin, 1 mM non-essential amino acids and 10% (v/v) heat-inacti-
vated fetal bovine serum (Sigma Aldrich), and grown at 37 °C in
a humidified incubator with 5% CO2.
Cells were then incubated in culture medium that contained
various concentrations of test compounds (100, 50, 10, 5, 1, 0.5,
0.1, 0.05 mM), each dissolved in less than 0.1% DMSO. After 72 h
of incubation, cell growth was estimated by the colorimetric MTT
(thiazolyl blue tetrazolium bromide) assay.
22. Naisbitt DJ, Ruscoe JE, Williams DP, O’Neill PM, Pirmohamed M, Park BK.
Disposition of amodiaquine and related antimalarial agents in human
Acknowledgements
neutrophils: implications for drug design.
1997;280:884–893.
J
Pharmacol Exp Ther.
23. Tingle MD, Jewell H, Maggs JL, O’Neill PM, Park BK. The bioactivation of
amodiaquine by human polymorphonuclear leucocytes in vitro: chemical
mechanisms and the effects of fluorine substitution. Biochem Pharmacol.
1995;50:1113–1119.
24. O’Neill PM, Mukhtar A, Stocks PA, et al. Isoquine and related amodiaquine
analogues: a new generation of improved 4-aminoquinoline antimalarials. J
Med Chem. 2003;46:4933–4945.
We express our thanks to the NMR facility (Lille 2 University),
the Region Nord-Pas de Calais (France), the Ministere de la Jeu-
nesse, de l’Education Nationale et de la Recherche (MJENR) and
the Fonds Europeens de Developpement Regional (FEDER). This
work was supported by Lille 2 University, ANR – France and Inserm
– France. Marion Gay is the recipient of a fellowship from Lille 2
University.
25. Kotecka BM, Barlin GB, Edstein MD, Rieckmann KH. New quinoline di-Mannich
base compounds with greater antimalarial activity than chloroquine,
amodiaquine,
1997;41:1369–1374.
26. Werbel LM, Cook PD, Elslager EF, et al. Synthesis, antimalarial activity, and
or
pyronaridine.
Antimicrob
Agents
Chemother.
A. Supplementary data
quantitative structure-activity relationships of tebuquine and
related 5-[(7-chloro-4-quinolinyl)amino]-3-[(alkylamino)methyl]
biphenyl]-2-ols and N omega-oxides. J Med Chem. 1986;29:924–939.
a
series of
[1,10-
Supplementary data associated with this article can be found, in
the online version, at https://doi.org/10.1016/j.bmc.2018.03.016.
27. Raynes KJ, PStocks PA, O’Neill PM, Park BK, Ward SA. New 4-aminoquinoline
Mannich base antimalarials. 1. Effect of an alkyl substituent in the 50-position
of the 40-hydroxyanilino side chain. J Med Chem. 1999;42:2747–2751.
28. Kesten SJ, Johnson J, Werbel LM. Synthesis and antimalarial effects of 4-[(7-
chloro-4-quinolinyl)amino]-2-[(diethylamino) methyl]-6-alkylphenols and
their N omega-oxides. J Med Chem. 1987;30:906–911.
References
29. Delarue S, Girault S, Maes L, et al. Synthesis and in vitro and in vivo antimalarial
activity of new 4-anilinoquinolines. J Med Chem. 2001;44:2827–2833.
30. Delarue-Cochin S, Paunescu E, Maes L, et al. Synthesis and antimalarial activity
of new analogues of amodiaquine. Eur J Med Chem. 2008;43:252–260.
31. Delarue-Cochin S, Grellier P, Maes L, Mouray E, Sergheraert C, Melnyk P.
Synthesis and antimalarial activity of carbamate and amide derivatives of 4-
anilinoquinoline. Eur J Med Chem. 2008;43:2045–2055.
1. Medapi B, Suryadevara P, Renuka J, Sridevi JP, Yogeeswari P, Sriram D. 4-
Aminoquinoline derivatives as novel Mycobacterium tuberculosis GyrB
inhibitors: Structural optimization, synthesis and biological evaluation. Eur J
Med Chem. 2015;103:1–16.
2. Antinarelli LM, Dias RM, Souza IO, et al. 4-Aminoquinoline derivatives as
potential antileishmanial. Agents Chem Bio Drug Des. 2015;86:704–714.
