Synthesis and Anticancer Activity of Amide Derivatives of 1,2-Isoxazole Combined 1,2,4-Thiadiazole

Article abstract of DOI:10.1134/S1070363219020257

A series of amide derivatives of 1,2-isoxazole combined with 1,2,4-thiadiazole are synthesized 11a–11j. Their chemical structures are confirmed by ¹H and ¹³C NMR, and mass spectra. The products are tested for their anticancer activit

Full text of DOI:10.1134/S1070363219020257

ISSN 1070-3632, Russian Journal of General Chemistry, 2019, Vol. 89, No. 2, pp. 324–329. © Pleiades Publishing, Ltd., 2019.
Synthesis and Anticancer Activity of Amide Derivatives
of 1,2-Isoxazole Combined 1,2,4-Thiadiazole
a
b
c
d
a
S. Shahinshavali , R. Sreenivasulu , V. R. Guttikonda , D. Kolli , and M. V. B. Rao *
a
Department of Chemistry, Krishna University, Machilipatnam, Andhra Pradesh, 521001 India
*
e-mail: professormandava@gmail.com
b
Department of Chemistry, University College of Engineering (Autonomous),
Jawaharlal Nehru Technological University, Kakinada, Andhra Pradesh, 533003 India
c
Department of Chemistry, SRR and CVR Government Degree College (Autonomous),
Vijayawada, Andhra Pradesh, 520004 India
d
Department of Chemistry, Koneru Lakshmaiah Education Foundation, Green Fields,
Vaddeswaram, Andhra Pradesh, 522502 India
Received November 26, 2018; revised February 15, 2019; accepted February 18, 2019
Abstract―A series of amide derivatives of 1,2-isoxazole combined with 1,2,4-thiadiazole are synthesized 11a–
1
13
1
1j. Their chemical structures are confirmed by H and C NMR, and mass spectra. The products are tested for
their anticancer activity against four types of human cancer cell lines, including MCF-7 (breast), A549 (lung),
Colo-205 (colon), and A2780 (ovarian). Etoposide is used as a positive control. Most of the compounds show
good anticancer activity. The compounds 11b, 11c, 11d, 11e, 11g, and 11j demonstrate more potent activity
than etoposide.
Keywords: Luminespib, Cefozopram, isoxazole, thiadiazole, anticancer activity
DOI: 10.1134/S1070363219020257
INTRODUCTION
RESULTS AND DISCUSSION
Different types of heterocyclic derivatives are used
efficiently in anticancer chemotherapy [1–14]. Isoxazole
derivatives are used extensively as agrochemicals and
in medicine [15–18] due to a broad spectrum of
activity, including anticancer [19], antifungal [20], anti-
inflammatory [21], and antimicrobial [22]. Among
these, Luminespib (1, NVP-AUY922) (see figure) is
an FDA approved anticancer drug candidate.
Thiadiazole derivatives are important functional
components of molecules of many natural compounds
Synthetic approach to the target compounds 11a–
11j (Scheme 1) started with introduction of compound
3 in the Claisen-Schmidt reaction with 4-cyano-
benzaldehyde 4 which led to pure chalcone 5 with
good yield. The following reaction of the intermediate
5 with 4-nitrobenzothioamide 6 in presence of AlCl3
gave the product of cycloaddition 7, which reacted
with hydroxylamine hydrochloride to give isoxazole
derivative 8. The following reduction of compound 8
with Zn-dust in acetic acid with formation of amine 9,
and reaction of the latter with aromatic
chloroanhydrides 10a–10j led to the title compounds
11a–11j.
[
23] and drugs, for example, such as antibiotic
Cefozopram (2) (see figure) which is used for
treatment of CNS [24].
Based on the above information accumulated for
isoxazole and thiadiazole and in continuation of our
studies of heterocyclic compounds, we designed and
synthesized a series of amide derivatives of 1,2-
isoxazole combined with 1,2,4-thiadiazole 11a–11j.
Their structures were confirmed by H and C NMR
and mass spectra. The compounds were tested for
anticancer activity against four human cancer cell lines.
Biological evaluation. In vitro cytotoxicity. The
synthesized compounds 11a–11j were screened for
their anticancer activity against four human cancer cell
lines such as MCF-7 (breast), A549 (lung), Colo-205
(colon), and A2780 (ovarian) by the MTT assay (see
the table). Etoposide was used as a positive control.
The products 11b, 11c, 11d, 11e, 11g, and 11j
displayed higher activity than etoposide. The com-
1
13
3
24

