Identification of new dual FABP4/5 inhibitors based on a naphthalene-1-sulfonamide FABP4 inhibitor

Article abstract of DOI:10.1016/j.bmc.2019.07.031

Fatty acid binding protein 4 (FABP4) and fatty acid binding protein 5 (FABP5) are mainly expressed in adipocytes and/or macrophages and play essential roles in energy metabolism and inflammation. When FABP4 function is diminished, FABP5 expression is high

Full text of DOI:10.1016/j.bmc.2019.07.031

Accepted Manuscript
Identification of New Dual FABP4/5 Inhibitors Based on a Naphthalene-1-sul-
fonamide FABP4 Inhibitor
Yulong He, Huixia Dou, Dingding Gao, Ting Wang, Mingming Zhang, Heyao
Wang, Yingxia Li
PII:
S0968-0896(19)30614-5
https://doi.org/10.1016/j.bmc.2019.07.031
BMC 15015
DOI:
Reference:
Bioorganic & Medicinal Chemistry
To appear in:
Received Date:
Revised Date:
Accepted Date:
14 April 2019
15 July 2019
17 July 2019
Please cite this article as: He, Y., Dou, H., Gao, D., Wang, T., Zhang, M., Wang, H., Li, Y., Identification of New
Dual FABP4/5 Inhibitors Based on a Naphthalene-1-sulfonamide FABP4 Inhibitor, Bioorganic & Medicinal
Chemistry (2019), doi: https://doi.org/10.1016/j.bmc.2019.07.031
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Identification of New Dual FABP4/5 Inhibitors Based on a
Naphthalene-1-sulfonamide FABP4 Inhibitor
Yulong He a,1, Huixia Dou b,c,1, Dingding Gao a, d, 1, Ting Wang b，Mingming Zhang a, *, Heyao
Wang b,*, Yingxia Li a,*
a School of Pharmacy, Fudan University, Shanghai 201203, China
b
State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese
Academy of Sciences, Shanghai 201203, China
c University of Chinese Academy of Sciences, Beijing 100049, China
d Innovation Research Institute of Traditional Chinese Medicine (IRI), Shanghai University of
Traditional Chinese Medicine, Shanghai 201203, China
1 These authors contributed equally to this work.
* Corresponding author: For Y. L. E-mail: liyx417@fudan.edu.cn
* Corresponding author: For H. W. E-mail: hywang@simm.ac.cn
* Corresponding author: For M. Z. E-mail: zmmworld@126.com

Abstract
Fatty acid binding protein 4 (FABP4) and fatty acid binding 5 (FABP5) are mainly expressed in
adipocytes and/or macrophages and play essential roles in energy metabolism and inflammation.
When FABP4 function is diminished, FABP5 expression is highly increased possibly as a
functional compensation. Dual FABP4/5 inhibitors are expected to provide beneficial synergistic
effect on treating diabetes, atherosclerosis, and inflammation-related diseases. Starting from our
previously reported selective FABP4 inhibitor 8, structural biology information was used to
modulate the selectivity profile and to design potent dual FABP4/5 inhibitors with good selectivity
against FABP3. Two compounds A16 and B8 were identified to show inhibitory activities against
both FABP4/5 and good selectivity over FABP3, which could also reduce the level of forskolin-
stimulated lipolysis in mature 3T3-L1 adipocytes. Compared with compound 8, these two
compounds exhibited better anti-inflammatory effects in lipopolysaccharide-stimulated
RAW264.7 murine macrophages, with decreased levels of pro-inflammatory cytokines TNFα and
MCP-1 and apparently inhibited IKK/NF-κB pathway.
Keywords
Dual FABP4/5 inhibitor; Structure-based design; Lipolysis inhibition; Anti-inflammatory effects
1 Introduction
FABPs are small (14-15kDa) cytosolic proteins that modulate lipid trafficking and
inflammatory responses in cells.1 They could reversibly bind to long-chain fatty acids and other
hydrophobic ligands with high affinity and extensive selectivity.2-3 Since the first report of FABPs
in 1972, at least ten members have been confirmed.4-5 Different isoforms of the FABPs exhibit
unique patterns of tissue expression and are involved in active lipid metabolism.6 FABP4, also
known as aP2 or adipocyte FABP (A-FABP), was first identified in mature adipocytes and also
expressed in macrophages and dendritic cells.7-10 It has been proved to transport hydrophobic fatty
acids within cells to various destinations for fatty acid oxidation, membrane homeostasis or
nuclear signaling.11 Previous studies have demonstrated that FABP4 knockout animals are
partially protected from insulin resistance associated with genetic or dietary obesity.12-13Ablation
of FABP4 protected apolipoprotein E (ApoE)-deficient mice against atherosclerosis with or

without high-cholesterol western-style diets.9 These results demonstrated a crucial role of FABP4
in the development of the metabolic syndrome.
Interestingly, under standard laboratory conditions, mice deficient in Fabp4 did not differ
from their wide-type in breeding, behavior or development.12 Researchers have discovered that the
loss of FABP4 in adipocytes is compensated by FABP5 (also known as E-FABP or mal 1), which
is highly expressed in epidermal cells and present in the normal adipocytes and macrophage cells
only in small amounts.14 Studies have shown that FABP5 deficiency mildly increased systemic
insulin sensitivity in dietary and genetically obese mice.15 FABP5-deficient mice have also
demonstrated favorable protection against atherosclerosis on a western-style hyper-cholesterol
diet.16 As described above, FABP4 or FABP5 single-knockout mice exhibited only modest
phenotypes, but the FABP4 and FABP5 double-knockout mice displayed significant protection
from insulin resistance, type 2 diabetes, and atherosclerosis, indicating a synergistic effect because
of the dual deletion of FABP4 and FABP5.17-18 Therefore, it is of high significance to develop
dual FABP4 and FABP5 inhibitors to treat inflammatory and metabolic diseases. In addition,
FABP4 and FABP5 also played an important role in tumourigenesis in different cancer types,
including bladder, breast, prostate, colorectal, oral, ovarian cancer and acute myeloid leukemia.19-
25 Pharmacological inhibition of FABP anandamide transporters (FABP5 and FBAP7) resulted in
beneficial effects on stress, inflammation and pain.26-29
In the past few years, a number of small molecule inhibitors towards FABP4/FBAP5 have
been identified and classified based on structures (Figure 1),30 for example, imidazole derivatives
(1), indole derivatives (2), thiophene derivatives (3), bicyclic pyridine derivatives (4), urea
derivatives (5), non-carboxylic acids (6), quinoline derivatives (7).31-37 Among these, compound 6
is a novel FABP4/5 inhibitor whose efficacy was evaluated in vitro and in vivo.36 Dual FABP4/5
inhibitor 7 possessed good potency and favorable physicochemical properties.37 Therefore, both
compounds could be used as suitable tool compounds.

COOH
N
N
O
N
C5H11
HOOC
O
N
NH
H
S
N
N
O
N
S
N
O
S
HOOC
O
O
O
4
3 (HTS01037)
1
2
F
Cl
OH
O
O
HN
S
N
N
O
O
O
N
N
Cl
N
NH COOH
N
N
H
Cl
N
O
Cl
N
H
NH
N
O
6
7 (RO6806051)
5
8
Figure 1. Structures of the representative FABP4/5 inhibitors.
Our research group previously reported the discovery of a potent and selective naphthalene-
1-sulfonamide FABP4 inhibitor 8.38 It's worth noting that a corrigendum to this work38 has been
published recently (The Ki values in Tables 3 do not match with the corresponding compound
structures and compound codes in the published article. This was caused due to the rearrangement
of structures in the tables during the publishing process).39In this work, the lead compound 8 was
further optimized to improve its FABP5 potency while maintaining the FABP4 activity based on
the differences between these two pockets. Most of the analogs showed comparable inhibitory
activities against FABP4 and FABP5. Particularly, compound A16 and B8 exhibited stronger
inhibitory activity towards FABP4/5 than positive control compound 6. In addition, A16 and B8
showed favorable inhibitory activity against forskolin-stimulated lipolysis in 3T3-L1 adipocytes
and anti-inflammatory effects in lipopolysaccharide-stimulated RAW264.7 macrophages.
2 Results and Discussion
2.1 Structure-Based Design
To provide a better structural understanding for the design of potent dual FABP4/5 inhibitors,
the co-crystal structures of several published FABP4 or/and FABP5 ligands were reviewed to get
detailed insights into binding features.40-42 As presented in Figure 2A (X-ray crystal of FABP4 in
complex with compound 8),38-39 the carboxyl group of forms hydrogen bonds with Arg 106, Arg
126 and Tyr 128, and the naphthalene ring forms a π-π interaction with Phe 16. In addition, the
oxygen atom of the sulfonamide forms hydrogen bonds through water molecules with Tyr 19, Gln

95, Glu 72, Arg 78 and Ala 75, which is a unique binding mode of compound 8 with FABP4. As
shown in Figure 2B (X-ray crystal of FABP5 in complex with compound 7),37 the tetrazole group
is engaged in multiple hydrogen bonds with Arg 129, Tyr 131 and Thr 56 directly or indirectly.
The quinoline core forms a π-π interaction with Phe 19, and the phenyl group points into a pocket
lined with residues Ala 39, Lys 40, Ser 58, and Lys 61. Subsequently, an overlay of these two
crystal structures (Figure 2C) indicates a similar binding mode of compound 8 in FABP4 and
compound 7 in FABP5. From this analysis, it could be identified that the hydrophobic cavity of
FABP5 where the phenyl group of compound 7 located was not optimally filled with the original
methoxy substituent of compound 8, and bulkier group may be ideally suited to target this region
for dual FABP4/5 activity. We first focused our attention on increasing the size of 4-naphthalene
substituent of compound 8 from methoxy to bulkier O-alkyl, O-phenyl, and benzyl substituents
(Series A, Figure 3). Nest in Series B, phenyl or heteroaromatic ring with various substituents
were introduced into the C3 position of naphthalene core to investigate the effect on potency.
Figure 2. (A) Crystal structure of compound 8 with human FABP4 (PDB: 5Y0F); (B) Crystal
structure of compound 7 with human FABP5 (PDB: 5HZ5); (C) An overlay of the complex crystal
structure of 8 (protein: cyan, ligand: green, residues: magenta, PDB: 5Y0F) in FABP4 with 7 in
FABP5 (protein: cyan, ligand: orange, residues: blue, PDB: 5HZ5). The pictures were generated
using Pymol.

