Design, synthesis, and biological evaluation of N,N-disubstituted-4-arylthiazole-2-methylamine derivatives as cholesteryl ester transfer inhibitors

Article abstract of DOI:10.3390/molecules22111925

Cholesteryl ester transfer protein (CETP) has been identified as a potential target for cardiovascular disease (CVD) for its important role in the reverse cholesteryl transfer (RCT) process. In our previous work, compound 5 was discovered as a moderate CETP inhibitor. The replacement of the amide linker by heterocyclic aromatics and then a series of N,N-substituted-4-arylthiazole-2-methylamine derivatives were designed by utilizing a conformational restriction strategy. Thirty-six compounds were synthesized and evaluated for their CETP inhibitory activities. Structure-activity relationship studies indicate that electron donor groups substituted ring A, and electron-withdrawing groups at the 4-position of ring B were critical for potency. Among these compounds, compound 30 exhibited excellent CETP inhibitory activity (IC₅₀ = 0.79 ± 0.02 μM) in vitro and showed an acceptable metabolic stability.

Full text of DOI:10.3390/molecules22111925

molecules
Article
Design, Synthesis, and Biological Evaluation of
N,N-Disubstituted-4-arylthiazole-2-methylamine
Derivatives as Cholesteryl Ester Transfer Inhibitors
Xinran Wang 1,†, Xuehua Lin 1,†, Xuanqi Xu 2, Wei Li 1, Lijuan Hao 1, Chunchi Liu 1,
Dongmei Zhao 1,
*
and Maosheng Cheng 1
ID
1
Key Laboratory of Structure-Based Drug Design & Discovery of Ministry of Education,
Shenyang Pharmaceutical University, Shenyang 110016, China; wangxinrancai@163.com (X.W.);
lin_xuehua1995@163.com (X.L.); 15542173071@163.com (W.L.); 18341482606@163.com (L.H.);
liuchunchi1990@163.com (C.L.); mscheng@263.net (M.C.)
Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53715, USA; xxu53@wisc.edu
Correspondence: medchemzhao@163.com; Tel.: +86-24-4352-0219
2
*
†
These authors contributed equally to this work.
Received: 15 October 2017; Accepted: 27 October 2017; Published: 7 November 2017
Abstract: Cholesteryl ester transfer protein (CETP) has been identified as a potential target for
cardiovascular disease (CVD) for its important role in the reverse cholesteryl transfer (RCT)
process. In our previous work, compound
5 was discovered as a moderate CETP inhibitor.
The replacement of the amide linker by heterocyclic aromatics and then a series of N,N-substituted-
4-arylthiazole-2-methylamine derivatives were designed by utilizing a conformational restriction
strategy. Thirty-six compounds were synthesized and evaluated for their CETP inhibitory activities.
Structure-activity relationship studies indicate that electron donor groups substituted ring A,
and electron-withdrawing groups at the 4-position of ring B were critical for potency. Among these
compounds, compound 30 exhibited excellent CETP inhibitory activity (IC50 = 0.79
in vitro and showed an acceptable metabolic stability.
±
0.02 µM)
Keywords: synthesis; N,N-disubstituted-4-arylthiazole-2-methylamine derivatives; CETP inhibitors
1. Introduction
Robust evidence suggests that a high level of low-density lipoprotein cholesterol (LDL-C) and a
low level of high-density lipoprotein cholesterol (HDL-C) are closely associated with cardiovascular
disease (CVD) [
reduces cardiovascular events by 22% [
be reduced 2% to 3% for each 0.1 mg/dL increase in HDL-C [
statins in clinical treatment for reducing LDL-C levels, the residual risk of CVD events remains at high
levels [ 10]. Plasma cholesteryl ester transfer protein (CETP), secreted mainly from the liver, plays a
1–4
]. Epidemiological studies have identified that each 1 mmol/L decrease of LDL-C
]. In contrast to LDL-C, the risk of cardiovascular events will
]. Despite the successful utilization of
5
6
7
–
coordinating part in reverse cholesteryl transfer (RCT) that facilitates the transfer of triglyceride and
cholesteryl ester (CE) between lipoproteins. The elevation of HDL-C via inhibiting CETP is an effective
strategy for reducing the risk of cardiovascular events.
Up to now, several CETP inhibitors have been reported, and four of them have exhibited
preeminent activity in phase III clinical trials (Figure 1) [11]. Torcetrapib was the first small molecule
CETP inhibitor be appraised in the clinic. Early evidence has demonstrated that torcetrapib exhibited
a dose-dependent increase of HDL-C greater than 100% and resulted in incremental LDL-C decreasing
by up to 42% in human studies. However, torcetrapib was prematurely halted because of off-target
hyperaldosteronism that lead to a 58% increase in deaths in the torcetrapib/atorvastatin group
Molecules 2017, 22, 1925; doi:10.3390/molecules22111925
www.mdpi.com/journal/molecules

Molecules 2017, 22, 1925
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compared to the atorvastatin group [12
–
14]. Compared with torcetrapib, dalcetrapib showed modest
CETP inhibition and no off-target effects. However, the phase III clinical trial was terminated due to the
fact that dalcetrapib did not significantly decrease the risk of cardiovascular events [15 16]. Recently,
,
DalCor Pharmaceuticals licensed dalcetrapib from Roche to conduct clinical trials for the treatment
of acute coronary syndrome. The effect of evacetrapib on a reduction in CVD events was similar to
trocetrapib, while avoiding torcetrapib’s side effects [17]. Subsequently, the ACCELERATE trials of
evacetrapib were terminated after just over two years, but the reason for failure has not been announced
by Lilly. Anacetrapib is currently ongoing in phase III trials at Merck and Co. (Kenilworth, NJ, USA)
for the treatment of coronary artery disease. More recently, Merck announced that anacetrapib
significantly reduced the incidence of major coronary events, while anacetrapib’s safety profile was
generally consistent with that of previous studies of the drug. The phase II clinical trials demonstrated
that AMG-899 seems to be free of the off-target effects of torcetrapib, effectively reduced LDL-C levels
by 45.3%, and increased HDL-C levels by 179.1% [18].
Figure 1. Representative cholesteryl ester transfer protein (CETP) inhibitors.
In previous work, we found that compound
the structure–activity relationship of compound
5
exhibited weak CETP inhibition activity. Based on
, we replaced amide fragments with different
5
heterocyclic aromatics and benzoheteroaromatics to decrease molecular flexibility while keeping
the key pharmacophores invariant. As shown in Figure 2, the replacement of amide linker with
seven fragments revealed a slight increase in activity, and the replacement of compound 17d with a
4-phenylthiazole side chain showed better CETP inhibition activities (IC50 = 9.03
±
0.21 µM). Under the
consideration of the structural novelty and the difficulty of synthesis, compound 17d was selected as
the leader for structure optimization, and a series of N,N-substituted-4-arylthiazole-2-methylamine
derivatives were synthesized. Further optimization efforts in part A and part B led to the discovery of
compound 30 (IC50 = 0.79 ± 0.02 µM).
Figure 2. Design of N,N-substituted-aryl-methylamines.

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2. Results and Discussion
2.1. Chemistry
1
Compounds 17a
for these target compounds are gave in supplementary materials. The commercially available
2-amino-1-phenylethan-1-one hydrochloride ( ) reacted with 2-chloroacetyl chloride to give
The resulting underwent cyclization reactions, respectively, with POCl3 and Lawesson’s reagent to
produce 13a and 13b. The treatment of with ethyl acetopyruvate achieved in moderate yield. Then 9
–g
were prepared according to Scheme 1 and H-NMR, 13C-NMR, HRMS
6
7.
7
8
9
was reacted with NaBH4 and, subsequently, SOCl2 to afford 13c. The key intermediate 11 was prepared
by 10 with ethyl 2-amino-2-thioxoacetate in ethanol under reflux conditions. In the next step, 11 was
treated with the same operation as
the cyclization of 12 14, and 15 with different derivatives of chloroacetic acid. Compounds 16a
obtained by the nucleophilic substitution of 13a and 3-phenoxyaniline in the presence of K2CO3
were treated with 1-(bromomethyl)-4-fluorobenzene to
9
to obtain 13d. Compounds 13e
–f
were respectively prepared from
,
–g
were
–
g
and KI in DMF. The secondary amines 16a
–g
generate target compounds 17a–g.
Scheme 1. Synthesis of target compounds 17a
TEA, DCM, 0 ◦C, 62.9%; (
) POCl3, CH3CN, reflux, 66.2%; (
59.6%; ( ) Ethyl acetopyruvate, EtOH, reflux, 43.6%; ( ) (i) NaBH4, THF, r.t.; (ii) SOCl2, DMF, r.t.,
75.9~80.5%; ( ) Ethyl 2-amino-2-thioxoacetate, EtOH, reflux, 73.6%; ( ) 2-Chloroacetic acid, POCl3,
reflux, 81.1%; ( ) 2-Chloroacetyl chloride, p-TsOH,
) Ethyl 2-chloroacetate, HCl, 110 ◦C, 91.3%; (
pyridine, chlorobenzene, reflux, 90.2%; ( ) 3-Phenoxyaniline, K2CO3, KI, DMF, r.t., 52.6~70.3%;
(k) 1-(Bromomethyl)-4-fluorobenzene, K2CO3, KI, DMF, r.t., 64.9~71.6%.
–
g. Reagents and conditions: (a) 2-Chloroacetyl chloride,
b
c) Lawesson’s reagent, THF, reflux,
d
e
f
g
h
i
j
The synthesis of compounds 21–
49 was outlined in Scheme 2 and 1H-NMR, 13C-NMR, HRMS for
these target compounds are gave in supplementary materials. The intermediate 18 was prepared
by the cyclization of 2-bromo-1-phenylethan-1-one with ethyl 2-amino-2-thioxoacetate in ethanol
under reflux conditions. Then the ester function in 18 was reduced with NaBH4 and reacted
subsequently with SOCl2 to afford 19. Compound 20 was obtained by the nucleophilic substitution
of 19 and 3-phenoxyaniline in the presence of K2CO3 and KI in DMF. Intermediate 20 and
1-(bromomethyl)-4-fluorobenzene underwent a nucleophilic reaction to get target compounds 21
to 49.

