Synthesis and biological evaluation of 2-phenylthiazole-4-carboxamide derivatives as anticancer agents

Article abstract of DOI:10.1016/j.ejmech.2010.08.063

A series of substituted 2-phenylthiazole-4-carboxamide derivatives were synthesized as potential cytotoxic agents and evaluated against three human cancer cell lines including T47D (Breast cancer), Caco-2 (Colorectal cancer) and HT-29 (Colon cancer). The SAR of the arylacetamido pendent connected to the para-position of 2-phenylthiazole were explored. It was found that substitution at the 4-position by a methoxy group led to improvement of activity against Caco-2 cells while 2-methoxy substituent could maintain the high activity against HT-29 and T47D cell lines. Also, 3-fluoro analog showed good cytotoxic activity profile against all cell lines with IC₅₀ values less than 10 μg/mL.

Full text of DOI:10.1016/j.ejmech.2010.08.063

European Journal of Medicinal Chemistry 45 (2010) 5384e5389
Contents lists available at ScienceDirect
European Journal of Medicinal Chemistry
journal homepage: http://www.elsevier.com/locate/ejmech
Original article
Synthesis and biological evaluation of 2-phenylthiazole-4-carboxamide
derivatives as anticancer agents
Alireza Aliabadi a, Fazel Shamsa a, Seyed Nasser Ostad b, Saeed Emami c, Abbas Shafiee a,
,
Jamshid Davoodi d, Alireza Foroumadi a
*
a Department of Medicinal Chemistry, Faculty of Pharmacy and Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Tehran 14174, Iran
b Department of Toxicology and Pharmacology, Tehran University of Medical Sciences, Tehran, Iran
c Department of Medicinal Chemistry and Pharmaceutical Sciences Research Center, Faculty of Pharmacy, Mazandaran University of Medical Sciences, Sari, Iran
d Institute of Biochemistry and Biophysics, University of Tehran, Enghelab Avenue, P.O. Box 13145-1384, Tehran, Iran
a r t i c l e i n f o
a b s t r a c t
Article history:
A series of substituted 2-phenylthiazole-4-carboxamide derivatives were synthesized as potential
cytotoxic agents and evaluated against three human cancer cell lines including T47D (Breast cancer),
Caco-2 (Colorectal cancer) and HT-29 (Colon cancer). The SAR of the arylacetamido pendent connected to
the para-position of 2-phenylthiazole were explored. It was found that substitution at the 4-position by
a methoxy group led to improvement of activity against Caco-2 cells while 2-methoxy substituent could
maintain the high activity against HT-29 and T47D cell lines. Also, 3-fluoro analog showed good cytotoxic
Received 24 June 2010
Received in revised form
25 August 2010
Accepted 26 August 2010
Available online 16 September 2010
activity profile against all cell lines with IC50 values less than 10 mg/mL.
Keywords:
Synthesis
Ó 2010 Elsevier Masson SAS. All rights reserved.
2-Phenylthiazole-4-carboxamide
Thiazole
Cytotoxicity
MTT assay
1. Introduction
activity (Fig. 1). Structureeactivity relationship (SAR) study of the
cyclic amine attached to the oxazole-4-carbonyl group revealed
a strong preference for 6- and 7-membered cyclic amines at this
position. Also, an interesting correlation was found between the
van der Waals volume of the molecule with caspase activation in
one subgroup of analogs. At benzylamine fragment, a single
methylene unit was determined to be the best spacer between the
aryl/heteroaryl group and the amide group (Fig. 1) [4].
Since many of the current anticancer agents which are under
investigation act by induction of apoptosis, we are interested in the
synthesis and assessment of new analogs of apoptosis inducers as
potential anticancer agents. In this research, we synthesized and
investigated biological activity of new analogs of 2-phenylthiazole-
4-carboxamide with the replacement of the thiazole ring instead of
the oxazole ring (Fig. 1). All compounds were evaluated against
three human cancer cell lines consist of T47D (Breast cancer), Caco-
2 (Colorectal cancer) and HT-29 (Colon cancer).
Cancer is one of the leading causes of mortality in developed
countries, and the discovery and development of new anticancer
drugs is urgently needed due to problems with currently available
drugs, such as toxicities and drug resistance [1]. Apoptosis, or
programmed cell death, plays an important role in normal
embryonic development, as well as for daily elimination of
dispensable or excess cells [2]. Apoptosis is a normal process that
organisms use to eliminate unwanted and excessive cells and is
important in animal development, as well as in tissue homeostasis.
However, improperly regulated apoptosis can lead to many path-
ological conditions. Inadequate or abnormal inhibition of apoptosis,
which leads to unchecked cell proliferation and results in cell
accumulation, is a hallmark of cancer [3]. Two major mechanisms
are involved in the induction of apoptosis: agents that activate
a family of death receptors leading to the activation of the apoptotic
cascade; or agents that trigger the release of cytochrome c from
mitochondria followed by apoptosis [4]. Recently, Tai et al. have
reported the discovery of 2-phenyl-oxazole-4-carboxamide deriv-
atives as potent apoptosis inducers with potential anticancer
2. Chemistry
The target compounds 9aej were synthesized according to the
Scheme 1. Bromination of p-toluonitrile (1) in the presence of
N-bromosuccinimide (NBS) and benzoyl peroxide (Bz2O2) in
refluxing chloroform led to the p-cyanobenzylbromide (2) [5].
* Corresponding author. Tel.: þ98 21 66954708; fax: þ98 21 66461178.
E-mail address: aforoumadi@yahoo.com (A. Foroumadi).
0223-5234/$ e see front matter Ó 2010 Elsevier Masson SAS. All rights reserved.
doi:10.1016/j.ejmech.2010.08.063

A. Aliabadi et al. / European Journal of Medicinal Chemistry 45 (2010) 5384e5389
5385
O
O
N
N
N
N
O
O
O
HN
S
HN
Ar
n
2-Phenylthiazole-4-carboxamides
2-Phenyloxazole-4-carboxamides
X
Fig. 1. The structures of previously described apoptosis inducers, 2-phenyloxazole-4-carboxamides and new designed compounds, 2-phenylthiazole-4-carboxamides.
Compound 2 and potassium phthalimide were reacted in acetoni-
trile under reflux conditions to produce 4-((1,3-dioxoisoindolin-2-
(Colorectal cancer) and HT29 (Colon cancer) using MTT (3-(4, 5-
dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay
[12e14]. Cells were seeded in 96-well plates and incubated for 48 h
to allow cell attachment. The cells were then incubated with
various concentrations of compounds 9aej. After washing of cells
with PBS, MTT solution was added to each well. The amount of
produced purple formazan is proportional to the number of viable
cells. The absorbance of each well was measured by plate reader.
Two independent experiments in triplicate were performed for
determination of sensitivity to each compound, the IC50 were
calculated by linear regression analysis, expressed in mean ꢀ SD.
