Design, synthesis and biological evaluation of 4-aryl-5-aminoalkyl-thiazole-2-amines derivatives as ROCK II inhibitors

Article abstract of DOI:10.1016/j.bmc.2020.115683

A series of 4-aryl-5-aminoalkyl-thiazole-2-amines were designed and synthesized, and their inhibitory activity on ROCK II was screened by enzyme-linked immunosorbent assay (ELISA). The results showed that 4-aryl-5-aminomethyl-thiazole-2-amines derivatives had certain ROCK II inhibitory activities. Compound 10l showed ROCK II inhibitory activity with IC₅₀ value of 20 nM.

Full text of DOI:10.1016/j.bmc.2020.115683

Bioorganic & Medicinal Chemistry 28 (2020) 115683
Contents lists available at ScienceDirect
Bioorganic & Medicinal Chemistry
journal homepage: www.elsevier.com/locate/bmc
Design, synthesis and biological evaluation of 4-aryl-5-aminoalkyl-thiazole-
2
-amines derivatives as ROCK II inhibitors
⁎
Shuchao Ma, Linan Wang, Ben Ouyang, Meixia Fan, Junhui Qi, Lei Yao
School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Collaborative Innovation Center of
Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Yantai University, Yantai 264003, China
A R T I C L E I N F O
A B S T R A C T
Keywords:
ROCK
A series of 4-aryl-5-aminoalkyl-thiazole-2-amines were designed and synthesized, and their inhibitory activity on
ROCK II was screened by enzyme-linked immunosorbent assay (ELISA). The results showed that 4-aryl-5-ami-
nomethyl-thiazole-2-amines derivatives had certain ROCK II inhibitory activities. Compound 10l showed ROCK
II inhibitory activity with IC50 value of 20 nM.
Inhibitors
4
-Aryl-5-aminoalkyl-thiazole-2-amines
Synthesis
1
. Introduction
2. Results and discussion
Rho-associated kinase (ROCK) belongs to a family of serine/threo-
2.1. Chemistry
nine protein kinases. It plays an important role in a variety of biological
processes such as smooth-muscle-cell contraction, cell migration, pro-
The syntheses of these series of 4-aryl-5-aminoalkyl-thiazole-2-
amines with two carbons in the aminoalkyl side chain were achieved in
five steps transformation from commercially available starting mate-
rials, as shown in Scheme1. Firstly, compound 2 was prepared from
3(4)-pyridinecarboxaldehyde and N,N-dimethylacrylamide by a mod-
1
–3
liferation and adhesion.
Many studies are showing that the dysre-
gulation of ROCK activity or overexpression of ROCK kinase is asso-
4
5
ciated with various diseases, including hypertension, , stroke,
6
,7
8–11
12–14
15
asthma, glaucoma,
cancer,
and spinal cord injury. ROCK
2
3
kinase inhibitor has emerged as an exciting new drug class in the
treatment of all kinds of diseases. For example, Fasudil, is indicated for
improvement and prevention of cerebral vasospasm. Ripasudil and
Netarsudil are used for the treatment of glaucoma and ocular hy-
ified method reported by Kim. Secondly, the thiazole-2-amine com-
pound 3 was obtained by selective α-bromination of compound 2, then
2
4
cyclization with thiourea in ethanol under reflux condition. During
the bromination step, the classical condition, bromine in acetic acid, led
to a mess product. Then we found that pyridinium tribromide could
1
6
pertension.
2
5
ROCK has two isomers, ROCK I and ROCK II, which share ap-
provide neat intermediate and then afford the thiazole-2-amine. Re-
ducing the amide group of compound 3 by lithium aluminium hydride
(LAH), afforded compound 4 in moderate yield. Finally, an amide for-
mation reaction of compound 3 or 5 with corresponding carboxylic acid
under classical peptide coupling condition (EDCI, HOBt, DIPEA), af-
forded the corresponding target compound 4 or 6 in moderate yield.
The syntheses of the compounds with one carbon atom in the
aminoalkyl side chain were shown in Scheme 2. Firstly, compound 8
1
7,18
proximately 90% identity within the kinase domain.
Previously, a
potent and selective ROCK II inhibitor I (Fig. 1) was reported, and the
1
9,20
selectivity was ascribed to the aminoalkyl side chain.
However,
high clearance and low bioavailability were not desirable for oral ex-
posure of compound I. CID5056270 (II, Fig. 1), a pyridine-thiazole
2
1
based amide, showed potent ROCK-II inhibitory activity, but had a
2
2
large shift in cell-based potency. In order to further optimize these
leads, 4-aryl-5-aminoalkyl-thiazole-2-amines (Fig. 1) were designed.
This structure incorporated both the aminoalkyl side chain and thia-
zoleamine moieties of compound I and II.
2
6
was prepared by a modified procedure reported by Green et al.
Treatment of 4(3)-acetylpyridine with bromine, followed by cyclization
reaction with thiourea, afforded the thiazole-2-amine 8. Then an amide
formation reaction between thiazoleamine 8 and a series of carboxylic
acid under classical peptide coupling condition (EDCI, HOBt, DIPEA),
afforded the corresponding amide 9 in moderate yield. Finally, the
aminomethyl group was introduced by treatment of compound 9 with
⁎
Corresponding author.
https://doi.org/10.1016/j.bmc.2020.115683
Received 15 June 2020; Accepted 15 July 2020
Available online 03 August 2020
0968-0896/ © 2020 Elsevier Ltd. All rights reserved.

S. Ma, et al.
Bioorganic & Medicinal Chemistry 28 (2020) 115683
Fig. 1. The design of 4-aryl-5-aminoalkyl-thiazole-2-amines.
Scheme 1. Reagents and conditions: (a) N,N-dimethylacrylamide, TBUP, THF, reflux; (b) PyBr
3
, DCM, 0 to r.t.; (c) NH
2
2
CSNH , EtOH, reflux; (d) R
1
CO H, EDCI,
2
HOBt, DMF, r.t.; (e) LAH, THF, reflux.