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Scheme 2. Synthesis of target compounds 21 to 49. Reagents and conditions: (
2-thioxoacetate, EtOH, reflux, 70.6~79.1%; ( ) ( ) NaBH4, THF, r.t.; (ii) SOCl2, DMF, r.t., 75.9~80.5%;
) Corresponding anilines, K2CO3, KI, DMF, r.t., 52.6~70.3%; ( ) 1-(Bromomethyl)-4-fluorobenzene,
a) Ethyl 2-amino-
b
i
(
c
d
K2CO3, KI, DMF, r.t., 64.9~71.6%.
2.2. In Vitro Activity and Structure–Activity Relationships
The biological activity of N,N-disubstituted-aryl-methylamine derivatives and reference
compound anacetrapib ( ) against CETP was evaluated by a BODIPY-CE fluorescence assay with the
4
CETP RP Activity Assay Kit (catalog # RB-RPAK; Roar, New York, NY, USA). The results showed that
most of the target compounds exhibit potent CETP inhibitory activity.
As shown in Table 1, 4-phenylthiazole (17d) revealed better activity than other links.
Further optimization based on N,N-substituted-4-arylthiazole-2-methylamine scaffolding was
underway, and in vitro activity against CETP is shown in Table 2. We investigated the relationship
between various groups at the 2-position, 3-position, and 4-position of the benzene (Ring A) and the
CETP inhibitory activity. The introduction of the 3,4-dimethoxy group (22, 30–33) was beneficial to
activity. The replacement of hydrogen by trifluoromethoxy (23) and N-methyl-5-yl-pyrazole (29) at
the 3-position was detrimental to activity. Changing the 3-H group to 3-OCH3 (21) and 3-CF3 (24
slightly decreased CETP inhibition activity. Thus, we could conclude that electron donor groups,
in particular the 3,4-dimethoxy group, substituted in ring A were conducive to activity. Next, the effect
of the aromatic ring on activity was investigated; then phenyl, 2-thienyl and N-methyl-5-yl-pyrazolyl
were induced to modify ring A. Specifically, it was observed that the activity of compound 27
)
(
IC50 = 1.02 ± 0.01 µM) was a seven-fold improvement over compound 26
and an eight-fold improvement over compound 25 (IC50 = 9.05 0.08
phenyl-substituted ring A at the 3-position (26), 2-thienyl (28) and N-methyl-5-yl-pyrazolyl (29
(
IC50 = 8.98 ± 0.05 µM
)
±
µM). Compared to the
)
showed no advantage. The results from the modification of the ring A moiety indicated that
phenyl-substituted compounds were favorable for activity compared to thienyl and pyrazolyl, and the
position of the phenyl group provided an important contribution to the inhibitory activity. However,
the potency of compound 30 (IC50 = 0.79
reason, the (3,4-dimethoxyl) phenyl fragment was chosen for further study of the relationship between
±
0.02 µM) was superior to compound 27, and, for that
ring B and the CETP inhibitory activity. For this purpose, another nineteen compounds, 31 to 49
were synthesized and evaluated for their activities. Compounds containing electron withdrawing
groups (31 to 33) at the 4-position of ring B revealed significant improvement of activity compared to
,
those compounds with electron donor groups (42 to 45). The nitro group at the 4-position of ring B (30
)
exhibited better potency of CETP inhibitory activity than that substituted at the 2-position (35) and the
3-position (34). The introduction of bromine (36), 1-methylpyrazole (37, 39), isoxazole (38), thiazole (40),
and benzene (41) was tolerated, but 4-morpholinyl (49) led to a disappearance of activity. Replacing the
nitro group on the 4-position of ring B with an ester side chain (48) caused nearly a 10-fold decrease of
activity. Changing the 4-NH2 group (44) to a 4-NHCOCH3 group (46) showed a dramatic decrease
in the activity; however, potency was recovered when modified by a 4-NHCOCF3 group (45) was
introduced. Based on these in vitro structure-activity relationshipstudies, we could speculate that

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electron-withdrawing groups at the 4-position of ring B provide an important contribution to the
potency compared with electron withdrawing groups and bulkier rigid fragments.
Table 1. Structures and activities of compounds 17a to g.
Compound
17a
Het
IC50 (µM)
Compound
17e
Het
IC50 (µM)
25.73 ± 0.41
26.87 ± 0.35
17b
10.60 ± 0.32
17.10 ± 0.44
17f
13.68 ± 0.63
17c
17g
15.23 ± 0.52
0.04 ± 0.01
17d
9.03 ± 0.21
Anacetrapib a
a
Used as a positive control.
Table 2. Structures and activities of compounds 21 to 49.
Compound
R1
R2
IC50 (µM)
Compound
36
R1
R2
4-Br
IC50 (µM)
8.96 ± 0.15
21
3-OCH3
—
13.96 ± 0.11
3,4-diOCH3
22
3,4-diOCH3
3-OCF3
—
3.58 ± 0.03
37
38
3,4-diOCH3
3,4-diOCH3
4.02 ± 0.05
7.57 ± 0.10
4-
4-
23
4-NO2
31.69 ± 0.25
24
25
3-CF3
4-Ph
4-NO2
4-NO2
13.79 ± 0.14
9.55 ± 0.08
39
40
3,4-diOCH3
3,4-diOCH3
6.38 ± 0.09
6.03 ± 0.04
4-
4-
26
27
3-Ph
2-Ph
4-NO2
4-NO2
8.98 ± 0.05
1.02 ± 0.01
41
42
3,4-diOCH3 [3,4-a] benzene
3.51 ± 0.06
14.05 ± 0.21
3,4-diOCH3
4-CH3
28
29
4-NO2
4-NO2
7.77 ± 0.13
43
44
3,4-diOCH3
4-OCH3
10.96 ± 0.31
3-
3-
24.56 ± 0.22
3,4-diOCH3
4-NH2
16.66 ± 0.23

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Table 2. Cont.
Compound
R1
R2
4-NO2
4-F
IC50 (µM)
Compound
R1
R2
IC50 (µM)
30
31
3,4-diOCH3
3,4-diOCH3
0.79 ± 0.02
2.46 ± 0.06
45
46
3,4-diOCH3
3,4-diOCH3
4-NHCOCF3
4-NHCOCH3
15.30 ± 0.17
>50 b
32
33
3,4-diOCH3
4-CF3
4-CN
0.97 ± 0.01
47
48
3,4-diOCH3
3,4-diOCH3
3.54 ± 0.03
8.40 ± 0.04
4-
4-
3,4-diOCH3
3,4-diOCH3
1.50 ± 0.03
1.38 ± 0.07
6.36 ± 0.12
>50 b
34
35
3-NO2
2-NO2
49
Anace a
3,4-diOCH3 4-morpholinyl
3,4-diOCH3
0.04 ± 0.01
a
Used as a positive control; b Considered with no CETP inhibition activity.
2.3. In Vitro Metabolic Stability Study
Based on the result of the in vitro CETP inhibitory assay, potent inhibitors 30 and 32 were
selected for the in vitro metabolic stability study. As shown in Table 3, compound 30 showed weak
stability, with a clearance rate of 48.1 and 121.7 µL/min/mg in human and rat liver microsomes,
while compound 32 exhibited acceptable stability, with a clearance rate of 29.8 and 79.3 µL/min/mg
in human and rat liver microsomes.
Table 3. In vitro metabolic stability study of 30, 32.
Human Liver Microsome Rat Liver Microsome
CL a
(µL/min/mg) (T = 60 min)
Remaining
Remaining
CL a
(µL/min/mg) (T = 60 min)
Remaining
Remaining
Compound
(NCF = 60 min) b
(NCF = 60 min) b
30
32
a
48.1
29.8
22.9%
39.3%
68.0%
69.1%
121.7
79.3
3.2%
10.1%
90.5%
101.3%
Clearance rate, CL < 100
µ
L/min/mg means acceptable stability; b The abbreviation of no co-factor. No NADPH
(nicotinamide adenine dinucleotide phosphate) regenerating system is added into NCF (no co-factor) sample
(replaced by buffer) during the 60 min incubation.
3. Experimental
3.1. Chemicals and Instruments
All chemicals and reagents were obtained from commercial sources and were used without
purification. TLC, performed on silica gel plates (Indicator F-254), was used to monitor the reactions.
Column chromatography, performed on silica gel (200 to 300 mesh) was utilized to purify the
compounds. The melting points (uncorrected) were determined on a Buchi 353 melting-point
apparatus. The purities of the target compounds were detected by HPLC, performed on a Waters
1525-2489 (Waters, Milford, MA, USA), with a chromatographic column (Kromasil, C-18, 5
150 mm × 4.6 mm), at 95%. The method conditions were as follows: a mixture of solvents H2O (A)
and CH3CN (B) (VA:VB = 5:95) as eluent and a flow rate of 1.0 mL/min. Peaks were detected at
= 254 nm. NMR spectra were collected on Bruker (Billerica, MA, USA) 400 MHz and 600 MHz
µm,
≥
λ
instruments, using tetramethylchlorosilane as an internal standard and CDCl3 or DMSO-d6 as solvent.
ESI-HRMS spectra were obtained on a Bruker Micromass time of flight mass spectrometer.
3.2. Synthesis
2-Chloro-N-(2-oxo-2-phenylethyl)acetamide (7). 2-amino-1-phenylethan-1-one hydrochloride 6 (0.50 g,
2.9 mmol) was dissolved in dichloromethane (10 mL), and triethylamine (13 mL, 8.9 mmol) was added.
The mixture was cooled, and 2-chloroacetyl chloride (0.45 g, 4.0 mmol) was added in drops at 0 ◦C.
After 2 h, the solution was recovered to room temperature for 16 h. Then the mixture was poured into
water (20 mL) and extracted with dichloromethane (10 mL
×
3), and the combined organic layers were
washed with water (10 mL 3) and brine (10 mL 3), dried over Na2SO4, and concentrated in vacuo.
×
×