3. De Meneses Santos R, Barros PR, Bortoluzzi JH, et al. Synthesis and evaluation of
the anti-nociceptive and anti-inflammatory activity of 4-aminoquinoline
derivatives. Bioorg Med Chem. 2015;23:4390–4396.
4. Gignoux E, Azman AS, de Smet M, et al. Effect of artesunate-amodiquine on
mortality related to Ebola virus disease. N Engl J Med. 2016;374:23–32.
5. Kim CH, Leblanc P, Kim KS. 4-Amino-7-chloroquinoline derivatives for treating
Parkinson’s disease: implications for drug discovery. Expert Opin Drug Discov.
2016;11:337–341.
6. Korth C, May BCH, Cohen FE, Prusiner BS. Acridine and phenothiazine
derivatives as pharmacotherapeutics for prion disease. Proc Natl Acad Sci USA.
2001;98:9836–9841.
32. Paunescu E, Susplugas S, Boll E, et al. Replacement of the 40-hydroxy group of
amodiaquine and amopyroquine by aromatic and aliphatic substituents:
synthesis and antimalarial activity. ChemMedChem. 2009;4:549–561.
33. Paunescu E, Susplugas S, Boll E, et al. Synthesis and antimalarial activity of new
amino analogues of amodiaquine. Med Chem. 2008;4:407–425.
34. Vingtdeux V, Hamdane M, Loyens A, et al. Alkalizing drugs induce
accumulation of amyloid precursor protein by-products in luminal vesicles of
multivesicular bodies. J Biol Chem. 2007;282:18197–18205.
35. De Strooper B. Proteases and proteolysis in Alzheimer disease: a multifactorial
view on the disease process. Physiol Rev. 2010;90:465–494.
36. Caporaso GL, Gandy SE, Buxbaum JD, Greengard P. Chloroquine inhibits
intracellular degradation but not secretion of Alzheimer beta/A4 amyloid
precursor protein. Proc Natl Acad Sci USA. 1992;89:2252–2256.
37. Haass C, Hung AY, Schlossmacher MG, Teplow DB, Selkoe DJ. Beta-amyloid
peptide and a 3-kDa fragment are derived by distinct cellular mechanisms. J
Biol Chem. 1993;268:3021–3024.
38. Schrader-Fischer G, Paganetti PA. Effect of alkalizing agents on the processing
of the beta-amyloid precursor protein. Brain Res. 1996;716:91–100.
39. Tam JH, Cobb MR, Seah C, Pasternak SH. Tyrosine binding protein sites regulate
the intracellular trafficking and processing of amyloid precursor protein
through a novel lysosome-directed pathway. PLoS One. 2016;11:e0161445.
40. Vingtdeux V, Sergeant N, Buee L. Potential contribution of exosomes to the
prion-like propagation of lesions in Alzheimer’s disease. Front Physiol.
2012;3:229–250.
7. Doh-ura K, Iwaki T, Caughey B. Lysosomotropic agents and cysteine protease
inhibitors inhibit scrapie-associated prion protein accumulation.
2000;74:4894–4897.
J Virol.
8. Kocisko DA, Baron GS, Rubenstein R, Chen J, Kuizon S, Caughey B. New
inhibitors of scrapie-associated prion protein formation in a library of 2000
drugs and natural products. J Virol. 2003;77:10288–10294.
9. Klingenstein R, Melnyk P, Leliveld RS, Ryckebusch A, Korth C. Similar structure-
activity relationships of quinoline derivatives for antiprion and antimalarial
effects. Similar structure-activity relationships of quinoline derivatives for
antiprion and antimalarial effects. J Med Chem. 2006;49:5300–5308.
10. Ashfaq UA, Javed T, Rehman S, Nawaz Z, Riazuddin S. An overview of HCV
molecular biology, replication and immune responses. J Virol. 2011;8:163–168.
11. Blanchard E, Belouzard S, Goueslain S, et al. Hepatitis C virus entry depends on
clathrin-mediated endocytosis. J Virol. 2006;80:6964–6972.
Please cite this article in press as: Gay M., et al. Bioorg. Med. Chem. (2018), https://doi.org/10.1016/j.bmc.2018.03.016

14
M. Gay et al. / Bioorganic & Medicinal Chemistry xxx (2018) xxx–xxx
41. Vingtdeux V, Marambaud P. Identification and biology of
a
-secretase.