F
F
F
OH
OH
OH
HN
S
HN
S
HN
S
O
O
O
O
O
O
O
O
O
Structure-based Design
1
2
3
R2
4
O
O
O
R1
8
Series A (A1-A21)
(B1-B14)
Series B
Figure 3． Structure-based design of target compounds
2.2 Chemistry
2.2.1 Synthesis of Compounds A1-A21
The synthesis of target compounds A1-A21 is outlined in Scheme 1. Commercially available
material 9 was converted to intermediates 10a-10u by reacting with different alkyl bromides or
substituted benzyl bromides in a mixed solvent of ethanol and water in the presence of sodium
hydroxide. Then, the reaction of 10a-10u with thionyl chloride in DMF led to the formation of
compounds 11a-11u, which were further coupled with the commercially available material 12 in
the presence of pyridine to give intermediates 13a-13u. Finally, methyl esters of 13a-13u was
hydrolyzed to give the target compounds A1-A21.
F
Na
O
O
F
Na
O
O
O
S
Cl
S
O
S
NH
NH2
O
O
O
O
O
O
O
S
O
12
i
ii
iii
O
O
OH
O
R
R
R
9
10a-10u
11a-11u
13a-13u
F
HO
NH
A8
A9
A15
A16
A17
A18
A19
A20
A21
O
O
R
S
O
,h:R=n-octyl
,i:R=n-decyl
, o:R=methyl cyclohexyl
, p:R=ethyl cyclohexyl
, q:R=propyl cyclohexyl
, r:R=methyl adamantyl
, s:R=methyltetrahydro-2H-pyran
, t: R=phenyl
A1
A2
A3
A4
A5
A6
A7
,a:R=ethyl
,b:R=isopropyl
,c:R=isobutyl
,d:R=isopentyl
,e:R=n-pentyl
,f: R=n-hexyl
,g:R=n-heptyl
A10
A11
A12
A13
A14
, j:R=n-dodecyl
, k:R=cyclopentyl
, l:R=cyclohexyl
, m:R=cycloheptyl
, n:R=cyclooctyl
iv
O
, u:R=benzyl
A1-A21
Scheme 1. Synthesis of compounds A1-A21. Reagents and conditions: (i) RX, NaOH, EtOH: H2O
= 1/1, 80 oC, overnight; (ii) SOCl2, DMF, 1 h, rt ; (iii) Pyridine, acetone, 55 oC, 1 h ; (iv) NaOH,
H2O, MeOH, 1 h, rt.
2.2.2 Synthesis of Compounds B1-B14
The series B compounds were synthesized as described in Scheme 2. The reaction of 14 with
NBS in the presence of catalytic amount of diethylamine provided intermediate 15, which was

mixed with methyl iodide in acetonitrile leading to the formation of compound 16. Treatment of
16 with chlorosulfonic acid in chloroform afforded chlorosulfonylation product 17, which
followed by reaction with 12 in acetone to give key intermediate 18. Coupling of 18 with different
substituted aryl boronic acids via Suzuki reaction provided 19a-19n, which subsequently were
hydrolyzed with sodium hydroxide to afford desired compounds B1-B14.
F
O
F
Cl
S
NH
S
O
O
O
O
O
O
NH2
O
12
iv
i
ii
iii
Br
Br
Br
Br
OH
O
OH
14
O
O
16
17
18
15
F
F
O
OH
NH
S
NH
S
B1
B2
B3
B4
B5
B6
B7
, a:R=phenyl ;
, b:R=4-pyridyl ;
, c:R=2-pyrimidyl;
, d:R=3-furyl ;
, e:R=1-methyl-1H-pyrazol-5-yl ;
, f:R=4-fluorophenyl;
B8
B9
, h:R=3-chloro-4-fluorophenyl;
, i:R=3,4-dichlorophenyl;
, j:R=3-aminophenyl;
, k:R=3-hydroxyphenyl;
, l:R=4-hydroxyphenyl;
, m:R=4-(hydroxymethyl)phenyl;
,n:R=3,4-dimethoxyphenyl;
O
O
O
O
O
O
v
vi
B10
B11
B12
B13
B14
R
R
O
O
, g:R=3,4-difluorophenyl;
19a-19n
B1-B14
Scheme 2. Synthesis of compounds B1-B14. Reagents and conditions: (i) NBS, diethylamine,
CH2Cl2, 40 oC, overnight; (ii) CH3I, KOH, CH3CN, 40 oC, 12 h ; (iii) HSO3Cl, CH3Cl, 0 oC to rt.;
o
(iv) Pyridine, acetone, 55 C, 1 h; (v) R-B(OH)2, K2CO3, PdCl2(dppf).CH2Cl2, DMF, H2O ; (vi)
NaOH, H2O, MeOH, 1 h, rt.
2.3 Biochemical Evaluations and Structure-Activity Relationships.
All of the target compounds were evaluated for the inhibitory activity against FABP4 and
FABP5 at a concentration of 25 μM, and compounds with inhibition rate of FABP4 and FABP5
above 50% were further selected to test IC50 values. Ligand binding was measured via
38-39
displacement of 1-anilinonaphthalene-8-sulfonic acid (1,8-ANS), as described previously.
The binding of 1,8-ANS fluorescent probe molecule to FABP4/5 increases the fluorescence
intensity. The excitation and emission wavelength of the binding of ANS to protein is 370/470 nm,
and the compound can compete with ANS to bind FABP4/5. The inhibitory activity of the
compounds against FABP4/5 can be detected by measuring the fluorescence value at 370/470 nm.
Since compound 7 had spontaneous emission at 370/470 nm and interfered with the readout, it
was not selected as positive control. Compound 6 and 8 were chosen as positive compounds.
The results of the tested compounds are summarized in Tables 1 and Table 2. For Series A,

the gradually lengthened alkyl carbon chain (A2-A7) maintained the inhibitory activity against
FABP4 but very considerably increased the inhibitory activity against FABP5. The result suggests
that the sub-pocket in FABP5 is able to accommodate bulkier group, while further increasing the
length of the alkyl chain (A8-A10) might cause a steric clash with the sub-pocket resulting in a
decrease in activity. Among these compounds, A7 showed strong and balanced activity towards
both FABP4 (IC50 = 2.30 μM) and FABP5 (IC50 = 2.76 μM), indicating n-heptyl to be the optimal
linear alkyl group. Next, aiming to reduce entropy loss and lock the ligand in its active
conformation, we replaced the flexible alkyl group with a rigid cycloalkane substituent. The
cyclopentyl A11 showed an increased inhibition rate against FABP5. Expanding the cyclopentyl
(A11) to cyclohexyl (A12) and cycloheptyl (A13) further increased the inhibitory activity against
FABP5 with the IC50 ranging from 3.30 to 7.66 μM. These results encouraged us to go on with a
more bulky group such as cyclooctyl (A14). However, it exhibited weak activities towards both
FABP4 and FABP5. Then, the length of alkyl chain between the naphthalene core and the
cycloalkane was explored. Compound A15 with methylcyclohexyl group (FABP4: IC50 = 2.41 μM,
FABP5: IC50 = 8.12 μM) showed comparable inhibitory activity with A12 (FABP4: IC50 = 2.20
μM, FABP5: IC50 = 7.66 μM). Elongation to the ethyl (A16) and propyl (A17) resulted in retained
potency on FABP4 and slightly improved activity against FABP5. Replacing the
methylcyclohexane with 1-methyladamantane (A18) showed a decreased activity on FABP4 (IC50
= 14.78 μM). When a hydrophilic tetrahydropyran ring was introduced (A19), both of FABP4/5
inhibitory activities significantly declined. This may be due to the conformational difference
between cyclohexyl and tetrahydropyran or changes in physicochemical properties.The phenyl
analog A20 and the benzyl analog A21 showed increased inhibitory activities against FABP5
compared with compound 8, but less potent compared with saturated cycloalkyl analogs A12 and
A15, indicating phenyl moiety can decrease the binding affinity..
F
F
OH
OH
NH
S
NH
S
O
O
O
O
O
O
O
O
R1
Series (A1-A21)
Compound 8
Table 1. Inhibitory activities of Series A compounds.

FABP4
FABP5
Compd.
R1
@25µM
IC50 (µM）
@25μM
IC50 (µM）
Inhibition%
Inhibition%
A1
A2
95%
2.64±0.19
/
13%
30%
48%
59%
53%
66%
71%
72%
61%
50%
54%
63%
71%
/
85%
84%
90%
88%
94%
96%
91%
84%
71%
82%
84%
86%
/
A3
/
/
A4
/
/
A5
2.99±0.00
2.43±0.17
2.30±0.05
4.04±0.16
4.73±0.25
24.83±4.21
/
8.32±0.61
4.17±0.37
2.76±0.88
4.19±0.83
4.48±0.26
23.42±0.32
/
A6
A7
A8
A9
A10
A11
A12
A13
2.20±0.15
2.37±0.08
7.66±0.60
3.30±2.11

