Development of coumarine derivatives as potent anti-filovirus entry inhibitors targeting viral glycoprotein

Article abstract of DOI:10.1016/j.ejmech.2020.112595

Filoviruses, including Ebolavirus (EBOV), Marburgvirus (MARV) and Cuevavirus, cause hemorrhagic fevers in humans with up to 90% mortality rates. In the 2014–2016 West Africa Ebola epidemic, there are 15,261 laboratory confirmed cases and 11,325 total deaths. The lack of effective vaccines and medicines for the prevention and treatment of filovirus infection in humans stresses the urgency to develop antiviral therapeutics against filovirus-associated diseases. Our previous study identified a histamine receptor antagonist compound CP19 as an entry inhibitor against both EBOV and MARV. The preliminary structure-activity relationship (SAR) studies of CP19 showed that its piperidine, coumarin and linker were related with its antiviral activities. In this study, we performed detailed SAR studies on these groups with synthesized CP19 derivatives. We discovered that 1) the piperidine group could be optimized with heterocycles, 2) the substitution groups of C3 and C4 of coumarin should be relatively large hydrophobic groups and 3) the linker part should be least substituted. Based on the SAR analysis, we synthesized compound 32 as a potent entry inhibitor of EBOV and MARV (IC₅₀ = 0.5 μM for EBOV and 1.5 μM for MARV). The mutation studies of Ebola glycoprotein and molecular docking studies showed that the coumarin and its substituted groups of compound 32 bind to the pocket of Ebola glycoprotein in a similar way to the published entry inhibitor compound 118a. However, the carboxamide group of compound 32 does not have strong interaction with N61 as compound 118a does. The coumarin skeleton structure and the binding model of compound 32 elucidated by this study could be utilized to guide further design and optimization of entry inhibitors targeting the filovirus glycoproteins.

Full text of DOI:10.1016/j.ejmech.2020.112595

European Journal of Medicinal Chemistry 204 (2020) 112595
Contents lists available at ScienceDirect
European Journal of Medicinal Chemistry
journal homepage: http://www.elsevier.com/locate/ejmech
Research paper
Development of coumarine derivatives as potent anti-filovirus entry
inhibitors targeting viral glycoprotein
,
,
,
, *
Yinyi Gao a 1, Han Cheng b 1, Sameer Khan b, Gaokeng Xiao c, Lijun Rong b **, Chuan Bai a
a Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, 510080, China
b Department of Microbiology and Immunology, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA
c Guangzhou Molcalx Information & Technology Ltd, Guangzhou, Guangdong, 510630, China
a r t i c l e i n f o
a b s t r a c t
Article history:
Filoviruses, including Ebolavirus (EBOV), Marburgvirus (MARV) and Cuevavirus, cause hemorrhagic fe-
vers in humans with up to 90% mortality rates. In the 2014e2016 West Africa Ebola epidemic, there are
15,261 laboratory confirmed cases and 11,325 total deaths. The lack of effective vaccines and medicines
for the prevention and treatment of filovirus infection in humans stresses the urgency to develop
antiviral therapeutics against filovirus-associated diseases. Our previous study identified a histamine
receptor antagonist compound CP19 as an entry inhibitor against both EBOV and MARV. The preliminary
structure-activity relationship (SAR) studies of CP19 showed that its piperidine, coumarin and linker
were related with its antiviral activities. In this study, we performed detailed SAR studies on these groups
with synthesized CP19 derivatives. We discovered that 1) the piperidine group could be optimized with
heterocycles, 2) the substitution groups of C3 and C4 of coumarin should be relatively large hydrophobic
groups and 3) the linker part should be least substituted. Based on the SAR analysis, we synthesized
Received 24 April 2020
Received in revised form
15 June 2020
Accepted 16 June 2020
Available online 12 July 2020
compound 32 as a potent entry inhibitor of EBOV and MARV (IC50 ¼ 0.5
mM for EBOV and 1.5 mM for
MARV). The mutation studies of Ebola glycoprotein and molecular docking studies showed that the
coumarin and its substituted groups of compound 32 bind to the pocket of Ebola glycoprotein in a similar
way to the published entry inhibitor compound 118a. However, the carboxamide group of compound 32
does not have strong interaction with N61 as compound 118a does. The coumarin skeleton structure and
the binding model of compound 32 elucidated by this study could be utilized to guide further design and
optimization of entry inhibitors targeting the filovirus glycoproteins.
© 2020 Elsevier Masson SAS. All rights reserved.
1. Introduction
biggest Ebolavirus outbreak in 2014e2016 West Africa Ebola epi-
demics which results in 15,261 laboratory-confirmed infections
Filoviruses, consisting of Marburgvirus (MARV), Ebolavirus
(EBOV), and Ceuvavirus, are negative-sense RNA enveloped viruses
with filamentous morphology. The Marburgvirus was the first
discovered filovirus as the infectious agent responsible for a few
small outbreaks in Marburg, Germany in 1967, which led to 7
deaths among the 31 reported cases. The Ebolavirus was discovered
later in 1976 in the Democratic Republic of Congo (formerly Zaire).
Since then small Ebolavirus outbreaks occurred sporadically in
Africa, during which EBOV typically infected less than 500 people
with high mortality rate (up to 90%). The world witnessed the
and 11,325 reported deaths (74% mortality rate). The 2018 Kivu
Ebola outbreak started 1st August 2018 again in the Democratic
Republic of Congo. Although a few experimental treatment options
like rVSV-ZEBOV Ebola vaccine, Zmapp, GS-5734, REGN monoclonal
antibody combination, and mAb114 have been approved for use in
the current outbreak 1ꢀ6, they haven’t shown dramatically effect
against ebolavirus disease spread. The case figures are still rising
and a total of 3444 cases (confirmed and probable) and 2264 deaths
7
(66% mortality rate) have been reported as of 8th March 2020
.
Novel treatment options, especially small molecule based new
drugs which are more affordable and easier to store and deliver in
these economically disadvantaged countries, are in urgent need to
prevent and control future outbreaks and potential bioterrorism
attacks.
* Corresponding author.
** Corresponding author.
E-mail addresses: lijun@uic.edu (L. Rong), baichuan@mail.sysu.edu.cn (C. Bai).
These authors contributed equally to this work.
Viral entry has been proved to be a suitable target for antiviral
1
https://doi.org/10.1016/j.ejmech.2020.112595
0223-5234/© 2020 Elsevier Masson SAS. All rights reserved.

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Y. Gao et al. / European Journal of Medicinal Chemistry 204 (2020) 112595
development since the approval of anti-HIV drug maraviroc and T-
20 by FDA, which target HIV-1 entry receptor CCR5 and HIV-1
fusion with the target cell respectively 8. Filovirus entry is medi-
ated by a single viral glycoprotein (GP), which is composed of two
subunits, GP1 and GP2 9, 10. GP1 mediates the initial attachment of
virion to the host cell surface which triggers the viral internaliza-
tion via macropinocytosis and trafficking of the virion to late
endosomes/lysosomes where the mucin-like domain and the
glycan cap of GP1 are removed by cathepsin B/L to expose the re-
ceptor binding domain (RBD) 11ꢀ15. Then the interaction of RBD and
Niemann-Pick C1 (NPC1) protein anchors the virion and induces
conformational change of GP2, leading to viral-endosomal mem-
brane fusion 16ꢀ19. The critical role of viral GP in the indispensable
entry process makes it a promising target protein for developing
small molecule entry inhibitors.
2.1. The SAR study on the carboxamide group (Table 1)
We first tested if the hydrophobic alkyne (2), cyclopropane (3),
phenyl (4e6) and benzyl (7) groups could increase the antiviral
activity compared with CP19 (1). Only benzyl (7) group displayed
comparable anti-filovirus activity and SI value than CP19. This
result provided partial support for our postulation that the nitrogen
atom of carboxamide could form H-bond with residues in the active
site. We then tested if the oxygen atom in the alcohol (8, 9) and
cyclic ether substitution groups (10) could form the desired in-
teractions as carboxamide dose. However, these modifications did
not significantly improve the activity. Then compounds with hetero
cycles (11e18) were synthesized and most of them exhibited
slightly better antiviral activities but more cytotoxicity in A549 cell
line when compared with CP19. The compounds with ethyl-o-
pyridine (13) showed the best inhibitory activity on EBOV entry and
best SI in this series of compounds. However, other larger hetero
cycles (17e18) did not increase the activity, which indicated that
the binding pocket for this part is relatively small or has strict
requirement for ligands.
We previously identified compound CP19 as a potent entry in-
hibitor against EBOV and MARV from a focused GPCR antagonist
library 20. In this study, we performed SAR studies with 58 de-
rivatives of CP19 on both EBOV and MARV. From these SAR studies,
compound 32 was identified as a potent inhibitor of EBOV and
MARV (IC50 ¼ 0.5
mM for EBOV and 1.2 mM for MARV). The mo-
lecular docking analysis revealed that compound 32 binds in the
same pocket on EBOV glycoprotein as a few previous reported EBOV
21, 22
entry inhibitors (e.g. toremifene and compound 118a) do
.
However, the mutation studies showed that compound 32 did not
form vital interactions with N61 or D522, which have been proved
to be important for the binding of compound 118a. The coumarin
and its hydrophobic substituted groups may bind to the pocket
close to Y517 which is occupied by the hydroxyphenol ring of
compound 118a. Our studies showed that the carboxamide group
should interact with R164 on the surface of Ebola glycoprotein and
the coumarin skeleton of compound 32 could be further optimized
for more potent anti-filovirus lead compounds with better drug-
like properties.
2.2. The SAR study on the C-3 of coumarin (Table 2)
Previous reported data suggested that the benzyl groups on the
C-3 of coumarin was vital for the activity. Consistent with this
result, the coumarin without any substitutions (19) lost most of the
activity. Thereof, the effects of large aromatic groups with different
substitutions on this site were evaluated. First, we synthesized
compounds with substituted benzyl rings (20e33). Basically, most
the halogen substitutions (21e27) afforded better antiviral activ-
ities than CP19 and compound 21 and 23 showed good SI. More-
over, most other larger phenyl groups with strong electro-
withdrawing substitutions (28e32) also displayed improved ac-
tivity. Compound 32 showed the strongest antiviral activity against
EBOV. This indicated that the binding pocket for this part could be
relatively large and thus large aromatic substitution groups would
benefit the binding. However, these modifications did not improve
the cytotoxicity significantly, indicating that the metabolism
properties of halogen and strong electro-withdrawing groups on
the aromatic ring should be optimized.
To further exploit the possibly large binding pocket for this part,
we synthesized compounds with larger aromatic groups such as
naphthalene (34) and phenyl-heterocycle group (35). The naph-
thalene group displayed similar IC50 and SI value as CP19. We then
increased the size of substitution by installing bi-phenyl groups
(36e43). Compound 36 showed better antiviral activities for EBOV
and MARV with better SI values than CP19. These results showed
that the binding pocket could accommodate ligands with groups as
large as bi-phenyl.
2. Results
The previous preliminary SAR studies of compound CP19 mainly
focused on the substitutions of its piperidine ring (Fig. 1.Cyan oval).
The carboxamide group on the piperidine ring was important for
CP19’s activity and replacement with alkyl substitution groups
resulted in dramatic antiviral activity loss. These results indicated
that the piperidine and carboxamide group may interact with
amino acid residues possibly via H-bond. Thus, groups with hetero
atoms that can form H-bond interactions would probably show
better activity. Moreover, the benzyl substitution at the C-3 of
coumarin (Fig.1.Magentas oval) was also a key group for the activity
because the unsubstituted counterpart was totally inactive. Based
on these results, herein we performed SAR studies on the carbox-
amide, C-3 and C-4 (Fig. 1.Green oval) positions of coumarin. We
also studied the SAR on the secondary hydroxyl group (Fig. 1.Yellow
circle) in the linker, which has not been reported before.
We conducted the SAR studies with the general synthesis
method (Scheme 1).
Fig. 1. The strategy of SAR studies in this work.

Y. Gao et al. / European Journal of Medicinal Chemistry 204 (2020) 112595
3
Scheme 1. The synthesis route of the target compounds.Reagents and conditions:(a)Ethyl acetoacetate, Benzyl bromide, CH3ONa, Methonal, RT/68 ꢁC, 0.5 h; (b)Resorcino, PPA,
65 ꢁC, 4 h, 67%; (c)Epichlorohydrin, K2CO3, TBAB, 80 ꢁC, 2.3 h, 81%; (d)Organic amine, AcNMe2, 50 ꢁC, 24 h, 85%; (e)PPh3, DIAD, THF/DMF, 0 ꢁC, 66%; (f)Pd(PPh3)4, diox-NaHCO3
solution, under Ar protection, 95 ꢁC, overnight, 65%.
2.3. The SAR study on the linker (Table 3)
antiviral activity of CP19. In this study, the cyclopropane (53) and
phenyl (54) groups on this site were evaluated but they did not
display better activity and cytotoxicity. Considering the steric hin-
drance between the substitution groups on the sterically adjacent
C-3 and C-4, we removed the benzyl group on C-3 (55) but this
compound lost most of the antiviral activity. These results
confirmed that R3 group had vital roles for the activity its functions
on the binding pocket and could not be replaced by the adjacent R4
group.
The SAR of the linker in CP19 had not been studied. Herein, we
focused on the substitutions of the secondary hydroxyl group of the
linker. We first studied whether the stereochemistry of the sec-
ondary carbon could affect the activity. The two isomers of com-
pound 32 (44, 45) showed little difference in activity and
cytotoxicity, which indicated that this secondary hydroxyl group
had not stereospecific interactions in the binding site. So we did not
consider stereochemistry in further SAR studies on the linker. The
phenyl ring with EWG and EDG (46e49) caused obvious loss of
activity compared with CP19, which indicated that the aromatic
substitution groups in this site may not be favored. To test whether
the hydroxyl group itself may have important H-bond at the active
site, we installed a group with multiple heteroatoms (50), but
compound 50 did not afford better activity. Then we proposed that
the binding pocket for the linker was small and thus had no vital
interaction with the linker part. Compound 51 with smallest methyl
group afforded less anti-viral activity than compound 13. Then we
removed the hydroxyl group on the linker (52) and it showed lower
antiviral activity and SI compared with compound 15. These results
indicated that the binding site of the linker should be tunnel-like
and so the linker should not have large substitution groups.
2.5. The synergy of R1, R2 and R3 groups (Table 5)
To test whether the synergic effects could be acquired from the
groups of R1, R2 and R3, we accordingly synthesized compounds
with the substitution groups that had afforded best activity or had
reduced toxicity in our SAR studies (56e59). Among them, com-
pound (56) afforded strong activity and low cytotoxicity. The syn-
ergic effect was not as high as expected (SI EBOV ¼ 66 for compound
56 and SI
¼ 29 for CP19). Considering that the linker group
EBOV
took minor roles for the activity, we proposed that the C3 on
coumarin and the terminal carboxamide groups influenced each
other and cross talk between these groups should be considered.
2.4. The SAR study on the C-4 of coumarin (Table 4)
The previous study showed that the substitutions on the C-4 of
coumarin could reduce the cytotoxicity but had little effect on the

4
Y. Gao et al. / European Journal of Medicinal Chemistry 204 (2020) 112595
Table 1
The SAR study on the carboxamide group (R1).
Compd. NO.
R1
IC50
(
m
M) EBOV
IC50
(m
M) MARV
CC50
(m
M)
SI
SI
EBOV
MARV
1 (CP19)
3.4 0.6
29.5 11.7
＞100
29.4
3.4
2
3
5.9 2.1
3.0 1.1
5.6 1.5
3.2 0.9
95.5 4.5
16.1
33.3
17.2
31.6
＞100
4
5
＞100
＞100
＞100
＞100
＞100
1
1
1
81.3 18.8
1.2
6
7
＞100
＞100
＞100
＞100
1
1
1.3 0.3
2.2 0.5
75.0
45.5
8
8.9 1.9
8.4 1.6
53.4 3.7
6.0
6.3
9
Q1
2.4 0.2
2.2 0.7
40.3 2.6
38.2 3.8
14.6
17.4
16.6
17.1
10
2.2 0.8
11
12
3.6 1.0
1.3 0.3
5.9 0.8
1.7 0.3
54.9 8.3
27.4 6.5
15.6
20.5
9.3
16.4
13
0.9 0.1
2.7 0.4
＞100
111.1
36.6
14
15
3.5 0.3
2.1 0.0
3.5 0.6
2.8 0.7
87.3 12.7
93.0 7.0
24.9
44.3
24.9
33.2
16
17
＞100
＞100
＞100
＞100
＞100
＞100
1
1
1
1
18
10.2 2.0
8.8 0.4
＞100
9.8
11.3
2.6. The binding model of compound 32 in GP protein
structure of EBOV GP complexed with compound 118a, we located a
few key amino acid residues which might be involved in the GP-
compound 32 interaction. Then we evaluated the inhibitory activ-
ities of compound 32 against a few EBOV pseudovirions carrying
mutated glycoprotein. Compound 32 did not show obvious loss of
activity against EBOV pseudovirions carrying glycoprotein mutant
N61A, N61V, N61D (Fig. 2A) or D522A (Fig. 2B). These data suggest
Compound CP19 has been shown to target a late step of Ebola
virus entry, very likely via binding to the GP to prevent GP-
mediated fusion event. Its analog compound 32 has a similar
structure to compound 118a, which has been reported to be able to
bind EBOV GP and inhibit virus entry. Thus, based on the crystal

Y. Gao et al. / European Journal of Medicinal Chemistry 204 (2020) 112595
5
Table 2
The SAR studies on the C-3 of coumarin (R2).
Compd. NO.
R2
IC50
(
mM) EBOV
IC50
(m
M) MARV
CC50
(
mM)
SI
SI
EBOV
MARV
19
20
9.3 0.9
8.4 0.7
5.8 1.7
＞100
10.8
1.3
12.0
2.5
11.7 2.0
14.7 1.3
89.3 5.0
21
1.1 0.1
1.1 0.1
78.8
83.7
22
23
1.6 0.4
2.5 0.5
2.4 0.2
2.9 0.3
53.3 9.2
40 0.2
34.0
16.3
22.5
13.8
24
25
0.9 0.1
1.2 0.3
1.2 0.2
3.0 0.7
＞100
＞100
111.1
81.1
85.7
33.3
26
27
28
1.2 0.1
3.1 1.0
2.5 0.1
4.2 0.4
11.9 5.4
5.2 1.0
＞100
81.1
29.0
18.0
23.6
7.7
90.8 2.5
44.4 2.9
8.6
29
30
3.7 1.4
1.1 0.0
2.7 0.9
1.1 0.1
90.5 9.5
89.3 5.0
24.2
78.8
33.5
83.7
31
32
1.6 0.1
0.5 0.0
3.0 0.3
1.2 0.1
＞100
63.8
33.0
56.8
68.2 14.3
136.4
33
34
7.5 1.9
1.5 0.4
9.1 2.2
1.2 0.1
＞100
13.3
28.5
11.0
36.6
42.4 8.2
(continued on next page)