SYNTHESIS AND ANTICANCER ACTIVITY OF AMIDE DERIVATIVES
a) (b)
325
(
OH
N
OMe
N
O
OH
N
H
N
N
S
H
S
O
N
N
.
HCl
O
O
N
H N
N+
2
N
O
O
NH
−
O
1
2
Structures of (a) Luminespib and (b) Cefozopram.
pounds were examined for structure-activity
relationship (SAR). The compound 11b containing
11h with 3,5-dinitro substitution exhibited very poor
activity. Compounds 11f and 11i with the 4-cyano
substituent was of moderate activity.
3
,4,5-trimethoxy substituents on the phenyl ring
demonstrated high activity with IC values MCF-7 =
5
0
EXPERIMENTAL
0
0
.24±0.089 µM, A549 = 0.18±0.023 µM, Colo-205 =
.11±0.05 µM, and A2780 = 0.55±0.072 µM,
All chemicals and reagents were obtained from
Aldrich (Sigma-Aldrich, St. Louis, MO, USA) and
Lancaster (Alfa Aesar, Johnson Matthey Company,
Ward Hill, MA, USA), and were used without further
purification. Reactions were monitored by TLC,
performed on silica gel glass plates containing 60 F-254,
respectively. Compound 11c with 3,5-dimethoxy
substituents displayed lower activity (MCF-7 =
0
0
.39±0.033, A549
.93±0.065, and A2780 = 1.37±0.35 µM) than 11b.
=
1.33±0.45, Colo-205
=
The compound 11d containing one 4-methoxy
substituent exhibited the activity lower than the above
two analogues. Replacement of 4-methoxy group by 4-
chloro substituent on the phenyl ring 11e resulted in its
poorest activity. The compound 11g with the 4-nitro
group exhibited the highest activity. The compound
1
and visualized by UV light or iodine indicator. H and
1
3
C NMR spectra were measured on a Gemini Varian-
VXR-unity (300 MHz) spectrometer using DMSO-d
as a solvent (CDCl for 5) and TMS as the internal
6
3
standard. ESI spectra were recorded on a Micro mass,
a
Anticancer activity of the synthesized compounds 11a–11j (IC50 µM)
b
c
d
e
Compound
MCF-7
A549
Colo-205
A2780
1
1
1
1
1
1
1
1
1
1
1a
1b
1c
1d
1e
1f
2.090±1.87
0.240±0.089
0.390±0.033
1.990±0.540
2.440±1.900
4.110±2.400
0.034±0.004
2.170±1.230
10.40±6.330
1.460±0.320
2.110±0.024
3.410±1.930
0.180±0.023
1.330±0.450
1.830±0.560
1.760±0.190
9.670±5.100
0.011±0.001
2.880±1.990
3.190±2.150
1.670±0.450
3.080±0.135
Not active
0.11±0.050
0.93±0.065
1.44±0.880
3.65±1.980
Not active
1.23±0.480
7.33±4.100
13.2±7.230
1.42±0.360
4.55±2.330
0.55±0.072
1.37±0.350
2.43±1.880
Not active
8.34±5.090
0.33±0.022
5.60±4.300
6.23±5.770
Not active
1.31±0.270
1g
1h
1i
1j
Etoposide
0.13±0.017
b
a
c
Each data is represented as mean ±S.D. of different experiments performed in triplicates. (MCF-7) human breast cancer cell line.
A549) human lung cancer cell line. (Colo-205) human colon cancer cell line. (A2780) human ovarian cancer cell line.
d
e
(
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 89 No. 2 2019