Scheme 2. Reagents and conditions: (a) Br
HBr (48%), AcOH, 70 °C; (b) NH CSNH , EtOH,
reflux; (c) EDCI, HOBt, R COOH, DMF, r.t.; (d)
HNR , (CH O)n, AcOH, 70 °C;
2
,
2
2
1
2
R
3
2
appropriate amines and paraformaldehyde under acetic acid condition,
afforded the compound 10.
initially evaluated for their percentage inhibition against ROCK II with
a ROCK II assay kit (CY-1160, Cycle, Japan) at 10 µM (Table 1). The
compounds with significant inhibition against ROCK II were further
evaluated in full concentration–response plots to determine their IC50
The synthesis of compound 13, 2,4-thiazolediamine derivative, was
shown in Scheme 3. Bromination of compound 8 with N-bromosucci-
nimide (NBS), afforded the intermediate 11, followed by the replace-
ment of the bromide of compound 11 with appropriate amines, gave
the 2,4-thiazolediamine 12. Finally, an amide formation reaction of
compound 12 with corresponding aromatic acid under classical peptide
coupling condition, afforded the final amide 13 in moderate yield.
2
7
values (Table 2). CID5056270 was chosen as control.
From the above biological screening results, the structure–activity-
relationship (SAR) of this series of compounds was observed as fol-
lowing: Firstly, for the acid part (R group), compounds with 2,3-di-
1
hydrobenzo [b][1,4] dioxine group generally shown better potency
than compounds with pyridine group. For example, compound 10l
(
(
(
IC50
=
0.02 µM) was more potent than compound 10a
2.2. The ROCK II inhibitory activity study
IC50 = 9.12 µM) and 10b (IC50
= 8.56 µM); compound 6a
IC50 = 0.09 µM) was more potent than compound 6b. Secondly, for
group), compounds with morpholine
The inhibitory activities on ROCK II of compounds were screened by
the aminoalkyl side chain (R
2
enzyme-linked immunosorbent assay (ELISA). All compounds were
Scheme 3. Reagents and conditions: (a) NBS,
CHCl , r.t; (b) K CO , DMF, 100 °C; (c) EDCI,
HOBt, R CO H, DMF, r.t.
3
2
3
1
2
2

S. Ma, et al.
Bioorganic & Medicinal Chemistry 28 (2020) 115683
Table 1
Table 2
The structures and inhibitory activities.
The IC50 values of compounds against ROCK II.
Compd.
ROCK II(µM)
Compd.
ROCK II (µM)
4
1
1
1
1
a
8.83
9.12
0.02
1.56
0.13
6a
0.09
8.56
1.73
4.96
0.01
0a
0l
0n
3a
10b
10m
10o
CID5056270
group generally were more potent than compounds with other groups,
such as dimethylamine, N-methylpiperazine, N-methyl-N-iso-
propylamine, piperidine, and pyrrolidine. For example, compound 10b
(IC50 = 8.56 µM) was more potent than compound 10c and 10d;
compounds 10m (IC50 = 1.73 µM) were more potent than compound
Compd.
X
Y
C
n
1
R
1
R
2
% Inhibition of ROCK II
56.9
4
4
6
a
b
a
N
1
0o (IC50 = 4.96 µM) and 10p. Thirdly, for the position of the N in the
N
N
C
C
1
2
38.1
78.5
pyridine substituent, compounds with 4-position substitution generally
were more potent than compounds with 3-position substitution. For
example, compound 10a (IC50 = 9.12 µM) was more potent than
compound 10g. Compounds 10b (IC50 = 8.56 µM) was more potent
than compound 10f. Finally, it seemed that the basic tertiary amine
group in the side chain was beneficial to the ROCK II inhibitory activity.
For example, compound 6a (IC50 = 0.09 µM) was more potent than
compound 4a (IC50 = 8.83 µM); compound 6b was more potent than
compound 4b. In addition, 2,4-thiazolediamine derivatives showed the
tendency to decrease the inhibitory activity. For example, compound
10l was more potent than compound 13a.
6
1
b
N
N
C
C
2
1
48.8
52.2
0a
1
1
1
1
1
1
0b
0c
0d
0e
0f
N
N
N
C
C
C
C
C
C
N
N
N
1
1
1
1
1
1
58.1
47.6
48.2
35.3
51.1
41.1
In summary, the results showed that 4-aryl-5-aminomethyl-thiazole-
2-amines derivatives had certain ROCK II inhibitory activities.
Compound 10l showed the best ROCK II inhibitory activity with IC50
value of 20 nM.
2.3. Molecular docking studies
0g
To identify the possible binding modes of the designed ROCK II
inhibitors, molecular docking of compound 10l and two lead com-
pounds I and II were performed to elucidate key interactions within the
active site of ROCK II. The molecular docking was performed on the
Sybyl-X2.0 software package. The crystal structure of the ROCK II was
1
1
1
1
0h
0i
C
C
C
C
N
N
N
N
1
1
1
1
32.1
38.1
33.9
28.5
28
taken from the RSCB Protein Data Bank (PDB code: 4L6Q). As shown
in Fig. 3, docking of compounds I and II into the binding site of Rho
kinase indicated a key hydrogen-bond interaction between the N in the
pyridine or pyrazole ring and Met 172. This bond is very important for
stabilizing the orientation and conformation of ROCK inhibitors. The
0j
0k
2
,3-dihydrobenzo [b][1,4]dioxine group of lead compounds formed a
key hydrogen bond with Lys121. This bond is beneficial for stabilizing
the conformation of compound. The aminoalkyl side chain of com-
pound I is predicted to form a key hydrogen bond with Asp176. This
bond is beneficial for improving the selectivity of compound. In addi-
tion, molecular docking of compound 10l was also performed. Two key
hydrogen-bond interactions between the compound 10l with Met 172
and Lys121 were still maintains. However, the hydrogen-bond inter-
actions between aminoalkyl side chain of compound 10l and Asp176
was not observed, which explains why the slight decrease of inhibitory
activity. Base on above observation, further optimization of compound
1
1
1
1
1
0l
N
C
C
C
N
C
N
N
N
C
1
1
1
1
0
87.4
63.8
61.3
58.1
76.3
0m
0n
0o
3a
1
3
0l is the direction of future research.
. Conclusion
1
1
3b
3c
N
N
C
C
0
0
34.3
32.1
In summary, we had identified a series of 4-aryl-5-aminomethyl-
thiazole-2-amines as a new class of potent ROCK II inhibitors. Then, in
vitro ROCK II inhibitory activity assay showed that 10l was the most
potent compound, with the IC50 value of 20 nM. It might represent a
promising lead compound for the further development of novel ROCK II
inhibitors. Further optimization of this scaffold, including selectivity,
the biological evaluation in cell-based assay and in vivo studies will be
CID 5,056,270
N
C
/
/
91.3
Percentage inhibition of compound against ROCK II under the concentration of
0 µM.