6
Y. Gao et al. / European Journal of Medicinal Chemistry 204 (2020) 112595
Table 2 (continued )
Compd. NO.
R2
IC50
(m
M) EBOV
IC50
(m
M) MARV
CC50
(m
M)
SI
SI
EBOV
MARV
35
5.2 2.5
3.2 0.8
36.9 1.4
7.1
11.4
36
0.7 0.1
0.9 0.0
＞100
142.9
111.1
37
38
39
1.5 0.2
1.4 0.4
1.5 0.4
1.1 0.1
1.0 0.4
2.1 0.1
19.3 2.7
32.9 10.3
91.6 7.3
13.1
22.9
16.6
18.1
31.8
30.0
40
1.8 0.7
1.8 0.2
33.2 4.2
17.5
18.2
41
42
1.2 0.0
1.3 0.3
5.2 1.5
＞100
85.7
5.7
76.9
11.9
10.9 0.3
62.4 10.8
43
3.5 0.1
2.3 0.6
29.1 9.4
8.2
12.8
that the carboxamide piperidine group of compound 32 does not
have key interaction with N61 or D522 of Ebola GP, which is sub-
stantially different to the interaction profile of compound 118a,
even though these two compounds have the same carboxamide
group. Moreover, compound 32 showed ~3 fold lower activity
against the infection of pseudovirion carrying Y517S mutant
compared with the WT pseudovirions (Fig. 2C). It has been shown
that methylpyrazole group of compound 118a interacts with Y517
via ring stacking and chlorophenyl ring of compound 118a binds to
a hydrophobic pocket formed by V106, A101, L515 and Y517. These
data indicates that the trifluomethoxybenzyl group of compound
32 binds to the hydrophobic pocket close to Y517 via hydrophobic
interaction or/and ring stacking interaction like compound 118a.
To further elucidate the binding mechanism of compound 32,
we performed molecular docking simulations with the crystal
structure of Ebola glycoprotein complexed with compound 118a.
The co-crystal structure (PDB: 6HRO) was prepared by removing all
ligands and unrelated water molecules and the whole protein was
used as binding pocket for compound 32. The docking results
showed that the model of compound 32 with the highest binding
affinity score bound to the same pocket as the reported molecule I
of compound 118a22 (Fig. 3A). Thus this pocket was chosen for
further docking studies. As shown in Fig. 3B, except the carbox-
amide part, compound 32 has a similar binding pose to that of
compound 118a [1]: The linker moiety of compound 32 takes
almost the same pose as the ethyl moiety of 118a. Although the
linker of compound 32 is one carbon-carbon bond longer than that
of 118a and possesses a hydroxyl group that 118a does not have,
neither the linker chain nor the hydroxyl group produces key in-
teractions with EBOV GP. Moreover, the docking results of com-
pound 32 showed that the hydroxyl groups is in the “neck” of the
tunnel-like binding pocket, which is consistent with the SAR re-
sults that the substitutions on the hydroxyl group reduced activity
(Fig. S1) [2]. The coumarin moiety of compound 32 occupies similar
space as the phenol group of 118a. Due to the lack of ring structure
between coumarin and benzyl group on C-3, compound 32 does
not form ring stacking with Y517 as the methylpyrazole group of
compound 118a does. The oxygen atoms of the lactone structure of
compound 32 does not form hydrogen bond with GP protein, which
is comparable with the fact that the phenol group of 118a is not
involved in key interactions with GP protein [3]. The tri-
fluomethoxybenzyl group of compound 32 also has a very similar
pose as the o-chlorobenzene of 118a. However, because lack of the
s-hole in the fluorine atom, compound 32 (Fig. 3C) cannot form the
critical halogen bond with G67 which was an important contributor
for the high efficacy of 118a (Fig. 3D). In the SAR studies of this part,
we synthesized compounds (23, 24 27 and 28) which had halogen
substitutions on the benzene, but none of them increased antiviral
activities. We also performed docking studies of compound 23 and
24 with 4-chlorobenzyl and 4-bromobenzyl groups respectively,
but these two compounds did not form halogen bond with G67 in
the docking results. These results are consistent with the halogen-
bond requirement that the carbonyl group of amino acid residues
must strictly point to the s-hole in the halogen atom of the ligand
to form the electrostatic interactions. Moreover, the docking results
show that the carboxamide group of compound 32 forms H-bond
with R164 but does not interact with N61 or R587 as compound
118a does, probably due to that glycerol linker of compound 32 is
longer than the ethyl linker of compound 118a, which may afford
more freedom for carboxamide and cause more entropy loss in
binding process. Finally, we compared the binding mechanism of
compound 32 in glycoprotein of Ebola virus (PDB: 6HRO) and
Marburg Virus (PDB: 6BP2) with docking studies. Compound 32 is
shown to bind in the same binding pocket in glycoprotein of Mar-
burg virus as it does in Ebola GP, but in an obviously different pose.
The oxygen atom of coumarine ring may form hydrogen bond with
Gly547 and the nitrogen atom of piperidine ring may form
hydrogen bind with Glu45 of Marburg GP (Fig. S2).

Y. Gao et al. / European Journal of Medicinal Chemistry 204 (2020) 112595
7
Table 3
The SAR study on the linker (R3).
Compd. NO.
R3
IC50
(
m
M) EBOV
IC50
(m
M) MARV
CC50
(
m
M) MARV
SI
SI
EBOV
MARV
44 (R)
0.9 0.1
1.4 0.2
52.0 14.3
55.7
36.3
45 (S)
0.7 0.1
1.4 0.3
64.9 11.6
92.6
46.3
46
47
22.5 6.4
10.4 0.8
20.3 5.6
12.1 2.3
79.6 9.0
66.4 7.8
3.5
6.4
3.9
5.5
48
49
50
10.5 2.0
16.0 5.6
14.2 7.1
8.0 1.2
8.2 1.7
13.4 4.3
94.9 5.1
94.8 3.2
＞100
9.1
5.9
7.0
11.9
11.5
7.4
51
52
2.8 0.4
1.7 0.3
16.6 7.5
50.1 1.4
5.9
2.8
9.6
3.1
18.0 1.7
16.0 0.7
3. Materials and methods
mutated using the Agilent Technologies QuickChange Lightning
Site-Directed Mutagenesis Kit (Agilent, Santa Clara, CA, USA).
Primer pairs were designed using QuickChange Primer Design
program and purchased through Sigma (Sigma, St. Louis, MO, USA).
Plasmids containing GP mutations were made following manu-
facturer’s instructions and were sequenced to ensure the correct
mutation.
3.1. Cell culture
Human embryonic kidney cells (239T, ATCC# CRL-1573), human
lung epithelial cells (A549, ATCC#CCL185) were cultured in DMEM
(Cellgro, Manassas, VA, USA) supplemented with 10% fetal bovine
serum (FBS, Sigma, St. Louis, MO, USA), 100 mg/mL of streptomycin
and 100 units of penicillin (Invitrogen, Carlsbad, CA, USA).
3.3. Pseudovirion infection assay and cell viability assay
3.2. Generation of Zaire Ebolavirus glycoprotein mutants
The HIV/MARV and HIV/EBOV pseudovirions were generated by
transient co-transfection of replication-defective HIV vector (pNL4-
3.Luc.R-E-) and plasmid encoding MARV GP or EBOV GP into 293T
Plasmid containing the Zaire Ebolavirus glycoprotein gene was

8
Y. Gao et al. / European Journal of Medicinal Chemistry 204 (2020) 112595
Table 4
The SAR studies on the C-4 of coumarin (R4).
Compd. NO
R4
IC50
(m
M) EBOV
IC50
(
m
M) MARV
CC50
(
mM) MARV
SI
SI
EBOV
MARV
53
54
9.4 1.6
2.9 1.0
6.5 2.7
2.2 0.7
＞100
10.6
15.3
25.2 2.4
8.6
11.6
55
17.7 4.2
33.5 0.5
＞100
5.7
3.0
Table 5
The synergy of all R1, R2 and R3 groups.
Compd. NO.
R1
R2
IC50
(m
M) EBOV
IC50
(m
M) MARV
CC50
(
m
M) MARV
SI
EBOV
SI
MARV
56
1.5 0.1
2.2 0.5
1.2 0.2
1.3 0.1
99.0 0.9
14.3 0.9
66
82.5
57
6.6
10.7
58
59
2.7 0.4
3.4 0.9
1.3 0.4
1.3 0.2
38.1 2.4
42.2 0.8
14.1
12.4
29.3
32.5
Fig. 2. The in vitro dose-response curves of compound 32 are shown in (A) against the infections of pseudotyped EBOV carrying wild-type GP (black) or GP with N61A (red),
N61V(blue) or N61D (orange), (B) GP with D522A (red), and (C) GP with Y517S (red) in A549 cells. (For interpretation of the references to colour in this figure legend, the reader is
referred to the Web version of this article.)

Y. Gao et al. / European Journal of Medicinal Chemistry 204 (2020) 112595
9
Fig. 3. The molecular docking studies of compound 32. (A) Compound 32 (Green) bound in the GP protein, sharing the binding site of compound 118a (Yellow). (B) The details of the
interactions of compound 32 with GP protein, comparing with 118a. The carboxamide formed a hydrogen bond with R164 with distance 3.2 Å between the nitrogen atom of
carboxamide and the oxygen atom carbonyl group of R164. The carboxamide of comound 118a formed H-bond with N61. The trifluoromethoxy group on the benzene of compound
32 could not form hydrogen bond as the o-chloride group of 118a did. (C) The fluorine atom in trifluoromethoxyl group of compound 32 could not form halogen bond with Asn67
(yellow circle) because the fluorine atom does not have
s-hole (yellow circle). The electrostatic density is shown in blue. (D) The Chlorine atom in o-chlorobezene group of
compound 118a formed halogen bond with N67 via the
s-hole on chlorine (yellow circle). (For interpretation of the references to colour in this figure legend, the reader is referred to
the Web version of this article.)
cells, using a polyethylenimine (PEI)-based transfection protocol.
Six hours after transfection, cells were washed with phosphate-
buffered saline (PBS) and 20 mL of fresh media was added to
each plate (150 mm). Twenty-four hours post-transfection, the
negative controls and the signals from these cells were used for
data normalization. IC50 and CC50 values were determined by fitting
the dose-response curves with logistic regression in GraphPad.
General Methods for Chemistry. All starting materials were
commercially available and used without further purification. All
reactions were carried out with the use of standard techniques
under an inert atmosphere (Ar or N2). NMR spectra were generated
on a Bruker 500 or 400 MHz instrument and obtained as CDCl3 or
DMSO‑d6 solutions (reported in ppm), using CDCl3 as the reference
standard (7.26 ppm) or DMSO‑d6 (2.50 ppm). Mass spectral data
(ESI) were gathered on Thermofisher LCQ or QE Mass spectrometry.
HPLC (Agilent Prostar 218 or 1200) was employed for purity
determination, using the following method: Eclipse XDB C18 col-
supernatants were collected and filtered through 0.45 mm pore size
filter (Nalgene, Rochester, NY, USA). The pseudovirion stocks were
stored at 4 ꢁC prior to use.
Low-passage A549 cells were seeded at the density of 5000/well
in 96-well plates 24 h before infection. The synthesized compounds
were prepared as 3-fold serial dilutions and mixed with HIV/MARV
or HIV/EBOV pseudotyped virus or fresh media for IC50 and CC50
evaluation. The A549 cells were incubated with 100
mL/well of
above-mentioned mixtures for 48 h. The luciferase activity of
infected A549 cells was quantified using the neolite Reporter Gene
Assay System (PerkinElmer, Waltham, MA, USA). The cell viability
was measured with the CellTiter-Glo kit (Promega, Madison, WI,
USA). Cells incubated with virus or medium alone was used as the
umn, 5
m
m, 4.6 mm ꢂ 150 mm, column temperature 40 ꢁC; solvent
A: H2O or 0.1 formic acid in H2O; solvent B: methanol or ACN;
gradient of 40e70% B (0e10 min), 70e90% B (10e15 min), 90ꢀ40%
B (15e20 min), with minor adjustoin according to the retention

10
Y. Gao et al. / European Journal of Medicinal Chemistry 204 (2020) 112595
time of the target compounds; flow rate of 1.5 mL/min. Compound
purity was determined by high pressure liquid chromatography
(HPLC) with a confirming purity of ꢃ95% for all of the final bio-
logically tested compounds.
150.19 (s), 141.16 (s), 130.25 (s), 129.86 (s), 128.42 (s), 127.89 (s),
122.82 (s), 115.34 (s), 114.31 (s), 111.37 (s), 102.89 (s), 73.61 (s), 68.27
(s), 62.97 (s), 55.50 (d, J ¼ 9.7 Hz), 43.47 (s), 33.97 (s), 30.45 (s), 17.02
(s).
3.4. Synthesis of derivatives of CP19
3.4.2. 3-Benzyl-7-(2-hydroxy-3-(prop-2-yn-1-ylamino)propoxy)-
4-methyl-2H-chromen-2-one [2]
The syntheses of derivatives of CP19 in this study were per-
formed according to the methods in Scheme 2 with minor modi-
fications as described in each compounds.
Reagents and conditions:(a) Ethyl acetoacetate, Benzyl bromide,
CH3ONa, Methonal, RT/68 ꢁC, 0.5 h; (b) Resorcino, PPA, 65 ꢁC, 4 h,
67%; (c) Epichlorohydrin, K2CO3, TBAB, 80 ꢁC, 2.3 h, 81%; (d)Organic
amine, AcNMe2, 50 ꢁC, 24 h, 85%.
The title compound was synthesized according to the procedure
of preparing Compound NO.1.1H NMR (500 MHz, DMSO)
d 7.71 (d,
J ¼ 9.6 Hz, 1H), 7.27e7.22 (m, 2H), 7.20 (d, J ¼ 7.0 Hz, 2H), 7.16 (d,
J ¼ 7.1 Hz, 1H), 6.98e6.92 (m, 2H), 4.07 (dd, J ¼ 10.0, 4.1 Hz, 1H),
3.98e3.93 (m, 2H), 3.93 (s, 2H), 3.75 (dd, J ¼ 5.7, 2.4 Hz, 1H), 3.08 (s,
1H), 3.04 (t, J ¼ 2.4 Hz, 1H), 2.93 (s, 1H), 2.77 (s, 1H), 2.67e2.64 (m,
2H), 2.62 (s, 1H), 2.41 (s, 3H), 1.97 (s, 1H), 1.94 (s, 1H). ESI-MS m/z:
377.16 [MþH] þ
.
13C NMR (101 MHz, DMSO)
d 163.02 (s), 155.17 (s), 150.22 (s),
141.15 (s), 130.26 (s), 129.85 (s), 128.43 (s), 127.90 (s), 122.84 (s),
115.36 (s), 114.36 (s), 102.86 (s), 84.66 (s), 75.63 (s), 74.85 (s), 73.20
(s), 70.17 (s), 69.75 (s), 67.05 (s), 52.74 (s), 48.37 (s), 39.46 (s), 33.96
(s), 31.62 (s), 17.02 (s).
Reagents and conditions:(a) Ethyl acetoacetate, 4-(Trifluoro
methoxy)benzyl bromide, CH3ONa, Methonal, RT/68 ꢁC, 0.5 h; (b)
Resorcino, PPA, 65 ꢁC, 4 h, 67%; (c) (R)-(-)-Epichlorohydrin or (S)-
(þ)-Epichlorohydrin, K2CO3, TBAB, 80 ꢁC, reflux 2.3 h, 53%; (d)
Hexahydroisonicotinamide, AcNMe2, 50 ꢁC, 24 h, 89%.
3.4.3. 3-Benzyl-7-(3-((cyclopropylmethyl)amino)-2-
hydroxypropoxy)-4-methyl-2H-chromen-2-one [3]
The title compound was synthesized according to the procedure
of preparing Compound NO.1.1H NMR (400 MHz, DMSO)
d
7.28e7.14 (m, 6H), 6.95 (dd, J ¼ 6.0, 2.4 Hz, 2H), 4.07 (dd, J ¼ 10.0,
3.4.1. 1-(3-((3-benzyl-4-methyl-2-oxo-2H-chromen-7-yl)oxy)-2-
hydroxypropyl)piperidine-4-carboxamide [1]
4.3 Hz, 1H), 3.97 (dd, J ¼ 10.0, 6.1 Hz, 1H), 3.93 (s, 2H), 3.90 (d,
J ¼ 4.6 Hz, 1H), 2.70 (d, J ¼ 4.9 Hz, 1H), 2.65 (d, J ¼ 6.9 Hz, 1H), 2.44
(s, 1H), 2.41 (s, 3H), 2.33 (d, J ¼ 12.6 Hz, 1H), 0.39 (ddd, J ¼ 8.0, 5.6,
A mixture of ethyl acetoacetate (5 mmol) and CH3ONa (1 eq) in
MeOH (4 mL) was stirred at room temperature for 10 min. Then,
benzyl bromide derivatives (1.1 eq) in 5 mL MeOH was added
dropwise when the reaction solution was slightly boiling. The re-
action mixture was continued to heat under reflux until it was
almost neutral. After cooling, the reaction solution was filtered off
and concentrated by vacuum to give ethyl acetoacetate derivatives.
To a stirred solution of the above mentioned products in PPA 3 g,
resorcino (1 eq) was added. The reaction mixture was stirred at
65 ꢁC for 4 h. The mixture solution had to rest overnight, then
diluted with 100 mL water. The precipitated solid was filtered off,
washed with water to give the crude product. The crude product
was purified by silica gel chromatography using cyclohexane-ethyl
acetate as eluate to give 7-hydroxy-chromen-2-one derivatives
(67%).
A mixture of the above products, epichlorohydrin (1e3 mL),
potassium carbonate (2 eq) and TBAB (1 eq) was stirred at 80 ꢁC for
2.3 h. Then the mixture was extracted with ethyl acetate, washed
with water. The organic phase was collected and the solvent was
removed under vacuum. The product was purified by silica gel
chromatography using cyclohexane-ethyl acetate as eluate to give
4-methyl-7-(oxiran-2-ylmethoxy)-chromen-2-one
4.0 Hz, 2H), 0.09 (dt, J ¼ 15.4, 7.6 Hz, 2H). ESI-MS m/z: 394.23
þ
[MþH]
.
13C NMR (101 MHz, DMSO)
d 163.02 (s), 155.18 (s), 150.19 (s),
141.16 (s), 130.25 (s), 129.86 (s), 128.43 (s), 127.89 (s), 122.85 (s),
115.36 (s), 114.35 (s), 102.86 (s), 73.22 (s), 69.60 (s), 55.88 (s), 53.65
(s), 33.97 (s), 17.02 (s), 12.64 (s), 5.08 (s).
3.4.4. 3-Benzyl-7-(2-hydroxy-3-(phenylamino)propoxy)-4-methyl-
2H-chromen-2-one [4]
The title compound was synthesized according to the procedure
of preparing Compound NO.1.1H NMR (400 MHz, DMSO)
d
7.74e7.68 (m, 1H), 7.26e7.14 (m, 5H), 7.04 (dd, J ¼ 8.4, 7.4 Hz, 2H),
6.97 (dd, J ¼ 6.9, 2.4 Hz, 2H), 6.60 (d, J ¼ 7.7 Hz, 2H), 6.50 (t,
J ¼ 7.2 Hz, 1H), 4.12 (dd, J ¼ 9.8, 3.8 Hz, 1H), 4.06e3.97 (m, 2H), 3.93
(s, 2H), 3.24e3.18 (m, 1H), 3.13e3.04 (m, 1H), 2.41 (s, 3H), 1.40e1.18
(m, 2H). ESI-MS m/z: 415.97 [MþH] þ
.
13C NMR (101 MHz, DMSO)
d
163.04 (d, J ¼ 8.2 Hz), 155.17 (s),
150.60 (s), 150.19 (s), 141.15 (s), 130.72 (s), 130.26 (s), 129.86 (s),
128.44 (s), 127.90 (s), 122.87 (s), 117.57 (s), 115.39 (s), 114.36 (s),
113.96 (s), 102.87 (s), 72.88 (s), 69.22 (s), 47.91 (s), 33.97 (s), 17.03
(s).
derivatives(81%).
The above mentioned products was added to a stirred solution
of organic amine (2.5 eq) in 1e2 mL dimentylacetamide then the
reaction mixture was stirred at 50 ꢁC for 24 h. The reaction solution
was allowed to cool to room temperature and concentrated by
vacuum. The residue was dissolved in acetone, absorbed onto silica
and purified by flash column chromategraphy using dichloro
methane-methanol as eluate to give compound NO.1 (85%).
3.4.5. 3-Benzyl-7-(2-hydroxy-3-((2-hydroxy-5-nitrophenyl)amino)
propoxy)-4-methyl-2H-chromen-2-one [5]
The title compound was synthesized according to the procedure
of preparing Compound NO.1.1H NMR (500 MHz, DMSO)
d 7.71 (d,
J ¼ 9.3 Hz, 1H), 7.44 (dd, J ¼ 8.6, 2.7 Hz, 1H), 7.31 (d, J ¼ 2.7 Hz, 1H),
7.27e7.22 (m, 2H), 7.20 (d, J ¼ 7.1 Hz, 2H), 7.16 (t, J ¼ 7.1 Hz, 1H),
7.01e6.96 (m, 2H), 6.78 (d, J ¼ 8.6 Hz, 1H), 4.14e4.10 (m, 1H),
4.09e4.05 (m, 2H), 3.93 (s, 2H), 3.15 (d, J ¼ 5.0 Hz, 3H), 2.93 (s, 1H),
1H NMR (500 MHz, DMSO)
d
7.71 (d, J ¼ 9.5 Hz, 1H), 7.25 (t,
-
J ¼ 7.4 Hz, 3H), 7.17 (dd, J ¼ 17.2, 8.6 Hz, 4H), 6.99e6.90 (m, 2H),
4.11e4.01 (m, 1H), 3.97e3.94 (m, 2H), 3.93 (s, 2H), 2.90 (d,
J ¼ 11.2 Hz, 1H), 2.84 (d, J ¼ 11.2 Hz, 1H), 2.40 (d, J ¼ 6.6 Hz, 3H), 2.33
(dd, J ¼ 12.6, 5.8 Hz, 1H), 2.08e1.86 (m, 4H), 1.61 (d, J ¼ 2.4 Hz, 2H),
2.77 (s, 1H), 2.41 (s, 3H). ESI-MS m/z: 475.64 [MþH] .
13C NMR (101 MHz, DMSO)
d 163.35e163.11 (m), 162.96 (d,
J ¼ 20.6 Hz), 155.16 (s), 152.85 (s), 150.17 (s), 142.34 (s), 141.14 (s),
139.70 (s), 130.25 (s), 129.85 (s), 128.43 (s), 127.89 (s), 122.90 (s),
115.26 (d, J ¼ 38.6 Hz), 114.16 (d, J ¼ 31.8 Hz), 113.99e113.71 (m),
105.03 (s), 102.88 (s), 72.82 (s), 68.96 (s), 47.64 (s), 33.97 (s), 17.01 (s).
1.57e1.46 (m, 2H). ESI-MS m/z: 451.07 [MþH] þ
.
13C NMR (101 MHz, DMSO)
d 178.42 (s), 163.11 (s), 155.18 (s),