A14
A15
A16
A17
A18
A19
A20
A21
6
23%
90%
92%
86%
47%
35%
84%
81%
97%
92%
/
24%
65%
66%
65%
59%
20%
52%
42%
52%
5%
/
2.41±0.11
1.97±0.15
3.59±0.26
14.78±0.74
/
8.12±1.33
4.85±1.03
3.63±0.68
4.61±3.52
/
O
/
/
3.15±0.11
6.34±0.01
1.69±0.12
/
23.42±0.32
8
/
Based on the docking results (Figure 2), the alternative way to occupy the sub-pocket of
FABP4 and FABP5 is to incorporate substituent at the C-3 of the naphthalene core. A series of
aromatic groups were introduced and the results were shown in Table 2. Phenyl substituted B1
exhibited comparable FABP4 inhibitory activity (IC50 = 1.19 μM) to compound 8 and improved
potency on FABP5 (IC50 = 15.96 μM). Replacement of phenyl with pyridyl group caused a
decrease in activity against FABP4 (IC50 = 3.54 μM) and FABP5 (IC50 = 17.18 μM) compared
with B1. While the substituents of pyrimidine (B3), furan (B4), and N-methyl pyrazole (B5)
demonstrated only moderate inhibitory rate against FABP4 and weak activity on FABP5. Further
introducing halogens on the phenyl substituent led to compound B6-B9, which keep their
activities and on FABP4 and 5 compared with B1. Incorporation of amino (B10) or hydroxyl (B11)

to the meta-position was well tolerated in FABP4 and FABP5 activity. Switching the hydroxyl
from the meta-position to the para-position (B12) had no significant effect. While changing the
hydroxyl to hydroxymethyl (B13) caused a dramatic loss in FABP4 and FABP5 potency. In
addition, incorporation of two methoxy groups on the meta- and para-position of the phenyl (B14)
was also not tolerated, which resulted in a significant loss of potency toward both FABP4 and
FABP5. Therefore, we postulated that small groups introduced in the meta- or para-position of the
phenyl was well tolerated in FABP4/5 potency, whereas bulky substituents were not preferred,
such as methoxy and hydroxymethyl group.
F
F
OH
OH
NH
S
NH
S
O
O
O
O
O
O
R2
O
O
Compound 8
Series B (B1-B14)
Table 2. Inhibitory activities of Series B compounds
FABP4
FABP5
Compd.
R2
@25µM
IC50(µM)
1.19±0.03
3.54±0.27
/
@25µM
IC50(µM)
15.96±2.31
17.18±1.15
/
Inhibition %
Inhibition%
68%
B1
B2
B3
B4
B5
97%
83%
57%
90%
88%
42%
N
N
27% (100µM)
36%
N
3.53±0.13
30.94±3.07
O
/
48% (100µM)
/
N
N

B6
B7
96%
88%
97%
85%
91%
90%
95%
19%
26%
97%
92%
1.74±0.04
2.98±0.28
1.58±0.66
4.38±0.14
1.70±0.05
1.89±0.08
1.19±0.07
/
65%
54%
71%
60%
53%
67%
59%
29%
26%
52%
5%
10.00±1.44
17.13±5.12
10.08±1.99
14.63±1.92
20.86±3.58
17.74±6.92
15.77±1.82
/
F
F
F
F
B8
Cl
B9
Cl
Cl
H2N
HO
B10
B11
B12
B13
B14
6
HO
HO
/
/
O
O
6.34±0.01
1.69±0.12
23.42±0.32
8
/
2.4 FABP3 Selectivity Evaluation
Fatty acid binding protein 3 (FABP3), also known as H-FABP, is mainly expressed in cardiac
muscle tissue and plays an important role in cell proliferation, apoptosis and gene transcription.43
Studies in a zebrafish model demonstrated that silencing of FABP3 leads to apoptosis-induced

44
mitochondrial dysfunction
and knocking down of FABP3 impairs cardiac development.45
Therefore, selectivity versus FABP3 is thought to be critical for FABP4 inhibitors as therapeutic
agents. The phenyl ring of compound 8 would clash with large side chain of Leu 115 and Leu 117
in FABP3 and exhibited good selectivity over FABP3 (Figure S1). Based on the results above, two
representative compound A16 and B8 were selected to test their inhibitory activity against FABP3
(Table 3, compound 6 as a positive control). A16 and B8 both showed weak inhibitory activity
against FABP3 and much better selectivity profile over FABP3 than positive control 6. In detail,
compound A16 showed a 28.3-fold selectivity of FABP4 and 11.4-fold preference of FABP5 over
FABP3. B8 exhibited comparative selectivity of FABP4 (29.6-fold) but a lower preference of
FABP5 (4.6-fold) over FABP3. Therefore, compound A16 and B8 may have lower cardiac
toxicity, which is an important benefit for further study.
Table 3. Selectivity of representative compounds against FABP3
Compd
FABP4 IC50
(μM)
FABP5 IC50
(μM)
FABP3 IC50 FABP3/FABP FABP3/FABP
(μM)
4
5
6
6.34±0.01
23.42±0.32
1.95±0.01
0.31
0.08
A16
B8
1.97±0.15
1.58±0.66
4.85±1.03
55.62±1.32
46.84±1.14
28.23
29.64
11.46
4.64
10.08±1.99
2.5 Molecular Docking Studies of A16 with FABP4 and FABP5 Protein
In order to gain further insight into the binding interactions with FABP4 and FABP5,
compound A16 was selected to perform docking studies. Before docking, the important water
molecules which formed key hydrogen bonds with FABP4 or FABP5 was retained. The predicted
binding mode of A16 with FABP4 was presented in Figure S2. The carboxy group forms
important hydrogen bonds with residues Arg 126 and Tyr 128. The naphthalene ring formed an
edge-to-face π-π stacking interaction with Phe 16. One oxygen of the sulfonamide group formed
two hydrogen bonds with Arg 78 and Gln 95. Besides, the ethyl cyclohexyl moiety occupied the
hydrophobic pocket formed by Ala 36, Ser 55, Phe 57, Ser 53 and Pro 38. We can infer that the
compound with ethyl cyclohexyl group (A16) maintains a similar binding mode with FABP4 as

the lead compound 8.
On the other hand, the interactions between A16 and FABP5 were demonstrated in Figure 4A.
The carboxy group formed one hydrogen bond with Arg 129 and an indirect hydrogen bond with
Arg 109 via a water molecular. The naphthalene moiety formed an edge-to-face π-π stacking
interaction with Phe 19. Moreover, another Pi-cation interaction was observed between the phenyl
ring and Arg 109. One oxygen of the sulfonamide group formed a hydrogen bond with Thr 63. An
overlay of A16 with compound 7 in FABP5 was exhibited in Figure 4B. Interestingly, the key
binding interactions of A16 and compound 7 were almost the same. Most importantly, the
ethylcyclohexyl moiety of A16 occupied the pocket where the phenyl ring of compound 7 located,
which was consistent with our initial design strategy. This might be the reason that compound A16
along with some designed compounds showed potent dual FABP4/FABP5 inhibitory activities.
B
A
Figure 4． (A) Predicted binding mode of A16 with FABP5 (protein: cyan, ligand: yellow,
residues: magenta, PDB: 5HZ5); (B) A comparison of the binding mode of A16 (yellow) and
compound 7 (green) with FABP5 (cyan). The pictures were generated using Pymol.
2.6 Lipolysis Inhibition in 3T3-L1 Adipocytes
There have been reported cases that targeted ablation or chemical inhibition of FABP4 could
decrease the lipolysis effects in adipocytes.33, 46 In our previous study,38-39 the selective FABP4
inhibitor 8 exhibited inhibitory ability of forskolin-stimulated lipolysis in mature adipocytes. Here,
the effects of our dual FABP4/5 inhibitors A16 and B8 on the lipolysis of 3T3-L1 adipocytes was
investigated, with the reported FABP4/5 inhibitor 6 as positive control. Firstly, an MTT assay was
carried out to evaluate the cytotoxicity effects of the above-mentioned compounds on 3T3-L1 pre-
adipocytes. As illustrated in Figure 5A, compound 6 slightly inhibited cell survival at 30 μM and
60 μM. In comparison, our compounds have no effect on cell viability even at 60 μM. As shown

in Figure 5B, all compounds at 30 μM attenuated forskolin-stimulated lipolysis in 3T3-L1 cells,
and the FABP 4/5 dual inhibitor A16 and B8 showed slightly better lipolytic inhibition compared
with positive control (compound 6) and FABP4 selective inhibitor 8. It is worth noting that
compound A16 with higher selectivity fold (FABP4/5 = 2.46x) showed slightly better activity
than B8 (FABP4/5 = 6.38x), which indicates that dual inhibition of FABP4 and FABP5 may
provide beneficial effects on a number of metabolic parameters.
A
B
Figure 5. (A) Effects of compounds A16, B8, 6, and 8 on the viability of 3T3-L1 preadipocytes.
Cell viability was determined by MTT assay. *P<0.05, ***P<0.001 vs. control group. (B) Effect
of FABP4/5 inhibitors A16 and B8 on the release of glycerol from forskolin-stimulated mature
3T3-L1 adipocytes. Compound 6 and 8 were used as the positive controls. *P < 0.05, ***P <
0.001 vs. FSK group.△P < 0.05 vs compd 6 group. ##P < 0.01 vs compd 8 group.
2.7 Anti-inflammatory Effects of A16 and B8 on RAW264.7 Macrophages

It has been demonstrated that genetic ablation or knockdown of FABP4 can decrease
inflammatory responses in macrophages.47-48 The inflammatory response was extensively studied
in RAW 264.7 murine macrophage for compound 8, A16, and B8 (6 as a positive control). Firstly,
a RAW264.7-MTT evaluation was conducted to test the effects of these compounds on cell
viability and the results were shown in Figure 6A. Compound 6 dose-dependently affects cell
viability at at 30 and 60 μM, while compound 8, A16, and B8 have no effects. As quantitative
PCR results shown in Figure 6B, the expression level of pro-inflammatory cytokines MCP-
1/CCL2, TNFα, IL-6 and pro-inflammatory enzyme COX-2 were robustly increased with the cell
stimulated by lipopolysaccharide (LPS). Compared with FABP4 selective inhibitor 8, the
expression of inflammatory cytokines were down-regulated by both of the dual FABP4/5
inhibitors A16 and B8 at 30 μM with statistical significance (compared to the LPS group),
especially reflected in the decreased expression of MCP-1 (29% and 32% decrease for A16 and
B8, respectively) and TNFα (24% and 23% decrease for A16 and B8, respectively). These results
also demonstrated that dual inhibition of FABP4 and FABP5 may provide a beneficial anti-
inflammatory effect.
A
B

Figure 6. (A) Effects of compounds 6, 8, A16, and B8 on the viability of RAW264.7
macrophages. Cell viability was determined by MTT assay. *P<0.05, ***P<0.001 vs. control
group. (B) Effects of compounds 6, 8, A16, and B8 on the expression of pro-inflammatory
cytokines of MCP-1, TNF-α, IL-6 and COX-2 in LPS-induced RAW264.7 macrophages.
Expression levels of cytokines were measured by quantitative PCR. *P<0.05, **P < 0.01, ***P <
0.001 vs. LPS group.
2.8 The Anti-inflammatory Mechanism of A16 and B8
As compounds A16 and B8 exhibited anti-inflammatory effects in LPS-stimulated RAW
264.7 cells. We preliminarily explored the mechanism of their anti-inflammatory effects. Studies
have shown that FABP4 can induce inflammatory responses through the activation of the IKK-
NF-κB and JNK-AP-1 pathways.48-49 In order to confirm whether our compounds work through
this mechanism, the level of NF-κB and IKK was examined using a western-blot analysis. As
shown in Figure 7, compared with the positive control (compound 6), there was an obvious
decrease of p-NF-κB and p-IKK levels when treated with compound 8, A16 and B8, especially for
the IKK activity at 60 μM, whose phosphorylation was apparently inhibited. The dual FABP4/5
inhibitor B8 were more potent than compound 8 on inhibiting the IKK phosphorylation. So, we
could infer that our compounds exerted anti-inflammatory activity at least partly by regulating the
IKK-NF-κB pathway.
Figure 7. Effects of compounds 6, 8, A16, and B8 on the expression of p-NF-κB/NF-κB, p-
IKK/IKK in LPS-induced RAW264.7 macrophage, which were analyzed by western blot.