Methotrexate was used as a standard drug.
yl)methyl)benzonitrile (3) [6]. Stirring of compound
3 with
ammonium sulfide in N,N-dimethylformamide (DMF) was formed
the related thioamide derivative 4 [7,8]. Reaction of thioamide
derivative 4 and ethyl bromopyruvate in refluxing ethanol afforded
thiazole-4-carboxylic acid ethyl ester derivative 5 [9]. The ethyl
ester was hydrolyzed under alkaline conditions by stirring in
sodium hydroxide solution for 24 h to form the carboxylic acid
derivative 6. The coupling reaction of piperidine and carboxylic acid
derivative 6 was carried out in acetonitrile using EDC/hydrox-
ybenzotriazole (HOBt) to produce corresponding amide 7 [10,11].
Phthalimide cleavage using methylamine in refluxing ethanol led to
the formation of primary amine 8 [6]. Diverse phenylacetic acid
derivatives were coupled with amine moiety of compound 8 to
form the final compounds 9aej [10,11].
4. Results
The results of biological activity were summarized as IC50 (mg/
mL) of compounds in Table 1. The IC50 values of compounds against
3. Pharmacology
Caco-2 cell line revealed that most compounds showed significant
cytotoxic activity at concentrations less than 100
mg/mL. The
The cytotoxic activity of compounds 9aej were evaluated
4-methoxy analog (compound 9j) was the most potent compound
against three cell lines consisting of T47D (Breast cancer), Caco-2
with IC50 of 1.88
m
g/mL. The growth inhibitory concentrations of
O
O
N
NK
O
NBS
NC
NC
CH3
CH2Br
CHCl3 ,
Reflux
CH3CN
O
NC
2
1
3
O
O
O
N
Br
OEt
N
O
(NH4)2S
DMF
S
O
O
N
H2N
EtO
O
EtOH, Reflux
S
4
5
O
N
O
EDC, HOBt
CH3CN
O
O
N
N
NaOH
EtOH
N
O
N
HO
S
O
S
NH
7
6
OH
O
O
O
MeNH2
X
N
S
N
N
N
EtOH,
Reflux
O
EDC,
HOBt
S
NH2
HN
8
9a-j
X
X = F, Cl, Br, OCH3
Scheme 1. Synthetic pathway to compounds 9aej.

5386
A. Aliabadi et al. / European Journal of Medicinal Chemistry 45 (2010) 5384e5389
Table 1
agents. We have explored the SAR of the arylacetamido pendent
Cytotoxic activity (IC50, mg/mL) of compounds 9aej against Caco-2 (colorectal
cancer), HT-29 (colon cancer) and T47D (breast cancer) cell lines.
connected to the para-position of 2-phenylthiazole. It was found
that substitution at the 4-position by a methoxy group led to
improvement of activity against Caco-2 cells while 2-methoxy
substituent could maintain the high activity against HT-29 and
T47D cell lines. Also, 3-fluoro analog (compound 9e) showed good
cytotoxic activity profile against all cell lines with IC50 values less
O
N
S
N
O
HN
X
than 10 mg/mL.
7. Experimental protocols
Compound
X
Caco-2
HT-29
T47D
7.1. Chemistry
9a
9b
9c
9d
9e
9f
9g
9h
2-Cl
3-Cl
4-Cl
2-F
3-F
4-F
4-Br
2-OCH3
3-OCH3
4-OCH3
12.75 ꢀ 1.99
154.79 ꢀ 14.32
89.92 ꢀ 12.32
18.12 ꢀ 4.93
4.32 ꢀ 0.86
26.8 ꢀ 0.84
64.33 ꢀ 9.82
5.37 ꢀ 0.99
24.26 ꢀ 6.57
37.62 ꢀ 2.16
11.79 ꢀ 1.45
18.83 ꢀ 6.56
2.02 ꢀ 0.67
14.19 ꢀ 4.56
29.47 ꢀ 3.34
6.83 ꢀ 4.71
40.29 ꢀ 34.16
21.58 ꢀ 5.67
0.16 ꢀ 0.09
All starting materials, reagents and solvents were purchased
from Merck and Aldrich companies. The purity of the synthesized
compounds was confirmed by thin layer chromatography (TLC)
using various solvents of different polarities. Merck silica gel 60
F254 plates were applied for analytical TLC. Column chromatog-
raphy was performed on Merck silica gel (70e230 mesh) for puri-
fication of intermediate and final compounds. 1H NMR spectra were
recorded using a Varian 400 spectrometer, and chemical shifts are
>1000
9.84 ꢀ 0.94
113.62 ꢀ 24.19
52.04 ꢀ 0.89
28.07 ꢀ 1.27
41.09 ꢀ 16.84
1.88 ꢀ 31.12
0.32 ꢀ 0.04
52.04 ꢀ 12.06
45.28 ꢀ 2.37
4.46 ꢀ 0.98
447.17 ꢀ 64.12
>1000
9i
9j
Methotrexate
0.23 ꢀ 0.02
expressed as
d (ppm) with tetramethylsilane (TMS) as internal
standard. The IR spectra were obtained on a Shimadzu 470 spec-
trophotometer (potassium bromide disks). Melting points were
determined on a Kofler hot stage apparatus and are uncorrected.
The mass spectra were run on a Finigan TSQ-70 spectrometer
(Finigan, USA) at 70 eV. Elemental analyses were carried out on
a CHN-O-rapid elemental analyzer (GmbH-Germany) for C, H and
N, and the results are within ꢀ0.4% of the theoretical values.
compounds against HT-29 cells indicate that 2-methoxy derivative
(compound 9h) showed the highest cytotoxic activity against
colon cancer cells at concentrations less than 5
m
g/mL (IC50
¼
4.46 ꢀ 0.98
mg/mL). Moreover, compound 9c (4-chloro analog) had
similar activity profile against HT-29 cells in comparison with
compound 9h being statistically equipotent. The comparison of IC50
values against T47D cells demonstrated that compound 9e had the
most potent activity against this cell line (IC50 ¼ 2.02 ꢀ 0.67
m
g/mL).
7.1.1. p-Cyanobenzylbromide (2)
The overall activity profiles of compounds demonstrated that the
A mixture of p-toluonitrile (5 g, 0.043 mol), N-bromosuccini-
mide (7.6 g, 0.043 mol) and benzoyl peroxide (50 mg) was refluxed
in chloroform (150 mL) for 24 h. The completion of reaction was
detected by TLC. The solvent was evaporated under reduced pres-
sure and then ethyl acetate and H2O was added. The organic layer
was extracted and washed 3 times with brine. After evaporation of
ethyl acetate, compound 2 was obtained as a white solid (7.7 g,
yield 92%). This product was used for the next step without any
further purification. M.p 115e119 ꢁC; IR (KBr, cmꢂ1): 3406, 3064,
2229, 1934, 1813, 1693, 1603, 1502, 1417, 1289, 1231, 1203, 1099. 1H
T47D cell line has more sensitivity respect to other cell lines.