Y. Gao et al. / European Journal of Medicinal Chemistry 204 (2020) 112595
11
Scheme 2. The synthesis route of the target compounds.
3.4.6. 3-Benzyl-7-(3-((4-bromophenyl)amino)-2-
hydroxypropoxy)-4-methyl-2H-chromen-2-one [6]
3.07 (dd, J ¼ 12.5, 6.4 Hz, 1H), 2.41 (s, 3H). ESI-MS m/z: 494.20
þ
[MþH]
.
The title compound was synthesized according to the procedure
13C NMR (101 MHz, DMSO)
d
163.01 (d, J ¼ 12.6 Hz), 155.17 (s),
of preparing Compound NO.1.1H NMR (500 MHz, DMSO)
150.19 (s), 149.93 (s), 141.15 (s), 133.18 (s), 130.26 (s), 129.86 (s),
128.44 (s), 127.90 (s), 122.89 (s), 115.86 (s), 115.42 (s), 114.35 (s),
108.03 (s), 102.89 (s), 72.74 (s), 69.12 (s), 47.83 (s), 33.97 (s), 17.03
(s).
d
7.73e7.69 (m, 1H), 7.25 (t, J ¼ 7.4 Hz, 2H), 7.20 (d, J ¼ 7.1 Hz, 2H),
7.18e7.15 (m, 3H), 6.97 (dd, J ¼ 5.7, 2.4 Hz, 2H), 6.57 (d, J ¼ 8.9 Hz,
2H), 4.09 (dd, J ¼ 10.0, 4.1 Hz,1H), 4.03 (dd, J ¼ 10.0, 5.9 Hz,1H), 3.97
(dd, J ¼ 10.3, 5.2 Hz, 1H), 3.93 (s, 2H), 3.20 (dd, J ¼ 12.8, 6.4 Hz, 1H),

12
Y. Gao et al. / European Journal of Medicinal Chemistry 204 (2020) 112595
3.4.7. 3-Benzyl-7-(3-(benzylamino)-2-hydroxypropoxy)-4-methyl-
2H-chromen-2-one [7]
J ¼ 9.9, 6.2 Hz, 1H), 3.93 (s, 3H), 3.81 (d, J ¼ 2.2 Hz, 2H), 2.68 (dd,
J ¼ 11.8, 5.1 Hz,1H), 2.61 (dd, J ¼ 11.9, 6.5 Hz,1H), 2.41 (s, 3H),1.38 (s,
þ
The title compound was synthesized according to the procedure
1H). ESI-MS m/z: 430.92 [MþH]
.
of preparing Compound NO.1.1H NMR (400 MHz, DMSO)
d
7.70 (d,
13C NMR (101 MHz, DMSO)
d
163.07 (d, J ¼ 5.4 Hz), 162.02 (s),
J ¼ 9.6 Hz, 1H), 7.34e7.17 (m, 10H), 6.94 (dd, J ¼ 7.2, 2.4 Hz, 2H), 4.09
155.18 (s), 150.60 (s), 150.20 (s), 141.16 (s), 138.28 (s), 130.26 (s),
129.86 (s), 128.42 (s), 127.89 (s), 123.67 (d, J ¼ 7.3 Hz), 122.83 (s),
115.34 (s), 114.37 (s), 102.85 (s), 73.17 (s), 69.93 (s), 56.52 (s), 53.64
(s), 33.97 (s), 17.02 (s).
(dd, J ¼ 9.9, 4.1 Hz, 1H), 3.97 (dd, J ¼ 9.9, 6.2 Hz, 2H), 3.93 (s, 2H),
3.71 (s, 2H), 2.61 (ddd, J ¼ 18.3, 11.9, 5.8 Hz, 2H), 2.41 (s, 3H), 2.32 (d,
þ
J ¼ 14.1 Hz, 1H). ESI-MS m/z: 430.24 [MþH]
.
13C NMR (101 MHz, DMSO)
d 163.06 (s), 155.18 (s), 150.20 (s),
142.62 (s), 141.17 (s), 130.25 (s), 130.08e129.47 (m), 127.89 (s),
122.83 (s), 115.33 (s), 114.37 (s), 102.84 (s), 73.24 (s), 69.89 (s), 54.89
(s), 53.40 (s), 33.97 (s), 17.02 (s).
3.4.12. 3-Benzyl-7-(2-hydroxy-3-((2-(pyridin-3-yl)ethyl)amino)
propoxy)-4-methyl-2H-chromen-2-one [12]
The title compound was synthesized according to the procedure
of preparing Compound NO.1.1H NMR (500 MHz, DMSO)
d 8.43 (d,
3.4.8. 3-Benzyl-7-(2-hydroxy-3-((3-hydroxypropyl)amino)
propoxy)-4-methyl-2H-chromen-2-one [8]
J ¼ 1.8 Hz, 1H), 8.37 (dd, J ¼ 4.7, 1.5 Hz, 1H), 7.73e7.68 (m, 1H), 7.63
(d, J ¼ 7.8 Hz, 1H), 7.28e7.26 (m, 1H), 7.24 (d, J ¼ 7.3 Hz, 2H), 7.21 (d,
J ¼ 7.0 Hz, 2H), 7.16 (t, J ¼ 7.1 Hz, 1H), 6.94 (dd, J ¼ 5.8, 2.4 Hz, 2H),
4.04 (dd, J ¼ 10.0, 4.3 Hz, 1H), 3.95 (d, J ¼ 6.2 Hz, 1H), 3.93 (s, 2H),
3.86 (d, J ¼ 5.2 Hz, 1H), 2.76 (d, J ¼ 6.2 Hz, 1H), 2.70 (dd, J ¼ 12.0,
5.7 Hz, 3H), 2.66 (s, 1H), 2.63e2.57 (m, 1H), 2.41 (s, 3H). ESI-MS m/z:
The title compound was synthesized according to the procedure
of preparing Compound NO.1.1H NMR (500 MHz, DMSO)
d 7.71 (s,
1H), 7.24 (d, J ¼ 7.2 Hz, 3H), 7.21 (s, 3H), 7.17 (d, J ¼ 7.1 Hz, 2H), 6.95
(d, J ¼ 2.5 Hz, 1H), 4.07 (dd, J ¼ 9.6, 3.8 Hz, 2H), 4.00e3.96 (m, 2H),
3.93 (s, 3H), 3.45 (t, J ¼ 6.2 Hz, 4H), 2.93 (s, 1H), 2.81e2.77 (m, 1H),
2.77 (s, 1H), 2.69 (dd, J ¼ 9.2, 4.7 Hz, 4H), 2.40 (s, 3H), 1.94 (s, 1H),
444.83 [MþH] þ
.
13C NMR (101 MHz, DMSO)
d
163.06 (d, J ¼ 5.7 Hz), 155.18 (s),
1.60 (d, J ¼ 6.7 Hz, 2H), 1.22 (s, 2H). ESI-MS m/z: 397.90 [MþH] þ
.
151.70 (s), 150.19 (s), 148.96 (s), 141.17 (s), 137.86 (d, J ¼ 16.7 Hz),
130.26 (s), 129.86 (s), 128.41 (s), 127.89 (s), 125.13 (s), 122.84 (s),
115.34 (s), 114.33 (s), 102.84 (s), 73.22 (s), 69.86 (s), 53.86 (s), 52.49
(s), 34.76 (s), 33.97 (s), 17.02 (s).
13C NMR (101 MHz, DMSO)
150.19 (s), 141.15 (s), 130.26 (s), 129.86 (s), 128.44 (s), 127.90 (s),
122.89 (s), 115.41 (s), 114.34 (s), 102.88 (s), 72.99 (s), 68.88 (s), 60.91
(s), 53.38 (s), 48.27 (s), 33.97 (s), 33.30 (s), 17.03 (s).
d
162.99 (d, J ¼ 16.5 Hz), 155.16 (s),
3.4.13. 3-Benzyl-7-(2-hydroxy-3-((2-(pyridin-4-yl)ethyl)amino)
propoxy)-4-methyl-2H-chromen-2-one [13]
3.4.9. 3-Benzyl-7-(2-hydroxy-3-((6-hydroxyhexyl)amino)
propoxy)-4-methyl-2H-chromen-2-one [9]
The title compound was synthesized according to the procedure
The title compound was synthesized according to the procedure
of preparing Compound NO.1.1H NMR (500 MHz, DMSO)
d 8.45 (d,
of preparing Compound NO.1.1H NMR (500 MHz, DMSO)
d
7.71 (d,
J ¼ 5.9 Hz,1H), 8.40 (d, J ¼ 5.9 Hz, 2H), 7.70 (d, J ¼ 9.6 Hz,1H), 7.27 (s,
1H), 7.25 (s,1H), 7.23 (s, 2H), 7.22 (d, J ¼ 4.9 Hz, 3H), 7.20 (s,1H), 7.16
(t, J ¼ 7.1 Hz, 1H), 6.95 (s, 2H), 6.93 (d, J ¼ 2.5 Hz, 1H), 5.01 (d,
J ¼ 4.9 Hz, 1H), 4.05 (d, J ¼ 4.3 Hz, 1H), 4.03 (d, J ¼ 4.3 Hz, 1H), 3.95
(d, J ¼ 6.1 Hz, 1H), 3.93 (d, J ¼ 4.6 Hz, 2H), 3.86 (d, J ¼ 5.3 Hz, 1H),
3.15 (d, J ¼ 5.2 Hz, 1H), 2.78 (d, J ¼ 6.6 Hz, 2H), 2.72 (d, J ¼ 6.9 Hz,
J ¼ 9.6 Hz,1H), 7.24 (d, J ¼ 7.3 Hz, 2H), 7.20 (d, J ¼ 7.0 Hz, 2H), 7.17 (d,
J ¼ 7.1 Hz,1H), 6.95 (dd, J ¼ 6.1, 2.5 Hz, 2H), 4.06 (dd, J ¼ 10.0, 4.2 Hz,
1H), 3.95 (dd, J ¼ 10.1, 6.3 Hz, 1H), 3.93 (s, 2H), 3.88e3.82 (m, 1H),
3.37 (d, J ¼ 6.5 Hz, 2H), 2.64 (d, J ¼ 5.2 Hz, 1H), 2.62 (d, J ¼ 5.0 Hz,
1H), 2.57 (s, 1H), 2.56 (s, 1H), 2.40 (d, J ¼ 9.0 Hz, 3H), 2.22 (s, 1H),
1.39e1.36 (m, 5H), 1.26e1.24 (m, 4H). ESI-MS m/z: 439.98 [MþH] þ
.
2H), 2.69 (s, 1H), 2.66 (s, 1H), 2.60 (dd, J ¼ 11.9, 6.6 Hz, 1H), 2.41 (s,
þ
13C NMR (101 MHz, DMSO)
d
163.07 (s), 155.18 (s), 150.20 (s),
3H). ESI-MS m/z: 444.99[MþH]
.
141.16 (s), 130.25 (s), 129.85 (s), 128.41 (s), 127.89 (s), 122.82 (s),
115.32 (s), 114.34 (s), 102.84 (s), 73.28 (s), 69.80 (s), 62.49 (d,
J ¼ 6.9 Hz), 54.12 (s), 51.30 (s), 34.68e33.89 (m), 31.47 (s), 28.58 (s),
27.34 (s), 27.10 (s), 17.02 (s).
13C NMR (126 MHz, DMSO)
d
161.68 (d, J ¼ 7.9 Hz), 153.80 (s),
150.50e150.07 (m), 149.87 (d, J ¼ 21.1 Hz), 148.83 (s), 139.79 (s),
128.88 (s), 128.48 (s), 127.05 (s), 126.52 (s), 124.70 (s), 121.47 (s),
113.97 (s), 112.97 (s), 101.47 (s), 71.82 (s), 68.47 (s), 52.44 (s), 50.33
(s), 35.54 (s), 32.60 (s), 15.66 (s).
3.4.10. 3-Benzyl-7-(2-hydroxy-3-((tetrahydro-2H-pyran-4-yl)
amino)propoxy)-4-methyl-2H-chromen-2-one [10]
3.4.14. 3-Benzyl-7-(2-hydroxy-3-((thiophen-2-ylmethyl)amino)
propoxy)-4-methyl-2H-chromen-2-one [14]
The title compound was synthesized according to the procedure
of preparing Compound NO.1.1H NMR (500 MHz, DMSO)
d
7.71 (d,
The title compound was synthesized according to the procedure
J ¼ 9.2 Hz, 1H), 7.31e7.11 (m, 5H), 6.96 (d, J ¼ 7.9 Hz, 2H), 4.07 (dd,
J ¼ 10.0, 4.2 Hz, 1H), 3.97 (dd, J ¼ 10.1, 6.1 Hz, 2H), 3.93 (s, 2H), 3.85
(d, J ¼ 4.9 Hz, 1H), 3.81e3.74 (m, 2H), 3.27e3.17 (m, 2H), 2.70 (dd,
J ¼ 11.8, 5.1 Hz, 1H), 2.64e2.54 (m, 2H), 2.40 (d, J ¼ 7.9 Hz, 3H), 1.73
(dd, J ¼ 8.5, 4.5 Hz, 2H), 1.38 (s, 1H), 1.21 (dd, J ¼ 18.3, 11.5 Hz, 2H).
of preparing Compound NO.1.1H NMR (400 MHz, DMSO)
d 7.72 (d,
J ¼ 8.7 Hz, 1H), 7.35 (dd, J ¼ 4.7, 1.5 Hz, 1H), 7.29 (s, 1H), 7.27 (s, 1H),
7.25 (s, 1H), 7.22 (s, 1H), 7.20 (s, 1H), 7.17 (s, 1H), 7.15 (s, 1H), 6.96 (d,
J ¼ 3.4 Hz, 2H), 6.94 (s, 2H), 4.09 (dd, J ¼ 9.8, 3.9 Hz, 1H), 3.98 (t,
J ¼ 4.9 Hz, 2H), 3.94 (s, 2H), 3.92 (s, 2H), 2.73e2.62 (m, 2H), 2.42 (s,
ESI-MS m/z: 424.21 [MþH] þ
.
3H). ESI-MS m/z: 435.94 [MþH] þ
.
13C NMR (101 MHz, DMSO)
d
163.05 (s), 155.18 (s), 150.18 (s),
13C NMR (101 MHz, DMSO)
d
163.06 (s), 162.86 (s), 155.16 (s),
141.16 (s), 130.25 (s), 129.85 (s), 128.41 (s), 127.89 (s), 122.83 (s),
115.33 (s), 114.36 (s), 102.84 (s), 73.24 (s), 70.08 (s), 67.64 (s), 55.23
(s), 50.58 (s), 35.06 (s), 33.97 (s), 17.02 (s).
152.86 (s), 150.17 (s), 142.34 (s), 141.14 (s), 139.70 (s), 130.25 (s),
129.85 (s), 128.43 (s), 127.89 (s), 122.90 (s), 115.45 (s), 115.06 (s),
114.32 (s), 114.00 (s), 105.03 (s), 102.88 (s), 72.82 (s), 68.96 (s), 50.43
(s), 47.64 (s), 33.97 (s), 17.01 (s).
3.4.11. 3-Benzyl-7-(2-hydroxy-3-((2-(pyridin-2-yl)ethyl)amino)
propoxy)-4-methyl-2H-chromen-2-one [11]
3.4.15. 3-Benzyl-7-(2-hydroxy-3-(thiazol-2-ylamino)propoxy)-4-
methyl-2H-chromen-2-one [15]
The title compound was synthesized according to the procedure
of preparing Compound NO.1.1H NMR (500 MHz, DMSO)
d
8.47 (d,
The title compound was synthesized according to the procedure
J ¼ 4.8 Hz, 1H), 7.71 (t, J ¼ 7.1 Hz, 2H), 7.40 (d, J ¼ 7.8 Hz, 1H), 7.27 (s,
1H), 7.24 (d, J ¼ 7.3 Hz, 2H), 7.20 (d, J ¼ 7.0 Hz, 3H), 7.17 (d, J ¼ 7.2 Hz,
1H), 6.95 (d, J ¼ 7.9 Hz, 2H), 4.09 (dd, J ¼ 10.0, 4.2 Hz, 1H), 3.98 (dd,
of preparing Compound NO.1.1H NMR (500 MHz, DMSO)
d 7.72 (d,
J ¼ 9.5 Hz, 1H), 7.20 (qd, J ¼ 14.6, 7.4 Hz, 6H), 6.98e6.92 (m, 2H),
6.73 (d, J ¼ 4.9 Hz, 1H), 4.18e4.11 (m, 1H), 3.99 (dt, J ¼ 14.3, 5.1 Hz,