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The residue was purified by chromatography on silica gel (petroleum ether:ethyl acetate = 4:1) to give
7 (0.39 g, 62.9%) as a white solid.
2-(Chloromethyl)-5-phenyloxazole (13a). Intermediate
7 (0.20 g, 1 mmol) was dissolved in acetonitrile
(10 mL), and phosphorus oxychloride (0.17 mL, 1.9 mmol) was added in a slow stream. The solution
was heated at reflux for 4 h and then cooled to room temperature and concentrated. Ethyl acetate
(20 mL) was added, washed with water and brine, dried over Na2SO4, and concentrated in vacuo.
The residue was purified by chromatography on silica gel (petroleum ether:ethyl acetate = 20:1) to give
13a (0.13 g, 66.2%) as a white solid.
2-(Chloromethyl)-5-phenylthiazole (13b). Intermediate
7 (0.30 g, 1.4 mmol) was dissolved in
tetrahydrofuran (5 mL), and Lawesson’s reagent (0.34 g, 0.80 mmol) was added. The solution was
heated at reflux for 4 h and then cooled to room temperature. The solvent was removed under
reduced pressure, and the resulting residue was dissolved in ethyl acetate. The solution was washed
with water and brine, dried over Na2SO4, and concentrated in vacuo. The residue was purified by
chromatography on silica gel (petroleum ether:ethyl acetate = 10:1) to give 13b (0.10 g, 59.6%) as a
white solid.
Ethyl 5-Methyl-1-phenyl-1H-pyrazole-3-carboxylate (9). Phenylhydrazine (0.50 g, 5.0 mmol) and ethyl
acetopyruvate (1.1 g, 7.0 mmol) were dissolved in ethanol (10 mL). After being heated at reflux for
2 h, the reaction mixture was cooled to room temperature and concentrated in vacuo. The residue
was dissolved in ethyl acetate, washed with water and brine, dried over Na2SO4, and concentrated in
vacuo. The residue was purified by chromatography on silica gel (petroleum ether:ethyl acetate = 10:1)
to give 9 (0.50 g, 43.6%) as a white solid.
3-(Chloromethyl)-5-methyl-1-phenyl-1H-pyrazole (13c). In a solution of intermediate 9 (92.1 mg, 0.40 mmol)
dissolved in ethanol (5 mL), sodium borohydride (19.0 mg, 0.50 mmol) was added. The mixture was
stirred at room temperature for 30 min, and then water was added. The solution was extracted
with ethyl acetate, and the combined organic layers were washed with water and brine, dried
over Na2SO4, and concentrated in vacuo. The residue was dissolved in DMF (2 mL); then thionyl
chloride (0.10 mL, 1.4 mmol) was added. After reflux for 1 h, water was added and extracted
with ethyl acetate. The combined organic layers were washed with water and brine, dried over
Na2SO4, and concentrated in vacuo. The residue was purified by chromatography on silica gel
(petroleum ether:ethyl acetate = 10:1) to give 13c (66.6 mg, 80.5%) as a white solid.
Ethyl 4-Phenylthiazole-2-carboxylate (11). A mixture of 2-bromo-1-phenylethan-1-one (0.50 g, 2.5 mmol)
and ethyl 2-amino-2-thioxoacetate (0.50 g, 3.8 mmol) was dissolved in ethanol (10 mL). The solution
was heated at reflux for 6 h and then cooled to room temperature. After being concentrated, the residue
was dissolved in ethyl acetate (20 mL); then the solution was washed with water and brine, dried over
Na2SO4, and concentrated in vacuo. The residue was purified by chromatography on silica gel
(petroleum ether:ethyl acetate = 20:1) to give 11 (0.43 g, 73.6%) as a white solid.
2-(Chloromethyl)-4-phenylthiazole (13d). The ester function in 11 was reduced with NaBH4 and reacted
subsequently with SOCl2 to afford 13d, and this operation was the same as the step in the synthetic
intermediate 13c. Compound 13d was obtained as a white solid. Yield: 75.9%.
2-(Chloromethyl)-5-phenyl-1,3,4-oxadiazole (13e). A mixture of benzohydrazide (0.50 g, 3.7 mmol),
2-chloroacetic acid (0.35 g, 3.7 mmol), and phosphorus oxychloride (1.0 mL, 11.0 mmol) was added to
a three-necked round bottom flask. The solution was heated at reflux for 6 h and then cooled to 0 ◦C
and neutralized to pH 9 with a saturated sodium carbonate aqueous solution. The precipitate was
filtered, washed with water, and dried under an infrared lamp. Compound 13e (0.58 g, 81.1%) was
obtained as a white solid.
2-(Chloromethyl)-1H-benzo[d]imidazole (13f). A mixture of benzene-1,2-diamine (2.0 g, 18.0 mmol)
and ethyl 2-chloroacetate, (2.6 mL, 24.0 mmol) was dissolved in dilute hydrochloric acid solution

Molecules 2017, 22, 1925
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(4 mol/L, 16 mL). The solution was heated at 110 ◦C for 4 h and then cooled to room temperature.
The reaction solution was poured into ice water and then neutralized to pH 9 with ammonium
hydroxide. The precipitate was filtered, washed with water, and dried under an infrared lamp to
obtain compound 13f (2.7 g, 91.3%) was obtained as a white solid.
2-(Chloromethyl)benzo[d]oxazole (13g). In a solution of 2-aminophenol (0.50 g, 4.6 mmol) dissolved in
chlorobenzene (5 mL), 2-chloroacetyl chloride (0.52 g, 4.6 mmol) and pyridine (0.02 mL) were added.
The mixture was stirred at room temperature for 2 h; then p-toluene sulfonic acid (0.08 g, 0.46 mmol)
was added. The mixture was heated at reflux for 8 h and then cooled to room temperature. The solvent
was removed under reduced pressure, and the resulting residue was dissolved in ethyl acetate (30 mL).
The solution was washed with water and brine, dried over Na2SO4, and concentrated in vacuo.
The residue was purified by chromatography on silica gel (petroleum ether:ethyl acetate = 10:1) to give
13g (0.70 g, 90.2%) as a yellow oil.
3-Phenoxy-N-((5-phenyloxazol-2-yl)methyl)aniline (16a). A mixture of 3-phenoxyaniline (0.20 g, 18.0 mmol)
and 13a (0.20 g, 18.0 mmol) was dissolved in DMF (10 mL), followed by the addition of potassium
carbonate (0.90 g, 6.48 mmol) and KI. The solution was stirred at room temperature for 12 h and
then poured into water and extracted with ethyl acetate. The combined organic layers were washed
with water and brine, dried over Na2SO4, and concentrated in vacuo. The residue was purified by
chromatography on silica gel (petroleum ether:ethyl acetate = 4:1) to give 16a (0.26 g, 70.3%) as a
colourless oil.
N-(4-Fluorobenzyl)-3-phenoxy-N-((5-phenyloxazol-2-yl)methyl)aniline (17a). Compound 16a (0.20 g,
0.60 mmol) was added to a solution of (Bromomethyl)-4-fluorobenzene (0.08 mL, 0.60 mmol) in
DMF (5 mL), followed by the addition of potassium carbonate (0.50 g, 3.6 mmol) and KI. The solution
was stirred at room temperature for 24 h and then poured into water and extracted with ethyl acetate.
The combined organic layers were washed with water and brine, dried over Na2SO4, and concentrated
in vacuo. The residue was purified by chromatography on silica gel (petroleum ether:ethyl acetate = 4:1)
◦
1
to give 17a (0.18 g, 66.9%) as a yellow solid. m.p. 81.0–82.4 C. H-NMR (400 MHz, DMSO-d6)
: 7.65~7.60 (m, 3H), 7.46 (t, J = 7.6 Hz, 2H), 7.38~7.27 (m, 5H), 7.18~7.11 (m, 3H), 7.06 (t, J = 7.4 Hz, 1H),
6.90 (d, J = 7.7 Hz, 2H), 6.61 (dd, J = 8.3, 2.2 Hz, 1H), 6.46 (t, J = 2.2 Hz, 1H), 6.26 (dd, J = 7.9, 1.8 Hz, 1H),
4.84 (s, 2H), 4.72 (s, 2H). 13C-NMR (150 MHz, DMSO-d6)
: 161.65(d, J = 240 Hz), 161.50, 157.82, 157.03,
151.18, 149.93, 135.13, 135.11, 130.67( 2), 130.26( 2), 129.55, 129.02, 128.97, 127.87, 124.26( 2), 123.52,
δ
δ
×
×
×
122.98, 118.77( 2), 115.75, 115.61, 108.70, 107.51, 104.09, 54.71, 48.70. HRMS calcd. for C29H23FN2O2,
×
[M + Na]+, 473.1641; found 473.1684. HPLC: tR = 11.84 min, 97.50%.
N-(4-Fluorobenzyl)-3-phenoxy-N-((5-phenylthiazol-2-yl)methyl)aniline (17b). Yellow solid, yield: 84.0%.
m.p. 90.5–92.5 ◦C. 1H-NMR (400 MHz, DMSO-d6)
δ: 8.13 (s, 1H), 7.65~7.60 (m, 2H), 7.43 (t, J = 7.5 Hz,
2H), 7.37~7.26 (m, 5H), 7.19~7.11 (m, 3H), 7.07 (t, J = 7.4 Hz, 1H), 6.91~6.86 (m, 2H), 6.59 (dd, J = 8.4,
2.2 Hz, 1H), 6.41 (t, J = 2.2 Hz, 1H), 6.27 (dd, J = 7.9, 1.9 Hz, 1H), 4.96 (s, 2H), 4.74 (s, 2H).
13C-NMR (150 MHz, DMSO-d6)
134.92, 131.32, 130.77, 130.25(
δ: 169.45, 161.69 (d, J = 240 Hz), 157.88, 156.93, 149.50, 138.98, 138.90,
×
2), 129.73(
×
2), 129.18, 129.13, 128.76, 126.76(
×
2), 123.57, 118.84( 2),
×
115.82, 115.68, 108.94, 107.62, 104.32, 54.47, 53.54. HRMS calcd. for C29H23FN2OS, [M + Na]+, 489.1413;
found 489.1462. HPLC: tR = 16.10 min, 95.77%.
N-(4-Fluorobenzyl)-N-((5-methyl-1-phenyl-1H-pyrazol-3-yl)methyl)-3-phenoxyaniline (17c). Yellow oil, yield:
64.9%. 1H-NMR (400 MHz, DMSO-d6)
δ
: 7.49~7.43 (m, 4H), 7.41~7.36 (m, 1H), 7.34~7.29 (m, 2H),
7.19~7.15 (m, 2H), 7.12~7.06 (m, 4H), 6.90~6.86 (m, 2H), 6.43~6.39 (m, 1H), 6.24~6.20 (m, 2H),
6.00 (s, 1H), 4.69 (s, 2H), 4.51 (s, 2H), 2.18 (s, 3H). 13C-NMR (150 MHz, DMSO-d6)
: 160.96
d, J = 240 Hz), 157.16, 156.37, 149.08, 147.95, 140.64, 139.21, 134.39, 130.02, 129.64( 2), 128.99( 2),
δ
(
×
×
128.27, 128.22, 127.27, 124.17(
×
2), 122.90, 118.14( 2), 115.13, 114.99, 107.92, 106.47, 106.02,
×
103.20, 53.23, 47.01, 13.15. HRMS calcd. for C30H26FN3O, [M + H]+, 464.2138; found 464.2176.
HPLC: tR = 10.74 min, 97.05%.