*P<0.05, ***P < 0.001 vs. LPS group.
3. Conclusion
In the current study, we reported the identification of dual FABP4/5 inhibitors starting from a
potent and selective FABP4 inhibitor 8. By comparing the crystal structures of dual FABP4/5
inhibitor 7 with FABP5 and FABP4 selective inhibitor 8 with FABP4, bulkier substituents were
introduced into compound 8 to occupy the key binding pocket of FABP5, which led to the
discovery of two series of new dual FABP4/5 inhibitors with naphthalene-1-sulfonamide core.
Two potent dual FABP4/5 inhibitors A16 and B8 were identified. Compared with positive control
6, A16 and B8 exhibited better potency against FABP4/5 and higher selectivity profile over
FABP3. Molecular docking study of A16 with FABP4 and FABP5 validated our initial hypothesis.
A16 and B8 were more potent than compound 6 and selective FABP4 inhibitor 8 in cellular level
assay, not only reflected in the inhibition of forskolin-stimulated lipolysis in mature 3T3-L1
adipocytes, but also the anti-inflammatory effects in lipopolysaccharide-stimulated RAW264.7
macrophage. All these results demonstrated that dual suppression of FABP4 and FABP5 may
provide beneficial effects on metaflammation-related diseases. A16 and B8 would be promising
molecules for further investigation.
4. Experimental Section
4.1 Chemistry Methods
Unless otherwise noted, all reagents were obtained from commercial suppliers and used
without further purification. All starting materials were commercially available. Nuclear magnetic
resonance (NMR) spectroscopy were recorded with a 400MHz Varian or Bruker 600MHz NMR
spectrometer at ambient temperature. Chemical shifts (δ) were expressed in parts per million (ppm)
downfield from tetramethylsilane, and coupling constants (J) values were described as hertz. MS
was measured on Agilent 6120 quadrupole LC/MS. High resolution mass spectrometry (HRMS)
determinations for all new compounds were carried out on AB SCIWX TRIPLETOF 5600+.
4.2. Synthesis of Series A compounds
4.2.1. 5-((4-Ethoxynaphthalene)-1-sulfonamido)-2-fluorobenzoic acid (A1)
(i) Sodium 4-ethoxynaphthalene-1-sulfonate (10a)

To a solution of sodium 4-hydroxynaphthalene-1-sulfonate (2.0 g, 8.12 mmol) in ethanol (6
mL) was added water (6 mL), sodium hydroxide (813 mg, 20.31 mmol) and bromoethane (1.33 g,
o
12.18 mmol). The mixture was stirred at 80 C overnight in a seal tube. The mixture was cooled
and white solid precipitated. The resulting precipitated solid was filtered and the filtercake was
washed with dichloromethane to give 10a as a white solid. (1.92 g, yield 86.2 %). ESI-MS: [M-
H]– m/z: 251.1.
(ii) 4-Ethoxynaphthalene-1-sulfonyl chloride (11a)
To a solution of 10a (0.8 g, 2.92 mmol) in dimethyl formamide (10 mL) was added thionyl
o
chloride (520 mg, 4.38 mmol) dropwise at 0 C. Then, the mixture was moved to room
temperature and stirred for another 1 h. The mixture was poured into ice water and extracted with
ethyl acetate. The combined organic layer was washed with water, dried over anhydrous sodium
sulfate and concentrated to give the desired product (0.5 g, yield 63.3 %) as a yellow oil. Rf = 0.8
(1:4, ethyl acetate : petroleum ether). The product was used for the next step without further
purification.
(iii) Methyl 5-((4-ethoxynaphthalene)-1-sulfonamido)-2-fluorobenzoate (13a)
To a solution of 11a (500 mg, 1.85 mmol) in acetone (10 mL) was added 12 (380 mg, 1.85
mmol) and pyridine (0.45 mL, 5.54 mmol). The mixture was stirred at 55 oC for 1 h. The mixture
was concentrated, diluted with ethyl acetate and washed with 1M HCl and brine twice. Then, the
ethyl acetate layer was dried over anhydrous sodium sulfate and concentrated to give the crude
product. The crude product was purified by silica column eluting with petroleum ether/ethyl
acetate (5/1–2/1) to give the desired product (0.33 g, yield 44.3 %) as grey solid. Rf = 0.3 (1:3,
ethyl acetate: petroleum ether) .1H NMR (400 MHz, DMSO-d6) δ 10.74 (s, 1H), 8.63 (d, J = 8.6
Hz, 1H), 8.26 (d, J = 8.7 Hz, 1H), 8.13 (dd, J = 8.4, 3.1 Hz, 1H), 7.78 – 7.73 (m, 1H), 7.65 – 7.61
(m, 1H), 7.53 – 7.50 (m, 1H), 7.26 – 7.23 (m, 1H), 7.18 – 7.13 (m, 1H), 7.04 – 7.00 (m, 1H), 4.27
– 4.23 (m, 2H), 3.77 (s, 3H), 1.47 – 1.42 (m, 3H). ESI-MS: [M-H]– m/z : 402.1.
(iv) 5-((4-Ethoxynaphthalene)-1-sulfonamido)-2-fluorobenzoic acid (A1)
To a mixture of 13a (330 mg, 0.82 mmol) in methanol (5 mL) was added sodium hydroxide
(1 M, 10 mL), and the mixture was stirred at room temperature for 1 h. The solvent was removed
under vacuum, and the residue was acidified to pH = 2 with HCl (1 M) solution. The solution was
extracted with ethyl acetate twice and the combined organic layer was dried over anhydrous

sodium sulfate and concentrated in vacuum. The resulting residue was purified via silica gel
chromatography to give the desired compound as a white solid (233 mg, yield 73.2 %). mp 196–
197 oC. 1H NMR (400 MHz, DMSO-d6) δ 13.26 (s, 1H), 10.69 (s, 1H), 8.63 (d, J = 8.6 Hz, 1H),
8.28 (d, J = 8.4 Hz, 1H), 8.12 (d, J = 8.3 Hz, 1H), 7.76 (t, J = 7.8 Hz, 1H), 7.64 (t, J = 7.7 Hz, 1H),
7.48 (dd, J = 6.4, 2.9 Hz, 1H), 7.23 – 7.19 (m, 1H), 7.11 (t, J = 9.6 Hz, 1H), 7.04 (d, J = 8.4 Hz,
1H), 4.27 (q, J = 7.0 Hz, 2H), 1.46 (t, J = 6.9 Hz, 3H). 13C NMR (150 MHz, DMSO-d6) δ 164.27,
158.29, 158.03, 156.34, 133.68, 132.07, 128.46, 126.20, 125.02, 124.92, 124.76, 123.97, 122.42,
122.01, 119.49, 117.64, 103.16, 64.21, 14.18. ESI-HRMS [M-H]– calcd for C19H16FNO5S:
388.0660, found: 388.0651.
4.2.2. 2-Fluoro-5-((4-isopropoxynaphthalene)-1-sulfonamido)benzoic acid (A2)
Compound A2 was prepared as a white solid in a similar manner as described for compound
A1. Yield 75.3 %. mp 208–209 oC.1H NMR (400 MHz, DMSO-d6) δ 13.27 (s, 1H), 10.69 (s, 1H),
8.62 (d, J = 8.5 Hz, 1H), 8.27 (d, J = 8.4 Hz, 1H), 8.12 (d, J = 8.2 Hz, 1H), 7.75 (t, J = 7.8 Hz, 1H),
7.63 (t, J = 7.9 Hz, 1H), 7.49 (dd, J = 6.5, 3.1 Hz, 1H), 7.25 – 7.21 (m, 1H), 7.14 (d, J = 9.8 Hz,
1H), 7.08 (d, J = 9.0 Hz, 1H), 4.93 – 4.91 (m, 1H), 1.40 (d, J = 6.5 Hz 6H). 13C NMR (150 MHz,
DMSO-d6) δ 164.24, 158.02, 157.28, 156.33, 133.73, 132.05, 128.70, 126.08, 125.60, 124.95,
124.38, 123.93, 122.63, 121.93, 119.39, 117.67, 103.95, 70.61, 21.35. ESI-HRMS [M-H]– calcd
for C20H18FNO5S: 402.0817, found: 402.0809.
4.2.3. 5-((4-(Sec-butoxy)naphthalene)-1-sulfonamido)-2-fluorobenzoic acid (A3)
Compound A3 was prepared as a white solid in a similar manner as described for compound
A1. Yield: 78.5 %. mp 198–200 oC.1H NMR (400 MHz, DMSO-d6) δ 13.29 (s, 1H), 10.71 (s, 1H),
8.63 (d, J = 8.6 Hz, 1H), 8.28 (d, J = 8.4 Hz, 1H), 8.13 (d, J = 8.3 Hz, 1H), 7.76 (t, J = 8.0 Hz, 1H),
7.64 (t, J = 7.8 Hz, 1H), 7.50 – 7.49 (m, 1H), 7.24 (d, J = 9.2 Hz, 1H), 7.15 (d, J = 9.9 Hz, 1H),
7.08 (d, J = 8.7 Hz, 1H), 4.73 – 4.70 (m, 1H), 1.80 – 1.71 (m, 2H), 1.35 (d, J = 5.9 Hz, 3H), 0.97
(t, J = 7.5 Hz, 3H). 13C NMR (150 MHz, DMSO-d6) δ 164.24, 158.00, 157.53, 156.32, 133.74,
132.03, 128.72, 126.12, 125.63, 124.87, 124.37, 123.96, 122.55, 121.88, 119.34, 117.67, 103.90,
75.25, 28.26, 18.48, 9.25. ESI-HRMS [M-H]– calcd for C21H20FNO5S: 416.0973, found: 416.0971.
4.2.4. 2-Fluoro-5-((4-(pentan-2-yloxy)naphthalene)-1-sulfonamido)benzoic acid (A4)
Compound A4 was prepared as a white solid in a similar manner as described for compound
A1. Yield 44.8 %. mp 183–184 oC. 1H NMR (400 MHz, DMSO-d6) δ 13.27 (s, 1H), 10.70 (s, 1H),