1
3

S. Ma, et al.
Bioorganic & Medicinal Chemistry 28 (2020) 115683
Fig. 3. A) Predicted binding mode of compound 10l (yellow) with ROCK II (PDB ID: 4L6Q); B) Predicted binding mode of I (yellow) and II (blue) with ROCK II (PDB
ID: 4L6Q); The residues in ROCK II are shown in green sticks. Hydrogen bonds are shown as red dashed lines.
presented in future communications.
. Experiments section
4.2.2. General procedure for the preparation of compound 3
Step 1. Pyridinium tribromide (15.5 g, 48.4 mmol) was added to a
solution of compound 2 (10.0 g, 48.4 mmol) in dry dichloromethane
4
(
300 mL) at 0 °C. The resultant reaction mixture was warmed to room
temperature and stirred for 1 h. A solution of sodium hydrogen car-
bonate (10%, 200 mL) was added and the aqueous layer extracted with
DCM (300 mL × 3), washed with water, dried over sodium sulfate, and
the solvent removed under reduced pressure. The residue was purified
by flash chromatography to afford the brominated intermediate and
used in the next step directly.
4.1. General methods
All reactions were carried out under a nitrogen atmosphere with dry
solvent under anhydrous conditions, unless otherwise noted. Reagents
were purchased at the highest commercial quality and used without
further purification, unless otherwise noted. The NMR spectra of the
intermediates and final products in deuterated solvent were detected on
a Bruker 400 or 600 MHz spectrometer. The following abbreviations
were used to designate the multiplicities: s = singlet, d = doublet,
t = triplet, q = quartet, h = heptett, m = multiplet, b = broad. High-
resolution mass spectra (HRMS) were recorded on an Agilent 6210 ESI/
TOF mass spectrometer. Melting points (MP) were recorded on a Büchi
B-540 melting point apparatus and are uncorrected. Flash column
chromatographic separation was achieved using a silica gel from
Qingdao Ocean Chemical (200–300 mesh) with a particle size from 54
to 74 μm using ethyl acetate and hexane (or petroleum ether) as the
eluent. Analytical TLC was carried out on Merck pre-coated silica gel 60
GF-254 using 0.25-mm-thick TLC plates.
Step 2. To a solution of above brominated intermediate (9.50 g,
3
3
.24 mmol) in 30 mL of ethanol, was added the thiourea (3.00 g,
.88 mmol) at room temperature. The reaction mixture was heated to
reflux for 16 h. After cooling, the pH of the reaction mixture was ad-
justed to 11 with ammonium hydroxide solution, and the solvent re-
moved under reduced pressure. The residue was purified by chroma-
tography to afford the title compound 3 (about 75% yield).
4.2.2.1. 2-(2-amino-4-(pyridin-3-yl)thiazol-5-yl)-N, N-dimethylacetamide
1
(3a). yield: 78%; yellow solid; m.p. 102–105 °C; H NMR (400 MHz,
CD OD) δ: 8.65–8.66 (m, 1H, ArH), 8.47–8.49 (m, 1H, ArH), 7.94–7.97
3
(m, 1H, ArH), 7.45–7.49 (m, 1H, ArH), 3.79 (s, 2H, ArCH
2
), 2.96 (s, 3H,
CH ), 2.92 (s, 3H, CH ).
3
3
4
.2. Experimental procedures and physical data of compounds.
4
.2.2.2. 2-(2-amino-4-(pyridin-4-yl)thiazol-5-yl)-N, N-dimethylacetamide
4.2.1. General procedure for the preparation of compound 2
(3b). yield: 73%; yellow solid; m.p. 101–103°C. The compound was
To a solution of 3(4)-pyridinecarboxaldehyde (10.70 g, 100 mmol)
used for the next step without further identified.
in 200 mL of THF, were added N, N-dimethylacrylamide (9.90 g,
1
00 mmol) and tributylphosphine (20.20 g, 100 mmol) at room tem-
4.2.3. General procedure for the preparation of compound 5
perature. The reaction mixture was allowed to stir at 80 °C for 4 h. The
solvent was removed under reduced pressure, and the residue was
purified by flash chromatography on silica gel (Hexane/EtOAc = 1/1,
V/V) to afford the title compound 2 (about 70% yield).
To a solution of LAH (3.00 g, 78.9 mmol) in THF, a solution of
compound 3 (6.89 g, 26.3 mmol) in THF was added at 0 °C. The re-
action mixture was heated at 70 °C for 4 h. Then the mixture was cooled
to 0 °C. Consecutively, water (3 mL), 10% NaOH (3 mL), and water
(
9 mL) were added. The solid was filtered out and the filtrate was
4
.2.1.1. N, N-dimethyl-4-oxo-4-(pyridin-3-yl)butanamide (2a). yield:
concentrated. The residue was purified with flash chromatography on
silica gel (EtOAc/CH3OH = 5/1, v/v) to afford title compound 5 (about
75% yield).
2
3 1
6
8%; yellow oil.
H NMR (400 MHz, CDCl ) δ: 9.23–9.24 (m, 1H,
3
ArH), 8.77–8.78 (m, 1H, ArH), 8.28–8.30 (m, 1H, ArH), 7.42–7.44 (m,
1
H, ArH), 3.32–3.34 (m, 2H, CH
2
), 3.10 (s, 3H,
CH ), 2.96 (s, 3H, CH ), 2.81–2.84 (m, 2H, CH ).
3
3
2
4
.2.3.1. 5-(2-(dimethylamino)ethyl)-4-(pyridin-4-yl)thiazole-2-amine
1
(
5a). yield: 73%; yellow solid; m.p. 145–147 °C; H NMR (400 MHz,
4
.2.1.2. N, N-dimethyl-4-oxo-4-(pyridin-4-yl)butanamide (2b). yield:
DMSO-d
s, 2H, NH
6H, 2CH ).
6
) δ: 8.52–8.53 (m, 2H, ArH), 7.45–7.47 (m, 2H, ArH), 6.84 (br
7
1%; yellow solid; m.p. 45–47 °C. The compound was used for the
2
), 2.85–2.88 (m, 2H, CH ), 2.39–2.42 (m, 2H, CH ), 2.13 (s,
2
2
next step without further identified.