Y. Gao et al. / European Journal of Medicinal Chemistry 204 (2020) 112595
13
2H), 3.93 (s, 2H), 3.89 (d, J ¼ 4.2 Hz, 1H), 3.86 (s, 1H), 3.74 (dd,
J ¼ 14.0, 7.1 Hz, 1H), 2.93 (s, 1H), 2.77 (s, 1H), 2.41 (s, 3H). ESI-MS m/
z: 423.13732[MþH] þ, delta (ppm) < 0.04.
101.76 (s), 72.26 (s), 66.88 (s), 61.58 (s), 54.12 (d, J ¼ 14.4 Hz), 42.09
(s), 29.07 (s), 18.59 (s).
13C NMR (126 MHz, DMSO)
d
161.67 (s), 161.35 (s), 153.76 (s),
3.4.20. 1-(3-((3-(4-(tert-butyl)benzyl)-4-methyl-2-oxo-2H-
chromen-7-yl)oxy)-2-hydroxypropyl)piperidine-4-carboxamide
[20]
148.81 (s), 139.76 (s), 130.34 (s), 128.88 (s), 128.48 (s), 127.12 (s),
126.53 (s), 121.62 (s), 114.18 (s), 112.95 (s), 101.52 (s), 71.00 (s), 67.23
(s), 49.85 (s), 32.61 (s), 15.68 (s).
The title compound was synthesized according to the procedure
of preparing Compound NO.1.1H NMR (500 MHz, DMSO)
d 7.68 (s,
3.4.16. 7-(3-((1H-1,2,3-triazol-1-yl)amino)-2-hydroxypropoxy)-3-
benzyl-4-methyl-2H-chromen-2-one [16]
1H), 7.28 (d, J ¼ 8.3 Hz, 3H), 7.23 (t, J ¼ 7.3 Hz, 3H), 7.19 (t, J ¼ 6.9 Hz,
4H), 7.14 (t, J ¼ 7.3 Hz, 3H), 7.00 (s, 1H), 6.69 (s, 1H), 4.82 (s, 2H), 4.08
(s, 1H), 4.02 (t, J ¼ 3.7 Hz, 1H), 4.00 (d, J ¼ 4.1 Hz, 1H), 3.98 (s, 1H),
3.96 (d, J ¼ 4.9 Hz, 3H), 3.89 (s, 3H), 2.85 (d, J ¼ 11.3 Hz, 1H), 2.74 (d,
J ¼ 11.0 Hz, 1H), 2.44 (s, 1H), 2.42 (s, 3H), 2.39e2.34 (m, 1H), 2.28
(dd, J ¼ 12.6, 6.3 Hz, 1H), 2.12 (s, 1H), 2.05e1.96 (m, 2H), 1.91 (dt,
J ¼ 11.5, 8.7 Hz, 3H), 1.60 (t, J ¼ 11.9 Hz, 3H), 1.51 (dq, J ¼ 11.8, 8.1 Hz,
3H), 1.24 (s, 12H), 1.23 (s, 8H), 1.21 (s, 2H), 1.15 (s, 1H). ESI-MS m/z:
The title compound was synthesized according to the procedure
of preparing Compound NO.1.1H NMR (500 MHz, DMSO)
d 7.89 (s,
1H), 7.73 (d, J ¼ 8.8 Hz, 1H), 7.27 (s, 1H), 7.24 (d, J ¼ 7.3 Hz, 2H), 7.20
(d, J ¼ 7.0 Hz, 2H), 7.17 (d, J ¼ 7.1 Hz, 1H), 6.99 (t, J ¼ 2.8 Hz, 2H), 6.97
(s, 1H), 5.92 (s, 2H), 5.65 (d, J ¼ 4.4 Hz, 1H), 4.08 (s, 1H), 4.05 (d,
J ¼ 4.2 Hz, 1H), 4.02 (d, J ¼ 4.1 Hz, 1H), 3.98 (dd, J ¼ 6.3, 3.6 Hz, 1H),
3.96e3.95 (m, 1H), 3.93 (s, 2H), 3.85 (dd, J ¼ 14.5, 7.9 Hz, 1H), 2.90
653.43 [MþH] þ
.
(dd, J ¼ 14.5, 7.2 Hz, 1H), 2.42 (s, 3H). ESI-MS m/z: 407.12 [MþH] þ
.
13C NMR (126 MHz, DMSO)
d 177.10 (s), 161.80 (s), 159.40 (s),
13C NMR (101 MHz, DMSO)
d
163.05 (s), 162.66 (s), 155.14 (s),
152.61 (s),149.30e148.43 (m),148.43e148.17 (m),138.08 (s),136.70
(s), 128.59 (s), 128.15 (d, J ¼ 7.2 Hz), 126.97 (d, J ¼ 9.0 Hz), 125.60 (s),
125.30 (s), 121.55 (s), 113.36 (s), 99.81 (s), 71.81 (s), 66.89 (s), 61.45
(s), 54.07 (d, J ¼ 13.5 Hz), 42.13 (s), 35.17 (s), 34.48 (d, J ¼ 4.2 Hz),
32.08 (s), 31.61 (s), 29.05 (s), 15.66 (s).
150.18 (s), 142.56 (s), 141.12 (s), 130.26 (s), 129.85 (s), 128.49 (s),
127.90 (s), 123.02 (s), 115.60 (s), 114.35 (s), 102.92 (s), 72.11 (s), 68.88
(s), 50.42 (s), 47.46 (s), 33.97 (s), 17.02 (s).
3.4.17. 7-(3-((1H-benzo[d]imidazole-2-yl)amino)-2-
hydroxypropoxy)-3-benzyl-4-methyl-2H-chromen-2-one [17]
The title compound was synthesized according to the procedure
3.4.21. 1-(3-((3-(4-fluorobenzyl)-4-methyl-2-oxo-2H-chromen-7-
yl)oxy)-2-hydroxypropyl)piperidine-4-carboxamide [21]
of preparing Compound NO.1.1H NMR (500 MHz, DMSO)
d
7.73 (d,
The title compound was synthesized according to the procedure
J ¼ 9.5 Hz, 1H), 7.28e7.23 (m, 2H), 7.21 (d, J ¼ 7.1 Hz, 2H), 7.16 (dd,
J ¼ 7.3, 3.6 Hz, 2H), 7.11 (d, J ¼ 7.7 Hz, 1H), 6.99 (d, J ¼ 2.4 Hz, 1H),
6.97 (s, 1H), 6.90 (t, J ¼ 7.1 Hz, 1H), 6.82 (t, J ¼ 7.2 Hz, 1H), 6.23 (s,
2H), 5.60 (d, J ¼ 5.3 Hz, 1H), 4.17 (d, J ¼ 8.2 Hz, 1H), 4.12 (d,
of preparing Compound NO.1.1H NMR (500 MHz, DMSO)
d 7.71 (d,
J ¼ 9.5 Hz, 1H), 7.24 (dd, J ¼ 8.5, 5.7 Hz, 2H), 7.17 (s, 1H), 7.07 (t,
J ¼ 8.9 Hz, 2H), 6.98e6.91 (m, 2H), 6.67 (s, 1H), 4.87 (s, 1H), 4.06 (t,
J ¼ 6.3 Hz, 1H), 3.97e3.92 (m, 2H), 3.90 (s, 2H), 2.90 (d, J ¼ 11.2 Hz,
1H), 2.84 (d, J ¼ 11.1 Hz, 1H), 2.41 (s, 3H), 2.39 (d, J ¼ 5.5 Hz, 1H),
2.34 (d, J ¼ 5.7 Hz, 1H), 2.31 (d, J ¼ 5.3 Hz, 1H), 2.05e1.91 (m, 3H),
J ¼ 4.2 Hz, 1H), 4.08 (dd, J ¼ 10.0, 3.9 Hz, 1H), 4.06e4.00 (m, 2H),
þ
3.93 (s, 2H), 2.42 (s, 3H). ESI-MS m/z: 455.93 [MþH]
.
13C NMR (101 MHz, DMSO)
d
163.06 (s), 162.73 (s), 157.14 (s),
1.61 (d, J ¼ 2.3 Hz, 2H), 1.52 (dd, J ¼ 23.2, 11.5 Hz, 2H). ESI-MS m/z:
þ
155.14 (s), 150.19 (s), 144.48 (s), 141.14 (s), 136.71 (s), 130.26 (s),
129.87 (s), 128.50 (s), 127.90 (s), 122.98 (s), 122.11 (s), 119.90 (s),
116.59 (s), 115.53 (s), 114.33 (s), 109.72 (s), 102.89 (s), 72.11 (s), 69.54
(s), 46.74 (s), 33.98 (s), 17.04 (s).
469.15 [MþH]
.
13C NMR (126 MHz, DMSO)
d
177.05 (s), 161.72 (d, J ¼ 11.7 Hz),
153.81 (s), 148.90 (s), 135.90 (s), 130.28 (d, J ¼ 7.9 Hz), 127.09 (s),
121.37 (s), 115.62 (s), 115.45 (s), 113.93 (s), 112.96 (s), 101.50 (s),
72.23 (s), 66.88 (s), 61.57 (s), 54.11 (d, J ¼ 12.2 Hz), 42.07 (s), 31.81
(s), 29.05 (s), 15.62 (s).
3.4.18. 3-Benzyl-7-(2-hydroxy-3-((6-methylbenzo[d]thiazol-2-yl)
amino)propoxy)-4-methyl-2H-chromen-2-one [18]
The title compound was synthesized according to the procedure
3.4.22. 1-(3-((3-(3-fluorobenzyl)-4-methyl-2-oxo-2H-chromen-7-
yl)oxy)-2-hydroxypropyl)piperidine-4-carboxamide [22]
of preparing Compound NO.1.1H NMR (500 MHz, DMSO)
d 7.70 (d,
J ¼ 8.9 Hz, 1H), 7.25 (t, J ¼ 7.5 Hz, 2H), 7.21e7.13 (m, 4H), 7.01 (d,
J ¼ 8.2 Hz,1H), 6.97e6.91 (m, 2H), 6.90 (d, J ¼ 2.3 Hz,1H), 4.26e4.21
(m, 1H), 4.07 (dd, J ¼ 10.5, 3.9 Hz, 2H), 4.02e3.99 (m, 1H), 3.92 (s,
The title compound was synthesized according to the procedure
of preparing Compound NO.1.1H NMR (500 MHz, DMSO)
d
7.75e7.67 (m, 1H), 7.30 (dd, J ¼ 14.3, 7.9 Hz, 1H), 7.17 (s, 1H),
2H), 2.40 (s, 3H), 2.21 (s, 3H). ESI-MS m/z: 487.15 [MþH] þ
.
7.07e6.93 (m, 5H), 6.68 (s, 1H), 4.08 (q, J ¼ 6.2 Hz, 1H), 4.01 (q,
J ¼ 7.1 Hz, 1H), 3.98e3.93 (m, 4H), 2.88 (dd, J ¼ 29.9, 11.2 Hz, 2H),
2.44e2.38 (m, 4H), 2.36e2.31 (m, 1H), 2.04e1.93 (m, 4H), 1.89 (s,
1H), 1.67e1.58 (m, 2H), 1.53 (dd, J ¼ 23.3, 11.6 Hz, 2H), 1.38 (s, 1H),
13C NMR (101 MHz, DMSO)
d 163.05 (s), 162.79 (s), 161.76 (s),
155.11 (s), 150.19 (s), 141.14 (s), 140.52 (s), 132.16 (s), 130.25 (s),
129.85 (s), 128.40 (d, J ¼ 8.3 Hz), 127.90 (s), 123.97 (s), 123.62 (s),
122.92 (s), 115.45 (s), 114.29 (s), 111.69 (s), 111.36 (s), 102.81 (s),
72.59 (s), 68.49 (s), 47.82 (s), 33.97 (s), 22.21 (s), 17.03 (s).
1.16 (t, J ¼ 7.1 Hz, 1H). ESI-MS m/z: 469.06 [MþH] þ
.
13C NMR (126 MHz, DMSO)
d 177.06 (s), 163.66 (s),
162.19e161.59 (m), 153.86 (s), 149.27 (s), 142.76 (d, J ¼ 7.2 Hz),
130.72 (d, J ¼ 8.3 Hz), 127.14 (s), 124.56 (s), 120.80 (s), 115.15 (s),
113.92 (s), 113.35 (d, J ¼ 20.9 Hz), 113.26e113.25 (m), 112.96 (s),
101.51 (s), 72.24 (s), 66.88 (s), 61.57 (s), 54.11 (d, J ¼ 12.0 Hz), 42.08
(s), 32.36 (s), 29.06 (s), 26.80 (s), 15.65 (s).
3.4.19. 1-(2-Hydroxy-3-((4-methyl-2-oxo-2H-chromen-7-yl)oxy)
propyl)piperidine-4-carboxamide [19]
The title compound was synthesized according to the procedure
of preparing Compound NO.1.1H NMR (500 MHz, DMSO)
d 7.68 (d,
J ¼ 9.2 Hz, 1H), 7.19 (s, 1H), 6.99 (d, J ¼ 2.4 Hz, 1H), 6.97 (s, 1H), 6.69
(s, 1H), 6.20 (d, J ¼ 1.1 Hz, 1H), 4.08 (t, J ¼ 6.4 Hz, 1H), 4.02e3.93 (m,
2H), 2.92 (d, J ¼ 11.1 Hz, 1H), 2.86 (d, J ¼ 11.1 Hz, 1H), 2.45e2.41 (m,
1H), 2.40 (d, J ¼ 0.9 Hz, 3H), 2.35 (dd, J ¼ 12.7, 5.9 Hz, 1H), 2.06e1.88
3.4.23. 1-(3-((3-(4-chlorobenzyl)-4-methyl-2-oxo-2H-chromen-7-
yl)oxy)-2-hydroxypropyl)piperidine-4-carboxamide (23)
1H NMR (500 MHz, DMSO)
d
7.71 (d, J ¼ 9.6 Hz, 1H), 7.65 (s, 1H),
(m, 3H), 1.68e1.59 (m, 2H), 1.54 (qd, J ¼ 11.8, 3.0 Hz, 2H). ESI-MS m/
7.31 (s, 1H), 7.29 (s, 1H), 7.27e7.25 (m, 1H), 7.24 (s, 1H), 7.22 (s, 1H),
7.20 (s, 1H), 6.99 (s, 1H), 6.97 (s, 1H), 6.95 (d, J ¼ 2.0 Hz, 1H), 6.70 (s,
1H), 6.18 (s, 1H), 4.07 (d, J ¼ 6.6 Hz, 1H), 3.96 (d, J ¼ 7.4 Hz, 2H), 3.91
(s, 2H), 3.15 (s, 1H), 2.91 (dd, J ¼ 22.3, 6.0 Hz, 2H), 2.40 (s, 3H), 2.37
þ
z: 361.24 [MþH]
.
13C NMR (126 MHz, DMSO)
d 177.05 (s), 162.38 (s), 160.63 (s),
155.18 (s), 153.88 (s), 126.90 (s), 113.52 (s), 112.88 (s), 111.55 (s),