5. Discussion
For investigation of structure activity relationship (SAR),
a diverse electron withdrawing groups of halogens like F, Cl, Br and
an electron donating group like methoxy were introduced to
evaluate the role of electronic effect at different positions of phenyl
ring. Introduction of Cl at position 4 of phenyl ring (compound 9c)
resulted in the best activity against HT-29 cell line in comparison
with other position and other cell lines. 2-Substitution of Cl
(compound 9a) led to the good cytotoxicity for Caco-2 colorectal
cell line. Replacement of 3-Cl with a more electron withdrawing
group like F (compound 9e) improved the potency in all cell lines
especially against T47D cell line. 2-Fluoro or 4-fluoro substitutions
could not significantly improve the cytotoxic activity in comparison
with chloro substituent and ortho-fluoro derivative (9d) was inac-
tive against HT-29 colon cancer cell line. 4-Bromo substitution
(compound 9g) increased the activity against Caco-2 cell line in
comparison with 4-chloro and 4-fluoro substituents. Introduction
of electron donating methoxy group in different positions led to the
high activity in all cell lines with different pattern. The position
ortho for methoxy was very critical because it enhanced the
potency against HT-29 and T47D. Caco-2 cell line was more sensi-
tive to para-methoxy derivative (compound 9j) and this derivative
was the most potent compound against Caco-2 cell line
NMR (
d
, CDCl3): 4.48 (s, 2H, CH2), 7.64 (d, 2H, J ¼ 8.8 Hz, phenyl),
7.50 (d, 2H, J ¼ 8 Hz, phenyl). 13C NMR (62.5 MHz, CDCl3)
d 31.6
(eCH2e), 112.1 (C-4, Phenyl), 118.4 (-CN), 129.7 (C-2 and C-6,
Phenyl), 132.6 (C-3 and C-5, Phenyl), 142.8 (C-1, Phenyl). MS (m/z,
%): 196 (Mþ), 168 (12), 90 (35), 26 (5). Anal. Calcd for C8H6BrN: C,
49.01; H, 3.08; N, 7.14. Found: C, 49.21; H, 3.1; N, 7.02.
7.1.2. 4-((1,3-Dioxoisoindolin-2-yl)methyl)benzonitrile (3)
A suspension of p-cyanobenzylbromide (7.5 g, 0.038 mol) and
potassium phthalimide (7.1 g, 0.038 mol) in acetonitrile (150 mL)
was heated under refluxed for 30 h. After completion of the
reaction, the solvent was removed under reduced pressure to
obtain a white solid (9.5 g, yield 95%). The crude product was
purified by column chromatography (silica gel, EtOAc/petroleum
ether ¼ 1:4). m.p 108e112 ꢁC; IR (KBr, cmꢂ1): 3460, 3071, 2947,
2233, 1937, 1777, 1724, 1607, 1510, 1464, 1436, 1398, 1328. 1H NMR
(
d
, CDCl3): 4.89 (s, 2H, CH2), 7.52 (d, 2H, J ¼ 8 Hz, phenyl), 7.62 (d,
(IC50 ¼ 1.88
m
g/mL). In contrast, HT-29 cell line was very resistant to
2H, J ¼ 8.4 Hz, phenyl), 7.73e7.88 (m, 4H, Ar). 13C NMR (62.5 MHz,
compound 9j with methoxy as para moiety.
CDCl3) d 41.1 (eCH2e), 111.8 (C-4, Phenyl), 118.5 (eCN), 123.5 (C-4,
C-7, Dioxoisoindolin), 129.1 (C-2, C-6, Phenyl), 131.8 (C-3a, C-7a,
Dioxoisoindolin), 132.5 (C-3, C-5, Phenyl), 134.3 (C-5, C-6, Dioxoi-
soindolin), 141.4 (C-1, Phenyl), 167.8 (C-1, C-3, Dioxoisoindolin). MS
(m/z, %): 262 (Mþ), 146 (17), 116 (20). Anal. Calcd for C16H10N2O2:
C, 73.27; H, 3.84; N, 10.68. Found: C, 73.11; H, 3.66; N, 10.78.
6. Conclusion
In conclusion, a series of substituted 2-phenylthiazole-4-car-
boxamide derivatives were synthesized and identified as cytotoxic

A. Aliabadi et al. / European Journal of Medicinal Chemistry 45 (2010) 5384e5389
5387
7.1.3. 4-((1,3-Dioxoisoindolin-2-yl)methyl)benzothioamide (4)
7.1.6. 2-(4-(4-(piperidine-1-carbonyl)thiazol-2-yl)benzyl)
isoindoline-1,3-dione (7)
A solution of compound 3 (9.3 g, 0.035 mol) and ammonium
sulfide 20% (11.67 mL, 0.035 mol) in N,N-dimethylformamide
(100 mL) was stirred at room temperature for 5 h. A yellow solid
was precipitated after the addition of crushed ice to the reaction
mixture. The precipitated solid was filtered and washed with
cool water and n-hexane, respectively. The recrytallization of
crude product from EtOH afforded pure product 4 (8.9 g, Yield
96%): m.p 181e184 ꢁC; IR (KBr, cmꢂ1): 3398, 3343, 3297, 3161,
Carboxylic acid derivative 6 (4.9 g, 0.016 mol), EDC (3.1 g,
0.016 mol) and hydroxybenzotriazole (HOBt) (2.1 g, 0.016 mol)
were stirred in acetonitrile (50 mL) at room temperature for
30 min. Then, piperidine (1.52 g, 1.8 mL, 0.016 mol) was added to
the reaction mixture and stirring was continued for 24 h. Aceto-
nitrile was evaporated under reduced pressure and ethyl acetate
was added to the residue. Ethyl acetate was washed with diluted
H2SO4, NaHCO3 and brine. Ethyl acetate phase was separated and
dried (Na2SO4). Evaporation of ethyl acetate yielded the related
amide derivative 7 (3.8 g, yield 66%): m.p 100e107 ꢁC; IR (KBr,
cmꢂ1): 3495, 3106, 2935, 2858, 2497, 1922, 1739, 1584, 1464, 1192,
2229, 1770, 1720, 1646, 1460, 1429, 1394, 1083, 939. 1H NMR (
d,
CDCl3): 4.89 (s, 2H, CH2), 7.41 (d, 2H, J ¼ 8 Hz, phenyl), 7.73e7.86
(m, 6H, Ar), 8.42 (brs, 2H, NH2). 13C NMR (62.5 MHz, CDCl3)
d
41.03 (eCH2e), 123.4 (C-3a, C-7a, Dioxoisoindolin), 123.5 (C-4,
C-7, Dioxoisoindolin), 127.8 (C-3, C-5, Phenyl), 127.9 (C-2, C-6,
Phenyl), 134.2 (C-5, C-6, Dioxoisoindolin), 139.1 (C-1, Phenyl),
139.7 (C-4, Phenyl), 167.8 (C-1, C-3, Dioxoisoindolin), 201.6 (C,
CSNH2). MS (m/z, %): 296 (Mþ), 236 (5), 146 (31), 149 (25). Anal.