Molecules 2017, 22, 1925
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N-(4-Fluorobenzyl)-3-phenoxy-N-((4-phenylthiazol-2-yl)methyl)aniline (17d). Colourless oil, yield: 70.3%.
1H-NMR (400 MHz, DMSO-d6)
: 8.02 (s, 1H), 7.95~7.91 (m, 2H), 7.44 (t, J = 7.5 Hz, 2H),
δ
7.37~7.31 (m, 3H), 7.29~7.25 (m, 2H), 7.19~7.11 (m, 3H), 7.03 (t, J = 7.4 Hz, 1H), 6.90~6.86 (m, 2H),
6.58 (dd, J = 8.3, 2.2 Hz, 1H), 6.42 (t, J = 2.2 Hz, 1H), 6.26 (dd, J = 8.0, 2.0 Hz, 1H), 5.02 (s, 2H), 4.75 (s, 2H).
13C-NMR (150 MHz, DMSO-d6)
134.95, 134.54, 130.75, 130.25(
δ: 170.52, 161.68 (d, J = 241 Hz), 157.88, 156.91, 154.70, 149.51, 134.97,
×
2), 129.25(
×
2), 129.21, 129.16, 128.47, 126.42(
×
2), 123.55, 118.81( 2),
×
115.80, 115.65, 114.58, 108.90, 107.62, 104.27, 54.49, 53.63. HRMS calcd. for C29H23FN2OS, [M + Na]+,
489.1413; found 489.1467. HPLC: tR = 17.55 min, 98.71%.
N-(4-Fluorobenzyl)-3-phenoxy-N-((5-phenyl-1,3,4-oxadiazol-2-yl)methyl)aniline (17e). White solid, yield:
64.9%. m.p. 97.3–98.2 ◦C. 1H-NMR (400 MHz, CDCl3)
δ
: 7.99 (d, J = 7.0 Hz, 2H), 7.58~7.48 (m, 3H),
7.32~7.26 (m, 4H), 7.21 (t, J = 8.2 Hz, 1H), 7.11~6.97 (m, 5H), 6.71 (dd, J = 8.3, 2.0 Hz, 1H), 6.60 (s, 1H),
6.47 (d, J = 8.0 Hz, 1H), 4.78 (s, 2H), 4.67 (s, 2H). 13C-NMR (150 MHz, DMSO-d6)
: 164.72, 164.67, 161.68
(d, J = 241 Hz), 157.88, 157.03, 149.70, 134.90, 134.88, 132.53, 130.77, 130.27( 2), 129.93, 129.07, 129.01,
δ
×
126.91(
×
2), 123.68, 123.56, 118.78( 2), 115.78, 115.64, 108.88, 107.87, 104.33, 54.49, 49.07. HRMS calcd.
×
for C28H22FN3O2, [M + Na]+, 474.1594; found 474.1638. HPLC: tR = 8.75 min, 96.33%.
N-((1H-Benzo[d]imidazol-2-yl)methyl)-N-(4-fluorobenzyl)-3-phenoxyaniline (17f). Yellow oil, yield: 57.3%.
1H-NMR (600 MHz, DMSO-d6)
δ: 7.65~7.60 (m, 1H), 7.42~7.39 (m, 1H), 7.31 (t, J = 7.9 Hz, 2H),
7.20~7.15 (m, 4H), 7.12~7.06 (m, 3H), 7.04 (t, J = 8.1 Hz, 1H), 6.93 (d, J = 7.8 Hz, 2H), 6.52~6.45 (m, 2H),
6.36 (t, J = 2.1 Hz, 1H), 6.16 (dd, J = 7.9, 2.0 Hz, 1H), 5.55 (s, 2H), 4.52 (d, J = 5.1 Hz, 2H).
13C-NMR (150 MHz, DMSO-d6)
135.93, 133.48, 130.52, 130.26(
δ: 161.90 (d, J = 241 Hz), 157.88, 157.29, 152.73, 150.39, 142.43,
×
2), 129.34, 129.28, 123.44, 122.81, 122.16, 119.42, 118.83( 2), 115.97,
×
115.83, 110.90, 108.31, 106.99, 103.35, 46.16, 41.14. HRMS calcd. for C27H22FN3O, [M + H]+, 424.1825;
found 424.1859. HPLC: tR = 5.72 min, 97.98%.
N-(Benzo[d]oxazol-2-ylmethyl)-N-(4-fluorobenzyl)-3-phenoxyaniline (17g). Colourless oil, yield: 71.0%.
1H-NMR (400 MHz, DMSO-d6)
δ
: 7.74~7.67 (m, 2H), 7.40~7.32 (m, 4H), 7.27~7.21 (m, 2H),
7.17~7.03 (m, 4H), 6.89~6.85 (m, 2H), 6.58 (dd, J = 8.3, 2.2 Hz, 1H), 6.41 (t, J = 2.2 Hz, 1H), 6.24 (dd, J = 8.0
1.9 Hz, 1H), 5.01 (s, 2H), 4.76 (s, 2H). 13C-NMR (150 MHz, DMSO-d6)
: 164.45, 161.66 (d, J = 241 Hz),
157.89, 156.89, 150.76, 149.81, 141.04, 135.06, 130.72, 130.21( 2), 128.95, 128.90, 125.59, 124.96, 123.56,
120.10, 118.83( 2), 115.78, 115.64, 111.28, 108.50, 107.39, 103.89, 54.81, 48.96. HRMS calcd. for
,
δ
×
×
C27H21FN2O2, [M + H]+, 425.1665; found 425.1725. HPLC: tR = 18.55 min, 96.41%.
3.3. General Procedure for the Synthesis of Compounds 21–49
A mixture of substituted 2-bromo-1-phenylethan-1-one (2.5 mmol) and ethyl 2-amino-
2-thioxoacetate (3.8 mmol) was dissolved in ethanol (10 mL). The solution was heated at reflux
for 6 h and then cooled to room temperature. After being concentrated, the residue was dissolved
in ethyl acetate (20 mL); then the solution was washed with water and brine, dried over Na2SO4,
and concentrated in vacuo. The residue was purified by chromatography on silica gel to give 18
The intermediate 19 was obtained by an operation similar to that described for the preparation of 13c
.
.
Subsequently, substituted arylamine reacted with 19 according to the synthesis condition of compound
16a to produce 20. Finally, target compounds 21 to 49 were prepared according to the procedure for
17a, except that different substrates were used.
N-(4-Fluorobenzyl)-3-methoxy-N-((4-phenylthiazol-2-yl)methyl)aniline (21). Colourless oil, yield: 64.1%.
1H-NMR (400 MHz, DMSO-d6)
δ: 8.00 (s, 1H), 7.98~7.94 (m, 2H), 7.45 (t, J = 7.6 Hz, 2H),
7.39~7.32 (m, 3H), 7.17 (t, J = 12.3 Hz, 2H), 7.04 (t, J = 8.2 Hz, 1H), 6.39 (dd, J = 8.3, 2.2 Hz, 1H),
6.31 (t, J = 2.2 Hz, 1H), 6.27 (dd, J = 8.1, 2.1 Hz, 1H), 5.01 (s, 2H), 4.76 (s, 2H), 3.62 (s, 3H).
13C-NMR (150 MHz, DMSO-d6)
135.30, 134.56, 130.30, 129.28(
δ
: 171.03, 162.47~160.87 (d, J = 240 Hz), 160.66, 154.60, 149.19,
×
3), 129.22, 128.47, 126.40( 2), 115.76, 115.62, 114.61, 106.54, 102.82,
×