14
Y. Gao et al. / European Journal of Medicinal Chemistry 204 (2020) 112595
(s, 1H), 2.05 (d, J ¼ 15.4 Hz, 3H), 1.62 (s, 2H), 1.59e1.48 (m, 2H), 1.21
d
7.76e7.71 (m, 1H), 7.44 (dd, J ¼ 8.7, 2.1 Hz, 1H), 7.20 (s, 1H),
(s, 1H), 0.89e0.79 (m, 1H). ESI-MS m/z: 485.40 [MþH] þ
.
7.07e7.03 (m, 2H), 7.00e6.96 (m, 2H), 6.70 (s, 1H), 4.08 (d,
J ¼ 6.8 Hz, 1H), 3.96 (d, J ¼ 7.7 Hz, 2H), 3.93 (s, 2H), 3.15 (s, 2H), 2.87
(dd, J ¼ 31.6, 11.1 Hz, 2H), 2.43e2.37 (m, 1H), 2.33 (s, 3H), 2.06e1.89
(m, 4H), 1.61 (s, 2H), 1.52 (dt, J ¼ 11.9, 8.9 Hz, 2H). ESI-MS m/z:
13C NMR (126 MHz, DMSO)
d
176.96 (s), 161.73 (d, J ¼ 14.0 Hz),
153.84 (s), 149.13 (s), 138.86 (s), 131.13 (s), 130.39 (s), 128.79 (s),
127.14 (s), 121.05 (s), 113.94 (s), 112.99 (s), 101.53 (s), 72.17 (s), 66.70
(s), 61.40 (s), 53.99 (s), 49.06 (s), 41.86 (s), 31.99 (s), 28.85 (s), 15.66
(s).
503.55[MþH] þ
.
13C NMR (126 MHz, DMSO)
d
177.09 (s), 161.71 (d, J ¼ 62.2 Hz),
159.94 (s), 154.04 (s), 150.36 (s), 133.98 (d, J ¼ 10.4 Hz), 133.00 (s),
130.46 (s), 127.20 (s), 119.37 (s), 116.84 (s), 114.90 (s), 113.87 (s),
113.04 (s), 101.56 (s), 72.27 (s), 66.88 (s), 61.59 (s), 54.14 (d,
J ¼ 17.1 Hz), 49.06 (s), 42.09 (s), 29.91 (s), 29.08 (s), 15.66 (s).
3.4.24. 1-(3-((3-(4-bromobenzyl)-4-methyl-2-oxo-2H-chromen-7-
yl)oxy)-2-hydroxypropyl)piperidine-4-carboxamide (24)
The title compound was synthesized according to the procedure
of preparing Compound NO.1.1H NMR (500 MHz, DMSO)
d 7.71 (d,
J ¼ 9.5 Hz,1H), 7.43 (d, J ¼ 8.1 Hz, 2H), 7.17 (d, J ¼ 7.7 Hz, 3H), 6.96 (d,
J ¼ 6.4 Hz, 2H), 6.68 (s, 1H), 4.07 (d, J ¼ 6.3 Hz, 1H), 3.95 (d,
J ¼ 6.3 Hz, 2H), 3.89 (s, 2H), 2.91 (d, J ¼ 8.8 Hz, 1H), 2.85 (d,
J ¼ 8.1 Hz, 1H), 2.40 (s, 3H), 2.35 (s, 1H), 2.00 (d, J ¼ 11.4 Hz, 2H), 1.61
3.4.28. 1-(3-((3-(2-bromo-4-methoxybenzyl)-4-methyl-2-oxo-2H-
chromen-7-yl)oxy)-2-hydroxypropyl)piperidine-4-carboxamide
(28)
(s, 2H), 1.53 (d, J ¼ 11.8 Hz, 2H), 1.21 (s, 1H). ESI-MS m/z: 530.94
The title compound was synthesized according to the procedure
þ
[MþH]
.
of preparing Compound NO.1.1H NMR (500 MHz, DMSO)
d 7.73 (d,
13C NMR (126 MHz, DMSO)
d
176.77 (s), 161.67 (d, J ¼ 8.0 Hz),
J ¼ 9.5 Hz, 1H), 7.53 (d, J ¼ 8.8 Hz, 1H), 7.19 (s, 1H), 6.99 (s, 1H),
6.98e6.94 (m, 1H), 6.80e6.73 (m, 1H), 6.70 (s, 1H), 6.51e6.47 (m,
1H), 6.43 (d, J ¼ 2.9 Hz, 1H), 4.91 (s, 1H), 4.08 (d, J ¼ 6.6 Hz, 1H), 3.96
(d, J ¼ 6.8 Hz, 2H), 3.89 (s, 2H), 3.68 (s, 1H), 3.61 (s, 3H), 3.15 (d,
J ¼ 4.8 Hz,1H), 2.91 (d, J ¼ 10.8 Hz,1H), 2.85 (d, J ¼ 10.9 Hz,1H), 2.41
(d, J ¼ 10.1 Hz, 2H), 2.34 (d, J ¼ 2.2 Hz, 1H), 2.31 (s, 3H), 2.06e1.91
153.82 (s), 149.13 (s), 139.27 (s), 131.70 (s), 130.77 (s), 127.13 (s),
121.00 (s), 119.55 (s), 113.96 (s), 112.99 (s), 101.53 (s), 72.05 (s), 66.40
(s), 61.08 (s), 53.80 (s), 41.52 (s), 32.05 (s), 29.48 (s), 28.49 (s), 15.65
(s).
3.4.25. 1-(3-((3-(4-fluoro-2-methylbenzyl)-4-methyl-2-oxo-2H-
chromen-7-yl)oxy)-2-hydroxypropyl)piperidine-4-carboxamide
(25)
(m, 4H), 1.61 (s, 2H), 1.53 (t, J ¼ 12.0 Hz, 2H), 1.23 (dd, J ¼ 15.0,
þ
10.3 Hz, 1H), 0.89e0.77 (m, 1H). ESI-MS m/z: 561.38[MþH]
.
13C NMR (126 MHz, DMSO)
d 177.08 (s), 161.95 (s), 161.54 (s),
The title compound was synthesized according to the procedure
159.30 (s), 154.05 (s), 150.40 (s), 139.35 (s), 133.67 (s), 127.20 (s),
119.48 (s), 115.44 (s), 114.72 (s), 113.84 (s), 113.37 (s), 113.02 (s),
101.59 (s), 72.26 (s), 66.87 (s), 61.59 (s), 55.72 (s), 54.13 (d,
J ¼ 14.1 Hz), 42.09 (s), 33.36 (s), 29.06 (s), 15.72 (s).
of preparing Compound NO.1.1H NMR (500 MHz, DMSO)
d 7.75 (d,
J ¼ 9.6 Hz, 1H), 7.22 (s, 1H), 7.16 (dd, J ¼ 15.1, 6.9 Hz, 1H), 7.06 (dd,
J ¼ 10.0, 2.6 Hz, 1H), 6.99 (dd, J ¼ 6.9, 2.4 Hz, 2H), 6.84 (td, J ¼ 8.5,
2.6 Hz, 1H), 6.81e6.77 (m, 1H), 6.73 (s, 1H), 6.54e6.49 (m, 1H), 4.93
(s, 1H), 4.10 (d, J ¼ 6.5 Hz, 1H), 3.97 (dd, J ¼ 12.2, 5.5 Hz, 2H), 3.81 (s,
2H), 2.94 (d, J ¼ 10.7 Hz, 1H), 2.87 (d, J ¼ 10.7 Hz, 1H), 2.45 (d,
J ¼ 5.7 Hz, 1H), 2.42 (d, J ¼ 4.6 Hz, 1H), 2.38 (s, 3H), 2.34 (s, 3H), 2.31
3.4.29. 1-(2-Hydroxy-3-((4-methyl-3-(3-nitrobenzyl)-2-oxo-2H-
chromen-7-yl)oxy)propyl)piperidine-4-carboxamide (29)
The title compound was synthesized according to the procedure
(d, J ¼ 4.8 Hz, 1H), 2.08e1.93 (m, 3H), 1.63 (s, 2H), 1.55 (dd, J ¼ 23.3,
þ
11.6 Hz, 2H), 1.23 (s, 1H). ESI-MS m/z: 483.63[MþH]
.
of preparing Compound NO.1.1H NMR (500 MHz, DMSO)
d 8.06 (dd,
13C NMR (126 MHz, DMSO)
d
176.94 (s), 163.83 (s), 161.37 (s),
J ¼ 18.6, 9.0 Hz, 2H), 7.74 (t, J ¼ 9.9 Hz, 1H), 7.69 (dd, J ¼ 17.5, 8.4 Hz,
1H), 7.60e7.51 (m, 1H), 7.20 (s, 1H), 7.02e6.93 (m, 2H), 6.71 (s, 1H),
4.14e4.02 (m, 3H), 3.97 (s, 2H), 2.91 (d, J ¼ 27.7 Hz, 2H), 2.47 (s, 3H),
2.39 (d, J ¼ 9.4 Hz, 1H), 2.02 (s, 3H), 1.63 (s, 2H), 1.55 (s, 2H), 1.20 (d,
153.89 (s), 146.67 (s), 131.30 (d, J ¼ 6.1 Hz), 127.17 (s), 122.48 (d,
J ¼ 12.5 Hz), 118.64 (s), 113.89 (s), 113.00 (s), 111.85 (s), 111.75 (d,
J ¼ 21.0 Hz), 104.10 (s), 101.53 (s), 72.20 (s), 66.76 (s), 61.45 (s), 54.02
(s), 41.95 (s), 29.47 (s), 28.93 (s), 25.64 (s), 15.53 (s).
J ¼ 9.6 Hz, 1H). ESI-MS m/z: 596.20[MþH] þ
.
13C NMR (126 MHz, DMSO)
d 176.96 (s), 161.90 (s), 161.68 (s),
3.4.26. 1-(3-((3-(2,4-difluorobenzyl)-4-methyl-2-oxo-2H-
chromen-7-yl)oxy)-2-hydroxypropyl)piperidine-4-carboxamide
(26)
153.90 (s), 149.68 (s), 148.30 (s), 142.19 (s), 135.35 (s), 130.37 (s),
127.25 (s), 123.13 (s), 121.69 (s), 120.40 (s), 113.86 (s), 113.05 (s),
101.55 (s), 72.20 (s), 66.74 (s), 61.43 (s), 54.01 (s), 41.92 (s), 32.29 (s),
28.91 (s), 15.72 (s).
The title compound was synthesized according to the procedure
of preparing Compound NO.1.1H NMR (500 MHz, DMSO)
d 7.73 (d,
J ¼ 9.5 Hz, 1H), 7.20 (d, J ¼ 2.5 Hz, 1H), 7.18 (s, 1H), 7.17 (d, J ¼ 1.6 Hz,
1H), 6.98 (d, J ¼ 2.4 Hz,1H), 6.96 (s, 2H), 6.94 (d, J ¼ 2.2 Hz,1H), 6.92
(d, J ¼ 2.1 Hz, 1H), 6.68 (s, 1H), 4.07 (d, J ¼ 6.5 Hz, 1H), 3.96 (d,
J ¼ 6.2 Hz, 2H), 3.89 (s, 2H), 2.89 (d, J ¼ 23.7 Hz, 2H), 2.40 (s, 3H),
2.35 (s, 1H), 2.01 (d, J ¼ 9.4 Hz, 2H), 1.62 (s, 2H), 1.53 (d, J ¼ 11.0 Hz,
3.4.30. 1-(2-Hydroxy-3-((4-methyl-2-oxo-3-(4-(trifluoromethyl)
benzyl)-2H-chromen-7-yl)oxy)propyl)piperidine-4-carboxamide
(30)
The title compound was synthesized according to the procedure
2H), 1.22 (s, 2H). ESI-MS m/z: 487.02[MþH] þ
.
of preparing Compound NO.1.1H NMR (500 MHz, DMSO)
13C NMR (126 MHz, DMSO)
d
176.97 (s), 161.83 (s), 161.37 (s),
d
7.78e7.69 (m, 1H), 7.61 (d, J ¼ 8.2 Hz, 2H), 7.44 (d, J ¼ 8.1 Hz, 2H),
153.89 (s), 149.60 (s), 131.30 (d, J ¼ 6.1 Hz), 127.17 (s), 122.48 (d,
J ¼ 12.5 Hz), 119.65 (s), 113.89 (s), 113.00 (s), 111.85 (s), 111.75 (d,
J ¼ 21.0 Hz), 104.10 (s), 101.53 (s), 72.20 (s), 66.76 (s), 61.45 (s), 54.02
(s), 41.95 (s), 29.47 (s), 28.93 (s), 25.54 (s), 15.51 (s).
7.18 (s, 1H), 6.98 (s, 1H), 6.97 (d, J ¼ 2.4 Hz, 1H), 4.07 (d, J ¼ 6.6 Hz,
1H), 4.03 (s, 2H), 3.99e3.92 (m, 2H), 2.91 (d, J ¼ 11.0 Hz,1H), 2.85 (d,
J ¼ 10.9 Hz, 1H), 2.42 (s, 3H), 2.40e2.37 (m, 1H), 2.37e2.29 (m, 1H),
2.06e1.92 (m, 3H), 1.61 (d, J ¼ 2.4 Hz, 2H), 1.52 (dd, J ¼ 23.6, 11.7 Hz,
þ
2H). ESI-MS m/z: 519.10[MþH]
.
3.4.27. 1-(3-((3-(2-chloro-4-fluorobenzyl)-4-methyl-2-oxo-2H-
chromen-7-yl)oxy)-2-hydroxypropyl)piperidine-4-carboxamide
(27)
13C NMR (126 MHz, DMSO)
d
177.03 (s), 161.90 (s), 161.76 (d,
J ¼ 29.5 Hz), 153.89 (s), 149.47 (s), 144.81 (s), 129.30 (s), 127.44 (s),
127.18 (s), 125.71 (d, J ¼ 3.2 Hz), 123.75 (s), 120.58 (s), 113.87 (s),
113.01 (s), 101.53 (s), 72.26 (s), 66.89 (s), 61.58 (s), 54.13 (d,
J ¼ 13.8 Hz), 42.09 (s), 32.54 (s), 29.07 (s), 15.70 (s).
The title compound was synthesized according to the procedure
of preparing Compound NO.1.1H NMR (500 MHz, DMSO)

Y. Gao et al. / European Journal of Medicinal Chemistry 204 (2020) 112595
15
3.4.31. 1-(2-Hydroxy-3-((4-methyl-2-oxo-3-(2-(trifluoromethyl)
benzyl)-2H-chromen-7-yl)oxy)propyl)piperidine-4-carboxamide
(31)
4.83 (s, 1H), 4.39 (s, 2H), 4.12 (t, J ¼ 6.7 Hz, 1H), 4.02 (dd, J ¼ 11.7,
5.7 Hz, 3H), 2.92 (dd, J ¼ 29.2, 10.2 Hz, 3H), 2.35 (s, 3H), 2.18 (s, 1H),
2.04 (dd, J ¼ 11.5, 4.0 Hz, 4H), 1.65 (s, 2H), 1.59e1.53 (m, 3H). ESI-MS
The title compound was synthesized according to the procedure
m/z: 501.30[MþH] þ
.
of preparing Compound NO.1.1H NMR (500 MHz, DMSO)
d
7.76 (t,
13C NMR (126 MHz, DMSO)
d 177.03 (s), 162.24e161.99 (m),
J ¼ 7.4 Hz, 2H), 7.51 (t, J ¼ 7.5 Hz, 1H), 7.42 (t, J ¼ 7.6 Hz, 1H), 7.21 (s,
1H), 7.09 (d, J ¼ 7.8 Hz, 1H), 7.02 (dd, J ¼ 4.7, 2.4 Hz, 1H), 7.00 (d,
J ¼ 2.5 Hz, 1H), 6.73 (s, 1H), 4.93 (s, 1H), 4.12 (s, 1H), 4.10 (s, 2H),
4.02e3.94 (m, 2H), 3.35 (s, 2H), 2.93 (d, J ¼ 11.0 Hz, 1H), 2.87 (d,
J ¼ 11.1 Hz, 1H), 2.44 (d, J ¼ 6.1 Hz, 1H), 2.42 (d, J ¼ 5.5 Hz, 1H), 2.37
(d, J ¼ 5.8 Hz, 1H), 2.32 (s, 3H), 2.04 (ddd, J ¼ 15.5, 7.6, 3.8 Hz, 1H),
161.79 (d, J ¼ 20.7 Hz), 154.05 (s), 150.25 (s), 134.88 (s), 133.87 (s),
132.05 (s), 129.04 (s), 127.07 (s), 126.67 (s), 126.19 (d, J ¼ 23.1 Hz),
123.87 (d, J ¼ 8.9 Hz), 120.26 (s), 114.04 (s), 113.01 (s), 101.71 (d,
J ¼ 19.2 Hz), 72.27 (s), 66.88 (s), 61.55 (s), 54.08 (s), 42.05 (s), 29.54
(s), 29.03 (s), 15.66 (s).
2.01e1.94 (m, 2H),1.63 (d, J ¼ 2.3 Hz, 2H),1.60e1.49 (m, 2H). ESI-MS
3.4.35. 1-(3-((3-(4-(3,5-dimethylisoxazol-4-yl)benzyl)-4-methyl-2-
oxo-2H-chromen-7-yl)oxy)-2-hydroxypropyl)piperidine-4-
carboxamide (35)
þ
m/z: 519.43[MþH]
.
13C NMR (126 MHz, DMSO)
d
177.05 (s), 161.72 (d, J ¼ 11.7 Hz),
153.81 (s), 148.90 (s), 135.90 (s), 130.28 (d, J ¼ 7.9 Hz), 127.09 (s),
121.37 (s), 115.62 (s), 115.45 (s), 113.93 (s), 112.96 (s), 101.50 (s),
72.23 (s), 66.88 (s), 61.57 (s), 54.11 (d, J ¼ 12.2 Hz), 42.07 (s), 31.81
(s), 29.05 (s), 15.62 (s).
A solution of compound NO.24 (0.227 mmol), phenylboronic
acid or benzene boric acid ester derivatives (2 eq) in diox(4 mL) and
saturated sodium bicarbonate solution (0.7 mL) was replaced the
air with argon for 10 min then Pd(PPh3)4 (0.05 eq) was added and
the reaction mixture was stirred at 95 ꢁC overnight. Then, the
mixture was extracted with ethyl acetate, washed with saline. The
organic phase was collected and the solvent was removed under
vacuum. The product was purified by silica gel chromatography
using DCM-methaonl as eluate to give compound NO. 35. Yield:
3.4.32. 1-(2-Hydroxy-3-((4-methyl-2-oxo-3-(4-(trifluoromethoxy)
benzyl)-2H-chromen-7-yl)oxy)propyl)piperidine-4-carboxamide
(32)
The title compound was synthesized according to the procedure
of preparing Compound NO.1.1H NMR (500 MHz, DMSO)
d
7.72 (d,
72%. 1H NMR (500 MHz, DMSO)
d 7.76e7.67 (m, 2H), 7.43 (d,
J ¼ 9.4 Hz, 1H), 7.33 (d, J ¼ 8.7 Hz, 2H), 7.24 (d, J ¼ 8.1 Hz, 2H), 7.17 (s,
1H), 6.97 (d, J ¼ 2.5 Hz, 1H), 6.95 (s, 1H), 6.67 (s, 1H), 4.06 (t,
J ¼ 6.4 Hz, 1H), 3.97 (s, 1H), 3.95 (s, 2H), 3.94 (s, 1H), 2.90 (d,
J ¼ 11.3 Hz, 1H), 2.84 (d, J ¼ 11.1 Hz, 1H), 2.42 (s, 3H), 2.39 (d,
J ¼ 5.3 Hz, 1H), 2.34 (d, J ¼ 5.8 Hz, 1H), 2.31 (d, J ¼ 5.5 Hz, 1H),
2.06e1.87 (m, 3H), 1.66e1.58 (m, 2H), 1.53 (t, J ¼ 11.7 Hz, 2H). ESI-
MS m/z: 535.2052 [MþH] þ, Delta <0.5 ppm.
J ¼ 8.4 Hz, 2H), 7.29 (dd, J ¼ 20.6, 8.2 Hz, 3H), 7.17 (d, J ¼ 8.2 Hz, 4H),
6.98e6.94 (m, 3H), 4.07 (d, J ¼ 6.4 Hz, 2H), 3.99e3.93 (m, 5H), 3.89
(s, 2H), 2.90 (d, J ¼ 11.1 Hz, 2H), 2.84 (d, J ¼ 11.2 Hz, 2H), 2.40 (s, 4H),
2.35 (s, 3H), 2.31 (d, J ¼ 5.6 Hz, 1H), 2.18 (s, 2H), 1.99 (ddd, J ¼ 28.7,
15.9, 8.2 Hz, 5H), 1.61 (s, 3H), 1.53 (t, J ¼ 11.7 Hz, 3H). ESI-MS m/z:
þ
546.10[MþH]
.
13C NMR (126 MHz, DMSO)
d 177.05 (s), 165.35 (s), 161.81 (s),
13C NMR (126 MHz, DMSO)
d
177.05 (s), 162.11e161.90 (m),
158.57 (s), 153.82 (s), 149.66e149.19 (m), 149.04 (d, J ¼ 20.9 Hz),
139.56e139.33 (m), 139.17 (d, J ¼ 27.9 Hz), 131.69 (s), 130.77 (s),
129.35 (s), 128.97 (s), 128.09 (s), 127.10 (s), 121.26 (s), 121.09 (d,
J ¼ 34.8 Hz), 119.55 (s), 116.12 (s), 113.92 (d, J ¼ 5.8 Hz), 112.97 (s),
101.51 (s), 72.24 (s), 66.90 (s), 61.60 (s), 54.13 (d, J ¼ 13.3 Hz), 42.10
(s), 32.21 (d, J ¼ 39.3 Hz), 32.01e31.59 (m), 29.08 (s), 15.64 (s), 11.77
(s), 10.95 (s).
161.73 (d, J ¼ 22.5 Hz), 153.85 (s), 149.19 (s), 147.13 (s), 139.33 (s),
130.28 (s), 127.15 (s), 121.48 (s), 120.97 (s), 113.90 (s), 112.98 (s),
101.51 (s), 72.24 (s), 66.89 (s), 61.58 (s), 54.12 (d, J ¼ 13.3 Hz), 42.09
(s), 40.48 (t, J ¼ 10.5 Hz), 31.99 (s), 29.07 (s), 15.66 (s).
3.4.33. Methyl-4-((7-(3-(4-carbamoylpiperidin-1-yl)-2-
hydroxypropoxy)-4-methyl-2-oxo-2H-chromen-3-yl)methyl)
benzoate (33)
3.4.36. 1-(3-((3-([1,10-biphenyl]-4-ylmethyl)-4-methyl-2-oxo-2H-
chromen-7-yl)oxy)-2-hydroxypropyl)piperidine-4-carboxamide
(36)
The title compound was synthesized according to the procedure
of preparing Compound NO.1.1H NMR (400 MHz, DMSO)
d 7.87 (d,
J ¼ 8.2 Hz, 2H), 7.74 (d, J ¼ 9.6 Hz,1H), 7.68 (d, J ¼ 9.2 Hz,1H), 7.37 (d,
J ¼ 8.2 Hz, 2H), 7.17 (s, 1H), 7.01e6.96 (m, 2H), 4.10 (d, J ¼ 6.7 Hz,
1H), 4.03 (s, 2H), 4.00e3.93 (m, 2H), 3.83 (s, 3H), 2.89 (dd, J ¼ 22.7,
11.2 Hz, 2H), 2.43 (s, 3H), 2.40 (s, 1H), 2.37 (d, J ¼ 5.8 Hz, 1H), 2.33 (s,
The title compound was synthesized according to the procedure
of preparing Compound NO.35.1H NMR (500 MHz, DMSO)
d
7.74e7.70 (m, 1H), 7.59 (d, J ¼ 7.3 Hz, 2H), 7.55 (d, J ¼ 8.2 Hz, 2H),
7.42 (t, J ¼ 7.7 Hz, 2H), 7.31 (dd, J ¼ 12.0, 7.8 Hz, 3H), 7.17 (s, 1H), 6.97
(dd, J ¼ 4.6, 2.3 Hz, 2H), 4.07 (t, J ¼ 6.2 Hz, 1H), 3.97 (s, 2H), 3.96 (d,
J ¼ 6.9 Hz, 2H), 2.88 (dd, J ¼ 29.8, 10.3 Hz, 2H), 2.45 (s, 3H), 2.41 (s,
1H), 2.35 (s, 1H), 2.06e1.92 (m, 3H), 1.61 (s, 2H), 1.54 (t, J ¼ 12.0 Hz,
1H), 2.07e1.95 (m, 3H), 1.64 (d, J ¼ 12.9 Hz, 2H), 1.59e1.48 (m, 2H).
þ
ESI-MS m/z: 509.30[MþH]
.
13C NMR (126 MHz, DMSO)
d 177.06 (s), 162.38 (s), 160.62 (s),
155.18 (s), 153.87 (s), 126.90 (s), 113.52 (s), 112.88 (s), 111.55 (s),
101.76 (s), 72.26 (s), 66.89 (s), 61.58 (s), 54.12 (d, J ¼ 14.5 Hz), 42.10
(s), 29.07 (s), 18.59 (s).
2H). ESI-MS m/z: 527.37[MþH] þ
.
13C NMR (126 MHz, DMSO)
d 177.02 (s), 161.74 (s), 153.82 (s),
148.89 (s), 140.43 (s), 139.08 (s), 138.51 (s), 129.37 (s), 129.21 (d,
J ¼ 33.1 Hz), 127.68 (s), 127.42e126.77 (m), 121.38 (s), 113.98 (s),
112.96 (s), 101.52 (s), 72.22 (s), 66.84 (s), 61.53 (s), 54.08 (d,
J ¼ 8.7 Hz), 42.03 (s), 32.27 (s), 29.01 (s), 15.70 (s).
3.4.34. 1-(2-Hydroxy-3-((4-methyl-3-(naphthalen-1-ylmethyl)-2-
oxo-2H-chromen-7-yl)oxy)propyl)piperidine-4-carboxamide (34)
The title compound was synthesized according to the procedure
of preparing Compound NO.1.1H NMR (500 MHz, DMSO)
d
8.27 (d,
3.4.37. 1-(3-((3-((40-fluoro-[1,10-biphenyl]-4-yl)methyl)-4-methyl-
2-oxo-2H-chromen-7-yl)oxy)-2-hydroxypropyl)piperidine-4-
carboxamide (37)
J ¼ 8.4 Hz, 1H), 8.23 (d, J ¼ 4.9 Hz, 1H), 8.21 (s, 1H), 7.95 (t, J ¼ 7.3 Hz,
1H), 7.93e7.92 (m, 1H), 7.82e7.77 (m, 2H), 7.76 (s, 1H), 7.70e7.67
(m, 1H), 7.65e7.61 (m, 1H), 7.61e7.59 (m, 1H), 7.59 (t, J ¼ 2.2 Hz,1H),
7.58e7.56 (m, 1H), 7.55e7.53 (m, 1H), 7.52 (s, 1H), 7.44e7.39 (m,
1H), 7.38e7.34 (m, 1H), 7.32 (d, J ¼ 7.9 Hz, 1H), 7.21 (s, 2H), 7.16 (d,
J ¼ 8.2 Hz, 1H), 7.03 (dd, J ¼ 5.9, 2.4 Hz, 1H), 7.01 (d, J ¼ 2.3 Hz, 1H),
6.99 (d, J ¼ 3.7 Hz, 1H), 6.98 (d, J ¼ 2.2 Hz, 1H), 6.96 (s, 1H), 6.71 (s,
1H), 6.55e6.49 (m, 1H), 5.54 (dd, J ¼ 10.9, 5.0 Hz, 1H), 4.93 (s, 1H),
The title compound was synthesized according to the procedure
of preparing Compound NO.35.1H NMR (500 MHz, DMSO)
d
7.74e7.70 (m, 1H), 7.66e7.61 (m, 2H), 7.52 (d, J ¼ 8.2 Hz, 2H), 7.29
(d, J ¼ 8.2 Hz, 2H), 7.24 (t, J ¼ 8.9 Hz, 2H), 7.17 (s,1H), 6.97 (td, J ¼ 4.8,
2.5 Hz, 2H), 4.07 (q, J ¼ 6.0 Hz, 1H), 3.96 (d, J ¼ 7.9 Hz, 4H), 2.88 (dd,
J ¼ 29.8, 10.1 Hz, 2H), 2.44 (s, 3H), 2.39 (d, J ¼ 14.0 Hz, 1H), 2.35 (s,