Calcd for C16H12N2O2S: C, 64.85; H, 4.08; N, 9.45. Found: C,
64.73; H, 4.22; N, 9.38.
986. 1H NMR (
d, CDCl3): 1.42e1.50 (m, 6H, eCH2e piperidine), 3.1
(m, 4H, eCH2eN piperidine), 4.48 (s, 2H, eCH2e), 7.27 (d, 2H,
J ¼ 7.2 Hz, phenyl), 7.69 (d, 2H, J ¼ 6.4 Hz, phenyl), 7.45e7.96 (m,
4H, Ar), 8.56 (s, 1H, thiazole). 13C NMR (62.5 MHz, CDCl3)
d 24.5 (C-
4, Piperidine), 25.9, 26.5 (C-3, C-5, Piperidine), 42.8 (eCH2e), 43.4,
43.8 (C-2, C-6, Piperidine), 126.7 (C-3a, C-7a, Dioxoisoindolin),
128.4 (C-4, C-7, Dioxoisoindolin), 128.9 (C-5, Thiazole), 129 (C-2, C-
6, Phenyl), 130.7 (C-3, C-5, Phenyl), 131.8 (C-5, C-6, Dioxoisoindo-
lin), 138.6 (C-4, Phenyl), 141.1 (C-1, Phenyl), 151.4 (C-4, Thiazole),
162.8 (C-2, Thiazole), 166.8 (CO-thiazole), 169.8 (C-1, C-3, Dioxoi-
soindolin). MS (m/z, %): 431 (Mþ), 319 (9), 285 (37), 112 (24). Anal.
Calcd for C24H21N3O3S: C, 66.80; H, 4.91; N, 9.74. Found: C, 66.79;
H, 5.12; N, 9.59.
7.1.4. Ethyl 2-(4-((1,3-dioxoisoindolin-2-yl)methyl)phenyl)thiazole-
4-carboxylate (5)
A mixture of thioamide derivative 4 (8.7 g, 0.029 mol) and
ethyl bromopyruvate (3.65 mL, 0.029 mol) in EtOH (100 mL) was
heated under reflux for 3 h and formation of a cream precipitate
was the sign of the reaction progress. The completion of the
reaction was proved by TLC and the precipitate was filtered and
washed with cool ethanol and water and then recrystallized from
ethyl acetate (7.5 g, yield 65%); m.p 165e170 ꢁC; IR (KBr, cmꢂ1):
3460, 3102, 3064, 2990, 2935, 2233, 1767, 1735, 1615, 1471, 1398,
7.1.7. (2-(4-(aminomethyl)phenyl)thiazol-4-yl)(piperidin-1-yl)
methanone (8)
Compound 7 (3.5 g, 0.008 mol) and methylamine 40% (2.76 mL,
0.08 mol) were refluxed in EtOH (50 mL) for 6 h. After evaporation
of volatile components, ethyl acetate was added to the residue and
the organic layer was washed with brine and dried over anhydrous
sodium sulfate. Evaporation of ethyl acetate yielded the cream
powder of compound 8 (1.9 g, yield 79%); m.p 145e150 ꢁC; IR (KBr,
cmꢂ1): 3440, 2939, 1732, 1627, 1456, 1378, 1254, 1130, 1087, 1017,
1332, 1203, 1091, 935. 1H NMR (
d, DMSO-d6): 1.32 (t, 3H, -CH3),
4.33 (q, 2H, eCH2e), 4.84 (s, 2H, CH2), 7.47 (d, 2H, J ¼ 8 Hz,
phenyl), 7.86e7.95 (m, 6H, Ar), 8.56 (s, 1H, thiazole). 13C NMR
(62.5 MHz, CDCl3)
d 14.3 (CH3), 41.2 (PhCH2N), 61.5 (eCH2e,
Ethyl), 123.4 (C-3a, C-7a, Dioxoisoindolin), 127.1 (C-4, C-7, Diox-
oisoindolin), 127.3 (C-5, Thiazole), 129.1 (C-2, C-6, Phenyl), 132.0
(C-3, C-5, Phenyl), 132.3 (C-5, C-6, Dioxoisoindolin), 134.1 (C-4,
Phenyl), 138.9 (C-1, Phenyl), 147.5 (C-4, Thiazole), 162.1 (Carbonyl,
COOEt), 167.9 (C-1, C-3, Dioxoisoindolin), 168.2 (C-2, Thiazole).
MS (m/z, %): 392 (Mþ), 318 (80), 294 (22), 280 (21). Anal. Calcd
for C21H16N2O4S: C, 64.27; H, 4.11; N, 7.14. Found: C, 64.09; H,
4.25; N, 7.31.
986. 1H NMR (
d, CDCl3): 1.68 (m, 6H, eCH2e piperidine), 3.73 (m,
4H, eCH2Ne piperidine), 3.91 (s, 2H, eCH2NH2), 4.61 (brs, 2H,
eNH2), 7.38 (d, 2H, J ¼ 8.1 Hz, phenyl), 7.82 (d, 2H, J ¼ 7.9 Hz,
phenyl), 8.1 (s, thiazole). MS (m/z, %): 301 (Mþ), 217(20), 190 (77),
161 (20), 150 (35), 84 (95), 43 (65). Anal. Calcd for C16H19N3OS: C,
63.76; H, 6.35; N, 13.94. Found: C, 63.82; H, 6.44; N, 14.19.
7.1.5. 2-(4-((1,3-dioxoisoindolin-2-yl)methyl)phenyl)thiazole-4-
carboxylic acid (6)
7.1.8. General procedure for the synthesis of compounds 9aej
Appropriate phenylacetic acid derivative was stirred with
equivalent amount of EDC and hydroxybenzotriazole (HOBt) in
acetonitrile at room temperature for 30 min. Then, the compound 7
was added and the stirring was continued overnight. After evapo-
ration of acetonitrile, ethyl acetate was added and the organic
phase was washed with diluted sulfuric acid, sodium bicarbonate
and brine. The organic layer was separated, dried (Na2SO4) and
evaporated to afford corresponding amide (9aej) as a white to
cream solid.
A
mixture of compound 5 (7.3 g, 0.019 mol) in sodium
hydroxide solution (5%, 20 mL) was stirred at room temperature
for 20 h. The reaction mixture was neutralized by HCl and the
precipitate was partitioned between EtOAc/H2O and the ethyl
acetate phase was separated and washed with NaHCO3, HCl
solutions and brine. The organic layer was dried over anhydrous
sodium sulfate and then the solvent was evaporated under vacuo.