3
4

S. Ma, et al.
Bioorganic & Medicinal Chemistry 28 (2020) 115683
4
.2.4. General procedure for the preparation of compound 4 or 6
filtered, washed, and dried to provide title compound 8 as a yellow
To a solution of corresponding aromatic acid (1.11 mmol) in 20 mL
solid (about 90% yield).
DCM, then EDCI (0.29 g, 1.66 mmol) and HOBt (0.14 g, 1.11 mmol)
were added. The mixture was allowed to stir at room temperature for
4.2.5.1. 3-(pyridin-4-yl)thiazol-2-amine (8a). yield: 92%; yellow solid;
1
3
0 min, then a solution of compound 3 (0.18 g, 1.11 mmol) in 10 mL
m.p. 272–275 °C; H NMR (400 MHz, DMSO-d
6
) δ: 8.51–8.55 (m, 2H,
DCM was added. The resulting reaction mixture was allowed to stir at
room temperature for 8 h. The reaction was washed with water and
saturated brine, the organic layers was dried, filtered, and con-
centrated. The residue was purified by chromatography to afford the
title compound 4 or 6 (about 80% yield).
ArH), 7.72–7.73 (m, 2H, ArH), 7.41–7.43 (m,1H, ArH), 7.16 (br s, 2H,
NH ).
2
4.2.5.2. 4-(pyridin-3-yl)thiazol-2-amine (8b). yield: 92%; yellow solid;
m.p. 265–267 °C.24
4
.2.4.1. N-5-(2-(dimethylamino)-2-oxoethyl)-4-(pyridin-4-yl)thiazol-2-
4.2.6. General procedure for the preparation of compound 9
yl)-2,3-dihydrobenzo[b][1,4]dioxine-2-carboxamide (4a). yield: 73%;
To a solution of nicotinic acid or isonicotinic acid (0.69 g,
5.64 mmol) in 10 mL DCM, then EDCI (1.60 g, 8.46 mmol) and HOBt
(0.76 g, 5.64 mmol) were added. The mixture was allowed to stir at
room temperature for 30 min, then a solution of compound 8 (1.00 g,
5.64 mmol) in 10 mL DCM was added. The resulting reaction mixture
was allowed to stir at room temperature for 8 h. The reaction was
washed with water and saturated brine, the organic layers was dried,
filtered, and concentrated. The residue was purified by chromatography
to afford the title compound 9 (about 80% yield) as a yellow solid, and
used in next step as obtained.
1
yellow solid; m.p. 232–235 °C; H NMR (400 MHz, DMSO-d
6
) δ:
8
.63–8.64 (m, 2H, ArH), 7.56–7.58 (m, 2H, ArH), 7.00–7.02 (m, 1H,
ArH), 6.84–6.91 (m, 3H, ArH), 5.15–5.17 (m, 1H, XOCH), 4.43-
4
.44 (m, 2H, XOCH
2
), 4.40 (s, 2H, ArCH
2
6
), 3.00 (s, 3H, CH ), 2.86
3
1
3
(
s, 3H, CH
3
); C NMR (100 MHz, DMSO-d ) δ: 169.1, 166.7, 150.4,
1
1
43.7, 143.4, 143.0, 142.3, 124.8, 123.0, 122.4, 122.3, 121.9, 117.7,
+
17.5, 72.4, 60.2, 37.4, 35.8, 31.4; HRMS calcd. For C21
H
21
N
4
4
O S [M
+
1] 425.1205, found 425.1208.
4
.2.4.2. N-(5-(2-(dimethylamino)-2-oxoethyl)-4-(pyridin-4-yl)thiazol-2-
1
yl)isonicotinamide (4b). yield: 76%; yellow solid; m.p. 243–245 °C;
NMR (400 MHz, DMSO-d ) δ: 8.76–8.78 (m, 2H, ArH), 8.61–8.62 (m,
H, ArH),7.95–7.97 (m, 2H, ArH), 7.57–7.58 (m, 2H, ArH), 4.10 (s, 2H,
H
4.2.7. General procedure for the preparation of compound 10
6
A mixture of compound 9 (0.19 g, 0.67 mmol), appropriate amine
(0.81 mmol) and paraformaldehyde (0.08 g, 2.01 mmol), in acetic acid
was heated for 1 h at 70 °C. The extra acetic acid was removed under
reduced pressure, and the residue was diluted with ethyl acetate. The
solution was neutralized with saturated sodium bicarbonate. The or-
ganic layer was separated, and washed with water and brine. The or-
ganic layer was dried, filtered, and concentrated. The residue was
purified by a flash chromatograph to afford the title compound 10
2
1
3
ArCH
2
), 3.00 (s, 3H, CH
3
), 2.86 (s, 3H, CH ); C NMR (100 MHz,
3
DMSO-d
6
) δ: 169.3, 164.4, 163.9, 151.0, 150.5, 144.0, 142.4, 139.7,
+
1
25.1, 123.1, 122.3, 36.3, 31.3; HRMS calcd. For C18
H
18
N
5
O S [M
2
+
1] 368.1103, found 368.1108.
N-(5-(2-(dimethylamino)ethyl)-4-(pyridin-4-yl)thiazol-2-yl)-2,3-di-
hydrobenzo[b].
(
about 85% yield).
4
2
7
.2.4.3. [1,4]dioxine-2-carboxamide (6a). yield: 75%; white solid; m.p.
1
35–237 °C; H NMR (400 MHz, DMSO-d
6
) δ: 8.59–8.61 (m, 2H, ArH),
4.2.7.1. N-(5-(Morpholinomethyl)-4-(pyridin-3-yl)thiazol-2-yl)
1
.55–7.56 (m, 2H, ArH), 6.95–6.96 (m, 1H, ArH), 6.80–6.88 (m, 3H,
), 3.32–3.33
nicotinamide (10a). yield: 79%; white solid; m.p. 178–180 °C; H NMR
(400 MHz, DMSO-d ) δ: 9.17–9.18 (m, 1H, ArH), 8.74–8.75 (m, 1H,
ArH), 8.62–8.63 (m, 2H, ArH), 7.37–7.39 (m, 1H, ArH), 7.55–7.56 (m,
2H, ArH), 7.52–7.53 (m, 1H, ArH), 3.78 (s, 2H, ArCH ), 3.56–3.58 (m,
); C NMR (100 MHz, DMSO-
) 164.5, 157.5, 153.5, 150.4, 149.7, 143.5, 142.2, 136.4, 129.6,
ArH), 5.12–5.13 (m,1H, XOCH), 4.39–4.44 (m, 2H, XOCH
2
3
6
1
3
(m, 2H, ArCH
100 MHz, DMSO-d
2
), 2.46–2.50 (m, 2H, CH
2
), 2.16 (s, 6H, 2CH
); C NMR
(
6
) δ: 166.6, 156.1, 150.4, 143.4, 143.0, 142.5,
2
1
3
1
2
4
42.4, 129.7, 123.2, 122.3, 121.9, 117.6, 117.5, 72.3, 65.1, 59.5, 45.1,
4H, 2XOCH
2
), 2.44–2.46 (m, 4H, 2XNCH
2
+
5.1; HRMS calcd. For
11.1417.