16
Y. Gao et al. / European Journal of Medicinal Chemistry 204 (2020) 112595
1H), 2.01 (dd, J ¼ 13.5, 9.9 Hz, 3H), 1.61 (s, 2H), 1.53 (dd, J ¼ 24.0,
3.4.41. 1-(2-Hydroxy-3-((4-methyl-2-oxo-3-((4’-(trifluoromethyl)-
[1,10-biphenyl]-4-yl)methyl)-2H-chromen-7-yl)oxy)propyl)
piperidine-4-carboxamide (41)
12.0 Hz, 2H). ESI-MS m/z: 545.10[MþH] þ
.
13C NMR (126 MHz, DMSO)
d 177.02 (s), 163.16 (s), 161.74 (s),
161.22 (s), 153.82 (s), 148.90 (s), 139.07 (s), 137.47 (s), 136.91 (s),
129.10 (s), 128.90 (d, J ¼ 8.0 Hz), 127.17 (s), 121.35 (s), 116.23 (s),
116.11 (d, J ¼ 21.3 Hz), 113.97 (s), 112.96 (s), 101.52 (s), 72.21 (s),
66.83 (s), 61.53 (s), 54.08 (d, J ¼ 9.0 Hz), 42.02 (s), 32.25 (s), 29.00
(s), 15.69 (s).
The title compound was synthesized according to the procedure
of preparing Compound NO.35.1H NMR (500 MHz, DMSO)
d 7.83 (d,
J ¼ 8.3 Hz, 2H), 7.77 (d, J ¼ 8.4 Hz, 2H), 7.74e7.70 (m, 1H), 7.63 (d,
J ¼ 8.2 Hz, 2H), 7.35 (d, J ¼ 8.2 Hz, 2H), 7.18 (s, 1H), 6.97 (dd, J ¼ 4.6,
2.3 Hz, 2H), 4.07 (d, J ¼ 6.3 Hz, 1H), 3.99 (s, 2H), 3.96 (d, J ¼ 6.4 Hz,
2H), 2.89 (d, J ¼ 20.6 Hz, 2H), 2.45 (s, 3H), 2.35 (d, J ¼ 1.8 Hz, 1H),
2.09e1.85 (m, 3H), 1.62 (s, 2H), 1.53 (d, J ¼ 12.0 Hz, 2H). ESI-MS m/z:
3.4.38. 1-(3-((3-((40-chloro-[1,10-biphenyl]-4-yl)methyl)-4-methyl-
2-oxo-2H-chromen-7-yl)oxy)-2-hydroxypropyl)piperidine-4-
carboxamide (38)
þ
557.10[MþH]
.
13C NMR (126 MHz, DMSO)
d 176.99 (s), 161.75 (s), 153.83 (s),
149.03 (s), 144.41 (s), 140.29 (s), 136.89 (s), 129.27 (s), 127.65 (d,
J ¼ 16.7 Hz), 127.12 (s), 126.21 (s), 121.22 (s), 113.97 (s), 112.98 (s),
101.53 (s), 72.18 (s), 66.76 (s), 61.44 (s), 54.02 (s), 32.32 (s), 28.91 (s),
15.72 (s).
The title compound was synthesized according to the procedure
of preparing Compound NO.35.1H NMR (500 MHz, DMSO)
d
7.76e7.70 (m, 1H), 7.64 (d, J ¼ 8.6 Hz, 2H), 7.57 (d, J ¼ 8.2 Hz, 2H),
7.48 (d, J ¼ 8.6 Hz, 2H), 7.32 (d, J ¼ 8.2 Hz, 2H), 7.20 (s, 1H), 6.98 (dd,
J ¼ 5.8, 2.4 Hz, 2H), 6.70 (s, 1H), 4.09 (d, J ¼ 6.4 Hz, 1H), 3.98 (s, 3H),
3.97 (s, 1H), 2.93 (d, J ¼ 11.2 Hz, 1H), 2.87 (d, J ¼ 11.1 Hz, 1H), 2.46 (s,
3H), 2.43 (d, J ¼ 5.0 Hz, 1H), 2.37 (d, J ¼ 5.6 Hz, 1H), 2.35 (d,
3.4.42. 1-(3-((3-((30-fluoro-40-formyl-[1,10-biphenyl]-4-yl)methyl)-
4-methyl-2-oxo-2H-chromen-7-yl)oxy)-2-hydroxypropyl)
piperidine-4-carboxamide (42)
J ¼ 5.6 Hz, 1H), 2.09e1.94 (m, 3H), 1.64 (d, J ¼ 12.8 Hz, 2H), 1.55 (td,
The title compound was synthesized according to the procedure
þ
of preparing Compound NO.35.1H NMR (500 MHz, DMSO)
d 10.23
J ¼ 12.0, 2.9 Hz, 2H), 1.23 (s, 1H). ESI-MS m/z: 561.10[MþH]
.
13C NMR (126 MHz, DMSO)
d
177.02 (s), 161.74 (d, J ¼ 4.6 Hz),
(s, 1H), 7.89 (t, J ¼ 7.9 Hz, 1H), 7.75 (s, 1H), 7.72 (d, J ¼ 8.6 Hz, 2H),
7.69 (d, J ¼ 6.7 Hz, 2H), 7.37 (d, J ¼ 8.2 Hz, 2H), 7.21 (s,1H), 7.01e6.95
(m, 2H), 6.71 (s, 1H), 4.12e4.06 (m, 1H), 4.01 (s, 2H), 3.98 (d,
J ¼ 6.3 Hz, 2H), 2.96 (d, J ¼ 10.7 Hz,1H), 2.90 (d, J ¼ 10.7 Hz,1H), 2.46
(s, 3H), 2.42 (d, J ¼ 8.2 Hz, 1H), 2.11e2.00 (m, 3H), 1.91 (s, 1H), 1.64
(s, 2H), 1.61e1.51 (m, 2H), 1.34 (s, 1H), 1.23 (s, 1H), 0.85 (t, J ¼ 6.7 Hz,
153.82 (s), 148.94 (s), 139.53 (s), 139.22 (s), 137.13 (s), 132.55 (s),
129.23 (d, J ¼ 15.4 Hz), 128.70 (s), 127.13 (d, J ¼ 9.5 Hz), 121.29 (s),
113.96 (s), 112.96 (s), 101.52 (s), 72.22 (s), 66.84 (s), 61.54 (s), 54.09
(d, J ¼ 9.9 Hz), 42.04 (s), 32.28 (s), 29.02 (s), 15.70 (s).
1H), 0.07 (s, 1H), 0.03 to ꢀ0.14 (m, 1H). ESI-MS m/z: 573.10[MþH] þ
.
3.4.39. 1-(2-Hydroxy-3-((3-((20-methoxy-[1,10-biphenyl]-4-yl)
methyl)-4-methyl-2-oxo-2H-chromen-7-yl)oxy)propyl)piperidine-
4-carboxamide (39)
13C NMR (126 MHz, DMSO)
d 187.89 (s), 176.95 (s), 165.25 (s),
163.21 (s), 161.72 (s), 153.83 (s), 149.10 (s), 141.24 (s), 135.77 (s),
130.41 (s), 129.33 (s), 127.75 (s), 127.13 (s), 123.37 (s), 122.75 (s),
121.12 (s), 114.68 (d, J ¼ 21.4 Hz), 114.59e114.40 (m), 113.96 (s),
112.99 (s),101.53 (s), 72.17 (s), 66.71 (s), 61.39 (s), 53.99 (s), 41.86 (s),
32.37 (s), 28.85 (s), 15.72 (s).
The title compound was synthesized according to the procedure
of preparing Compound NO.35.1H NMR (500 MHz, DMSO)
d
7.76e7.69 (m, 1H), 7.35 (d, J ¼ 8.2 Hz, 2H), 7.31 (d, J ¼ 1.7 Hz, 1H),
7.29 (s, 1H), 7.28 (d, J ¼ 1.7 Hz, 1H), 7.25e7.20 (m, 3H), 7.17 (s, 1H),
7.06 (d, J ¼ 8.1 Hz, 1H), 6.99 (s, 1H), 6.98 (d, J ¼ 2.1 Hz, 1H), 6.97 (d,
J ¼ 2.3 Hz, 2H), 4.07 (t, J ¼ 6.3 Hz,1H), 3.96 (t, J ¼ 6.3 Hz, 4H), 3.72 (s,
3H), 2.91 (d, J ¼ 11.2 Hz, 1H), 2.85 (d, J ¼ 10.9 Hz, 1H), 2.46 (s, 3H),
3.4.43. 1-(3-((3-((40-cyano-30-fluoro-[1,10-biphenyl]-4-yl)methyl)-
4-methyl-2-oxo-2H-chromen-7-yl)oxy)-2-hydroxypropyl)
piperidine-4-carboxamide (43)
2.40 (s, 1H), 2.34 (s, 1H), 1.99 (ddd, J ¼ 22.5, 15.5, 8.5 Hz, 3H), 1.61 (s,
þ
The title compound was synthesized according to the procedure
2H), 1.53 (dd, J ¼ 23.7, 11.8 Hz, 2H). ESI-MS m/z: 557.10[MþH]
.
of preparing Compound NO.35.1H NMR (500 MHz, DMSO)
13C NMR (126 MHz, DMSO)
d 177.04 (s), 161.73 (s), 156.53 (s),
d
8.00e7.94 (m,1H), 7.84 (dd, J ¼ 11.1,1.3 Hz,1H), 7.75 (s,1H), 7.73 (s,
153.81 (s), 148.82 (s), 138.30 (s), 136.43 (s), 130.71 (s), 129.76 (s),
129.15 (s), 128.12 (s), 127.10 (s), 121.18 (s), 112.11 (s), 101.52 (s), 72.23
(s), 66.87 (s), 61.57 (s), 55.85 (s), 54.11 (d, J ¼ 10.3 Hz), 42.07 (s),
32.35 (s), 29.05 (s), 15.73 (s).
1H), 7.72e7.69 (m, 2H), 7.37 (d, J ¼ 8.3 Hz, 2H), 7.21 (s, 1H),
7.01e6.95 (m, 2H), 6.72 (s, 1H), 4.09 (d, J ¼ 6.6 Hz, 1H), 4.01 (s, 2H),
4.00e3.92 (m, 2H), 2.96 (s, 1H), 2.90 (s, 1H), 2.46 (s, 3H), 2.42 (d,
J ¼ 3.1 Hz, 1H), 2.39 (d, J ¼ 19.7 Hz, 1H), 2.06 (s, 3H), 1.91 (s, 1H), 1.65
(s, 2H), 1.57 (d, J ¼ 11.5 Hz, 2H), 1.22 (s, 1H). ESI-MS m/z: 570.10
þ
3.4.40. 1-(3-((3-((20-cyano-[1,10-biphenyl]-4-yl)methyl)-4-methyl-
2-oxo-2H-chromen-7-yl)oxy)-2-hydroxypropyl)piperidine-4-
carboxamide (40)
[MþH]
.
13C NMR (126 MHz, DMSO)
d 176.93 (s), 164.40 (s), 162.37 (s),
161.73 (d, J ¼ 6.4 Hz), 153.83 (s), 149.11 (s), 148.03 (s), 141.45 (s),
135.33 (s), 134.70 (s), 129.35 (s), 127.81 (s), 127.13 (s), 123.82 (s),
121.08 (s), 114.64 (s), 113.96 (s), 112.99 (s), 101.53 (s), 98.82 (d,
J ¼ 15.3 Hz), 72.15 (s), 66.66 (s), 61.38 (s), 53.97 (s), 41.82 (s), 32.37
(s), 28.81 (s), 15.72 (s).
The title compound was synthesized according to the procedure
of preparing Compound NO.35.1H NMR (500 MHz, DMSO)
d 7.91 (d,
J ¼ 7.7 Hz, 1H), 7.77 (d, J ¼ 1.2 Hz, 1H), 7.76e7.72 (m, 2H), 7.59e7.52
(m, 3H), 7.48 (d, J ¼ 8.2 Hz, 2H), 7.37 (d, J ¼ 8.2 Hz, 2H), 7.17 (s, 1H),
6.98 (dd, J ¼ 5.7, 2.4 Hz, 2H), 6.68 (s, 1H), 4.87 (s, 1H), 4.08 (d,
J ¼ 6.6 Hz, 1H), 4.02 (s, 2H), 3.96 (d, J ¼ 7.0 Hz, 2H), 2.91 (d,
J ¼ 11.0 Hz, 1H), 2.85 (d, J ¼ 10.4 Hz, 1H), 2.47 (s, 3H), 2.39 (d,
J ¼ 6.2 Hz, 1H), 2.34 (d, J ¼ 1.7 Hz, 1H), 2.03e1.93 (m, 4H), 1.61 (s,
3.4.44. (R)-1-(2-hydroxy-3-((4-methyl-2-oxo-3-(4-
(trifluoromethoxy)benzyl)-2H-chromen-7-yl)oxy)propyl)
piperidine-4-carboxamide (44)
Step 1: A mixture of ethyl acetoacetate (1.3 mL, 10 mmol) and
CH3ONa (540 mg, 10 mmol, 1 eq) in MeOH (6 mL) was stirred at
room temperature for 10 min. Then, 4-(Trifluoromethoxy) benzyl
bromide (2805 mg, 11 mmol, 1.1 eq) in 5 mL MeOH was added
dropwise when the reaction solution was slightly boiling. The re-
action mixture was continued to heat under reflux condition until it
was almost neutral. After cooling, the reaction solution was filtered
2H), 1.53 (d, J ¼ 11.9 Hz, 2H). ESI-MS m/z: 552.26[MþH] þ
.
13C NMR (126 MHz, DMSO)
d
177.04 (s), 161.75 (d, J ¼ 10.3 Hz),
153.86 (s), 149.12 (s), 144.78 (s), 140.53 (s), 136.10 (s), 134.31 (s),
133.98 (s), 130.51 (s), 129.24 (s), 128.86 (s), 128.51 (s), 127.15 (s),
121.09 (s), 119.09 (s), 113.96 (s), 112.98 (s), 110.48 (s), 101.53 (s),
72.25 (s), 66.87 (s), 61.58 (s), 54.11 (d, J ¼ 11.0 Hz), 42.08 (s), 32.41
(s), 29.05 (s), 15.76 (s).