8.61 (d, J = 8.6 Hz, 1H), 8.26 (d, J = 8.4 Hz, 1H), 8.11 (d, J = 8.4 Hz, 1H), 7.74 (t, J = 7.8 Hz, 1H),
7.63 (t, J = 7.7 Hz, 1H), 7.49 (dd, J = 6.4, 2.9 Hz, 1H), 7.25 – 7.21 (m, 1H), 7.14 (d, J = 9.8 Hz,
1H), 7.10 – 7.04 (m, 1H), 4.78 (q, J = 6.1 Hz, 1H), 1.80 – 1.76 (m, 1H), 1.69 – 1.65 (m, 1H), 1.48
– 1.37 (m, 2H), 1.34 (d, J = 6.0 Hz, 3H), 0.90 (t, J = 7.4 Hz, 3H). 13C NMR (150 MHz, DMSO-d6)
δ 164.26, 158.00, 157.54, 156.31, 133.73, 132.05, 128.72, 126.13, 125.62, 124.86, 124.36, 123.96,
122.56, 121.89, 119.46, 117.66, 103.84, 73.99, 37.61, 18.97, 17.92, 13.71. ESI-HRMS [M–H]–
calcd for C22H22FNO5S: 430.1130, found: 430.1132.
4.2.5. 2-Fluoro-5-((4-(pentyloxy)naphthalene)-1-sulfonamido)benzoic acid (A5)
Compound A5 was prepared as a white solid in a similar manner as described for compound
A1. Yield 75.4 %. mp 187–188 oC. 1H NMR (400 MHz, DMSO-d6) δ 13.27 (s, 1H), 10.68 (s, 1H),
8.63 (d, J = 8.6 Hz, 1H), 8.27 (d, J = 8.4 Hz, 1H), 8.11 (d, J = 8.4 Hz, 1H), 7.75 (t, J = 7.8 Hz, 1H),
7.65 (t, J = 7.7 Hz, 1H), 7.49 – 7.47 (m, 1H), 7.22 – 7.20 (m, 1H), 7.11 (t, J = 9.6 Hz, 1H), 7.04 (d,
J = 8.4 Hz, 1H), 4.21 (t, J = 6.4 Hz, 2H), 1.89 – 1.82 (m, 2H), 1.52 – 1.44 (m, 2H), 1.43 – 1.33 (m,
2H), 0.91 (t, J = 7.2 Hz, 3H). 13C NMR (150 MHz, DMSO-d6) δ 164.23, 158.40, 158.02, 156.34,
133.70, 132.08, 128.46, 126.24, 125.07, 124.91, 124.73, 123.99, 122.34, 121.94, 119.38, 117.66,
103.14, 68.37, 27.94, 27.61, 21.68, 13.71. ESI-HRMS [M-H]– calcd for C22H22FNO5S: 430.1130,
found: 430.1129.
4.2.6. 2-Fluoro-5-((4-(hexyloxy)naphthalene)-1-sulfonamido)benzoic acid (A6)
Compound A6 was prepared as a white solid in a similar manner as described for compound
A1. Yield 66.1 %. mp 190–192 oC.1H NMR (400 MHz, DMSO-d6) δ 13.22 (s, 1H), 10.69 (s, 1H),
8.63 (d, J = 8.6 Hz, 1H), 8.26 (d, J = 8.4 Hz, 1H), 8.12 (d, J = 8.3 Hz, 1H), 7.75 (t, J = 7.7 Hz, 1H),
7.64 (t, J = 7.7 Hz, 1H), 7.49 (dd, J = 6.3, 2.9 Hz, 1H), 7.23 – 7.19 (m, 1H), 7.10 (t, J = 9.6 Hz,
1H), 7.03 (d, J = 8.4 Hz, 1H), 4.19 (t, J = 6.4 Hz, 2H), 1.87 – 1.80 (m, 2H), 1.50 – 1.46 (m, 2H),
1.35 – 1.28 (m, 4H), 0.88 – 0.85 (m, 3H). 13C NMR (150 MHz, DMSO-d6) δ 164.27, 158.40,
158.02, 156.34, 133.70, 132.08, 128.47, 126.23, 125.08, 124.84, 124.75, 124.00, 122.33, 121.93,
119.47, 117.63, 103.14, 68.38, 30.76, 28.18, 25.08, 21.86, 13.68. ESI-HRMS [M-H]– calcd for
C23H24FNO5S: 444.1286, found: 444.1290.
4.2.7 2-Fluoro-5-((4-(heptyloxy)naphthalene)-1-sulfonamido)benzoic acid (A7)
Compound A7 was prepared as a white solid in a similar manner as described for compound
A1. Yield 87.4 %. mp 175–177 oC. 1H NMR (400 MHz, DMSO-d6) δ 13.30 (s, 1H), 10.73 (s, 1H),

8.64 (d, J = 8.6 Hz, 1H), 8.27 (d, J = 8.4 Hz, 1H), 8.13 (d, J = 8.3 Hz, 1H), 7.76 (t, J = 7.7 Hz, 1H),
7.65 (t, J = 7.7 Hz, 1H), 7.52 – 7.49 (m, 1H), 7.24 – 7.20 (m, 1H), 7.12 (t, J = 9.6 Hz, 1H), 7.03 (d,
J = 6.9, 1H), 4.20 (s, 2H), 1.86 – 1.82 (m, 2H), 1.50 – 1.45 (m, 2H), 1.35 – 1.27 (m, 6H), 0.87 –
0.83 (m, 3H). 13C NMR (150 MHz, DMSO-d6) δ 164.24, 158.40, 158.03, 156.35, 133.71, 132.08,
128.47, 126.22, 125.08, 124.85, 124.74, 124.00, 122.33, 121.92, 119.36, 117.65, 103.13, 68.38,
31.03, 28.23, 25.39, 21.86, 13.73. ESI-HRMS [M-H]– calcd for C24H26FNO5S: 458.1443, found:
458.1447.
4.4.8 2-Fluoro-5-((4-(octyloxy)naphthalene)-1-sulfonamido)benzoic acid (A8)
Compound A8 was prepared as a white solid in a similar manner as described for compound
A1. Yield 61.9 %. mp 152–153 oC. 1H NMR (400 MHz, DMSO-d6) δ 13.27 (s, 1H), 10.69 (s, 1H),
8.63 (d, J = 8.6 Hz, 1H), 8.26 (d, J = 8.4 Hz, 1H), 8.11 (d, J = 8.4 Hz, 1H), 7.75 (t, J = 7.8 Hz, 1H),
7.64 (t, J = 7.7 Hz, 1H), 7.49 (dd, J = 6.5, 2.8 Hz, 1H), 7.22 – 7.19 (m, 1H), 7.11 (t, J = 9.6 Hz,
1H), 7.03 (d, J = 8.4 Hz, 1H), 4.20 (t, J = 6.4 Hz, 2H), 1.86 – 1.82 (m, 2H), 1.51 – 1.47 (m, 2H),
1.35 – 1.23 (m, 8H), 0.86 – 0.82 (m, 3H). 13C NMR (150 MHz, DMSO-d6) δ 164.24, 158.40,
158.02, 156.34, 133.70, 132.08, 128.47, 126.22, 125.08, 124.88, 124.74, 124.00, 122.33, 121.92,
119.37, 117.65, 103.15, 68.39, 31.04, 28.51, 28.45, 28.21, 25.41, 21.89, 13.76. ESI-HRMS [M-
H]– calcd for C25H28FNO5S: 472.1599, found: 472.1601.
4.2.9 5-((4-(Decyloxy)naphthalene)-1-sulfonamido)-2-fluorobenzoic acid (A9)
Compound A9 was prepared as a white solid in a similar manner as described for compound
1
A1. Yield 63.7 %. mp 143–145 oC. H NMR (400 MHz, DMSO-d6) δ 10.67 (s, 1H), 8.63 (d, J =
8.7 Hz, 1H), 8.26 (d, J = 8.4 Hz, 1H), 8.11 (d, J = 8.4 Hz, 1H), 7.75 (t, J = 7.8 Hz, 1H), 7.63 (t, J
= 7.6 Hz, 1H), 7.47 (dd, J = 6.5, 2.8 Hz, 1H), 7.20 – 7.16 (m, 1H), 7.08 (t, J = 9.6 Hz, 1H) ,7.03 (d,
J = 8.4 Hz, 1H), 4.19 (t, J = 6.4 Hz, 2H), 1.85 – 1.82 (m, 2H), 1.50 – 1.46 (m, 2H), 1.34 – 1.21 (m,
12H), 0.84 – 0.81 (m, 3H). 13C NMR (150 MHz, DMSO-d6) δ 164.38, 158.38, 157.94, 156.26,
133.64, 132.05, 128.48, 126.18, 125.08, 124.80, 124.53, 124.03, 122.31, 121.92, 120.11, 117.51,
103.13, 68.36, 31.11, 28.78, 28.74, 28.52, 28.49, 28.21, 25.40, 21.90, 13.75. ESI-HRMS [M-H]–
calcd for C27H32FNO5S: 500.1912, found: 500.1916.
4.2.10 5-((4-(Dodecyloxy)naphthalene)-1-sulfonamido)-2-fluorobenzoic acid (A10)
Compound A10 was prepared as a white solid in a similar manner as described for compound
A1. Yield 83.1 %. mp 150–152 oC. 1H NMR (400 MHz, DMSO-d6) δ 13.27 (s, 1H), 10.68 (s, 1H),