J
amyloid plaques and/or where a dysfunction of the APP metabolism occurs.
PCT EP2010069897, PCT US 8,680,095.
Neurochem. 2012;120:34–45.
42. Pardossi-Piquard R, Checler F. The physiology of the b-amyloid precursor
protein intracellular domain AICD. J Neurochem. 2012;120:109–124.
43. Li F, Wu JJ, Wang J, et al. Synthesis and pharmacological evaluation of novel
chromone derivatives as balanced multifunctional agents against Alzheimer’s
disease. Bioorg Med Chem. 2017;25:3815–3826.
44. Wang J, Wang ZM, Li XM, et al. Synthesis and evaluation of multi-target-
directed ligands for the treatment of Alzheimer’s disease based on the focus of
donepezil and melatonin. Bioorg Med Chem. 2016;24:4324–4338.
45. Knez D, Brus B, Coquelle N, et al. Structure-based development of nitroxoline
derivatives as potential multifunctional anti-Alzheimer agents. Bioorg Med
Chem. 2015;23:4442–4452.
51. Abdel-Magid AF, Carson KG, Harris BD, Maryanoff CA, Shah RD. Reductive
amination of aldehydes and ketones with sodium triacetoxyborohydride.
Studies on direct and indirect reductive amination procedures. J Org Chem.
1996;61:3849–3862.
52. Peng L, Wirz J, Goeldner M. Synthesis and characterization of photolabile
compounds releasing noracetylcholine in the microsecond time range. Angew
Chem Int Ed. 1997;36:398–400.
53. Kim S, Oh CH, Ko JS, Ahn KH, Kim YJ. Zinc-modified cyanoborohydride as a
selective reducing agent. J Org Chem. 1985;50:1927–1932.
54. Ram S, Ehrenkaufer RE. A general procedure for mild and rapid reduction of
aliphatic and aromatic nitro compounds using ammonium formate as
a
46. Lecoutey C, Hedou D, Freret T, et al. Design of donecopride,
a
dual
catalytic hydrogen transfer agent. Tetrahedron Lett. 1984;25:3415–3418.
serotonin receptor agonist/acetylcholinesterase inhibitor with potential
interest for Alzheimer’s disease treatment. Proc Natl Acad USA. 2014;111:
E3825–E3830.
4
55. Buil AMA, Gracia FJ, Moreno MIM, et al. (3-Oxo)pyridazin-4-ylurea derivatives
as PDE4 inhibitors. EP2196465 A1; 2010.
56. Davenport AJ, Hallett DJ, Corsi M. Azetidines and cyclobutanes as histamine H3
receptor antagonists. WO 2009 135842 (A1).
57. Lewis RJ, Francis CA, Lehr RE, LeRoy Blank C. Synthesis and neurotoxic potential
of racemic and chiral dihydroxytetrahydroquinoline derivatives. Tetrahedron.
2000;56:5345–5352.
58. Burkhardt ER, Matos K. Boron reagents in process chemistry: excellent tools for
selective reduction. Chem Rev. 2006;106:2617–2650.
59. Sergeant N, David JP, Champain D, Ghestem A, Wattez A, Delacourte A.
Progressive decrease of amyloid precursor protein carboxy terminal fragments
(APP-CTFs), associated with tau pathology stages, in Alzheimer’s disease. J
Neurochem. 2002;81:663–672.
47. Melnyk P, Sergeant N, Buée L, Delacourte A. Use of 1,4-bis(3-aminopropyl)
piperazine derivatives in therapy. WO 2006 051489.
48. Melnyk P, Vingtdeux V, Burlet S, et al. Chloroquine and chloroquinoline
derivatives as models for the design of modulators of amyloid peptide
precursor metabolism. ACS Chem Neurosci. 2015;6:559–569.
49. Barrier M, Buée L, Burlet S, Delacourte A, Estrella C, Melnyk P, Sergeant N,
Verwaerde P. Beta and gamma-carbolines derivatives for the treatment of
neurodegenerative diseases. WO 2014/102339.
50. Melnyk P, Burlet S, Le Fur N, Delacourte A. New heterocycle compounds and
uses thereof for the prevention or treatment of diseases involving formation of
Please cite this article in press as: Gay M., et al. Bioorg. Med. Chem. (2018), https://doi.org/10.1016/j.bmc.2018.03.016