Y. Gao et al. / European Journal of Medicinal Chemistry 204 (2020) 112595
17
off and concentrated by vacuum to give ethyl acetoacetate de-
rivatives which was used in subsequent steps without further
purification.
(2 eq), and PPh3(1.2 eq) was stirred in dry THF (4 mL) and
DMF(0.5 mL) at 0 ꢁC under a nitrogen atmosphere. To this mixture
was added dropwise DIAD (1.2 eq) over a period of 5 min, and the
reaction was monitored by TLC. After 4.5 h, the solvent was evap-
orated under reduced pressure and the resulting oil purified by
flash column chromatography, eluting with 0e12% methanol in
dichloromethane to give compound NO.46.Yield: 68%.1H NMR
Step 2: To a stirred solution of the above mentioned products in
PPA 5 g, resorcino (1102 mg, 10 mmol,1 eq) was added. The reaction
mixture was stirred at 65 ꢁC for 4 h. The mixture solution had to
rest overnight, then diluted with 300 mL water. The precipitated
solid was filtered off, washed with water to give the crude product.
The crude product was purified by silica gel chromatography using
16% ethyl acetate-cyclohexane as eluate to give the intermediate as
a white solid 7-hydroxy-4-methyl-3-(4-(trifluoromethoxy)benzyl)-
2H-chromen-2-one (1.4 g, 45%).
Step 3: A mixture of the above products (700 mg, 2 mmol), (R)-
(-)-Epichlorohydrin (2 mL), potassium carbonate (553 mg, 4 mmol,
2 eq) and TBAB (645 mg, 2 mmol,1 eq) was stirred at 80 ꢁC for 2.3 h.
Then the mixture was extracted with ethyl acetate, washed with
water. The organic phase was collected and the solvent was
removed under vacuum. The product was purified by silica gel
chromatography using 14% ethyl acetate-cyclohexane as eluate to
give the intermediate as a white solid (R)-3-benzyl-4-methyl-7-
(oxiran-2-ylmethoxy)-2H-chromen-2-one (410 mg, 51%).
(500 MHz, DMSO)
d
7.71 (d, J ¼ 8.9 Hz, 1H), 7.62 (d, J ¼ 1.2 Hz, 2H),
7.61 (d, J ¼ 1.2 Hz, 4H), 7.60 (s, 3H), 7.58 (s, 2H), 7.55 (d, J ¼ 3.1 Hz,
3H), 7.54 (d, J ¼ 2.9 Hz, 3H), 7.52 (s, 1H), 4.25 (ddd, J ¼ 18.5, 12.2,
5.6 Hz, 3H), 3.93 (s, 2H), 2.87 (s, 3H), 2.71 (s, 3H), 2.41 (s, 3H),1.16 (d,
J ¼ 6.2 Hz, 11H). ESI-MS m/z: 545.00[MþH] þ
.
13C NMR (101 MHz, DMSO)
d 178.40 (s), 164.14 (s), 163.06 (s),
158.00 (s), 150.17 (s), 141.14 (s), 135.08 (s), 133.97 (d, J ¼ 18.1 Hz),
133.32 (d, J ¼ 9.7 Hz), 130.59 (d, J ¼ 11.8 Hz), 130.25 (s), 129.85 (s),
128.47 (s), 127.90 (s), 126.63 (s), 122.95 (s), 117.15 (s), 114.42 (s),
103.00 (s), 69.66 (s), 63.53 (s), 37.61 (s), 33.98 (s), 32.61 (s), 31.08 (s),
23.75 (s), 17.03 (s).
3.4.47. 1-(3-((3-benzyl-4-methyl-2-oxo-2H-chromen-7-yl)oxy)-2-
(4-fluorophenoxy)propyl)piperidine-4-carboxamide (47)
Step 4: The above mentioned products(390 mg, 0.96 mmol) was
added to a stirred solution of Hexahydroisonicotinamide (246 mg,
2 mmol, 2 eq) in 2 mL dimentylacetamide then the reaction
mixture was stirred at 50 ꢁC for 24 h. The reaction solution was
allowed to cool to room temperature and concentrated by vacuum.
The residue was dissolved in acetone, absorbed onto silica and
purified by flash column chromategraphy using 4% methanol-
dichloromethane as eluate to give white compound NO.44
The title compound was synthesized according to the procedure
of preparing Compound NO.46.1H NMR (500 MHz, DMSO)
d 7.70 (d,
J ¼ 8.9 Hz, 1H), 7.25 (t, J ¼ 7.5 Hz, 2H), 7.20 (d, J ¼ 7.1 Hz, 2H), 7.16 (t,
J ¼ 7.1 Hz, 2H), 7.08 (t, J ¼ 8.8 Hz, 1H), 7.01 (d, J ¼ 2.4 Hz, 1H),
6.99e6.93 (m, 2H), 6.66 (s, 1H), 4.26 (dd, J ¼ 18.9, 5.9 Hz, 1H), 4.13
(dd, J ¼ 19.2, 5.7 Hz, 1H), 4.01 (dd, J ¼ 14.2, 7.1 Hz, 1H), 3.93 (s, 2H),
2.40 (s, 3H), 1.97 (s, 1H), 1.38 (s, 4H), 1.18e1.12 (m, 5H). ESI-MS m/z:
þ
545.33[MþH]
.
(467 mg, 85%).1H NMR (500 MHz, DMSO)
d
7.71 (d, J ¼ 9.5 Hz, 1H),
13C NMR (101 MHz, DMSO)
d 178.39 (s), 163.05 (s), 162.69 (s),
7.33 (d, J ¼ 8.7 Hz, 2H), 7.25 (s, 1H), 7.17 (s, 1H), 6.99e6.92 (m, 2H),
6.68 (s, 1H), 4.87 (s, 1H), 4.07 (d, J ¼ 6.6 Hz, 1H), 3.96 (d, J ¼ 8.3 Hz,
4H), 2.90 (d, J ¼ 11.1 Hz, 1H), 2.84 (d, J ¼ 11.2 Hz, 1H), 2.42 (s, 3H),
2.39 (d, J ¼ 5.4 Hz, 1H), 2.34 (d, J ¼ 5.8 Hz, 1H), 2.32 (d, J ¼ 5.6 Hz,
1H), 2.23 (t, J ¼ 6.7 Hz, 1H), 2.05e1.92 (m, 3H), 1.77e1.71 (m, 1H),
156.57 (s), 155.18 (s), 150.16 (s), 141.14 (s), 130.25 (s), 129.85 (s),
128.17 (d, J ¼ 55.6 Hz), 127.85e127.17 (m), 122.94 (s), 117.75 (s),
117.52 (s), 114.99 (d, J ¼ 105.3 Hz), 102.98 (s), 68.30 (s), 63.58 (s),
61.59 (s), 51.48 (s), 43.82 (s), 33.97 (s), 31.07 (s), 28.18 (s), 23.63 (s),
17.03 (s).
1.62 (dd, J ¼ 6.9, 3.8 Hz, 2H), 1.52 (dd, J ¼ 23.3, 11.6 Hz, 2H). ESI-MS
þ
m/z: 535.20[MþH]
.
3.4.48. 1-(3-((3-benzyl-4-methyl-2-oxo-2H-chromen-7-yl)oxy)-2-
(4-methoxyphenoxy)propyl)piperidine-4-carboxamide (48)
The title compound was synthesized according to the procedure
13C NMR (126 MHz, DMSO)
d 177.04 (s), 161.84 (s), 161.65 (s),
153.87 (s), 149.19 (s), 147.14 (s), 139.35 (s), 130.29 (s), 127.16 (s),
121.49 (s),120.98 (s),113.91 (s),112.99 (s),101.52 (s), 72.26 (s), 66.90
(s), 61.59 (s), 54.13 (d, J ¼ 13.4 Hz), 42.10 (s), 41.79 (s), 32.00 (s),
29.08 (s), 26.91 (s), 15.67 (s).
of preparing Compound NO.46.1H NMR (500 MHz, MeOD)
d 8.52 (d,
J ¼ 8.8 Hz, 1H), 8.05 (d, J ¼ 7.3 Hz, 2H), 8.01 (d, J ¼ 7.2 Hz, 3H), 7.97
(d, J ¼ 7.3 Hz, 2H), 7.82 (d, J ¼ 2.3 Hz, 1H), 7.80e7.73 (m, 2H), 7.69 (d,
J ¼ 9.1 Hz, 2H), 7.64 (s, 2H), 5.10 (d, J ¼ 10.0 Hz, 1H), 4.92 (d,
J ¼ 5.5 Hz, 1H), 4.82 (dd, J ¼ 14.3, 7.2 Hz, 2H), 4.74 (s, 2H), 4.48 (s,
3H), 3.22 (s, 4H), 2.78 (s, 2H), 2.70 (s, 1H), 2.45 (d, J ¼ 11.8 Hz, 2H),
3.4.45. (S)-1-(2-hydroxy-3-((4-methyl-2-oxo-3-(4-
(trifluoromethoxy)benzyl)-2H-chromen-7-yl)oxy)propyl)
piperidine-4-carboxamide (45)
The title compound was synthesized according to the procedure
of preparing Compound NO.44 except using the (S)-(þ)-Epichlo-
rohydrin to replace the (R)-(-)-Epichlorohydrin.1H NMR (500 MHz,
2.29 (d, J ¼ 10.9 Hz, 2H), 1.97 (t, J ¼ 7.1 Hz, 5H). ESI-MS m/z: 557.17
þ
[MþH]
.
13C NMR (101 MHz, DMSO)
d 178.40 (s), 163.06 (s), 155.18 (s),
154.23 (s), 150.18 (s), 141.15 (s), 130.25 (s), 129.85 (s), 128.45 (s),
127.90 (s), 122.92 (s), 117.40 (s), 116.42 (s), 114.98 (d, J ¼ 104.0 Hz),
114.38e114.16 (m),102.98 (s), 63.65 (s), 57.18 (s), 51.38 (s), 43.83 (s),
33.97 (s), 31.07 (s), 23.67 (s), 17.03 (s).
DMSO)
d
7.71 (d, J ¼ 9.5 Hz, 1H), 7.33 (d, J ¼ 8.6 Hz, 2H), 7.24 (d,
J ¼ 8.3 Hz, 2H), 7.17 (s, 1H), 7.02e6.91 (m, 2H), 6.68 (s, 1H), 4.87 (s,
1H), 4.06 (t, J ¼ 6.4 Hz,1H), 3.95 (s, 4H), 2.90 (d, J ¼ 11.1 Hz,1H), 2.84
(d, J ¼ 11.1 Hz, 1H), 2.42 (s, 3H), 2.39 (d, J ¼ 5.3 Hz, 1H), 2.34 (d,
J ¼ 5.7 Hz, 1H), 2.32 (d, J ¼ 5.6 Hz, 1H), 2.23 (t, J ¼ 6.7 Hz, 1H),
2.05e1.92 (m, 3H), 1.74 (dt, J ¼ 12.6, 6.2 Hz, 1H), 1.66e1.58 (m, 2H),
3.4.49. 1-(3-((3-benzyl-4-methyl-2-oxo-2H-chromen-7-yl)oxy)-2-
(4-nitrophenoxy)propyl)piperidine-4-carboxamide (49)
1.52 (dd, J ¼ 23.3, 11.6 Hz, 2H). ESI-MS m/z: 535.20[MþH] þ
.
The title compound was synthesized according to the procedure
13C NMR (126 MHz, DMSO)
d
177.04 (s), 161.84 (s), 161.65 (s),
of preparing Compound NO.46.1H NMR (500 MHz, DMSO)
d 8.18
153.87 (s), 149.19 (s), 147.14 (s), 139.35 (s), 130.30 (s), 127.16 (s),
121.49 (s),120.98 (s),113.92 (s),112.99 (s),101.53 (s), 72.26 (s), 66.89
(s), 61.59 (s), 54.13 (d, J ¼ 13.3 Hz), 42.10 (s), 41.79 (s), 32.00 (s),
29.08 (s), 15.67 (s).
(dd, J ¼ 9.2, 4.8 Hz, 2H), 7.70 (d, J ¼ 8.9 Hz, 1H), 7.24 (d, J ¼ 7.3 Hz,
3H), 7.20 (s, 1H), 7.18 (s, 2H), 7.16 (d, J ¼ 4.7 Hz, 2H), 7.02 (s, 1H), 6.97
(dd, J ¼ 8.9, 2.5 Hz, 1H), 6.67 (s, 1H), 4.31 (ddd, J ¼ 23.7, 14.3, 4.9 Hz,
4H), 4.01 (dd, J ¼ 14.2, 7.1 Hz, 1H), 3.92 (s, 2H), 2.97 (d, J ¼ 11.0 Hz,
2H), 2.40 (s, 3H), 2.37 (s, 1H), 2.02 (d, J ¼ 11.9 Hz, 1H), 1.97 (s, 1H),
3.4.46. 1-(3-((3-benzyl-4-methyl-2-oxo-2H-chromen-7-yl)oxy)-2-
(2-fluorophenoxy)propyl)piperidine-4-carboxamide (46)
1.89 (s, 1H), 1.64 (d, J ¼ 11.0 Hz, 3H), 1.48 (d, J ¼ 11.6 Hz, 2H), 1.38 (s,
þ
1H), 1.16 (t, J ¼ 7.1 Hz, 1H). ESI-MS m/z: 572.27[MþH]
.
A solution of compound NO.1 (0.267 mmol), phenol derivative
13C NMR (101 MHz, DMSO)
d 178.36 (s), 165.55 (s), 163.04 (s),

18
Y. Gao et al. / European Journal of Medicinal Chemistry 204 (2020) 112595
162.61 (s), 155.16 (s), 150.15 (s), 142.73 (s), 141.13 (s), 130.25 (s),
129.85 (s), 128.44 (s), 127.79 (d, J ¼ 20.8 Hz), 122.96 (s), 117.90 (s),
117.02 (s), 115.54 (s), 114.47 (s), 111.36 (s), 103.01 (s), 68.67 (s), 68.28
(s), 63.37 (s), 51.38 (d, J ¼ 20.8 Hz), 51.11e50.90 (m), 43.78 (s), 33.97
(s), 31.35e31.15 (m), 30.74 (d, J ¼ 63.4 Hz), 28.17 (s), 19.96 (s), 17.03
(s).
purified by column chromatography using ethyl acetate-hexane.
Reaction time: 24 h, Yield: 11.5%.
To a solution of 3-benzyl-7-hydroxy-4-methyl-2H-chromen-2-
one (0.338 mmol) in DMF (2 mL) was added TBAI (2.2 eq) and
CsCO3 (2 eq). To the resulting solution, the above-mentioned
products (2 eq) was added dropwise. The mixture was stirred for
31 h at 100 ꢁC, followed by addition of 2 mL water. The mixture was
extracted with 2 ꢂ 10 mL ethyl acetate, and the organic phase was
dried over anhydrous Na2SO4 and concentrated. The residue was
purified by column chromatography on silica gel (hexane-EtOAc) to
give compound NO.52. Yield: 21%.
3.4.50. 1-(2-(4-(2-aminothiazol-4-yl)phenoxy)-3-((3-benzyl-4-
methyl-2-oxo-2H-chromen-7-yl)oxy)propyl)piperidine-4-
carboxamide (50)
The title compound was synthesized according to the procedure
of preparing Compound NO.46.1H NMR (500 MHz, DMSO)
d
7.72
1H NMR (600 MHz, DMSO)
d
7.73 (d, J ¼ 8.5 Hz, 1H), 7.61 (s, 1H),
(dd, J ¼ 8.8, 4.8 Hz, 3H), 7.28e7.25 (m, 2H), 7.21 (d, J ¼ 7.1 Hz, 3H),
7.18 (d, J ¼ 7.2 Hz,1H), 7.05 (d, J ¼ 2.2 Hz,1H), 7.01 (d, J ¼ 2.3 Hz,1H),
6.99 (d, J ¼ 2.5 Hz, 1H), 6.98 (s, 2H), 6.96 (s, 1H), 4.47 (s, 3H), 4.35 (d,
J ¼ 16.5 Hz, 2H), 4.25 (d, J ¼ 16.1 Hz, 2H), 4.03 (q, J ¼ 7.1 Hz, 2H), 3.94
7.27 (d, J ¼ 7.5, Hz, 2H), 7.23 (d, J ¼ 7.4 Hz, 2H), 7.18 (t, J ¼ 7.2 Hz,
1H),7.01 (d, J ¼ 3.6 Hz,1H), 6.97 (d, J ¼ 2.4 Hz,1H), 6.61 (d, J ¼ 3.6 Hz,
1H), 4.16 (t, J ¼ 6.2 Hz, 2H), 3.99 (t, J ¼ 6.4 Hz, 1H), 3.95 (d,
J ¼ 10.0 Hz, 2H), 3.93e3.85 (m, 2H), 3.45e3.38 (m, 2H), 2.72 (t,
J ¼ 8.3 Hz, 2H), 2.70e2.62 (m, 2H), 2.57 (dd, J ¼ 12.7, 6.3 Hz, 1H),
2.44 (s, 3H), 2.29 (s, 2H), 1.63 (dd, J ¼ 12.0, 6.0 Hz, 1H), 1.40e1.33 (m,
(s, 2H), 2.42 (s, 3H), 1.98 (s, 2H), 1.91 (s, 1H), 1.17 (t, J ¼ 7.1 Hz, 2H).
þ
ESI-MS m/z: 625.30[MþH]
.
13C NMR (101 MHz, DMSO)
d
169.91 (s), 163.04 (s), 155.16 (s),
1H), 1.30 (d, J ¼ 8.5 Hz, 3H), 0.93e0.82 (m, 3H). ESI-MS m/z: 407.00
þ
151.40 (s), 150.17 (s), 141.13 (s), 130.26 (s), 129.85 (s), 128.58 (d,
J ¼ 16.9 Hz), 127.91 (s), 123.04 (s), 116.41 (s), 114.48 (s), 103.09 (s),
101.35 (s), 64.63 (s), 63.78 (s), 51.60 (s), 33.98 (s), 30.59 (s), 17.04 (s).
[MþH]
.
13C NMR (151 MHz, DMSO)
d 169.65 (s), 161.71 (s), 161.49 (s),
153.84 (s), 148.84 (s), 139.79 (s), 139.23 (s), 128.89 (s), 128.49 (s),
127.08 (s), 126.53 (s), 121.49 (s), 114.01 (s), 112.97 (s), 106.45 (s),
101.43 (s), 66.42 (s), 41.69 (s), 32.60 (s), 28.67 (s), 15.66 (s).
3.4.51. 3-Benzyl-7-(2-methoxy-3-((2-(pyridin-4-yl)ethyl)amino)
propoxy)-4-methyl-2H-chromen-2-one (51)
To a solution of compound NO.13 (0.112 mmol) in 5 mLTHF was
added MeI(1.1 eq) slowly and the mixture was stirred vigorously for
15 min at room temperature. To the resulting solution, Ag2O (1.6 eq)
was added slowly. The reaction mixture was stirred at room tem-
perature and the progress of the reaction was monitored by TLC.
When complete, the reaction mixture was extracted with ethyl
acetate. The organic layer was washed with brine two times and
dried over anhydrous Na2SO4. After filtration, organic layer is
concentrated under reduced pressure. The reaction mixture was
concentrated under reduced pressure. Then, the crude product was
purified by column chromatography to give compound NO.51. Re-
3.4.53. 1-(3-((3-benzyl-4-cyclopropyl-2-oxo-2H-chromen-7-yl)
oxy)-2-hydroxypropyl)piperidine-4-carboxamide (53)
The title compound was synthesized according to the procedure
of preparing Compound NO.1.1H NMR (400 MHz, DMSO)
d 7.95 (s,
1H), 7.90 (s, 1H), 7.29e7.19 (m, 4H), 7.14 (s, 2H), 6.99 (s, 1H), 6.76 (s,
1H), 6.64 (s, 1H), 5.88 (d, J ¼ 6.4 Hz, 1H), 5.84 (s, 1H), 4.15e3.88 (m,
5H), 3.65 (d, J ¼ 13.0 Hz, 1H), 3.04e2.96 (m, 1H), 2.83 (s, 1H), 2.76 (s,
1H), 2.67e2.57 (m, 1H), 2.32 (dd, J ¼ 7.4, 2.9 Hz, 1H), 2.29e2.23 (m,
1H), 2.14 (d, J ¼ 7.3 Hz, 1H), 1.96 (s, 1H), 1.91 (s, 1H), 1.87 (s, 1H), 1.72
(t, J ¼ 15.3 Hz, 1H), 1.60 (s, 2H), 1.55e1.46 (m, 2H), 1.41 (d, J ¼ 4.5 Hz,
1H), 1.38 (d, J ¼ 4.7 Hz, 1H), 1.34 (s, 1H), 1.31 (d, J ¼ 5.8 Hz, 1H), 1.28
(d, J ¼ 3.5 Hz, 1H), 1.22 (s, 2H), 1.07 (dd, J ¼ 8.1, 2.3 Hz, 1H),
action time: 24 h. Yield: 40.4%.1H NMR (500 MHz, DMSO)
d 8.39
(dd, J ¼ 4.4, 1.5 Hz, 2H), 7.75e7.71 (m, 1H), 7.68 (dd, J ¼ 5.9, 3.2 Hz,
1H), 7.30e7.26 (m, 2H), 7.25e7.21 (m, 4H), 7.18 (t, J ¼ 7.1 Hz, 1H),
6.94 (d, J ¼ 2.5 Hz, 1H), 6.92 (d, J ¼ 2.4 Hz, 1H), 4.89 (s, 1H), 4.45 (s,
1H), 4.14 (t, J ¼ 5.3 Hz, 1H), 3.99 (t, J ¼ 6.4 Hz, 1H), 3.95 (d,
J ¼ 10.0 Hz, 2H), 3.93e3.85 (m, 2H), 3.45e3.38 (m, 2H), 2.72 (t,
J ¼ 8.3 Hz, 2H), 2.70e2.62 (m, 2H), 2.57 (dd, J ¼ 12.7, 6.3 Hz, 1H),
2.44 (s, 3H), 2.29 (s, 2H), 1.63 (dd, J ¼ 12.0, 6.0 Hz,1H), 1.40e1.33 (m,
0.90e0.80 (m, 2H). ESI-MS m/z: 477.10[MþH] þ
.
13C NMR (126 MHz, DMSO)
d 177.06 (s), 176.19 (s), 161.16 (s),
160.04 (s), 141.03 (s), 129.00 (s), 128.83 (s), 128.65 (s), 126.30 (s),
105.63 (s), 66.87 (s), 61.54 (s), 54.11 (s), 44.92 (s), 42.09 (s), 38.86 (s),
29.28 (d, J ¼ 56.3 Hz), 28.24 (s), 14.42 (s), 11.84 (s), 9.56 (s), 9.07 (s).
3.4.54. 1-(3-((3-benzyl-4-cyclopropyl-2-oxo-2H-chromen-7-yl)
oxy)-2-hydroxypropyl)piperidine-4-carboxamide(54)
1H), 1.30 (d, J ¼ 8.5 Hz, 3H), 0.93e0.82 (m, 3H). ESI-MS m/z: 459.10
þ
[MþH]
.
The title compound was synthesized according to the procedure
13C NMR (126 MHz, DMSO)
d
161.71 (s), 153.80 (s), 150.02 (s),
of preparing Compound NO.1.1H NMR (500 MHz, DMSO)
d 7.56 (d,
149.70 (s), 148.84 (s), 139.79 (s), 132.06 (s), 129.12 (s), 128.89 (s),
128.48 (s), 127.04 (s), 126.52 (s), 124.70 (s), 121.45 (s), 113.95 (s),
112.92 (s),101.42 (s), 71.94 (s), 67.88 (s), 67.31 (s), 63.26 (s), 60.16 (s),
58.60 (s), 43.11 (s), 38.55 (s), 32.53 (d, J ¼ 18.4 Hz), 30.27 (s), 28.83
(s), 23.72 (s), 22.86 (s), 15.67 (s), 14.36 (s), 11.27 (s).
J ¼ 6.4 Hz,1H), 7.53 (d, J ¼ 2.3 Hz,1H), 7.52 (s,1H), 7.50 (d, J ¼ 6.7 Hz,
1H), 7.33e7.29 (m, 1H), 7.26 (dd, J ¼ 7.6, 1.7 Hz, 1H), 7.21e7.16 (m,
4H), 7.15e7.09 (m, 2H), 7.06 (d, J ¼ 2.5 Hz, 1H), 7.04 (s, 1H), 7.00 (t,
J ¼ 7.2 Hz, 2H), 6.89 (d, J ¼ 2.4 Hz, 1H), 6.87 (d, J ¼ 2.4 Hz, 1H), 6.83
(s, 1H), 6.82 (s, 1H), 6.69 (d, J ¼ 7.8 Hz, 1H), 4.89 (d, J ¼ 27.9 Hz, 1H),
4.14 (d, J ¼ 5.2 Hz, 1H), 4.08 (d, J ¼ 6.4 Hz, 1H), 4.04e4.00 (m, 1H),
3.96 (d, J ¼ 6.5 Hz, 1H), 3.83 (d, J ¼ 5.4 Hz, 1H), 3.61 (d, J ¼ 4.8 Hz,
2H), 3.17 (d, J ¼ 4.9 Hz, 1H), 2.91 (d, J ¼ 11.0 Hz, 1H), 2.84 (t,
J ¼ 11.1 Hz, 1H), 2.74 (d, J ¼ 11.1 Hz, 1H), 2.42 (dd, J ¼ 12.7, 5.4 Hz,
1H), 2.38e2.31 (m, 1H), 2.31e2.24 (m, 1H), 2.07e1.97 (m, 2H), 1.91
3.4.52. 3-Benzyl-4-methyl-7-(3-(thiazol-2-ylamino)propoxy)-2H-
chromen-2-one (52)
To a solution of thiazol-2-amine (10 mmol) in 2 mL DMF, K2CO3
(1.6 eq) was added slowly and the mixture was stirred vigorously
for 15 min at room temperature. To the resulting solution, 1, 3-
dibromopropane (3 equiv, 6057 mg, 30 mmol) in 2 mL of DMF
was added dropwise. The reaction mixture was heated at 60 ꢁC, and
the progress of the reaction was monitored by TLC. The reaction
mixture was quenched by addition of water and extracted with
ethyl acetate. The organic layer was washed with brine two times
and dried over anhydrous Na2SO4. After filtration, organic layer is
concentrated under reduced pressure. Then, the crude product was
(dd, J ¼ 21.2, 10.3 Hz, 1H), 1.61 (s, 2H), 1.58e1.46 (m, 2H). ESI-MS m/
þ
z: 513.10[MþH]
.
13C NMR (126 MHz, DMSO)
d 177.11 (s), 161.92 (s), 161.51 (s),
159.64 (s), 154.32 (s), 153.24 (s), 152.30 (s), 140.52 (s), 139.54 (d,
J ¼ 8.9 Hz), 134.70 (d, J ¼ 9.2 Hz), 129.25 (d, J ¼ 11.2 Hz),
128.93e128.85 (m), 128.69 (t, J ¼ 13.4 Hz), 128.37 (s), 126.85 (s),
126.35 (d, J ¼ 22.3 Hz), 121.41 (s), 114.06 (s), 113.38 (s), 113.22 (s),
101.66 (s), 100.07 (s), 72.27 (s), 72.08 (s), 66.85 (s), 61.51 (s), 54.09