8.63 (d, J = 8.6 Hz, 1H), 8.25 (d, J = 8.4 Hz, 1H), 8.11 (d, J = 8.4 Hz, 1H), 7.75 (t, J = 7.8 Hz, 1H),
7.63 (t, J = 7.7 Hz, 1H), 7.49 (dd, J = 6.4, 2.8 Hz, 1H), 7.22 – 7.18 (m, 1H), 7.10 (t, J = 9.6 Hz,
1H), 7.02 (d, J = 8.5 Hz, 1H), 4.19 (t, J = 6.3 Hz, 2H), 1.87 – 1.80 (m, 2H), 1.51 – 1.44 (m, 2H),
1.36 – 1.21 (m, 16H), 0.83 (t, J = 6.5 Hz, 3H). 13C NMR (150 MHz, DMSO-d6) δ 164.28,
158.39,158.00,156.32, 133.70, 132.06, 128.48, 126.16, 125.08, 124.78, 124.02, 122.31, 121.91,
119.56, 117.59, 103.10, 68.36, 31.11, 28.84, 28.78, 28.53, 28.21, 25.40, 21.91, 13.74. ESI-HRMS
[M-H]– calcd for C29H36FNO5S: 528.2225, found:528.2231.
4.2.11 5-((4-(Cyclopentyloxy)naphthalene)-1-sulfonamido)-2-fluorobenzoic acid (A11)
Compound A11 was prepared as a white solid in a similar manner as described for compound
A1. Yield 46.0 %. mp 217–219 oC. 1H NMR (400 MHz, DMSO-d6) δ 13.18 (s, 1H), 10.72 (s, 1H),
8.64 (d, J = 8.5 Hz, 1H), 8.25 (d, J = 8.4 Hz, 1H), 8.13 (d, J = 5.7 Hz, 1H), 7.78 – 7.74 (m, 1H),
7.66 – 7.62 (m, 1H), 7.51 – 7.49 (m, 1H), 7.26 – 7.23 (m, 1H), 7.14 (t, J = 10.0 Hz, 1H), 7.05 (d, J
= 8.4 Hz, 1H), 5.10 (s, 1H), 2.01 (s, 2H), 1.86 – 1.77 (m, 4H), 1.65 (s, 2H). 13C NMR (150 MHz,
DMSO-d6) δ 164.24, 158.02, 157.41, 156.34, 133.73, 131.98, 128.62, 126.15, 125.52, 124.96,
124.46, 123.95, 122.55, 121.95, 119.35, 117.67, 104.18, 79.99, 32.08, 23.52. ESI-HRMS [M-H]–
calcd for C22H20FNO5S: 428.0973, found: 428.0975.
4.2.12 5-((4-(Cyclohexyloxy)naphthalene)-1-sulfonamido)-2-fluorobenzoic acid (A12)
Compound A12 was prepared as a white solid in a similar manner as described for compound
1
A1. Yield 65.3 %. mp 213–214 oC. H NMR (400 MHz, DMSO-d6) δ 10.71 (s, 1H), 8.62 (d, J =
8.7 Hz, 1H), 8.29 (d, J = 8.4 Hz, 1H), 8.10 (d, J = 8.4 Hz, 1H), 7.75 (t, J = 7.8 Hz, 1H), 7.63 (t, J
= 7.6 Hz, 1H), 7.49 (dd, J = 6.3, 2.8 Hz, 1H), 7.24 – 7.10 (m, 1H), 7.15 – 7.10 (m, 2H), 4.72 (s,
1H), 1.99 – 1.96 (m, 2H), 1.74 (s, 2H), 1.65 – 1.61 (m, 2H), 1.55 – 1.37 (m, 4H). 13C NMR (150
MHz, DMSO-d6) δ 164.24, 158.00, 157.10, 156.31, 133.76, 132.00, 128.75, 126.13, 125.70,
124.88, 124.35, 123.95, 122.59, 121.84, 119.35, 117.67, 104.08, 74.94, 30.53, 24.85, 22.69. ESI-
HRMS [M-H]– calcd for C23H22FNO5S: 442.1130, found: 442.1131.
4.2.13 5-((4-(Cycloheptyloxy)naphthalene)-1-sulfonamido)-2-fluorobenzoic acid (A13)
Compound A13 was prepared as a white solid in a similar manner as described for compound
A1. Yield 58.2 %. mp 200–202oC. 1H NMR (400 MHz, DMSO-d6) δ 13.29 (s, 1H), 10.71 (s, 1H),
8.62 (d, J = 8.7 Hz, 1H), 8.28 (d, J = 8.4 Hz, 1H), 8.11 (d, J = 8.4 Hz, 1H), 7.75 (t, J = 7.8 Hz, 1H),
7.63 (t, J = 7.7 Hz, 1H), 7.49 (dd, J = 6.6, 2.8 Hz, 1H), 7.25 – 7.20 (m, 1H), 7.13 (t, J = 9.6 Hz,

1H), 7.03 (d, J = 8.5 Hz, 1H), 4.87 – 4.85 (m, 1H), 2.04 – 1.99 (m, 2H), 1.89 – 1.83 (m, 2H), 1.71
– 1.66 (m, 2H), 1.62 – 1.52 (m, 6H). 13C NMR (150 MHz, DMSO-d6) δ 164.24, 158.01, 157.12,
156.33, 133.76, 132.03, 128.74, 126.12, 125.70, 124.90, 124.30, 123.96, 122.60, 121.90, 119.36,
117.67, 104.09, 77.59, 32.63, 27.69, 22.16. ESI-HRMS [M-H]– calcd for C24H24FNO5S: 456.1286,
found: 456.1286.
4.2.14 5-((4-(Cyclooctyloxy)naphthalene)-1-sulfonamido)-2-fluorobenzoic acid (A14)
Compound A14 was prepared as a white solid in a similar manner as described for compound
A1. Yield 42.7%. mp 185–187oC. 1H NMR (400 MHz, DMSO-d6) δ 13.31 (s, 1H), 10.73 (s, 1H),
8.62 (d, J = 8.6 Hz, 1H), 8.27 (d, J = 8.4 Hz, 1H), 8.14 (d, J = 8.4 Hz, 1H), 7.75 (t, J = 7.8 Hz, 1H),
7.63 (t, J = 7.8 Hz, 1H), 7.53 – 7.49 (m, 1H), 7.26 – 7.22 (m, 1H), 7.18 – 7.10 (m, 1H), 7.02 (d, J
= 8.6 Hz, 1H), 4.85 – 4.81 (m, 1H), 1.94 – 1.90 (m, 4H), 1.79 –1.71 (m, 2H), 1.59 – 1.53 (m, 8H).
13C NMR (150 MHz, DMSO-d6) δ 164.25, 158.02, 157.04, 156.33, 133.75, 132.05, 128.76,
126.10, 125.76, 124.92, 124.30, 123.96, 122.62, 121.93, 119.39, 117.66, 104.11, 77.75, 30.51,
26.42, 24.76, 22.12. ESI-HRMS [M-H]– calcd for C25H26FNO5S: 470.1443, found: 470.1440.
4.2.15 5-((4-(Cyclohexylmethoxy)naphthalene)-1-sulfonamido)-2-fluorobenzoic acid (A15)
Compound A15 was prepared as a white solid in a similar manner as described for compound
A1. Yield 63.0%. mp 213–214oC. 1H NMR (400 MHz, DMSO-d6) δ 13.30 (s, 1H), 10.73 (s, 1H),
8.64 (d, J = 8.6 Hz, 1H), 8.28 (d, J = 8.4 Hz, 1H), 8.13 (d, J = 8.3 Hz, 1H), 7.76 (t, J = 7.8 Hz, 1H),
7.66 (t, J = 7.7 Hz, 1H), 7.51 (dd, J = 6.4, 2.9 Hz, 1H), 7.24 – 7.20 (m, 1H), 7.12 (t, J = 9.7 Hz,
1H), 7.02 (d, J = 8.4 Hz, 1H), 4.01 (d, J = 5.7 Hz, 2H), 1.87 (d, J = 11.6 Hz, 3H), 1.73 (d, J = 12.4
Hz, 2H), 1.67 (d, J = 11.8 Hz, 1H), 1.33 – 1.08 (m, 5H). 13C NMR (150 MHz, DMSO-d6) δ 164.25,
158.44, 158.01, 156.32, 133.70, 132.09, 128.45, 126.29, 125.12, 124.85, 124.71, 124.00, 122.34,
121.90, 119.45, 117.65, 103.13, 73.33, 36.86, 29.03, 25.80, 25.11. ESI-HRMS [M-H]– calcd for
C24H24FNO5S: 456.1286, found: 456.1284.
4.2.16 5-((4-(2-Cyclohexylethoxy)naphthalene)-1-sulfonamido)-2-fluorobenzoic acid (A16)
Compound A16 was prepared as a white solid in a similar manner as described for compound
A1. Yield 53.5 %. m.p 200–201oC. 1H NMR (400 MHz, DMSO-d6) δ 13.30 (s, 1H), 10.73 (s, 1H),
8.62 (d, J = 8.6 Hz, 1H), 8.24 (d, J = 8.4 Hz, 1H), 8.11 (d, J = 8.3 Hz, 1H), 7.75 (t, J = 7.7 Hz, 1H),
7.65 (t, J = 7.7 Hz, 1H), 7.50 – 7.48 (m, 1H), 7.23 – 7.19 (m, 1H), 7.11 (t, J = 9.6 Hz, 1H), 7.05 (d,
J = 8.5 Hz, 1H), 4.22 (t, J = 6.3 Hz, 2H), 1.77 – 1.72 (m, 4H), 1.67 – 1.50 (m, 4H), 1.25 – 1.14 (m,