Molecules 2017, 22, 1925
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100.12, 55.18, 54.44, 53.62. HRMS calcd. for C24H21FN2OS, [M + H]+, 405.1437; found 405.1480.
HPLC: tR = 8.71 min, 95.81%.
N-(4-Fluorobenzyl)-3,4-dimethoxy-N-((4-phenylthiazol-2-yl)methyl)aniline (22). Colourless oil, yield: 65.6%.
1H-NMR (600 MHz, DMSO-d6)
δ: 7.99 (s, 1H), 7.96~7.92 (m, 2H), 7.44 (t, J = 7.7 Hz, 2H),
7.40~7.36 (m, 2H), 7.34 (t, J = 7.4 Hz, 1H), 7.16 (t, J = 8.9 Hz, 2H), 6.74 (d, J = 8.8 Hz, 1H),
6.56 (d, J = 2.8 Hz, 1H), 6.27 (dd, J = 8.8, 2.8 Hz, 1H), 4.90 (s, 2H), 4.65 (s, 2H), 3.62 (d, J = 6.6 Hz,
6H). 13C-NMR (150 MHz, DMSO-d6)
δ: 171.25, 161.67 (d, J = 240 Hz), 154.40, 149.86, 142.94, 142.04,
135.47, 134.59, 130.06, 129.69, 129.28(
×
2), 129.45, 126.37( 2), 115.67, 115.53, 114.67, 113.96, 106.28,
×
101.19, 56.54, 55.79, 55.27, 54.19. HRMS calcd. for C25H23FN2O2S, [M + Na]+, 457.1362; found 457.1409.
HPLC: tR = 7.11 min, 98.24%.
N-(4-Fluorobenzyl)-N-((4-(4-nitrophenyl)thiazol-2-yl)methyl)-3-(trifluoromethoxy)aniline (23). Colourless oil,
1
yield: 54.9%. H-NMR (600 MHz, DMSO-d6)
δ
: 8.39 (s, 1H), 8.31 (d, J = 9.0 Hz, 2H), 8.22 (d, J = 9.0 Hz
,
2H), 7.40~7.35 (m, 2H), 7.24 (t, J = 8.3 Hz, 1H), 7.21~7.16 (m, 2H), 6.81 (dd, J = 8.5, 2.4 Hz, 1H),
6.72 (s, 1H), 6.61 (d, J = 8.1 Hz, 1H), 5.11 (s, 2H), 4.82 (s, 2H). 13C-NMR (150 MHz, DMSO-d6)
δ
: 171.07, 161.76 (d, J = 241 Hz), 152.47, 149.92, 149.43, 147.14, 140.39, 134.54, 131.01, 129.30, 129.25,
127.31(
×
2), 124.75( 2), 119.15, 115.87, 115.73, 112.34, 109.27, 105.94, 62.92, 54.30, 53.32. HRMS calcd.
×
for C24H17F4N3O3S, [M + H]+, 504.1005; found 504.1063. HPLC: tR = 12.63 min, 95.83%.
N-(4-Fluorobenzyl)-N-((4-(4-nit◦rophenyl)thiazol-2-yl)methyl)-3-(trifluoromethyl)aniline (24). Brown solid,
yield: 65.9%. m.p. 107.0–108.4 C. 1H-NMR (600 MHz, CDCl3)
δ: 8.31~8.27 (m, 2H), 8.06~8.03 (m, 2H),
7.61 (s, 1H), 7.31 (t, J = 8.0 Hz, 1H), 7.26 (d, J = 7.2 Hz, 2H), 7.14 (s, 1H), 7.07~7.03 (m, 3H),
6.97 (dd, J = 8.4, 2.6 Hz, 1H), 4.92 (s, 2H), 4.73 (s, 2H). 13C-NMR (150 MHz, DMSO-d6)
: 170.91,
161.76 (d, J = 241 Hz), 152.48, 148.16, 147.15, 140.37, 134.49, 130.57, 129.27, 129.23, 127.30( 2),
125.71, 124.75( 2), 123.91, 119.19, 117.13, 115.91, 115.77, 113.85, 109.41, 54.26, 53.21. HRMS calcd.
for C24H17F4N3O2S, [M + H]+, 488.1056; found 488.1104. HPLC: tR = 9.95 min, 96.05%.
δ
×
×
N-(4-Fluorobenzyl)-N-((4-(4-nitrophenyl)thiazol-2-yl)methyl)-[1,10-biphenyl]-4-amine (25). Light yellow
solid, yield: 54.9%. m.p. 164.5–166.2 ◦C. 1H-NMR (600 MHz, DMSO-d6)
: 8.38 (s, 1H),
8.34~8.30 (m, 2H), 8.25~8.22 (m, 2H), 7.54 (dd, J = 8.3, 1.1 Hz, 2H), 7.48 (d, J = 8.9 Hz, 2H),
7.41~7.35 (m, 4H), 7.23 (dt, J = 8.5, 1.1 Hz, 1H), 7.21~7.16 (m, 2H), 6.88 (d, J = 9.0 Hz, 2H), 5.10 (s, 2H)
4.84 (s, 2H). 13C-NMR (150 MHz, DMSO-d6)
: 172.20, 161.72 (d, J = 240 Hz), 152.53, 147.20, 147.11,
140.48, 140.39, 135.08, 129.59, 129.29, 129.24( 3), 127.80( 2), 127.33( 2), 126.65, 126.12( 2), 124.77( 2),
119.07, 115.85, 115.70, 113.94(
2), 54.34, 54.35. HRMS calcd. for C29H22FN3O2S, [M + H]+, 496.1495;
δ
,
δ
×
×
×
×
×
×
found 496.1552. HPLC: tR = 14.39 min, 97.20%.
N-(4-Fluorobenzyl)-N-((4-(4-nitrophenyl)thi◦azol-2-yl)methyl)-[1,10-biphenyl]-3-amine (26). Light yellow
1
solid, yield: 59.8%. m.p. 149.5–150.8 C. H-NMR (600 MHz, CDCl3)
δ: 8.27 (d, J = 8.8 Hz,
2H), 8.04 (d, J = 8.8 Hz, 2H), 7.59 (s, 1H), 7.48 (d, J = 7.3 Hz, 2H), 7.37 (t, J = 7.5 Hz, 2H),
7.32~7.27 (m, 4H), 7.10 (s, 1H), 7.06~7.02 (m, 3H), 6.83 (dd, J = 8.3, 2.3 Hz, 1H), 4.93 (s, 2H), 4.75 (s, 2H)
13C-NMR (150 MHz, DMSO-d6)
: 172.05, 161.70 (d, J = 240 Hz), 152.33, 148.25, 147.12, 141.53, 141.24,
.
δ
140.46, 135.22, 130.16, 129.37, 129.31, 129.25(
×
2), 127.82, 127.32(
×
2), 127.12(
×
2), 124.76( 2), 119.21,
×
116.52, 115.83, 115.69, 112.88, 112.12, 55.47, 53.52. HRMS calcd. for C29H22FN3O2S, [M + H]+, 496.1495;
found 496.1567. HPLC: tR = 13.88 min, 96.81%.
N-(4-Fluorobenzyl)-N-((4-(4-nitrophenyl)thiazol-2-yl)methyl)-[1,10-biphenyl]-2-amine (27). Colourless oil,
1
yield: 50.4%. H-NMR (600 MHz, DMSO-d6)
δ
: 8.31 (s, 1H), 8.28 (d, J = 8.9 Hz, 2H), 8.17 (d, J = 8.9 Hz
,
2H), 7.61 (d, J = 7.2 Hz, 2H), 7.49 (t, J = 7.6 Hz, 2H), 7.37 (t, J = 7.4 Hz, 1H), 7.23~7.19 (m, 2H),
7.13~7.10 (m, 3H), 7.10~7.04 (m, 3H), 4.31 (s, 2H), 4.00 (s, 2H). 13C-NMR (150 MHz, DMSO-d6)
δ
: 171.99, 161.71 (d, J = 240 Hz), 160.91, 152.34, 148.26, 147.09, 141.54, 141.24, 140.45, 135.17, 130.16,
129.35, 129.30, 129.24(
×
2), 127.80, 127.29(
×
2), 127.11(
×
2), 124.72( 2), 119.17, 116.54, 115.82, 115.68,
×
112.88, 112.13, 54.48, 53.51. HRMS calcd. for C29H22FN3O2S, [M + H]+, 496.1495; found 496.1563.
HPLC: tR = 15.05 min, 95.79%.

Molecules 2017, 22, 1925
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N-(4-Fluorobenzyl)-N-((4-(4-nitrophenyl)thiazol-2-yl)methyl)-3-(thiophen-2-yl)aniline (28). Dark yellow
solid, yield: 63.1%. m.p. 143.9–148.8 ◦C. 1H-NMR (600 MHz, DMSO-d6)
8.38 (s, 1H),
δ:
8.32 (d, J = 8.7 Hz, 2H), 8.24 (d, J = 8.7 Hz, 2H), 7.46 (d, J = 5.0 Hz, 1H), 7.41 (dd, J = 8.0, 5.8 Hz,
2H), 7.35 (d, J = 3.5 Hz, 1H), 7.18 (dd, J = 16.3, 8.2 Hz, 3H), 7.07 (t, J = 4.1 Hz, 2H), 6.96 (d, J = 7.5 Hz,
1H), 6.75 (dd, J = 8.3, 1.9 Hz, 1H), 5.12 (s, 2H), 4.84 (s, 2H). 13C-NMR (150 MHz, DMSO-d6)
δ: 171.84,
161.71 (d, J = 240 Hz), 152.38, 148.22, 148.12, 144.44, 140.46, 135.14, 134.90, 130.34, 129.36, 129.30,
128.75, 127.33(
×
2), 125.90, 124.76( 2), 123.91, 119.18, 115.85, 115.70, 115.31, 113.07, 110.66, 54.51, 53.55.
×
HRMS calcd. for C27H20FN3O2S2, [M + H]+, 502.1059; found 502.1118. HPLC: tR = 14.17 min, 98.03%.
N-(4-Fluorobenzyl)-3-(1-methyl-1H-pyrazol-5-yl)-N-((4-(4-nitrophenyl)thiazol-2-yl)methyl)aniline (29) Brown
solid, yield: 68.9%. m.p. 102.2–104.5 ◦C. 1H-NMR (600 MHz, DMSO-d6)
δ: 8.38 (s, 1H),
8.32 (d, J = 8.9 Hz, 2H), 8.22 (d, J = 8.9 Hz, 2H), 7.43~7.37 (m, 3H), 7.26 (t, J = 8.0 Hz, 1H),
7.19 (t, J = 8.8 Hz, 2H), 6.87 (dd, J = 8.4, 2.2 Hz, 1H), 6.84 (s, 1H), 6.80 (d, J = 7.5 Hz, 1H),
6.24 (d, J = 1.8 Hz, 1H), 5.14 (s, 2H), 4.85 (s, 2H), 3.59 (s, 3H). 13C-NMR (150 MHz, DMSO-d6)
δ: 171.92,
161.72 (d, J = 241 Hz), 152.46, 148.22, 147.11, 143.64, 140.41, 138.26, 134.99, 131.29, 130.05, 129.27,
129.22, 127.29(
×
2), 124.73( 2), 119.09, 117.99, 115.84, 115.70, 115.04, 113.58, 106.05, 54.48, 53.64, 49.08.
×
HRMS calcd. for C27H22FN5O2S, [M + H]+, 500.1556; found 500.1626. HPLC: tR = 6.76 min, 95.89%.
N-(4-Fluorobenzyl)-3,4-dimethoxy-N-((4-(4-nitrophenyl)thiazol-2-yl)methyl)aniline (30). Light yellow solid,
yield: 63.8%. m.p. 111.0–112.8 ◦C. 1H-NMR (400 MHz, DMSO-d6)
δ: 8.37 (s, 1H), 8.32 (d, J = 9.0 Hz,
2H), 8.22 (d, J = 8.9 Hz, 2H), 7.39 (dd, J = 8.4, 5.7 Hz, 2H), 7.17 (t, J = 8.8 Hz, 2H), 6.75 (d, J = 8.8 Hz,
1H), 6.56 (d, J = 2.7 Hz, 1H), 6.28 (dd, J = 8.8, 2.7 Hz, 1H), 4.94 (s, 2H), 4.66 (s, 2H), 3.62 (d, J = 4.1 Hz,
6H). 13C-NMR (150 MHz, DMSO-d6)
δ: 163.14, 162.02 (d, J = 241 Hz), 160.86, 153.36, 149.87, 142.92,
142.05, 135.47, 131.23, 129.64, 128.44, 128.38, 116.21, 116.07, 115.67( 2), 115.53, 114.48, 113.97, 106.27,
×
101.19, 56.55, 55.80, 55.26, 54.15. HRMS calcd. for C25H22FN3O4S, [M + Na]+, 502.1213; found 502.1217.
HPLC: tR = 7.59 min, 98.98%.
N-(4-Fluorobenzyl)-N-((4-(4-fluorophenyl)thiazol-2-yl)methyl)-3,4-dimethoxyaniline (31). Light yellow oil,
yield: 71.1%. 1H-NMR (400 MHz, DMSO-d6)
δ
: 8.05~7.94 (m, 3H), 7.38 (s, 2H), 7.27 (t, J = 7.6 Hz,
2H), 7.16 (t, J = 7.7 Hz, 2H), 6.74 (d, J = 8.1 Hz, 1H), 6.57 (s, 1H), 6.28 (d, J = 8.4 Hz, 1H), 4.90 (s, 2H),
4.65 (s, 2H), 3.63 (d, J = 2.7 Hz, 6H). 13C-NMR (150 MHz, DMSO-d6)
: 171.42, 162.33 (d, J = 243 Hz),
δ
162.47~160.86 (d, J = 241 Hz), 153.36, 149.87, 142.92, 142.05, 135.46, 131.24, 129.69, 129.64, 128.44, 128.38,
116.21, 116.07, 115.67, 115.53, 114.48, 113.97, 106.27, 101.19, 56.55, 55.80, 55.26, 54.15. HRMS calcd. for
C25H22F2N2O2S, [M + Na]+, 475.1268; found 475.1324. HPLC: tR = 4.87 min, 99.31%.
N-(4-Fluorobenzyl)-3,4-dimethoxy-N-((4-(4-(trifluoromethyl)phenyl)thiazol-2-yl)methyl)aniline (32). White solid,
yield: 69.9%. m.p. 88.7–89.5 ◦C. 1H-NMR (400 MHz, DMSO-d6)
δ: 8.24 (s, 1H), 8.17 (d, J = 8.1 Hz, 2H),
7.81 (d, J = 8.3 Hz, 2H), 7.39 (dd, J = 8.5, 5.7 Hz, 2H), 7.17 (t, J = 8.9 Hz, 2H), 6.75 (d, J = 8.8 Hz, 1H),
6.56 (d, J = 2.8 Hz, 1H), 6.28 (dd, J = 8.8, 2.8 Hz, 1H), 4.93 (s, 2H), 4.66 (s, 2H), 3.62 (d, J = 3.5 Hz, 6H).
13C-NMR (150 MHz, DMSO-d6)
δ: 172.03, 161.67 (d, J = 241 Hz), 152.76, 149.88, 142.87, 142.11, 138.26,
135.43, 135.42, 129.71, 129.66, 128.44, 126.94( 2), 126.28, 117.36, 115.67, 115.53, 113.94, 106.34, 101.24,
×
56.53, 55.80, 55.30, 54.16, 49.06. HRMS calcd. for C26H22F4N2O2S, [M + Na]+, 525.1236; found 525.1303.
HPLC: tR = 9.44 min, 98.71%.
4-(2-(((3,4-Dimethoxyphenyl)(4-fluorobenzyl)amino)methyl)thiazol-4-yl)benzonitrile (33). Yellow solid, yield:
◦
1
69.9%. m.p. 105.4–106.6 C. H-NMR (600 MHz, DMSO-d6) δ: 8.28 (s, 1H), 8.14 (d, J = 8.1 Hz,
2H), 7.91 (d, J = 8.3 Hz, 2H), 7.40~7.36 (m, 2H), 7.16 (t, J = 9.7 Hz, 2H), 6.74 (d, J = 8.8 Hz, 1H),
6.56 (d, J = 2.8 Hz, 1H), 6.28 (dd, J = 8.8, 2.9 Hz, 1H), 4.92 (s, 2H), 4.65 (s, 2H), 3.62 (d, J = 5.8 Hz, 6H).
13C-NMR (150 MHz, DMSO-d6)
135.42, 133.38(
δ: 172.18, 161.67 (d, J = 241 Hz), 152.54, 149.88, 142.84, 142.12, 138.66,
2), 129.72, 129.67, 127.00, 119.35, 118.27, 115.68, 115.54, 113.95, 110.60, 106.34, 101.25,
56.53, 55.82, 55.29, 54.12, 49.07. HRMS calcd. for C26H22FN3O2S, [M + Na]+, 482.1314; found 482.1375.
×
HPLC: tR = 5.87 min, 97.66%.