The residue was used for the next step without further purifica-
tion (5.1 g, yield 75%). m.p 235e240 ꢁC; IR (KBr, cmꢂ1): 3332,
3099, 2889, 2543, 1708, 1650, 1534, 1471, 1413, 1308, 1227, 1172,
7.1.8.1. 2-(2-Chlorophenyl)-N-(4-(4-(piperidine-1-carbonyl)thiazol-
2-yl)benzyl)acetamide (9a). Yield: 75%, m.p 136e140 ꢁC; IR (KBr,
cmꢂ1): 3429, 3351, 3273, 3130, 3060, 2928, 1716, 1650, 1545, 1483,
994, 916. 1H NMR (
phenyl), 7.87e7.95 (m, 6H, Ar), 8.44 (s, 1H, thiazole). 13C NMR
(62.5 MHz, CDCl3) 42.8 (eCH2e), 126.7 (C-3a, C-7a, Dioxoi-
d
, CDCl3): 4.84 (s, 2H, CH2), 7.46 (d, 2H, J ¼ 8 Hz,
d
1405, 1238, 1161, 982, 815. 1H NMR (
d, CDCl3): 1.7 (m, 6H, eCH2e
soindolin), 128.1 (C-4, C-7, Dioxoisoindolin), 128.5 (C-5, Thiazole),
129.6 (C-2, C-6, Phenyl), 129.7 (C-3, C-5, Phenyl), 131.2 (C-5, C-6,
Dioxoisoindolin), 138.7 (C-4, Phenyl), 142.7 (C-1, Phenyl), 148.6 (C-
4, Thiazole), 167.9 (COOH), 168.4 (C-1, C-3, Dioxoisoindolin), 169.3
(C-2, Thiazole). MS (m/z, %): 364 (Mþ), 319 (34), 218 (51), 146 (19).
Anal. Calcd for C19H12N2O4S: C, 62.63; H, 3.32; N, 7.69. Found: C,
62.51; H, 3.41; N, 7.49.
Piperidine), 3.8 (m, 4H, eCH2Ne Piperidine), 3.79 (s, 2H,
eCH2COe), 4.49 (d, 2H, J ¼ 5.6 Hz, eCH2NHCOe), 5.82 (brs, 1H,
eNHCOe), 7.28e7.49 (m, 6H, Ar), 7.87 (d, 2H, J ¼ 7.6 Hz), 8.68 (s, 1H,
Thiazole). 13C NMR (62.5 MHz, CDCl3)
d 26.1 (C-4, Piperidine), 27 (C-
3, C-5, Piperidine), 38.8 (C, PhCH2N), 41.6 (eCH2e, ePhCH2COe),
43.5, 43.8 (C-2, C-6, Piperidine), 122.8 (C-5, Thiazole), 126.8 (C-2, C-
6, Phenyl), 127 (C-5, 2-Chlorophenyl), 127.6 (C-6, 2-Chlorophenyl),

5388
A. Aliabadi et al. / European Journal of Medicinal Chemistry 45 (2010) 5384e5389
128.2 (C-3, C-5, Phenyl), 129.2 (C-4, 2-Chlorophenyl), 129.8 (C-3, 2-
Chlorophenyl), 131.8 (C-2, 2-Chlorophenyl), 132.0 (C-4, Phenyl),
132.8 (C-1, 2-Chlorophenyl), 141 (C-1, Phenyl), 151.2 (C-4, Thiazole),
162.5 (C-2, Thiazole), 167.5 (CO-thiazole), 170 (eNHCOe). MS (m/z,
%): 455 (Mþþ2, 10), 453 (Mþ, 33), 173 (44), 125 (83), 84 (100). Anal.
Calcd for C24H24ClN3O2S: C, 63.49; H, 5.33; N, 9.26. Found: C, 63.51;
H, 5.25; N, 9.35.
7.1.8.5. 2-(3-Fluorophenyl)-N-(4-(4-(piperidine-1-carbonyl)thiazol-
2-yl)benzyl)acetamide (9e). Yield: 77%, m.p 154e157 ꢁC; IR (KBr,
cmꢂ1): 3293, 3071, 2924, 2854, 1681, 1607, 1545, 1464, 1370, 1258,
1137, 1017, 982, 827. 1H NMR (
d, CDCl3): 1.75 (m, 6H, eCH2e
piperidine), 3.70e3.83 (m, 4H, eCH2Ne piperidine), 3.78 (s, 2H,
eCH2COe), 4.48 (d, 2H, J ¼ 6.4 Hz, eCH2NHCOe), 5.88 (brs, 1H,
eNHCOe), 7.27e7.42 (m, 6H, Ar), 7.79 (s, 1H, thiazole), 7.87 (d, 2H,
J ¼ 8 Hz). 13C NMR (62.5 MHz, CDCl3)
d 24.6 (C-4, Piperidine), 25.7,
7.1.8.2. 2-(3-Chlorophenyl)-N-(4-(4-(piperidine-1-carbonyl)thiazol-
2-yl)benzyl)acetamide (9b). Yield: 78%, m.p 152e160 ꢁC; IR (KBr,
cmꢂ1): 3433, 3275, 3173, 3130, 3060, 2945,1726,1642,1565,1487,1416,
26.6 (C-3, C-5, Piperidine), 41.3 (CH2, PhCH2Ne), 43.2 (CH2,
PhCH2COe), 43.9, 48.5 (C-2, C-6, Piperidine), 122.9 (C-5, Thiazole),
126.7 (C-2, C-6, Phenyl), 127.3 (C-4, 3-Fluorophenyl), 128.0 (C-3, C-
5, Phenyl),128.9 (C-2, 3-Fluorophenyl), 129.7 (C-6, 3-Fluorophenyl),
131.7 (C-5, 3-Fluorophenyl), 132.1 (C-1, 3-Fluorophenyl), 134.4 (C-3,
3-Fluorophenyl), 140.8 (C-1, Phenyl), 151.6 (C-4, Thiazole), 162.8 (C-
2, Thiazole), 166.8 (CO-thiazole), 169.8 (eNHCOe). MS (m/z, %): 437
(Mþ, 20), 392 (35), 359 (35), 300 (25), 257 (95), 222 (40), 179 (83),
163 (95), 135 (62), 84 (100). Anal. Calcd for C24H24FN3O2S: C, 65.88;
H, 5.53; N, 9.60. Found: C, 65.63; H, 5.71; N, 9.56.