3H), 1.02 – 0.96 (m, 2H). 13C NMR (150 MHz, DMSO-d6) δ 164.26, 158.41, 158.02, 156.34
133.72, 132.07, 128.46, 126.25, 125.08, 124.85, 124.75, 124.00, 122.35, 121.89, 119.39, 117.66,
103.16, 66.55, 35.57, 34.07, 32.47, 25.83, 25.53. ESI-HRMS [M-H]– calcd for
C25H26FNO5S:470.1443, found: 470.1443.
4.2.17 5-((4-(3-Cyclohexylpropoxy)naphthalene)-1-sulfonamido)-2-fluorobenzoic acid (A17)
Compound A17 was prepared as a white solid in a similar manner as described for compound
A1. Yield 78.1%. mp 176–177oC. 1H NMR (400 MHz, DMSO-d6) δ 13.32 (s, 1H), 10.73 (s, 1H),
8.64 (d, J = 8.6 Hz, 1H), 8.26 (d, J = 8.4 Hz, 1H), 8.13 (d, J = 8.3 Hz, 1H), 7.76 (t, J = 7.8 Hz, 1H),
7.65 (t, J = 7.7 Hz, 1H), 7.51 (dd, J = 6.3, 2.9 Hz, 1H), 7.24 – 7.20 (m, 1H), 7.12 (t, J = 9.6 Hz,
1H), 7.03 (d, J = 8.5 Hz, 1H), 4.18 (t, J = 6.3 Hz, 2H), 1.88 – 1.81 (m, 2H), 1.73 – 1.59 (m, 5H),
1.36 (dd, J = 9.6, 5.8 Hz, 2H), 1.30 – 1.07 (m, 4H), 0.88 (q, J = 11.8 Hz, 2H). 13C NMR (150 MHz,
DMSO-d6) δ 164.23, 158.40, 158.03, 156.34, 133.70, 132.08, 128.46, 126.23, 125.07, 124.88,
124.73, 124.00, 122.32, 121.92, 119.35, 117.66, 103.14, 68.73, 36.55, 33.16, 32.62, 25.98, 25.62.
ESI-HRMS [M-H]– calcd for C26H28FNO5S: 484.1559, found: 484.1602.
4.2.18 5-((4-(Adamantan-1-ylmethoxy)naphthalene)-1-sulfonamido)-2-fluorobenzoic acid (A18)
Compound A18 was prepared as a white solid in a similar manner as described for compound
A1. Yield 48.1%. mp 144–146oC. 1H NMR (400 MHz, DMSO-d6) δ 13.29 (s, 1H), 10.71 (s, 1H),
8.63 (d, J = 8.6 Hz, 1H), 8.32 (d, J = 8.4 Hz, 1H), 8.12 (d, J = 8.4 Hz, 1H), 7.76 (t, J = 7.7 Hz, 1H),
7.68 (t, J = 7.7 Hz, 1H), 7.50 (dd, J = 6.4, 2.8 Hz, 1H), 7.23 – 7.19 (m, 1H), 7.11 (t, J = 9.6 Hz,
1H), 7.02 (d, J = 8.5 Hz, 1H), 3.78 (s, 2H), 2.02 (s, 3H), 1.74 – 1.71 (m, 12H). 13C NMR (150
MHz, DMSO-d6) δ 164.24, 158.58, 158.00, 156.32, 133.71, 132.13, 128.45, 126.36, 125.21,
124.81, 124.67, 124.02, 122.29, 121.82, 119.30, 117.68, 103.10, 77.93, 38.94, 33.29, 27.35. ESI-
HRMS [M-H]– calcd for C28H28FNO5S: 508.1599, found: 508.1600.
4.2.19 2-Fluoro-5-((4-((tetrahydro-2H-pyran-4-yl)methoxy)naphthalene)-1-sulfonamido)benzoic
acid (A19)
Compound A19 was prepared as a white solid in a similar manner as described for compound
1
A1. Yield 65.1 %. mp 156–158oC. H NMR (400 MHz, DMSO-d6) δ 10.76 (s, 1H), 8.65 (d, J =
8.7 Hz, 1H), 8.27 (d, J = 8.6 Hz, 1H), 8.13 (d, J = 8.3 Hz, 1H), 7.74 (d, J = 8.3 Hz, 1H), 7.63 (t, J
= 7.9 Hz, 1H), 7.52 (d, J = 5.6 Hz, 1H), 7.23 (d, J = 9.0 Hz, 1H), 7.11 (t, J = 9.8 Hz, 1H), 6.98 (d,
J = 8.4 Hz, 1H), 3.99 (s, 2H), 3.87 (d, J = 11.2 Hz, 2H), 3.32 (t, J = 11.7 Hz, 2H), 2.08 (s, 1H),

1.69 (d, J = 13.1 Hz, 2H), 1.38 (q, J = 13.1 Hz, 2H). 13C NMR (150 MHz, DMSO-d6) δ 164.24,
158.30, 158.03, 156.35, 133.69, 132.07, 128.45, 126.32, 125.09, 124.94, 124.83, 124.01, 122.33,
121.93, 119.37, 117.68, 103.20, 72.59, 66.47, 34.24, 28.97. ESI-HRMS [M-H]– calcd for
C23H22FNO5S: 458.1079, found:458.1077.
4.2.20 2-Fluoro-5-((4-phenoxynaphthalene)-1-sulfonamido)benzoic acid (A20)
Compound A20 was prepared as a white solid in a similar manner as described for compound
1
A1. Yield 45.9 %. mp 221–223oC. H NMR (400 MHz, DMSO-d6) δ 10.78 (s, 1H), 8.71 (d, J =
8.5 Hz, 1H), 8.39 (d, J = 8.4 Hz, 1H), 8.10 (dd, J = 8.4, 2.8 Hz, 1H), 7.84 (t, J = 8.0 Hz, 1H), 7.73
(t, J = 8.1 Hz, 1H), 7.51 – 7.44 (m, 3H), 7.30 (t, J = 7.8 Hz, 1H), 7.24 – 7.19 (m, 3H), 7.13 (t, J =
9.5 Hz, 1H), 6.74 (dd, J = 8.3, 2.8 Hz, 1H). 13C NMR (150 MHz, DMSO-d6) δ 164.21, 158.16,
157.83, 156.48, 154.62, 133.49, 131.49, 130.34, 128.91, 127.43, 127.00, 125.52, 125.26, 125.15,
124.24, 122.38, 120.25, 119.54, 117.73, 108.06. ESI-HRMS [M-H]– calcd for C23H16FNO5S:
436.0660, found: 436.0662.
4.2.21 5-((4-(Benzyloxy)naphthalene)-1-sulfonamido)-2-fluorobenzoic acid (A21)
Compound A21 was prepared as a white solid in a similar manner as described for compound
A1. Yield 56.7%. mp 162–164oC. 1H NMR (400 MHz, DMSO-d6) δ 10.76 (s, 1H), 8.66 (d, J = 8.6
Hz, 1H), 8.28 (d, J = 8.4 Hz, 1H), 8.16 (d, J = 8.3 Hz, 1H), 7.77 (t, J = 7.7 Hz, 1H), 7.64 (t, J =
7.7 Hz, 1H), 7.55 – 7.51 (m, 3H), 7.42 (t, J = 7.3 Hz, 2H), 7.38 – 7.35 (m, 1H), 7.26 – 7.22 (m,
1H), 7.18 – 7.10 (m, 2H), 5.34 (s, 2H). 13C NMR (150 MHz, DMSO-d6) δ 164.24, 158.07, 158.02,
156.38, 135.99, 133.68, 131.91, 128.50, 128.42, 128.01, 127.66, 126.41, 125.21, 125.01, 124.03,
122.46, 122.01, 119.38, 117.70, 103.80, 70.01. ESI-HRMS [M-H]– calcd for C24H18FNO5S:
450.0817, found: 450.0813.
4.3. Synthesis of Series B compounds
4.3.1. 2-Fluoro-5-((4-methoxy-3-phenylnaphthalene)-1-sulfonamido)benzoic acid (B1)
(i) 2-Bromonaphthalen-1-ol (15)
1-Naphthol (10 g, 69.36 mmol) and diisopropylamine (0.972 mL, 6.94 mmol) was dissolved
in dichloromethane (100 mL). N-Bromosuccinimide (13.58 g, 76.3 mmol) was carefully added
and the reaction mixture was stirred at 40 °C overnight. The resulting mixture was allowed to cool
to room temperature, quenched with 2M H2SO4, and extracted with dichloromethane. The
combined organic layer was dried over anhydrous sodium sulfate and concentrated in vacuo. The

crude product was purified by silica gel column eluting with petroleum ether: ethyl acetate (20/1)
to give the desired product (11.2 g, yield 72.4 %) as a white solid. 1H NMR (400 MHz, CDCl3) δ
8.23 – 8.21 (m, 1H), 7.76 – 7.73 (m, 1H), 7.50 – 7.48 (m, 2H), 7.44 (d, J = 8.8 Hz, 1H), 7.28 (d, J
= 8.8 Hz, 1H), 5.97 (s, 1H). ESI-MS: [M-H]– m/z :221.0.
(ii) 2-Bromo-1-methoxynaphthalene (16)
A solution of 15 (10 g, 44.83 mmol), potassium hydroxide (5.03 g, 89.66 mmol), and methyl
iodide (16.74 mL, 268.98 mmol) in acetonitrile (80 mL) was stirred at 40 oC for 12 h. The mixture
was washed with water, extracted with dichloromethane, dried over anhydrous sodium sulfate and
concentrated in vacuo. The crude product was purified by silica gel column eluting with petroleum
ether: ethyl acetate (20/1) to give the desired product (9.1 g, yield 85.6%) as a white solid. Rf =
0.5 (1:6, ethyl acetate:petroleum ether).1H NMR (400 MHz, CDCl3) δ 8.14 (d, J = 7.2 Hz, 1H),
7.83 (d, J = 7.2 Hz,1H), 7.59 – 7.49 (m, 4H), 4.01 (s, 3H).
(iii) 3-Bromo-4-methoxynaphthalene-1-sulfonyl chloride (17)
To a solution of 16 (8.0 g, 33.74 mmol) in chloroform (50 mL) was added chlorosulfonic acid
o
(3.74 mL, 50.61 mmol) dropwise at 0 C, then the mixture was warmed to room temperature and
stirred for another 1 h. The mixture was poured into ice water and extracted with ethyl acetate
(150 mL× 2). The ethyl acetate layer was washed with water, dried over anhydrous sodium sulfate
and concentrated to give the desired product (9.3 g, yield 82.1%) as a colorless oil. Rf = 0.8 (1:4,
ethyl acetate:petroleum ether). ESI-MS: [M-H]– m/z: 314.7.
(iv) Methyl 5-((3-bromo-4-methoxynaphthalene)-1-sulfonamido)-2-fluorobenzoate (18)
To a solution of 17 (8.0 g, 23.84 mmol) in acetone (40 mL) was added pyridine (4.8 mL, 59.6
o
mmol) and 12 (4.03 g, 23.84 mmol), then the mixture was stirred at 55 C for 1 h. The mixture
was concentrated and the residue was diluted with ethyl acetate (200 mL). The ethyl acetate layer
was washed with 1M HCl solution and brine, dried over anhydrous sodium sulfate and
concentrated to give the crude product. The crude product was washed with ethyl acetate to give
the desired product (7.5 g, yield 67.2%) as a grey solid. Rf = 0.4 (1:2, ethyl acetate:petroleum
ether). 1H NMR (400 MHz, DMSO-d6) δ 11.02 (s, 1H), 8.66 (d, J = 8.4 Hz, 1H), 8.26 (s, 1H), 8.21
(d, J = 8.2 Hz, 1H), 7.82 (t, J = 7.7 Hz, 1H), 7.76 (t, J = 7.5 Hz, 1H), 7.52 – 7.49 (m, 1H), 7.32 –
7.27 (m, 1H), 7.21 (t, J = 19.3 Hz, 1H), 3.97 (s, 3H), 3.79 (s, 3H). ESI-MS: [M-H]– m/z: 466.0.
(v) Methyl 2-fluoro-5-((4-methoxy-3-phenylnaphthalene)-1-sulfonamido)benzonate (19a)