Y. Gao et al. / European Journal of Medicinal Chemistry 204 (2020) 112595
19
(d, J ¼ 11.9 Hz), 49.07 (s), 42.06 (s), 35.42 (s), 33.75 (s), 29.02 (s).
140.58 (s), 140.42 (s), 131.16 (s), 130.67 (d,
J
¼
39.0 Hz),
130.27e129.98 (m), 129.98e129.27 (m), 129.09 (s), 127.58 (s),
127.21 (s), 126.93 (s), 121.57 (s), 112.98 (s), 107.54 (s), 102.71e101.92
(m), 101.68 (d, J ¼ 34.5 Hz), 100.22 (s), 70.90 (s), 70.29 (s), 69.44 (s),
69.05 (s), 67.27 (s), 67.09 (s), 60.22 (s), 50.47 (s), 49.06 (s), 47.16 (s),
34.96 (s), 32.28 (s), 29.47 (s), 21.56 (s), 21.23 (s), 14.55 (s).
3.4.55. 1-(3-((4-cyclopropyl-2-oxo-2H-chromen-7-yl)oxy)-2-
hydroxypropyl)piperidine-4-carboxamide (55)
The title compound was synthesized according to the procedure
of preparing Compound NO.1.1H NMR (400 MHz, DMSO)
d
7.29e7.19 (m, 1H), 7.15 (t, J ¼ 8.0 Hz, 2H), 7.03e6.92 (m, 1H), 6.66
(s, 1H), 6.51 (dd, J ¼ 8.2, 2.6 Hz, 2H), 4.05e3.86 (m, 5H), 3.85e3.78
(m, 1H), 3.73 (dd, J ¼ 11.1, 4.6 Hz, 1H), 3.67e3.61 (m, 1H), 2.86 (s,
1H), 2.07 (s, 2H), 1.97 (s, 2H), 1.68e1.47 (m, 3H), 1.22 (s, 1H), 1.16 (t,
3.4.59. 7-(2-Hydroxy-3-(phenethylamino)propoxy)-4-methyl-3-
(4-(trifluoromethoxy)benzyl)-2H-chromen-2-one (59)
The title compound was synthesized according to the procedure
J ¼ 7.1 Hz, 2H), 1.08 (d, J ¼ 7.9 Hz, 1H), 0.89e0.81 (m, 1H). ESI-MS m/
of preparing Compound NO.1.1H NMR (500 MHz, DMSO)
d 7.75 (d,
þ
z: 387.00[MþH]
.
J ¼ 8.6 Hz, 1H), 7.34 (t, J ¼ 7.0 Hz, 3H), 7.30 (d, J ¼ 7.4 Hz,1H), 7.25 (d,
J ¼ 4.4 Hz, 2H), 7.24e7.19 (m, 3H), 6.99 (s, 1H), 6.97 (d, J ¼ 2.5 Hz,
1H), 4.15e4.09 (m, 1H), 4.09e4.02 (m, 2H), 3.96 (s, 2H), 3.11e3.01
(m, 3H), 2.98e2.85 (m, 3H), 2.44 (s, 3H), 2.24 (t, J ¼ 6.7 Hz, 1H), 1.90
13C NMR (126 MHz, DMSO)
d 177.05 (s), 160.43 (s), 160.04 (s),
130.44 (s), 129.80e129.04 (m), 128.83 (d, J ¼ 42.9 Hz), 107.61 (s),
107.14 (s), 101.76 (s), 71.57 (s), 69.42 (s), 69.06 (s), 66.92 (s), 61.70
(s), 60.22 (s), 54.05 (s), 47.18 (s), 42.04 (s), 31.16 (s), 29.00 (s), 21.23
(s), 14.55 (s), 11.84 (s), 9.56 (s), 9.22 (s).
(s,1H),1.77e1.70 (m, 1H),1.67e1.59 (m,1H), 0.88e0.81 (m,1H). ESI-
þ
MS m/z: 528.00[MþH]
.
13C NMR (126 MHz, DMSO)
d 161.62 (s), 161.37 (s), 153.84 (s),
3.4.56. 7-(2-Hydroxy-3-(thiazol-2-ylamino)propoxy)-4-methyl-3-
(4-(trifluoromethoxy)benzyl)-2H-chromen-2-one (56)
149.18 (s), 147.17 (s), 139.32 (s), 138.59 (s), 130.31 (s), 129.05 (d,
J ¼ 11.5 Hz), 127.12 (d, J ¼ 34.2 Hz), 121.51 (s), 121.20 (s), 114.16 (s),
113.05 (s), 101.58 (s), 71.14 (s), 66.11 (s), 50.53 (s), 49.47 (s), 41.80 (s),
33.15 (s), 32.01 (s), 26.91 (s), 15.70 (s).
The title compound was synthesized according to the procedure
of preparing Compound NO.1.1H NMR (500 MHz, DMSO)
d 7.73 (d,
J ¼ 9.6 Hz, 1H), 7.34 (d, J ¼ 8.6 Hz, 2H), 7.24 (d, J ¼ 8.2 Hz, 2H),
7.01e6.94 (m, 2H), 6.84 (d, J ¼ 4.5 Hz, 1H), 6.15 (s, 1H), 4.16 (d,
J ¼ 6.9 Hz,1H), 4.01 (ddd, J ¼ 16.1, 10.4, 5.2 Hz, 3H), 3.96 (s, 2H), 3.92
(d, J ¼ 3.9 Hz, 1H), 3.81 (dd, J ¼ 13.9, 7.3 Hz, 1H), 2.43 (s, 3H), 1.21 (d,
J ¼ 4.8 Hz, 4H), 0.84 (t, J ¼ 6.8 Hz, 1H). ESI-MS m/z: 507.11981[MþH]
þ, delta <0.5 ppm.
3.5. Molecular docking
The docking studies were prepared with Ligandscout (4.1) with
MMFF 94 energy minimization. The HBV capsid protein (PDB: 6HRO)
were prepared with ligandscout (4.1) by removing the ligand and
unnecessary water molecules. Then the whole protein was selected
for docking and the prepared molecules were inserted. The docking
was carried out by AutoDock Vina 1.1(Exhaustiveness ¼ 20, Max.
Energy difference ¼ 3). The halogen bond analysis was performed
with Flare.
13C NMR (126 MHz, DMSO)
d 161.61 (s), 161.44 (s), 153.80 (s),
149.18 (s), 147.14 (s), 139.31 (s), 130.29 (s), 127.22 (s), 121.49 (s),
121.13 (s), 114.11 (s), 113.00 (s), 101.52 (s), 71.02 (s), 67.25 (s), 49.75
(s), 32.00 (s), 29.47 (s), 15.69 (s).
3.4.57. 7-(2-Hydroxy-3-((2-(pyridin-4-yl)ethyl)amino)propoxy)-4-
methyl-3-(4-(trifluoromethoxy)benzyl)-2H-chromen-2-one (57)
The title compound was synthesized according to the procedure
4. Discussion
of preparing Compound NO.1.1H NMR (500 MHz, DMSO)
d
8.44 (dd,
We previously identified compound CP19 as an entry inhibitor
against Ebola virus infection. The preliminary SAR analysis of ten
CP19 derivatives indicated that the hydrophobic or aromatic sub-
stitutions on the C3 or C4 of coumarin were vital for its antiviral
activity and the carboxamide moiety was important for its activity.
However, the detailed SAR of these sites and the roles of the linker
between the coumarin and the piperidine were still elusive. In this
research, we performed a detailed SAR studies based on CP19 and
elucidate the different weights of these parts on their antivirus
efficacy. Our analysis discovered that the substitutions of large ar-
omatic groups on the C3 and C4 of coumarin could afford potent
antiviral activities and the most important part of CP19 derivatives
was the substitution groups on C3 of coumarin. In addition, the
piperidine group could be optimized with heterocycles, but not
with small hydrophilic groups, which indicates that this moiety
should have hydrogen bond interactions with the GP protein.
However, the substitutions on the linker would decrease its activity,
and the stereo structure had little influence on the activity, which
suggests that the linker structure did not take important role in the
interactions with the binding pocket.
Compound 32 is similar to compound 118a in its carboxamide
and piperidine groups, but compound 118a has more potent ac-
tivity to inhibit Ebolavirus entry. The crystal structure of Ebola GP
complexed with compound 118a and our studies strongly indicate
that [1] the coumarin of compound 32 occupies almost the same
pocket as the phenol ring of compound 118a. However, the lactone
of coumarin does not form H-bond or strong electrostatic in-
teractions with Ebola glycoprotein, and thus this structure could be
replaced by groups with smaller volume or better chemical
J ¼ 15.6, 4.5 Hz, 6H), 7.73 (d, J ¼ 9.4 Hz, 2H), 7.35 (d, J ¼ 8.3 Hz, 3H),
7.29 (d, J ¼ 6.6 Hz, 2H), 7.28e7.20 (m, 8H), 6.96 (s, 2H), 5.75 (s, 1H),
5.43 (s, 1H), 5.02 (d, J ¼ 34.1 Hz, 1H), 4.06 (dd, J ¼ 9.8, 4.0 Hz, 1H),
3.97 (s, 2H), 3.95e3.92 (m, 2H), 3.89 (d, J ¼ 6.9 Hz, 1H), 3.83 (s, 1H),
3.61 (dd, J ¼ 10.9, 4.4 Hz, 2H), 3.53 (dd, J ¼ 11.0, 5.3 Hz, 2H), 3.25 (d,
J ¼ 6.3 Hz, 2H), 2.81 (s, 2H), 2.76e2.71 (m, 5H), 2.69 (d, J ¼ 4.7 Hz,
1H), 2.64 (d, J ¼ 6.2 Hz, 1H), 2.44 (s, 3H), 2.07 (d, J ¼ 10.3 Hz, 1H),
1.98 (d, J ¼ 10.5 Hz, 1H), 1.76 (d, J ¼ 16.2 Hz, 1H), 1.19 (dd, J ¼ 21.0,
13.9 Hz, 1H), 1.07 (d, J ¼ 30.0 Hz, 1H). ESI-MS m/z: 529.40 [MþH] þ
.
13C NMR (126 MHz, DMSO)
d
161.69 (d, J ¼ 9.6 Hz), 156.43 (s),
153.84 (s), 149.82 (d, J ¼ 11.4 Hz), 148.69 (s), 147.14 (s), 139.33 (s),
130.28 (s), 127.15 (s), 124.70 (s), 121.48 (s), 120.99 (s), 113.91 (s),
113.01 (s), 101.47 (s), 71.82 (s), 68.84 (s), 68.43 (s), 65.29 (s), 52.40
(s), 50.29 (s), 47.08 (s), 41.08 (s), 35.48 (s), 34.91 (s), 31.99 (s), 15.67
(s).
3.4.58. 3-([1,10-biphenyl]-4-ylmethyl)-7-(2-hydroxy-3-(thiazol-2-
ylamino)propoxy)-4-methyl-2H-chromen-2-one (58)
The title compound was synthesized according to the procedure
of preparing Compound NO.1.1H NMR (500 MHz, DMSO)
d
7.74 (d,
J ¼ 9.3 Hz, 1H), 7.61e7.55 (m, 7H), 7.54 (s, 1H), 7.51 (dd, J ¼ 8.1,
3.2 Hz, 4H), 7.44e7.38 (m, 6H), 7.34e7.27 (m, 7H), 7.25 (d, J ¼ 8.2 Hz,
2H), 7.10e7.06 (m, 1H), 7.03e6.90 (m, 4H), 4.12 (s, 4H), 4.03e3.96
(m, 10H), 3.93 (dd, J ¼ 5.6, 4.1 Hz, 4H), 3.88 (dd, J ¼ 15.0, 5.7 Hz, 9H),
3.76e3.71 (m, 3H), 3.64 (ddd, J ¼ 11.2, 7.0, 4.9 Hz, 3H), 2.45 (s, 2H),
1.97 (s, 3H),1.89 (s, 2H),1.21 (d, J ¼ 3.7 Hz, 5H),1.15 (t, J ¼ 7.1 Hz, 3H),
þ
1.12 (s, 1H). ESI-MS m/z: 499.29[MþH]
.
13C NMR (126 MHz, DMSO)
d 172.51 (s), 161.69 (s), 160.05 (s),

20
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The authors declare that they have no known competing
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Acknowledgement
This work was supported by the grants from National Natural
Science Foundation of China (21572281, 21877132), Scientific Plan of
Guangzhou City (201704030087), and Scientific Plan of Guangdong
Province (2017A020211003) to C.B. This work was also supported by
the grants from NIH (R41AI126971 and R42AI126971) to L.R.
Appendix A. Supplementary data
Supplementary data to this article can be found online at
https://doi.org/10.1016/j.ejmech.2020.112595.
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