Molecules 2017, 22, 1925
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N-(4-Fluorobenzyl)-3,4-dimethoxy-N-((4-(3-nitrophenyl)thiazol-2-yl)methyl)aniline (34). Light yellow solid,
1
yield: 53.7%. m.p. 120.5–121.6 ◦C. H-NMR (600 MHz, CDCl3)
δ: 8.74 (t, J = 1.9 Hz, 1H),
8.21~8.16 (m, 2H), 7.59 (t, J = 8.0 Hz, 1H), 7.56 (s, 1H), 7.32 (dd, J = 8.5, 5.4 Hz, 2H), 7.05~7.01 (m, 2H),
6.76~6.74 (m, 1H), 6.56 (d, J = 2.1 Hz, 1H), 6.43 (dd, J = 8.7, 2.5 Hz, 1H), 4.80 (s, 2H), 4.58 (s, 2H),
3.80 (s, 3H), 3.76 (s, 3H). 13C-NMR (150 MHz, DMSO-d6)
δ: 172.21, 161.68 (d, J = 240 Hz), 151.94, 149.89,
148.86, 142.85, 142.14, 136.09, 135.44, 132.50, 130.98, 129.72, 129.69, 123.00, 120.71, 117.40, 115.68, 115.54,
113.95, 106.37, 101.28, 56.53, 55.81, 55.33, 54.16. HRMS calcd. for C25H22FN3O4S, [M + Na]+, 502.1213;
found 502.1272. HPLC: tR = 6.87 min, 95.41%.
N-(4-Fluorobenzyl)-3,4-dimethoxy-N-((4-(2-nitrophenyl)thiazol-2-yl)methyl)aniline (35). Light yellow oil,
yield: 54.6%. 1H-NMR (600 MHz, DMSO-d6)
δ
: 7.95 (s, 1H), 7.90 (dd, J = 8.0, 1.0 Hz, 1H),
7.83~7.78 (m, 1H), 7.76~7.72 (m, 1H), 7.64~7.60 (m, 1H), 7.36 (dd, J = 8.5, 5.6 Hz, 2H), 7.18~7.12 (m, 2H)
6.74 (d, J = 8.8 Hz, 1H), 6.52 (d, J = 2.8 Hz, 1H), 6.27 (dd, J = 8.8, 2.8 Hz, 1H), 4.78 (s, 2H), 4.59 (s, 2H),
3.63 (d, J = 10.9 Hz, 6H). 13C-NMR (150 MHz, DMSO-d6)
: 171.08, 161.68 (d, J = 241 Hz), 149.96, 149.86,
,
δ
149.21, 142.87, 142.20, 135.35, 132.97, 131.17, 129.85, 129.85, 129.79, 128.17, 124.43, 118.86, 115.65, 115.51,
113.85, 106.64, 101.40, 56.51, 55.76, 55.03, 49.07. HRMS calcd. for C25H22FN3O4S, [M + Na]+, 502.1213;
found 502.1277. HPLC: tR = 5.44 min, 98.06%.
N-((4-(4-Bromophenyl)thiazol-2-yl)methyl)-N-(4-fluorobenzyl)-3,4-dimethoxyaniline (36). Dark yellow oil,
yield: 71.6%. 1H-NMR (400 MHz, DMSO-d6)
2H), 7.38 (dd, J = 8.5, 5.7 Hz, 2H), 7.16 (t, J = 8.9 Hz, 2H), 6.74 (d, J = 8.8 Hz, 1H), 6.56 (d, J = 2.7 Hz
δ
: 8.06 (s, 1H), 7.91 (d, J = 8.6 Hz, 2H), 7.64 (d, J = 8.6 Hz
,
,
1H), 6.27 (dd, J = 8.8, 2.8 Hz, 1H), 4.90 (s, 2H), 4.65 (s, 2H), 3.62 (d, J = 4.2 Hz, 6H).
13C-NMR (150 MHz, DMSO-d6)
: 171.65, 161.67 (d, J = 240 Hz), 153.17, 149.88, 142.89, 142.07,
135.45, 133.79, 132.22(
δ
×
2), 129.69, 129.64, 128.38(
×
2), 121.54, 115.67, 115.53( 2), 113.97, 106.28, 101.20,
×
56.55, 55.81, 55.26, 54.16. HRMS calcd. for C25H22BrFN2O2S, [M + Na]+, 535.0467; found 535.0539.
HPLC: tR = 11.61 min, 97.19%.
N-(4-Fluorobenzyl)-3,4-dimethoxy-N-((4-(4-(1-methyl-1H-pyrazol-4-yl)phenyl)thiazol-2-yl)methyl)aniline (37).
◦
1
Brown solid, yield: 42.1%. m.p. 126.1–130.3 C. H-NMR (600 MHz, DMSO-d6) δ: 8.18 (s, 1H),
7.96 (s, 1H), 7.94~7.90 (m, 3H), 7.63 (d, J = 8.4 Hz, 2H), 7.39 (dd, J = 8.5, 5.6 Hz, 2H), 7.16 (t, J = 8.8 Hz
,
,
2H), 6.74 (d, J = 8.8 Hz, 1H), 6.57 (d, J = 2.8 Hz, 1H), 6.28 (dd, J = 8.8, 2.8 Hz, 1H), 4.91 (s, 2H), 4.65 (s, 2H)
3.87 (s, 3H), 3.62 (d, J = 9.6 Hz, 6H). 13C-NMR (150 MHz, DMSO-d6)
δ: 170.07, 160.59 (d, J = 240 Hz),
153.23, 148.79, 141.88, 140.95, 135.47, 131.62, 131.44, 131.16, 130.91, 130.84, 128.56, 128.20, 128.12, 127.30,
125.77, 124.57, 120,89, 114.59, 114.45, 112.90, 105.18, 100.11, 55.48, 54.73, 54.17, 53.13, 47.99. HRMS calcd.
for C29H27FN4O2S, [M + Na]+, 537.1736; found 537.1822. HPLC: tR = 5.19 min, 95.89%.
N-((4-(4-(3,5-Dimethylisoxazol-4-yl)phenyl)thiazol-2-yl)methyl)-N-(4-fluorobenzyl)-3,4-dimethoxyaniline (38).
Yellow solid, yield: 51.6%. m.p. 69.0–69.8 ◦C. 1H-NMR (400 MHz, DMSO-d6)
δ: 8.08~8.02 (m, 3H),
7.46 (d, J = 8.4 Hz, 2H), 7.39 (dd, J = 8.5, 5.6 Hz, 2H), 7.16 (t, J = 8.9 Hz, 2H), 6.74 (d, J = 8.8 Hz, 1H),
6.58 (d, J = 2.8 Hz, 1H), 6.29 (dd, J = 8.8, 2.8 Hz, 1H), 4.92 (s, 2H), 4.66 (s, 2H), 3.63 (d, J = 9.1 Hz, 6H),
2.43 (s, 3H), 2.26 (s, 3H). 13C-NMR (150 MHz, DMSO-d6)
δ: 171.35, 165.67, 161.68 (d, J = 240 Hz), 158.59,
153.93, 149.89, 142.95, 142.07, 135.48, 133.68, 129.86, 129.71( 2), 129.65, 126.79( 2), 116.07, 115.67,
×
×
115.53, 115.07, 113.97, 106.29, 101.23, 56.55, 55.81, 55.28, 54.16, 49.07, 11.90, 11.02. HRMS calcd. for
C30H28FN3O3S, [M + Na]+, 552.1733; found 552.1817. HPLC: tR = 7.26 min, 96.49%.
N-(4-Fluorobenzyl)-3,4-dimethoxy-N-((4-(4-(1-methyl-1H-pyrazol-5-yl)phenyl)thiazol-2-yl)methyl)aniline (39).
Dark yellow solid, yield: 49.0%. m.p. 102.4–103.3 ◦C. 1H-NMR (400 MHz, DMSO-d6)
δ: 8.11 (s, 1H),
8.06 (d, J = 8.3 Hz, 2H), 7.62 (d, J = 8.3 Hz, 2H), 7.49 (d, J = 1.8 Hz, 1H), 7.40 (dd, J = 8.4, 5.7 Hz,
2H), 7.17 (t, J = 8.8 Hz, 2H), 6.75 (d, J = 8.8 Hz, 1H), 6.57 (d, J = 2.8 Hz, 1H), 6.47 (d, J = 1.8 Hz,
1H), 6.29 (dd, J = 8.8, 2.8 Hz, 1H), 4.93 (s, 2H), 4.67 (s, 2H), 3.90 (s, 3H), 3.63 (d, J = 5.9 Hz, 6H).
13C-NMR (150 MHz, DMSO-d6)
138.44, 135.47, 134.38, 130.02, 129.71, 129.66, 129.27(
δ
: 171.50, 161.67 (d, J = 241 Hz), 153.73, 149.88, 142.93, 142.78, 142.06,
×
2), 126.67( 2), 115.68, 115.54, 115.48, 113.98,
×