To a mixture of 18 (250 mg, 0.534 mmol) in dimethyl formamide (6 mL) was added water
(0.1 mL), potassium carbonate (147 mg, 1.07 mmol), phenylboronic acid (98 mg, 0.8 mmol) and
[1,1'-bis (diphenylphosphino) ferrocene] dichloropalladium (II)] (40 mg, 0.053 mmol). The
o
mixture was stirred at 100 C for 12 h under nitrogen atmosphere. The mixture was poured into
water and extracted with ethyl acetate (50 mL × 2), the ethyl acetate layer then was washed with
brine, dried over anhydrous sodium sulfate and concentrated to give the crude product. The crude
product was purified by silica gel column eluting with petroleum ether: ethyl acetate (5/1–2/1) to
give the desired product (210 mg, yield 84.5%). as a white solid. Rf = 0.3 (1:3, ethyl
acetate:petroleum ether). 1H NMR (400 MHz, DMSO-d6) δ 10.96 (s, 1H), 8.70 (d, J = 8.5 Hz, 1H),
8.30 (d, J = 8.3 Hz, 1H), 8.17 (s, 1H), 7.82 – 7.78 (m, 1H), 7.76 – 7.73 (m, 1H), 7.60 (d, J = 8.1
Hz, 2H), 7.57 – 7.53 (m, 3H), 7.49 – 7.44 (m, 1H), 7.33 – 7.29 (m, 1H), 7.23 – 7.18 (m, 1H), 3.73
(s, 3H), 3.53 (s, 3H). ESI-MS: [M-H]– m/z: 464.1.
(vi) 2-Fluoro-5-((4-methoxy-3-phenylnaphthalene)-1-sulfonamido) benzoic acid (B1)
To a solution of methyl 2-fluoro-5-((4-methoxy-3-phenylnaphthalene)-1-sulfonamido)
benzoate (210 mg, 0.45 mmol) in methanol (5 mL) was added 1 M sodium hydroxide (9 mL), the
mixture was stirred at room temperature for 1 h. The mixture was concentrated and diluted with
water, the water solution was washed with ethyl acetate (50 mL × 2). The water solution was then
acidified to pH = 2 by 1M HCl and white solid precipitated out. The white mixture then was
extracted with ethyl acetate (50 mL × 3). The ethyl acetate layer was washed with brine, dried
over anhydrous sodium sulfate and concentrated to give the desired product (160 mg, yield 78.5%)
1
as a white solid. Rf = 0.3 (1:3:0.5, ethyl acetate:petroleum ether:acetic acid). mp 232–234oC. H
NMR (400 MHz, DMSO-d6) δ 10.91 (s, 1H), 8.71 (d, J = 8.5 Hz, 1H), 8.30 (d, J = 8.3 Hz, 1H),
8.16 (s, 1H), 7.81 – 7.78 (m, 1H), 7.76 – 7.72 (m, 1H), 7.61 – 7.59 (m, 2H), 7.56 – 7.52 (m, 3H),
7.48 – 7.44 (m, 1H), 7.30 – 7.26 (m, 1H), 7.19 – 7.14 (m, 1H), 3.53 (s, 3H). 13C NMR (150 MHz,
DMSO-d6) δ 164.25, 158.16, 157.05, 156.48, 136.37, 133.53, 132.98, 129.30, 128.76, 128.66,
128.53, 128.13, 127.90, 127.40, 127.12, 125.27, 124.26, 123.27, 121.65, 119.41, 117.91, 61.31.
ESI-HRMS [M-H]– calcd for C24H18FNO5S: 450.0817, found: 450.0826.
4.3.2 2-Fluoro-5-((4-methoxy-3-(pyridin-4-yl)naphthalene)-1-sulfonamido)benzoic acid (B2)
Compound B2 was prepared as a brown solid in a similar manner as described for compound
B1. Yield 65.3 %. mp 231–233oC. 1H NMR (400 MHz, DMSO-d6) δ 8.76 – 8.72 (m, 3H), 8.31 (d,

J = 8.3 Hz, 1H), 8.19 (s, 1H), 7.83 (t, J = 7.6 Hz, 1H), 7.77 (t, J = 7.6 Hz, 1H), 7.65 (d, J = 5.0 Hz,
2H), 7.58 – 7.51 (m, 1H), 7.29 – 7.25 (m, 1H), 7.12 (t, J = 9.6 Hz, 1H), 3.59 (s, 3H).13C NMR
(150 MHz, DMSO-d6) δ 164.52, 157.99, 157.68, 156.31，149.97, 143.98, 133.50, 131.88, 130.10,
129.10, 128.78, 128.47, 127.65, 124.76, 124.66, 124.54, 123.54, 123.41, 121.64, 117.66, 62.06.
ESI-HRMS [M-H]– calcd for C23H17FN2O5S:451.0769, found: 451.0770.
4.3.3 2-Fluoro-5-((4-methoxy-3-(pyrimidin-4-yl)naphthalene)-1-sulfonamido)benzoic acid (B3)
Compound B3 was prepared as a white solid in a similar manner as described for compound
B1. Yield 55.9 %. mp 230–232oC. 1H NMR (400 MHz, DMSO-d6) δ 13.25 (s, 1H), 11.00 (s, 1H),
9.28 (s, 1H), 9.07 (s, 2H), 8.74 (d, J = 8.4 Hz, 1H), 8.32 – 8.28 (m, 2H), 7.85 (t, J = 7.8 Hz, 1H),
7.78 (t, J = 7.7 Hz, 1H), 7.53 (s, 1H), 7.32 – 7.28 (m, 1H), 7.14 (t, J = 9.7 Hz, 1H), 3.62 (s, 3H).
13C NMR (150 MHz, DMSO-d6) δ 164.28, 158.08, 158.01, 157.48, 156.48, 156.40, 133.40,
132.03, 130.25, 129.19, 128.91, 128.26, 127.74, 125.15, 124.46, 123.40, 121.59, 121.44, 119.34,
117.92, 62.27. ESI-HRMS [M-H]– calcd for C22H16FN3O5S:452.0722, found: 452.0727.
4.3.4 2-Fluoro-5-((3-(furan-3-yl)-4-methoxynaphthalene)-1-sulfonamido)benzoic acid (B4)
Compound B4 was prepared as a white solid in a similar manner as described for compound
B1. Yield 56.2 %. mp 218–220oC. 1H NMR (400 MHz, DMSO-d6) δ 13.31 (s, 1H), 10.92 (s, 1H),
8.69 (d, J = 6.2Hz, 1H), 8.33 (d, J = 13.1 Hz, 2H), 8.21 (d, J = 6.2 Hz, 1H), 7.87 (s, 1H), 7.76 –
7.70 (m, 2H), 7.59 – 7.56 (m, 1H), 7.32 – 7.28 (m, 1H), 7.17 – 7.12 (m, 1H), 7.02 (s, 1H), 3.79 (s,
3H). 13C NMR (150 MHz, DMSO-d6) δ 164.26, 158.17, 156.49, 156.24, 143.97, 141.98, 133.48,
130.54, 130.06, 128.68, 128.10, 127.76, 127.48, 125.23, 124.47, 123.01, 121.90, 120.25, 119.39,
119.28, 117.89, 60.85. ESI-HRMS [M-H]– calcd for C22H16FNO6S: 440.0610, found: 440.0615.
4.3.5 2-Fluoro-5-((4-methoxy-3-(1-methyl-1H-pyrazol-5-yl)naphthalene)-1-sulfonamido)benzoic
acid (B5)
Compound B5 was prepared as a white solid in a similar manner as described for compound
B1. Yield 58.8%. mp 230–232 oC. 1H NMR (400 MHz, DMSO-d6) δ 13.38 (s, 1H), 10.96 (s, 1H),
8.72 (d, J = 8.5 Hz, 1H), 8.33 (d, J = 8.3 Hz, 1H), 8.01 (s, 1H), 7.86 (t, J = 7.7 Hz, 1H), 7.78 (t, J
= 7.7 Hz, 1H), 7.60 (s, 1H), 7.48 – 7.46 (m, 1H), 7.26 – 7.24 (m, 1H), 7.16 (t, J = 9.6 Hz, 1H),
6.49 (s, 1H), 3.63 (s, 3H), 3.56 (s, 3H). 13C NMR (150 MHz, DMSO-d6) δ 164.31, 158.15, 158.09,
156.46, 138.26, 137.69, 133.42, 133.10, 129.27, 128.76, 128.14, 127.60, 125.33, 124.32, 123.47,