C
21
H
23
4
N O
3
S
[M +1] 411.1413, found
d
6
128.4, 124.1, 123.3, 66.7, 54.4,
5
3.7; HRMS calcd. for C19
H
20
5
N O
2
S [M++1] 382.1332, found
4
.2.4.4. N-(5-(2-(dimethylamino)ethyl)-4-(pyridin-4-yl)thiazol-2-yl)
382.1329.
1
isonicotinamide (6b). yield: 75%; yellow solid; m.p. 242–245 °C;
H
NMR (400 MHz, DMSO-d
6
) δ: 8.70–8.72 (m, 2H, ArH), 8.59–8.60 (m,
4.2.7.2. N-(5-(morpholinomethyl)-4-(pyridin-4-yl)thiazol-2-yl)
2
H, ArH), 7.94–7.96 (m, 2H, ArH), 7.58–7.60 (m, 2H, ArH), 3.34–3.35
isonicotinamide (10b). yield: 79%; white solid; m.p. 175–178 °C; 1H
1
3
(
m, 2H, ArCH
2
), 2.50–2.53 (m, 2H, CH
2
), 2.18 (s, 6H, 2CH
3
); C NMR
NMR (400 MHz, DMSO-d ) δ: 8.77-
6
(
100 MHz, DMSO-d
6
) δ: 166.8, 160.8, 150.7, 150.4, 150.3, 150.1,
8.78 (m, 2H, ArH), 8.62–8.64 (m, 2H, ArH), 7.95–7.96 (m, 2H,
1
36.3, 123.3, 123.2, 122.4, 49.0, 45.2, 25,2; HRMS calcd. For
ArH), 7.64–7.65 (m,2H, ArH), 3.80 (s, 2H, ArCH
2
), 3.55–3.58 (m, 4H,
+
13
C
18
H
20
N
5
OS [M +1] 354.1320, found 354.1324.
2XOCH
2
), 2.45–2.46 (m, 4H, 2XOCH
2
); C NMR (100 MHz, DMSO-d
6
)
δ: 164.5, 157.4, 151.0, 150.9, 150.5, 142.1, 139.6, 129.9, 123.3, 122.3,
+
4.2.5. General procedure for the preparation of compound 8
66.8, 54.5, 53.8; HRMS calcd. For C19
H
20
5
N O
2
S [M +1] 382.1259,
Step 1. To a 0 °C solution of 4-acetylpyridine or 3-acetylpyridine
found 382.1263.
(
4.90 g, 41.30 mmol) and 48% HBr (7.0 mL) in acetic acid (46.0 mL)
was added, dropwise over 15 min, a solution of Br
2
(2.30 mL,
4.2.7.3. N-(4-(Pyridin-4-yl)-5-(pyrrolidin-1-ylmethyl)thiazol-2-yl)
1
4
5.00 mmol) in acetic acid (8.0 mL). After the addition was complete,
isonicotinamide (10c). yield: 81%; white solid; m.p. 192–195 °C; H
the mixture was allowed to warm to r.t. and then was heated at 70 °C
for 1 h. The mixture was cooled to 0 °C and treated with diethyl ether.
The resultant white solid was isolated by vacuum filtration to give the
bromoketone as the HBr salt, which was used in next step as obtained.
Step 2. A mixture of above salt (10.00 g, 35.59 mmol) and thiourea
NMR (400 MHz, DMSO-d ) δ: 8.76–8.77 (m, 2H, ArH), 8.61–8.63 (m,
6
2H, ArH), 7.94–7.96 (m, 2H, ArH), 7.64–7.65 (m,1H, ArH), 3.90 (s, 2H,
1
3
ArCH
2
), 2.53 (s, 4H, CH
2
), 1.69 (s, 4H, CH ); C NMR (100 MHz,
2
DMSO-d
6
) 164.5, 160.8, 151.0, 150.9, 150.5, 143.3, 142.2, 139.7,
+
123.2, 122.3, 54.2, 51.9, 23.8; HRMS calcd. for C19
H
20
N
5
OS [M +1]
(
2.71 g, 35.50 mmol) in absolute EtOH (100 mL) was refluxed over-
366.1383, found 366.1391.
night. After cooling, the reaction mixture was diluted with water
400 mL), the pH was adjusted to 11 with ammonium hydroxide so-
lution, and was further stirred for 2 h. The resulting precipitate was
(
4.2.7.4. N-(5-((4-Methylpiperazin-1-yl)methyl)-4-(pyridin-4-yl)thiazol-2-
1
yl)isonicotinamide (10d). yield: 87%; white solid; m.p. 203–205 °C;
H
5

S. Ma, et al.
Bioorganic & Medicinal Chemistry 28 (2020) 115683
1
3
NMR (400 MHz, DMSO-d
6
) δ: 12.93 (br s, 1H, NH), 8.76–8.77 (m, 2H,
(m, 1H, ArH), 3.63 (s, 2H, ArCH
2
), 2.19 (s, 6H, CH ); C NMR
3
ArH), 8.61–8.62 (m, 2H, ArH), 7.94–7.96 (m, 2H, ArH), 7.62–7.63 (m,
(100 MHz, DMSO-d ) δ: 164.5, 157.5, 153.4, 149.7, 149.6, 149.1,
6
2
H, ArH), 3.72 (s, 2H, ArCH
2
), 2.39 (m, 4H, CH
2
), 1.46–1.47 (m, 4H,
143.1, 136.4, 136.2, 131.1, 128.6, 128.3, 124.1, 124.0, 55.4, 45.5;
1
3
+
CH
2
), 1.33–1.34 (m, 2H, CH
2
); C NMR (100 MHz, DMSO-d
6
) δ: 164.4,
HRMS calcd. for C17
H
18
N
5
OS [M +1] 340.1227, found 340.1224.