1238, 1161, 985, 823. 1H NMR (
d, CDCl3): 1.75 (m, 6H, eCH2e Piperi-
dine), 3.04 (m, 4H, eCH2eNe Piperidine), 3.62 (s, 2H, eCH2COe), 4.47
(d, 2H, J ¼ 5.6 Hz, eCH2NHCOe), 5.82 (brs, 1H, eNHCOe), 7.20e7.45
(m, 6H, Ar), 7.86 (d, 2H, J ¼ 8.4 Hz), 8.03 (s, 1H, Thiazole). 13C NMR
(62.5 MHz, CDCl3) d 25.1 (C-4, Piperidine), 25.7, 26.6 (C-3, C-5, Piperi-
dine), 42.9 (CH2, PhCH2N), 43.3 (CH2, PhCH2COe), 43.9, 48.5 (C-2, C-6,
Piperidine),122.6 (C-5, Thiazole),126.9 (C-2, C-6, Phenyl),126.7 (C-2, 3-
Chlorophenyl), 127.6 (C-6, 3-Chlorophenyl), 128.1 (C-3, C-5, Phenyl),
129.5 (C-4, 3-Chlorophenyl),130.2 (C-5, 3-Chlorophenyl),132.0 (C-1, 3-
Chlorophenyl), 134.1 (C-3, 3-Chlorophenyl), 134.8 (C-4, Phenyl), 140.8
(C-1, Phenyl), 151.7 (C-4, Thiazole), 161.9 (C-2, Thiazole), 166.8 (CO-
thiazole),170.1 (eNHCOe). MS (m/z, %): 455 (Mþþ2,10), 453 (Mþ, 33),
437 (36), 307 (23), 173 (44), 109 (83), 84 (100). Anal. Calcd for
C24H24ClN3O2S: C, 63.49; H, 5.33; N, 9.26. Found: C, 63.62; H, 5.41;
N, 9.12.
7.1.8.6. 2-(4-Fluorophenyl)-N-(4-(4-(piperidine-1-carbonyl)thiazol-
2-yl)benzyl)acetamide (9f). Yield: 81%, m.p 111e116 ꢁC; IR (KBr,
cmꢂ1): 3468, 3269, 3071, 2932, 2854, 1689, 1506, 1460, 1343, 1285,
1161, 982, 815. 1H NMR (
d, CDCl3): 1.68 (m, 6H, eCH2e piperidine),
3.66 (s, 2H, eCH2COe), 3.76 (m, 4H, eCH2Ne piperidine), 4.46 (d,
2H, J ¼ 4.4 Hz, eCH2NHCOe), 5.90 (brs, 1H, eNHCOe), 7.04e7.28
(m, 6H, Ar), 7.79 (s, 1H, thiazole), 7.88 (d, 2H, J ¼ 6.4 Hz). 13C NMR
(62.5 MHz, CDCl3)
d 24.6 (C-4, Piperidine), 25.7, 26.6 (C-3, C-5,
7.1.8.3. 2-(4-Chlorophenyl)-N-(4-(4-(piperidine-1-carbonyl)thiazol-
2-yl)benzyl)acetamide (9c). Yield: 81%, m.p 94e104 ꢁC; IR (KBr,
cmꢂ1): 3468, 3269, 3137, 3056, 3029, 2924, 2862, 1642, 1596, 1549,
Piperidine), 42.7 (CH2, PhCH2Ne), 43.2 (CH2, PhCH2COe), 43.9, 48.5
(C-2, C-6, Piperidine), 115.75 (d, JC-F ¼ 18.8 Hz, C-3, C-5, 4-Fluo-
rophenyl), 122.9 (C-5, Thiazole), 126.8 (C-2, C-6, Phenyl), 128.0 (C-3,
C-5, Phenyl), 130.6 (C-1, 4-Fluorophenyl), 130.9 (d, JC-F ¼ 12.5 Hz, C-
2, C-6, 4-Fluorophenyl), 132.2 (C-4, Phenyl), 140.8 (C-1, Phenyl),
151.6 (C-4, Thiazole), 162.5 (d, JC-F ¼ 31.25 Hz, C-4, 4-Fluorophenyl),
162.9 (C-2, Thiazole), 168.0 (CO-thiazole), 171.0 (eNHCOe). MS (m/
z, %): 437 (Mþ, 35), 326 (25), 173 (33), 109 (88), 84 (100). Anal. Calcd
for C24H24FN3O2S: C, 65.88; H, 5.53; N, 9.60. Found: C, 65.92; H,
5.42; N, 9.50.
1487, 1460, 1429, 1235, 1095, 986, 846. 1H NMR (
d, CDCl3): 1.7 (m,
6H, eCH2e, Piperidine), 3.61 (s, 2H, eCH2COe), 3.75 (m, 4H,
eCH2eNe Piperidine), 4.45 (d, 2H, J ¼ 4 Hz, eCH2NHCOe), 5.82
(brs, 1H, eNHCOe), 7.23 (d, 2H J ¼ 8.4 Hz), 7.27 (d, 2H, J ¼ 7.6 Hz),
7.33 (d, 2H, J ¼ 8.4 Hz), 7.79 (s, 1H, thiazole), 7.87 (d, 2H, J ¼ 7.6 Hz).
13C NMR (62.5 MHz, CDCl3)
d 24.6 (C-4, Piperidine), 25.7, 26.6 (C-3,
C-5, Piperidine), 42.9 (CH2, PhCH2Ne), 43.3 (CH2, PhCH2COe), 43.9,
48.5 (C-2, C-6, Piperidine), 123.0 (C-5, Thiazole), 126.9 (C-2, C-6,
Phenyl), 128.1 (C-3, C-5, Phenyl), 129.1 (C-3, C-5, 4-Chlorophenyl),
130.7 (C-2, C-6, 4-Chlorophenyl), 132.4 (C-4, 4-Chlorophenyl), 133.2
(C-1, 4-Chlorophenyl), 133.3 (C-4, Phenyl), 140.6 (C-1, Phenyl), 151.8
(C-4, Thiazole), 163.0 (C-2, Thiazole), 166.8 (CO-thiazole), 170.5
(eNHCOe). MS (m/z, %): 455 (Mþþ2,10), 453 (Mþ, 33),173 (44),134
(20), 84 (100), 57 (65). Anal. Calcd for C24H24ClN3O2S: C, 63.49; H,
5.33; N, 9.26. Found: C, 63.72; H, 5.58; N, 9.49.
7.1.8.7. 2-(4-Bromophenyl)-N-(4-(4-(piperidine-1-carbonyl)thiazol-
2-yl)benzyl)acetamide (9g). Yield: 65%, m.p 71e79 ꢁC; IR (KBr,
cmꢂ1): 3428, 3263, 3168, 3133, 3068, 2941, 1731, 1649, 1569, 1482,
1412, 1231, 1166, 980, 827. 1H NMR (
d, CDCl3): 1.71 (m, 6H, eCH2e
piperidine), 3.60 (s, 2H, eCH2COe), 3.76 (m, 4H, eCH2Ne piperi-
dine), 4.45 (d, 2H, J ¼ 5 Hz, CH2NHCOe), 5.89 (brs, 1H, eNHCOe),
7.78 (s, 1H, thiazole), 7.17e7.91 (m, 8H, Ar). 13C NMR (62.5 MHz,
CDCl3) d 24.7 (C-4, Piperidine), 25.6, 26.8 (C-3, C-5, Piperidine), 42.9
7.1.8.4. 2-(2-Fluorophenyl)-N-(4-(4-(piperidine-1-carbonyl)thiazol-
2-yl)benzyl)acetamide (9d). Yield: 85%, m.p 112e116 ꢁC; IR (KBr,
cmꢂ1): 3293, 3137, 3060, 2924, 2854, 1712, 1650, 1615, 1549, 1464,
(CH2, PhCH2Ne), 43.5 (CH2, PhCH2COe), 44.0, 48.6 (C-2, C-6,
Piperidine), 123.2 (C-5, Thiazole), 123.4 (C-4, 4-Bromophenyl),
126.9 (C-2, C-6, Phenyl), 128.2 (C-3, C-5, Phenyl), 131.2 (C-2, C-6, 4-
Bromophenyl), 132.1 (C-3, C-5, 4-Bromophenyl), 134.1 (C-1, 4-Bro-
mophenyl), 138.5 (C-4, Phenyl), 140.4 (C-1, Phenyl), 151.6
(C-4, Thiazole), 162.8 (C-2, Thiazole), 166.5 (CO-thiazole), 170.4
(eNHCOe). MS (m/z, %): 497 (Mþ, 4), 431 (42), 320 (66), 280 (48),
84 (100). Anal. Calcd for C24H24BrN3O2S: C, 55.34; H, 4.35; N, 8.07.