Molecules 2017, 22, 1925
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106.34, 106.29, 101.22, 56.56, 55.82, 55.28, 54.17, 49.07. HRMS calcd. for C29H27FN4O2S, [M + Na]+,
537.1736; found 537.1815. HPLC: tR = 5.84 min, 99.44%.
N-(4-Fluorobenzyl)-3,4-dimethoxy-N-((4-(4-(thiophen-2-yl)phenyl)thiazol-2-yl)methyl)aniline (40). Dark yellow
solid, yield: 43.7%. m.p. 115.8–119.0 ◦C. 1H-NMR (400 MHz, DMSO-d6)
δ:
8.04 (s, 1H),
7.99 (d, J = 8.4 Hz, 2H), 7.74 (d, J = 8.4 Hz, 2H), 7.61~7.56 (m, 2H), 7.39 (dd, J = 8.4, 5.7 Hz, 2H),
7.20~7.14 (m, 3H), 6.75 (d, J = 8.8 Hz, 1H), 6.57 (d, J = 2.7 Hz, 1H), 6.28 (dd, J = 8.8, 2.7 Hz,
1H), 4.92 (s, 2H), 4.66 (s, 2H), 3.63 (d, J = 5.9 Hz, 6H). 13C-NMR (150 MHz, DMSO-d6)
δ: 171.41,
161.68 (d, J = 241 Hz), 153.90, 149.89, 143.41, 142.95, 142.08, 135.45, 133.71, 133.67, 129.69, 129.64,
129.07, 127.05(
×
2), 126.31, 126.19( 2), 124.34, 115.67, 115.53, 114.84, 113.97, 106.31, 101.22, 56.54,
×
55.80, 55.28, 54.21. HRMS calcd. for C29H25FN2O2S2, [M + Na]+, 539.1239; found 539.1324.
HPLC: tR = 13.67 min, 97.82%.
N-(4-Fluorobenzyl)-3,4-dimethoxy-N-((4-(naphthalen-2-yl)thiazol-2-yl)methyl)aniline (41). Light yellow oil,
yield: 76.1%. 1H-NMR (400 MHz, DMSO-d6)
δ: 8.54 (s, 1H), 8.14~8.08 (m, 2H), 7.98 (t, J = 8.4 Hz,
2H), 7.92 (d, J = 7.3 Hz, 1H), 7.57~7.48 (m, 2H), 7.40 (dd, J = 8.3, 5.7 Hz, 2H), 7.17 (t, J = 8.8 Hz, 2H),
6.74 (d, J = 8.8 Hz, 1H), 6.60 (d, J = 2.6 Hz, 1H), 6.30 (dd, J = 8.8, 2.7 Hz, 1H), 4.95 (s, 2H), 4.67 (s, 2H),
3.63 (d, J = 12.8 Hz, 6H). 13C-NMR (150 MHz, DMSO-d6)
δ: 171.60, 161.68 (d, J = 241 Hz), 154.35,
149.90, 142.96, 142.09, 135.50, 133.66, 133.07, 132.04, 129.71, 129.66, 128.84, 128.70, 128.09, 127.04, 126.71,
125.03, 124.61, 115.69, 115.54, 115.28, 113.99, 106.32, 101.25, 56.55, 55.82, 55.31, 49.07. HRMS calcd. for
C29H25FN2O2S, [M + Na]+, 507.1518; found 507.1588. HPLC: tR = 11.73 min, 96.23%.
N-(4-Fluorobenzyl)-3,4-dimethoxy-N-((4-(p-tolyl)thiazol-2-yl)methyl)aniline (42). Yellow solid, yield: 67.1%.
1
m.p. 105.3–107.0 ◦C. H-NMR (400 MHz, DMSO-d6)
δ: 7.90 (s, 1H), 7.85 (d, J = 8.1 Hz, 2H),
7
.38 (dd, J = 8.5, 5.7 Hz, 2H), 7.25 (d, J = 8.0 Hz, 2H), 7.16 (t, J = 8.9 Hz, 2H), 6.74 (d, J = 8.8 Hz,
1H), 6.57 (d, J = 2.8 Hz, 1H), 6.27 (dd, J = 8.8, 2.8 Hz, 1H), 4.90 (s, 2H), 4.65 (s, 2H), 3.62 (d, J = 5.9 Hz,
6H), 2.33 (s, 3H). 13C-NMR (150 MHz, DMSO-d6)
: 171.06, 161.67 (d, J = 240 Hz), 160.87, 154.50, 149.87,
δ
142.97, 142.03, 137.76, 135.48, 131.97, 129.82(
×
2), 129.67, 129.62( 2), 126.31, 115.66, 115.52, 113.98,
×
113.75, 106.25, 101.17, 56.55, 55.78, 55.25, 54.21, 21.28. HRMS calcd. for C26H25FN2O2S, [M + Na]+,
471.1518; found 471.1578. HPLC: tR = 9.58 min, 97.85%.
N-(4-Fluorobenzyl)-3,4-dimethoxy-N-((4-◦(4-methoxyphenyl)thiazol-2-yl)methyl)aniline (43). Dark yellow
1
solid, yield: 83.7%. m.p. 76.3–79.0 C. H-NMR (400 MHz, DMSO-d6)
δ: 7.88 (d, J = 8.8 Hz,
2H), 7.82 (s, 1H), 7.39 (dd, J = 8.5, 5.7 Hz, 2H), 7.16 (t, J = 8.8 Hz, 2H), 7.00 (d, J = 8.8 Hz,
2H), 6.74 (d, J = 8.8 Hz, 1H), 6.56 (d, J = 2.8 Hz, 1H), 6.27 (dd, J = 8.8, 2.8 Hz, 1H), 4.89 (s, 2H),
4.65 (s, 2H), 3.80 (s, 3H), 3.62 (d, J = 4.0 Hz, 6H). 13C-NMR (150 MHz, DMSO-d6)
δ
: 170.93,
2), 127.48,
2), 113.98, 112.54, 106.25, 101.17, 56.54, 55.79, 55.60, 55.25, 54.20. HRMS calcd. for
C26H25FN2O3S, [M + Na]+, 487.1468; found 487.1535. HPLC: tR = 7.05 min, 98.64%.
161.67 (d, J = 241 Hz), 159.56, 154.34, 149.88, 142.99, 142.03, 135.48, 129.67, 129.61, 127.73(
115.66, 115.52, 114.60(
×
×
N-((4-(4-Aminophenyl)thiazol-2-yl)methyl)-N-(4-fluorobenzyl)-3,4-dimethoxyaniline (44). Light yellow solid,
◦
1
yield: 87.3%. m.p. 144.7–146.2 C. H-NMR (400 MHz, DMSO-d6)
7.55 (s, 1H), 7.40~7.36 (m, 2H), 7.16 (dd, J = 12.3, 5.4 Hz, 2H), 6.74 (d, J = 8.8 Hz, 1H), 6.60 (d, J = 8.6 Hz
2H), 6.55 (d, J = 2.8 Hz, 1H), 6.25 (dd, J = 8.8, 2.8 Hz, 1H), 5.28 (s, 2H), 4.86 (s, 2H), 4.64 (s, 2H),
3.62 (d, J = 4.2 Hz, 6H). 13C-NMR (150 MHz, DMSO-d6)
: 170.23, 161.65 (d, J = 241 Hz), 155.52, 149.86,
δ: 7.61 (d, J = 8.5 Hz, 2H),
,
δ
149.12, 143.04, 141.95, 135.54, 129.65, 129.60, 127.41(
×
2), 122.83, 115.65, 115.51, 114.27( 2), 114.00,
×
109.74, 106.17, 101.11, 56.57, 55.78, 55.21, 54.23. HRMS calcd. for C25H24FN3O2S, [M + Na]+, 472.1471;
found 472.1538. HPLC: tR = 4.25 min, 95.78%.
N-(4-(2-(((3,4-Dimethoxyphenyl)(4-fluorobenzyl)amino)methyl)thiazol-4-yl)phenyl)-2,2,2-trifluoroacetamide
(
45). Light yellow solid, yield: 75.8%. m.p. 143.6–145.8 ◦C. 1H-NMR (600 MHz, DMSO-d6)
δ
: 11.34
(s, 1H), 8.01~7.96 (m, 3H), 7.76 (d, J = 8.7 Hz, 2H), 7.38 (dd, J = 8.4, 5.7 Hz, 2H), 7.16 (t, J = 8.8 Hz, 2H),
6.74 (d, J = 8.8 Hz, 1H), 6.56 (d, J = 2.8 Hz, 1H), 6.28 (dd, J = 8.8, 2.8 Hz, 1H), 4.90 (s, 2H), 4.65 (s, 2H)
3.62 (d, J = 6.5 Hz, 6H). 13C-NMR (150 MHz, DMSO-d6)
: 171.42, 161.67 (d, J = 240 Hz), 155.02,
,
δ