1
5
57.3, 150.9, 150.4, 143.1, 142.2, 139.6, 131.3, 123.3, 122.3, 54.9,
+
4.6, 26.1, 24.3; HRMS calcd. for C20
H
22
N
6
OS [M +1] 380.1467,
4.2.7.11. N-(5-(Piperidin-1-ylmethyl)-4-(pyridin-3-yl)thiazol-2-yl)
1
found 380.1465.
nicotinamide (10k). yield: 75%; white solid; m.p. 198–199 °C; H NMR
(
400 MHz, DMSO-d ) δ: 9.18–9.19 (m, 1H, ArH), 8.83–8.84 (m, 1H,
6
4
.2.7.5. N-(5-((dimethylamino)methyl)-4-(pyridin-3-yl)thiazol-2-yl)
isonicotinamid (10e). yield: 75%; white solid; m. p. 201–202 °C;
NMR (400 MHz, DMSO-d ) δ: 8.84–8.85 (m, 1H, ArH), 8.76–8.77 (m,
H, ArH), 8.53–8.55 (m, 1H, ArH), 8.01–8.04 (m, 1H, ArH), 7.95–7.96
ArH), 8.74–8.76 (m, 1H, ArH), 8.52–8.53 (m, 1H, ArH), 8.37–8.38 (m,
1H, ArH), 8.01–8.03 (m, 1H, ArH), 7.52–7.56 (m, 1H, ArH), 7.44–7.47
1
H
6
(m, 1H, ArH), 3.67 (s, 2H, ArCH
2
), 2.37 (s, 4H, 2NCH ), 1.48 (s, 4H,
2
1
3
2
CH
2
), 1.35 (m, 2H, CH
2
); C NMR (100 MHz, DMSO-d ) δ: 164.5,
6
(
m, 2H, ArH), 7.49–7.50 (m, 1H, ArH), 3.65 (s, 2H, ArCH
2
), 2.19 (s, 6H,
157.5, 153.4, 149.7, 149.0, 142.9, 136.4, 136.2, 131.1, 128.6, 124.1,
1
3
+
CH
3
); C NMR (100 MHz, DMSO-d
6
) δ: 164.4, 157.4, 150.9, 149.1,
124.1, 54.8, 54.5, 26.1, 24.4; HRMS calcd. for C20
H
22
N
5
OS [M +1]
1
43.1, 139.7, 136.2, 131.0, 128.6, 124.0, 122.3, 55.3,45.5; HRMS
380.1540, found 380.1533.
+
calcd. for C17
H
18
N
5
OS [M +1] 340.1154, found 340.1158.
4
.2.7.12. N-(5-(morpholinomethyl)-4-(pyridin-4-yl)thiazol-2-yl)-2,3-
4
.2.7.6. N-(5-(morpholinomethyl)-4-(pyridin-3-yl)thiazol-2-yl)
isonicotinamide (10f). yield: 81%; yellow solid; m. p. 185–187 °C;
NMR (400 MHz, DMSO-d ) δ: 8.86–8.87(m, 1H, ArH), 8.79–8.80 (m,
H, ArH), 8.65–8.66 (m, 1H, ArH), 8.09–8.12 (m, 1H, ArH), 7.96–7.98
m, 2H, ArH), 7.56–7.59 (m, 1H, ArH), 4.34 (s, 2H, ArCH ), 3.65–3.67
); C NMR (100 MHz,
) δ: 190.0, 164.8, 158.9, 150.9, 149.1, 148.9, 139.5, 137.8,
dihydrobenzo[b][1,4]dioxine-2-carboxamide (10l). yield: 75%; yellow
1
1
H
solid; m. p. 178–180 °C; H NMR (400 MHz, CD
3
OD) δ: 8.55–8.57
6
(m, 2H, ArH), 7.74–7.76 (m, 2H, ArH),7.05–7.07 (m, 1H, ArH),
2
6.85–6.89 (m, 3H, ArH), 5.01–5.04 (m,1H, OCH), 4.40–4.43 (m, 2H,
(
(
2
OCH
2
), 3.78 (s, 2H, ArCH
2
), 3.66–3.68 (m, 4H, 2CH ), 2.49–2.50 (m,
2
1
3
13
m, 4H, 2XOCH
2
), 2.93–2.94 (m, 4H, 2XOCH
2
4H, 2CH
2
); C NMR (100 MHz, CD
3
OD) δ: 166.8, 156.3, 148.8, 143.3,
DMSO-d
6
141,9, 130.0, 123.4, 121.9, 121.7, 117.3, 117.0, 72.8, 66.6, 64.4, 54.0,
+
1
30.6, 127.2, 124.6, 122.3,
53.3; HRMS calcd. forC22
439.1364.
H
23
N
4
O
4
S
[M +1] 439.1362, found
6
4.6, 51.8, 26.8; HRMS calcd. For C19
H
20
N
5
O
2
S [M++1] 382.4540,
found 382.4544.
4
.2.7.13. N-(5-(morpholinomethyl)-4-(pyridin-3-yl)thiazol-2-yl)-2,3-
4
.2.7.7. N-(5-(Morpholinomethyl)-4-(pyridin-3-yl)thiazol-2-yl)
nicotinamide (10g). yield: 75%; white solid; m.p. 168–171 °C; H NMR
400 MHz, DMSO-d ) δ: 12.83 (br s, 1H, NH), 9.17–9.18 (m, 1H, ArH),
.83–8.84 (m, 1H, ArH), 8.73–8.74 (m, 1H, ArH), 8.51–8.52 (m, 1H,
ArH), 8.38–8.40 (m, 1H, ArH), 8.00–8.02 (m, 1H, ArH), 7.51–7.53 (m,
dihydrobenzo[b][1,4]dioxine-2-carboxamide (10m). yield: 72%; yellow
1
1
solid; m. p. 177–179 °C; H NMR(400 MHz, DMSO-d
6
) δ: 8.81–8.82 (m,
(
6
1H, ArH), 8.51–8.53 (m, 1H, ArH), 7.97–8.00 (m, 1H, ArH), 7.43–7.47
(m, 1H, ArH), 6.96–6.98 (m, 1H, ArH), 6.81–6.88 (m, 3H, ArH),
8
5.11–5.13 (m, 1H, OCH), 4.40–4.42 (m, 2H, OCH ), 3.83 (s, 2H,
2
13
1
H, ArH), 7.43–7.45 (m, 1H, ArH), 3.73 (s, 2H, ArCH
2
), 3.56–3.57
ArCH
2
), 2.46–2.48 (m, 4H, CH
2
),1.66–1.67 (m, 4H, CH ); C NMR
2
1
3
(
m,4H, 2XOCH
2
), 2.43–2.46 (m, 4H, 2XNCH
2
); C NMR (100 MHz,
(100 MHz, DMSO-d ) δ: 166.9, 156.3, 149.5, 149.0, 143.4, 143.0,
6
DMSO-d
6
) δ: 164.4, 153.4, 149.7, 149.6, 149.0, 136.3, 136.2, 131.0,
136.0, 131.0, 124.0, 122.3, 121.9, 117.7, 117.5, 72.3, 65.0, 55.4, 54.1,
+
+
1
24.0, 123.9, 66.8, 54.4, 53.7; HRMS calcd. for C19
H
20
N
5
O
2
S [M +1]
23.7; HRMS calcd. forC22
439.1366.