Found: C, 55.21; H, 4.46; N, 7.87.
1355, 1223, 1102, 1021, 982, 854, 796. 1H NMR (
d, CDCl3): 1.70 (m,
6H, eCH2e piperidine), 3.67 (s, 2H, -CH2CO), 3.76 (m, 4H,
eCH2Ne piperidine), 4.47 (d, 2H, J ¼ 6 Hz, eCH2NHCOe), 5.93
(brs, 1H, eNHCOe), 7.1e7.35 (m, 6H, Ar), 7.79 (s, 1H, thiazole), 7.88
(d, 2H, J ¼ 8.4 Hz). 13C NMR (62.5 MHz, CDCl3)
d 24.7 (C-4, Piper-
idine), 25.7, 26.6 (C-3, C-5, Piperidine), 36.9 (CH2, PhCH2N), 43.3
(CH2, PhCH2COe), 43.9, 48.5 (C-2, C-6, Piperidine), 115.65 (d, JC-
¼ 18.8 Hz, C-3, 2-Fluorophenyl), 123 (C-5, Thiazole), 124.6 (d, JC-
7.1.8.8. 2-(2-Methoxyphenyl)-N-(4-(4-(piperidine-1-carbonyl)thia-
zol-2-yl)benzyl)acetamide (9h). Yield: 69%, m.p 76e84 ꢁC; IR (KBr,
cmꢂ1): 3275, 3090, 2921, 2863, 1712, 1646, 1510, 1452, 1347, 1226,
F
¼ 6.25 Hz, C-1, 2-Fluorophenyl), 126.8 (C-2, C-6, Phenyl), 128
F
(C-3, C-5, Phenyl), 129.35 (d, JC-F ¼ 6.25 Hz, C-4, 2-Fluorophenyl),
131.7 (d, JC-F ¼ 6.25 Hz, C-6, 2-Fluorophenyl), 132.3 (C-4, Phenyl),
140.7 (C-1, Phenyl), 151.7 (C-4, Thiazole), 160 (C-2, 2-Fluo-
rophenyl), 162.8 (C-2, Thiazole), 166.7 (CO-thiazole), 169.9
(eNHCOe). MS (m/z, %): 437 (Mþ, 35), 326 (25), 173 (33), 109 (88),
84 (100). Anal. Calcd for C24H24FN3O2S: C, 65.88; H, 5.53; N, 9.60.
Found: C, 65.51; H, 5.68; N, 9.33.
1163, 1111, 1032, 987, 810. 1H NMR (
d, CDCl3): 1.70 (m, 6H, eCH2e
piperidine), 3.65 (s, 3H, -OCH3), 3.76 (m, 4H, eCH2Ne piperidine),
3.82 (s, 2H, eCH2COe), 4.44 (d, 2H, J ¼ 8 Hz, CH2NHCOe), 6.1 (brs,
1H, eNHCOe), 6.9e7.91 (m, 8H, Ar). MS (m/z, %): 449 (Mþ, 44), 174
(25), 121 (87), 84 (100). Anal. Calcd for C25H27N3O3S: C, 66.79; H,
6.05; N, 9.35. Found: C, 66.53; H, 6.21; N, 9.12.

A. Aliabadi et al. / European Journal of Medicinal Chemistry 45 (2010) 5384e5389
5389
7.1.8.9. 2-(3-Methoxyphenyl)-N-(4-(4-(piperidine-1-carbonyl)thia-
zol-2-yl)benzyl)acetamide (9i). Yield: 71%, m.p 86e90 ꢁC; IR (KBr,
cmꢂ1): 3283, 3087, 2933, 2871, 1702, 1642, 1514, 1453, 1342, 1231,
each cell line) with various concentrations of compounds 9aej.
Cells were then washed in PBS, and 20 L of MTT (3-(4, 5-dime-
thylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) solution
(5 mg/mL) were added to each well. An additional 4 h of incubation
at 37 ꢁC were done, and then the medium was discarded. Dimethyl
m
1169, 1117, 1038, 981, 805. 1H NMR (
d, CDCl3): 1.70 (m, 6H, eCH2e
piperidine), 3.63 (s, 3H, -OCH3), 3.70e3.90 (m, 4H, eCH2Ne
piperidine), 3.80 (s, 2H, eCH2COe), 4.42 (d, 2H, J ¼ 5.6 Hz,
CH2NHCOe), 5.90 (brs, 1H, eNHCOe), 6.82e6.90 (m, 4H, Ar), 7.25
(d, 2H, J ¼ 8 Hz), 7.78 (s, 1H, thiazole), 7.85 (d, 2H, J ¼ 8 Hz). 13C
sulfoxide (60 mL) was added to each well, and the solution was
vigorously mixed to dissolve the purple tetrazolium crystals. The
absorbance of each well was measured by plate reader (Anthous
2020; Austria) at a test wavelength of 550 nm against a standard
reference solution at 690 nm. The amount of produced purple
formazan is proportional to the number of viable cells. Two
independent experiments in triplicate were performed for deter-
mination of sensitivity to each compound, the IC50 were calculated
by linear regression analysis, expressed in mean ꢀ SD.
NMR (62.5 MHz, CDCl3)
d 24.6 (C-4, Piperidine), 25.7, 26.6 (C-3, C-
5, Piperidine), 43.1 (CH2, PhCH2Ne), 43.9 (CH2, -PhCH2COe), 44.2,
48.4 (C-2, C-6, Piperidine), 55.3 (CH3Oe), 113 (C-4, 3-CH3OePhe),
115.2 (C-2, 3-CH3OePhe), 121.9 (C-6, 3-CH3OePhe), 123.6 (C-5, 3-
CH3OePhe), 123.8 (C-5, Thiazole), 126.9 (C-2, C-6, Phenyl), 128.0
(C-3, C-5, Phenyl), 130.1 (C-1, 3-CH3OePhe), 132.2 (C-4, Phenyl),
140.8 (C-1, Phenyl), 151.6 (C-4, Thiazole), 160.2 (C-3, 3-
CH3OePhe), 162.8 (C-2, Thiazole), 166.8 (CO-thiazole), 171.0
(eNHCOe). MS (m/z, %): 449 (Mþ, 44), 217 (45), 190 (25), 121 (87),
84 (100). Anal. Calcd for C25H27N3O3S: C, 66.79; H, 6.05; N, 9.35.