Molecules 2017, 22, 1925
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154.78, 153.72, 149.88, 142.93, 142.06, 136.43, 135.47, 131.92, 129.69, 129.64, 126.95(
115.53, 114.62, 113.98, 106.28, 101.20, 56.55, 55.80, 55.26, 54.19, 49.06. HRMS calcd. for C27H23F4N3O3S,
[M + Na]+, 568.1294; found 568.1379. HPLC: tR = 5.34 min, 97.66%.
×
2), 121.69, 115.67,
N-(4-(2-(((3,4-Dimethoxyphenyl)(4-fluorobenzyl)amino)methyl)thiazol-4-yl)phenyl)acetamide (46). Light yellow
solid, yield: 86.1%. m.p. 134.6–137.0 ◦C. 1H-NMR (600 MHz, DMSO-d6)
δ: 10.03 (s, 1H),
7.88~7.83 (m, 3H), 7.64 (d, J = 8.6 Hz, 2H), 7.38 (dd, J = 8.4, 5.7 Hz, 2H), 7.16 (t, J = 8.8 Hz,
2H), 6.74 (d, J = 8.8 Hz, 1H), 6.55 (d, J = 2.8 Hz, 1H), 6.27 (dd, J = 8.8, 2.8 Hz, 1H), 4.89 (s, 2H),
4.64 (s, 2H)
161.66 (d, J = 241 Hz), 154.29, 149.87, 142.95, 142.03, 139.57, 135.48, 129.69, 129.63, 129.48, 126.81(
119.49( 2), 115.66, 115.52, 113.98, 113.25, 106.26, 101.18, 56.55, 55.80, 55.24, 54.20, 49.07. HRMS calcd.
for C27H26FN3O3S, [M + Na]+, 514.1577; found 514.1662. HPLC: tR = 3.84 min, 97.51%.
,
3.62 (d, J = 6.2 Hz, 6H), 2.06 (s, 3H). 13C-NMR (150 MHz, DMSO-d6)
δ: 171.06, 168.81,
×
2),
×
Methyl(4-(2-(((3,4-dimethoxyphenyl)(4-fluorobenzyl)amino)methyl)thiazol-4-yl)phenyl)glycinate (47). Light yellow
◦
1
solid, yield: 79.4%. m.p. 103.5–105.4 C. H-NMR (600 MHz, DMSO-d6) δ: 7.67 (d, J = 8.6 Hz,
2H), 7.59 (s, 1H), 7.37 (dd, J = 8.5, 5.6 Hz, 2H), 7.15 (t, J = 8.8 Hz, 2H), 6.73 (d, J = 8.8 Hz, 1H),
6.60 (d, J = 8.7 Hz, 2H), 6.54 (d, J = 2.8 Hz, 1H), 6.27~6.22 (m, 2H), 4.86 (s, 2H), 4.63 (s, 2H),
3.96 (d, J = 6.4 Hz, 2H), 3.66 (s, 3H), 3.61 (d, J = 5.2 Hz, 6H). 13C-NMR (150 MHz, DMSO-d6)
δ: 172.19,
170.39, 161.65 (d, J = 240 Hz), 155.25, 149.85, 148.47, 143.02, 141.95, 135.53, 129.66, 129.61, 127.37( 2),
×
123.48, 115.65, 115.51, 114.00, 112.55, 110.26, 106.18, 101.12, 56.57, 55.79, 55.20, 54.22, 52.11, 49.07, 44.89.
HRMS calcd. for C28H28FN3O4S, [M + Na]+, 544.1682; found 544.1757. HPLC: tR = 4.77 min, 95.90%.
Ethyl-4-(4-(2-(((3,4-dimethoxyphenyl)(4-fluorobenzyl)amino)methyl)thiazol-4-yl)phenoxy)butanoate
yellow oil, yield: 32.9%. 1H-NMR (400 MHz, DMSO-d6)
: 7.86 (d, J = 8.6 Hz, 2H), 7.81 (s, 1H),
7.38 (dd, J = 8.3, 5.8 Hz, 2H), 7.16 (t, J = 8.8 Hz, 2H), 6.98 (d, J = 8.8 Hz, 2H), 6.74 (d, J = 8.8 Hz, 1H),
6.55 (d, J = 2.6 Hz, 1H), 6.27 (dd, J = 8.8, 2.7 Hz, 1H), 4.89 (s, 2H), 4.64 (s, 2H), 4.08 (q, J = 7.1 Hz
2H), 4.03 (t, J = 6.3 Hz, 2H), 3.62 (d, J = 3.7 Hz, 6H), 2.47 (t, J = 7.3 Hz, 2H), 2.03~1.95 (m, 2H),
1.19 (t, J = 7.1 Hz, 3H). 13C-NMR (150 MHz, DMSO-d6)
: 173.04, 170.93, 161.67 (d, J = 240 Hz), 158.77,
154.31, 149.87, 142.98, 142.01, 135.50, 129.68, 129.62, 127.73( 2), 127.50, 115.67, 115.53, 115.09( 2),
(48).
δ
,
δ
×
×
113.99, 112.57, 106.23, 101.16, 67.00, 60.36, 56.56, 55.79, 55.24, 54.19, 30.61, 24.70, 14.58. HRMS calcd. for
C31H33FN2O5S, [M + Na]+, 587.1992; found 587.2083. HPLC: tR = 8.39 min, 96.53%.
N-(4-Fluorobenzyl)-3,4-dimethoxy-N-((4-(4-morpholinophenyl)thiazol-2-yl)methyl)aniline (49). White solid,
yield: 53.7%. m.p. 139.0–140.4 ◦C. 1H-NMR (600 MHz, DMSO-d6)
δ
:
7.81~7.78 (m, 2H),
7.74 (s, 1H), 7.38 (dd, J = 8.6, 5.6 Hz, 2H), 7.17~7.14 (m, 2H), 6.99 (d, J = 9.0 Hz, 2H),
6.73 (d, J = 8.8 Hz, 1H), 6.55 (d, J = 2.8 Hz, 1H), 6.26 (dd, J = 8.8, 2.9 Hz, 1H), 4.88 (s, 2H), 4.64 (s, 2H)
3.76~3.73 (m, 4H) : 170.13,
3.61 (d, J = 5.7 Hz, 6H), 3.17~3.14 (m, 4H). 13C-NMR (150 MHz, DMSO-d6)
161.08 (d, J = 241 Hz), 154.11, 150.51, 149.28, 142.42, 141.41, 134.93, 129.09, 129.04, 126.65( 2), 125.16,
,
,
δ
×
115.08, 114.44, 114.20(
×
2), 113.42, 111.12, 105.63, 100.56, 65.93( 2), 55.99, 55.21, 54.65, 53.64, 48.49, 47.92.
×
HRMS calcd. for C29H30FN3O3S, [M + Na]+, 542.1890; found 542.1975. HPLC: tR = 6.29 min, 98.33%.
3.4. In Vitro CETP Inhibitory Assay
All tested compounds were dissolved in 100% DMSO. The compound was dissolved totally,
and the solution was vibrated hard on an oscillator for more than 30 s and then stored in a
nitrogen cabinet. The stock solutions (10 mM) were diluted with DMSO for an eight-point titration
(1:5 serial dilutions) in a 96-well dilution plate. The activity was estimated in accordance with the
instructions for the CETP inhibitor screening kit and recombinant CETP. The compounds were
tested at eight concentrations, and the fluorescence intensities were measured using a fluorometer
(ExEm = 465/535 nm). The IC50 was determined from a curve fit of the data with each concentration
tested three times.

Molecules 2017, 22, 1925
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3.5. Metabolic Stability Study
Ten microliters (10
and incubated at 37 C for 10 min, and then 10
µ
L, 100
µ
M/L) of compounds and 80
µ
L of liver microsomes were mixed
◦
µL of NADPH regenerating system was added.
Samples were obtained at 0 min, 5 min, 10 min, 20 min, 30 min and 60 min. respectively, and 300
µ
L
◦
stop solution (cold in 4 C, including 100 ng/mL tolbutamide and 100 ng/mL labetalol) was added to
terminate the reaction. After oscillating for 10 min, the plates were centrifuged (4000 rpm) at room
temperature for 20 min, and the supernatants were used for analysis.
4. Conclusions
A series of N,N-disubstituted-4-arylthiazole-2-methylamine derivatives were designed,
synthesized, and evaluated for their inhibitory activity against CETP by a BODIPY-CE fluorescence
assay. Compounds 30 and 32 displayed substantial CETP inhibitory activity in vitro with IC50 values of
0.79
±
0.02
µ
M and 0.97
±
0.01 µM, respectively, and demonstrated weak human/rat liver microsome
stability. This suggests that compounds 30 and 32 could act as potential CETP inhibitors to be used for
further optimization.
Supplementary Materials: Supplementary materials are available online.
Acknowledgments: We gratefully acknowledge the financial support from the National Natural Science
Foundation of China (Grant No. 81373324), the National Science Fund for Fostering Talents in Basic Science
(
Grant No. J1103606), the Program for Innovative Research Team of the Ministry of Education, and the Program
for Innovative Research Team at Liaoning University.
Author Contributions: Xinran Wang and Xuehua Lin are co-authors; they contributed equally to the work.
They designed and carried out the experiments and wrote the paper; Xuanqi Xu, Wei Li, Lijuan Hao,
and Chunchi Liu assisted in the experiment; and Dongmei Zhao and Maosheng Cheng supervised the whole
experiment and provided technical guidance. All authors have read and approved the final manuscript.
Conflicts of Interest: The authors declare no conflicts of interest.
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