H
23
N
4
O
4
S
[M +1] 439.1362, found
3
82.1332, found 382.1331.
4
.2.7.8. N-(5-((4-Methylpiperazin-1-yl)methyl)-4-(pyridin-3-yl)thiazol-2-
4.2.7.14. N-(4-(pyridin-3-yl)-5-(pyrrolidin-1-ylmethyl)thiazol-2-yl)-2,3-
1
yl)Nicotinamide (10h). yield: 80%; white solid; m.p. 198–201 °C;
H
dihydrobenzo[b][1,4]dioxine-2-carboxamide (10n). yield: 78%; yellow
1
NMR (400 MHz, DMSO-d
H, ArH), 8.74–8.75 (m, 1H, ArH), 8.53–8.54 (m, 1H, ArH), 8.37–8.40
m, 1H, ArH), 8.01–8.03 (m, 1H, ArH), 7.53–7.56 (m, 1H, ArH),
6
) δ: 9.17–9.18 (m, 1H, ArH), 8.84–8.85 (m,
solid; m.p. 181–182 °C; H NMR (400 MHz, DMSO-d
6
) δ: 8.79–8.80 (m,
1
1H, ArH), 8.52–8.53 (m, 1H, ArH), 7.96–7.99 (m, 1H, ArH), 7.44–7.47
(
(m, 1H, ArH), 6.95–6.97 (m, 1H, ArH), 6.80–6.88 (m, 3H, ArH),
7
4
1
1
.45–7.48 (m, 1H, ArH), 3.73 (s, 2H, ArCH
2
), 2.33–2.46 (m, 8H,
5.16–5.17 (m, 1H, XOCH), 4.36–4.45 (m, 2H, XOCH
2
), 3.69 (s, 2H,
1
3
13
XNCH
2
), 2.15 (s, 3H, CH
3
); C NMR (100 MHz, DMSO-d
6
) δ: 164.5,
ArCH
2
), 3.50–3.52 (m, 4H, CH
2
), 2.36–2.38 (m, 4H, CH
2
); C NMR
57.6, 153.5, 149.8, 149.6, 149.1, 143.2, 136.4, 136.2, 131.1, 128.6,
(100 MHz, DMSO-d ) δ:166.8, 149.5, 149.1, 143.4, 143.0, 136.1, 130.9,
6
+
27.9, 124.1, 55.1, 54.0, 53.0, 46.0; HRMS calcd. for C20
H
23
N
6
OS [M
127.5, 124.1, 122.3, 121.9, 117.6, 117.5, 72.3, 66.7, 55.4, 54.3, 53.6;
+
+
1] 395.1649, found 395.1644.
HRMS calcd. forC22
H
23
N
4
O
3
S [M +1] 423.5030, found 423.5034.
4
.2.7.9. N-(5-((i-Propyl(methyl)amino)methyl)-4-(pyridin-3-yl)thiazol-2-
4.2.7.15. N-(5-((dimethylamino)methyl)-4-(pyridin-3-yl)thiazol-2-yl)-
1
yl)Nicotinamide (10i). yield: 78%; white solid; m.p. 178–180 °C;
H
2,3-dihydrobenzo[b][1,4]dioxine-2-carboxamide (10o). yield: 75%;
1
NMR (400 MHz, DMSO-d
H, ArH), 8.74–8.76 (m, 1H, ArH), 8.52–8.54 (m, 1H, ArH), 8.37–8.40
m, 1H, ArH), 8.00–8.03 (m, 1H, ArH), 7.54–7.56 (m, 1H, ArH),
6
) δ: 9.17–9.18 (m, 1H, ArH), 8.84–8.85 (m,
white solid; m.p. 192–196 °C; H NMR (400 MHz, DMSO-d
6
) δ:
1
8.80–8.81 (m, 1H, ArH), 8.52–8.53 (m, 1H, ArH), 7.97–8.00 (m, 1H,
ArH), 7.43–7.47 (m, 1H, ArH), 6.96–6.99 (m, 1H, ArH), 6.81–6.87 (m,
(
7
2
1
1
.44–7.47 (m, 1H, ArH), 3.77 (s, 2H, ArCH
2
), 2.90–2.92 (m, 1H, CH),
3H, ArH), 5.11–5.13 (m, 1H, OCH), 4.40–4.41 (m, 2H, OCH
2
6
), 3.62 (s,
) δ: 166.6,
1
3
13
.12 (s, 3H, CH
3
), 0.97 (s, 6H, CH
3
); C NMR (100 MHz, DMSO-d
6
) δ:
2H, ArCH
2
), 2.16 (s, 6H, CH
3
); C NMR (100 MHz, DMSO-d
64.4, 157.5, 153.4, 149.7, 149.5, 149.0, 142.3, 136.4, 136.1, 131.2,
156.4, 149.5, 149.0, 143.3, 143.0, 136.1, 130.9, 124.0, 122.3, 121.9,
30.8, 128.6, 124.2, 124.1, 53.1, 49.8, 37.0, 18.1; HRMS calcd. for
117.7, 117.5, 72.4, 65.0, 55.4, 45.4; HRMS calcd. for C20
H
21
N
4
O S
3
+
+
C
19
H
22
N
5
OS [M +1] 368.1540, found 368.1543.
[M +1] 397.4650, found 397.4652.