Found: C, 66.82; H, 6.32; N, 9.44.
Acknowledgements
This work was supported by grants from the Research Council of
Tehran University of Medical Sciences and Iran National Science
Foundation (INSF).
7.1.8.10. 2-(4-Methoxyphenyl)-N-(4-(4-(piperidine-1-carbonyl)thia-
zol-2-yl)benzyl)acetamide (9j). Yield: 75%, m.p 112e115 ꢁC; IR (KBr,
cmꢂ1): 3277, 3075, 2932, 2850, 1712, 1646, 1510, 1452, 1347, 1246,
References
1176, 1099, 1029, 990, 807. 1H NMR (
d, CDCl3): 1.69 (m, 6H, eCH2e
piperidine), 3.60 (s, 3H, -OCH3), 3.70e3.90 (m, 4H, eCH2Ne
piperidine), 3.81 (s, 2H, eCH2COe), 4.45 (d, 2H, J ¼ 5.6 Hz,
eCH2NHCOe), 5.84 (brs, 1H, eNHCOe), 6.89 (d, 2H, J ¼ 8.4 Hz), 7.19
(d, 2H, J ¼ 8.4 Hz), 7.25 (d, 2H, J ¼ 8.4 Hz), 7.79 (s, 1H, thiazole), 7.87
[1] H. Zhang, S. Kasibhatla, J. Kuemmerle, W. Kemnitzer, K. Ollis-Mason, L. Qiu,
C. Crogan-Grundy, B. Tseng, J. Drewe, S. Xiong Cai, J. Med. Chem. 48 (2005)
5215.
[2] J. Drewe, S. Kasibhatla, B. Tseng, E. Shelton, D. Sperandio, R.M. Yee, J. Litvak,
M. Sendzik, J.R. Spencer, S. Xiong Caia, Bioorg. Med. Chem. Lett. 17 (2007)
4987.
(d, 2H, J ¼ 8.4 Hz). 13C NMR (62.5 MHz, CDCl3)
d 24.6 (C-4, Piperi-
[3] S. Xiong Cai, B. Nguyen, S. Jia, J. Herich, J. Guastella, S. Reddy, B. Tseng,
J. Drewe, S. Kasibhatla, J. Med. Chem. 46 (2003) 2474.
dine), 25.7, 26.6 (C-3, C-5, Piperidine), 42.9 (CH2, PhCH2Ne), 43.1
(CH2, PhCH2COe), 43.9, 48.5 (C-2, C-6, Piperidine), 55.3 (CH3Oe),
114.5 (C-3, C-5, 4-CH3OePhe), 126.7 (C-2, C-6, Phenyl), 126.8 (C-3,
C-5, Phenyl), 128.0 (C-1, 4-CH3OePhe), 128.1 (C-5, Thiazole), 130.5
(C-2, C-6, 4-CH3OePhe), 132.2 (C-4, Phenyl), 140.8 (C-1, Phenyl),
151.7 (C-4, Thiazole), 158.9 (C-4, 4-CH3OePhe), 162.8 (C-2, Thia-
zole), 166.7 (CO-thiazole), 171.5 (eNHCOe). MS (m/z, %): 449 (Mþ,
44), 190 (24), 174 (25), 84 (100). Anal. Calcd for C25H27N3O3S: C,
66.79; H, 6.05; N, 9.35. Found: C, 66.45; H, 5.91; N, 9.54.
[4] V.W.-F. Tai, D. Sperandio, E.J. Shelton, J. Litvak, K. Pararajasingham, B. Cebon,
J. Lohman, J. Eksterowicz, S. Kantak, P. Sabbatini, C. Brown, J. Zeitz, C. Reed,
B. Maske, D. Graupe, A. Estevez, J. Oeh, D. Wong, Y. Ni, P. Sprengeler, R. Yee,
C. Magill, A. Neri, S. Xiong Cai, J. Drewe, L. Qiu, J. Herich, B. Tseng, S. Kasibhatla,
J.R. Spencer, Bioorg. Med. Chem. Lett. 16 (2006) 4554.
[5] R.A. Forsch, J.E. Wright, A. Rosowsky, Bioorg. Med. Chem. 10 (2002) 2067.
[6] S.J. Brickner, D.K. Hutchinson, M.R. Barbachyn, P.R. Manninen, D.A. Ulanowicz,
S.A. Garmon, K.C. Greg, S.K. Hendes, D.S. Toops, C.W. Ford, G.E. Zurenko, J. Med.
Chem. 39 (1996) 673.
[7] L.J. Crane, M. Anastassiadou, J. Stigliani, G. Baziard-Mouysset, M. Payard,
Tetrahedron 60 (2004) 5325.
[8] S. Dixon, R.J. Whitby, Tetrahedron Lett. 47 (2006) 8147.
[9] C. Glover, E.A. Merritt, M.C. Bagley, Tetrahedron Lett. 48 (2007) 7027.
[10] V. Onnis, M.T. Cocco, V. Lilliu, C. Congiu, Bioorg. Med. Chem. 16 (2008) 2367.
[11] E.O. De Oliveira, C.A. Brandt, M.A.B. Da Silveiraa, R.A. Glennon, Tetrahedron 48
(2007) 6393.
[12] S.P. Akhlaghi, S.N. Ostad, R. Dinarvand, F. Atyabi, Nanomed. Nanotechnol. Biol. Med.,
in press, doi:10.1016/j.nano.2010.01.011.
[13] V. Virsodia, A. Manvar, K. Upadhyay, R. Loriya, D. Karia, M. Jaggi, A. Singh,
R. Mukherjee, M.S. Shaikh, E.C. Coutinho, A. Shah, Eur. J. Med. Chem. 44 (2009)
1355.
7.2. Cytotoxicity assay
Compounds 9aej were tested for cytotoxic activity at
0.1e250 mg/mL concentrations against three human cancer cell
lines including Caco-2 (colorectal cancer), HT-29 (colon cancer) and
T47D (breast cancer) cells. Cells from different cell lines were
seeded in 96-well plates at the density of 8000e10,000 viable cells
per well and incubated for 48 h to allow cell attachment. The cells
were then incubated for another 48e96 h (depends to cell cycle of
[14] Z. Nazarian, S. Emami, S. Heydari, S.K. Ardestani, M. Nakhjiri, F. Poorrajab,
A. Shafiee, A. Foroumadi, Eur. J. Med. Chem. 44 (2010) 1424.