4
.2.7.10. N-(5-((Dimethylamino)methyl)-4-(pyridin-3-yl)thiazol-2-yl)
4.2.8. General procedure for the preparation of compound 12
1
nicotinamide (10j). yield: 75%; white solid; m.p. 169–171 °C; H NMR
Step 1. To a solution of compound 8a (1.00 g, 5.64 mmol) in 10 mL
(
400 MHz, DMSO-d
ArH), 8.74–8.75 (m, 1H, ArH), 8.52–8.53 (m, 1H, ArH), 8.37–8.40 (m,
H, ArH), 8.01–8.04 (m, 1H, ArH), 7.52–7.55 (m, 1H, ArH), 7.46–7.47
6
) δ: 9.18–9.19 (m, 1H, ArH), 8.84–8.85 (m, 1H,
CHCl , then NBS (1.10 g, 6.77 mmol) were added. The resulting reac-
3
tion mixture was allowed to stir at room temperature for 3 h. The re-
action was washed with water and saturated NaCl, the organic layer
1
6

S. Ma, et al.
Bioorganic & Medicinal Chemistry 28 (2020) 115683
was dried, filtered, and concentrated. The residue was purified by
chromatography to afford the brominated intermediate 0.89 g (63%
yield) as a yellow solid and used directly.
methylbenzidine (TMB), which can be catalyzed from a colorless so-
lution to a blue solution. The absorbance was measured at a wavelength
of 450 nm on a microplate reader. The color reflects the relative level of
ROCK II activity. The inhibitory rates of the compounds on ROCK II
were obtained from OD 450 nm and the IC50 values were calculated by
nonlinear regression.
Step 2. To a solution of above intermediate (1.00 g, 3.92 mmol) in
5
3
6
0 mL DMF, then K
2
CO (1.60 g, 11.76 mmol) and morpholine (0.32 g,
3
.92 mmol) were added. The reaction mixture was heated at 100 °C for
h. The reaction solution was diluted with water and extracted with
ethyl acetate. The organic layer was washed with water and saturated
brine, the organic layer was dried, filtered, and concentrated. The re-
sidue was purified by chromatography to afford the compound 12
4.4. Molecular docking
Molecular docking was performed with Sybyl-X2.0 software
package. The crystal structure of experimental protein, with co-crystal
ligand obtained from the Protein Data Bank (PDB code: 4L6Q), was
used to simulate the binding mode between our compounds and pro-
tein. Co-crystalized ligand was removed from the structure, water
molecules were removed, H atoms were added and side chains were
fixed during protein preparation. Protein structure minimization was
performed by applying Tripos force field and partial atomic charges
were calculated by the Gasteiger-Huckel method. The default para-
meter settings were used.
0
.89 g (63% yield) as a yellow solid.
4
.2.9. General procedure for the preparation of compound 13
To a solution of corresponding aromatic acid (1.11 mmol) in 20 mL
DCM, then EDCI (0.29 g, 1.66 mmol) and HOBT (0.14 g, 1.11 mmol)
were added. The mixture was allowed to stir at room temperature for
3
0 min, then a solution of compound 11 or 13 (1.11 mmol) in 10 mL
DCM was added. The resulting reaction mixture was allowed to stir at
room temperature for 8 h. The reaction was washed with water and
saturated brine, the organic layers was dried, filtered, and con-
centrated. The residue was purified by chromatography to afford the
title compound (about 75% yield).
Author contribution
The manuscript was written through contributions of all authors. All
authors have given approval to the final version of the manuscript.
4
.2.9.1. N-(5-morpholino-4-(pyridin-4-yl)thiazol-2-yl)-2,3-dihydrobenzo
[
b][1,4]dioxine-2-carboxamide(13a). yield: 77%; yellow solid; m.p.
1
1
92–194 °C; H NMR(400 MHz, DMSO-d
6
) δ: 8.58–8.59 (m, 2H,
Declaration of Competing Interest
ArH), 7.97–7.99 (m, 2H, ArH), 6.90–6.96 (m, 1H, ArH), 6.83–6.89
(
m, 3H, ArH), 5.11–5.12 (m,1H, OCH), 4.39–4.40 (m, 2H, OCH
2
),
The authors declare that they have no known competing financial
interests or personal relationships that could have appeared to influ-
ence the work reported in this paper.
1
3
3
.73–3.75 (m, 4H, 2CH
2
), 2.84–2.86 (m, 4H, 2CH
2
);
C
NMR
(
100 MHz, DMSO-d
6
) δ: 166.7, 150.6, 150.5, 147.4, 143.4, 143.0,
1
5
4
41.3, 133.7, 122.3, 121.9, 121.4, 117.6, 117.5, 100.0, 66.5, 65.0,
+
4.7; HRMS calcd. For
25.1207.
C
21
H
20
4
N O
4
S
[M +1] 425.1205, found
Acknowledgements
The author would like to thank the Doctoral Foundation of Yantai
University (No. YX13B04), and the Talent Development Project of Blue
Economic Zone of Shandong Province (No. RS11YX) for financial sup-
port.
4
.2.9.2. N-(5-(4-methylpiperazin-1-yl)-4-(pyridin-4-yl)thiazol-2-yl)
1
isonicotinamide(13b). yield: 79%; yellow solid; m.p. 211–213 °C;
H
NMR (400 MHz, DMSO-d ) δ: 8.75–8.77 (m, 2H, ArH), 8.58–8.59 (m,
6
2
H, ArH), 7.99–8.00 (m, 2H, ArH), 7.93–7.94 (m, 2H, ArH), 2.93–2.96
1
3
(
m, 4H, CH
2
), 2.58–2.59 (m, 4H, CH
2
), 2.29 (s, 3H, CH
3
); C NMR
Appendix A. Supplementary data
(
100 MHz, DMSO-d
6
) δ: 164.5, 150.9, 150.5, 141.4, 137.1, 133.6,
1
32.7, 133.6, 132.7, 130.1, 122.3, 121.4, 54.6, 54.0, 27.3; HRMS calcd.
Supplementary data to this article can be found online at https://
doi.org/10.1016/j.bmc.2020.115683.
+
for C19
H
20
N
6
OS [M +1] 381.1420, found 381.1419.
4
.2.9.3. N-(5-(isopropyl(methyl)amino)-4-(pyridin-4-yl)thiazol-2-yl)
isonicotinamide(13c). yield: 80%; yellow solid; m. p. 198–199 °C;
NMR (400 MHz, DMSO-d ) δ: 8.76–8.77 (m, 2H, ArH), 8.57–8.58 (m,
H, ArH), 7.97–7.99 (m, 2H, ArH), 7.92–7.94 (m, 2H, ArH), 3.13–3.18
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