3
26
SHAHINSHAVALI et al.
Scheme 1. Synthesis of amide derivatives of 1,2-isoxazole combined with 1,2,4-thiadiazole.
S
NH2
O
CHO
O
MeO
MeO
MeO
MeO
EtOH, piperedine
reflux, 2 h
+
+
CN
OMe
CN
OMe
NO2
3
4
5
6
AlCl , n-BuOAc
3
7
0°C, 5 h
O N
MeO
O
NH OH HCl, IPA
2
piperedine
N
N
N
N
S
MeO
S
reflux, 6 h MeO
OMe
MeO
OMe
7
NO2
NO2
8
Zn, AcOH,
room temperature, 1 h
O N
MeO
MeO
N
S
OMe
N
9
NH2
O N
+
MeO
O
Cl
THF, Et N
3
N
MeO
room temperature, 6 h
S
OMe
N
R
R
10a−10j
HN
11a−11j
O
R = H (10a, 11a), 3,4,5-trimethoxy (10b, 11b), 3,5-dimethoxy (10c, 11c), 4-methoxy (10d, 11d), 4-cloro (10e, 11e), 4-bromo
10f, 11f), 4-nitro (10g, 11g), 3,5-dinitro (10h, 11h), 4-cyano, (10i, 11i), 4-methyl (10j, 11j).
(
Quattro LC using ESI+ software with capillary voltage
.98 kV and ESI mode positive ion trap detector.
Melting points were determined on an electrothermal
melting point apparatus, and are uncorrected.
4-[(E)-3-(3,4,5-Trimethoxyphenyl)-3-oxoprop-1-
enyl]benzonitrile (5). 3,4,5-Trimethoxyacetophenone
3 (20 g, 0.0951 mmol) was dissolved in 50 mL of
ethanol, followed by addition of 4-cyanobenzaldehyde
3
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 89 No. 2 2019

SYNTHESIS AND ANTICANCER ACTIVITY OF AMIDE DERIVATIVES
327
4
(12.5 g, 0.0951 mmol) and 3 drops of piperdine base.
4-{3-(4-[5-(3,4,5-Trimethoxyphenyl)isoxazol-3-
yl]phenyl)-1,2,4-thiadiazol-5-yl}benzenamine (9).
To a solution of (E)-1-(3,4,5-trimethoxyphenyl)-3-{4-
[5-(4-nitrophenyl)-1,2,4-thiadiazol-3-yl]phenyl}prop-
2-en-1-one (8) (13 g, 0.0251 mmol) in acetic acid
(40 mL) was added zinc powder (2.3 g, 0.0751 mmol).
The reaction mixture was stirred at room temperature
for 1 h. After completion of the process, according to
TLC, the reaction mixture was filtered (Celite), and the
filtrate was evaporated to dryness giving pure
The reaction mixture was refluxed for 2 h. After
cooling the reaction mixture down, water (20 mL) was
added slowly to it. The crystalline precipitate was
filtered off and purified by column chromatography
using ethyl acetate–hexane (1 : 1) as an eluent to afford
pure compound 5. Yield 73%. H NMR spectrum, δ,
ppm: 3.93 s (3H), 3.96 s (6H), 7.28 s (2H), 7.55 d (1H,
J = 15.5 Hz), 7.68 d (2H, J = 7.23 Hz), 7.73 d (2H, J =
7
1
.23 Hz), 7.78 d (1H, J = 15.5 Hz). MS (ESI): 325
+
1
[
M + H] .
compound 9. Yield 76%. H NMR spectrum, δ, ppm:
3
.93 s (3H), 3.96 s (6H), 5.51 br.s (2H), 6.66 s (1H),
(
E)-1-(3,4,5-Trimethoxyphenyl)-3-{4-[5-(4-nitro-
7.28 s (2H), 7.70 d (2H, J = 7.25 Hz), 7.76 d (2H, J =
7.25 Hz), 7.80 d (2H, J = 7.27 Hz), 8.09 d (2H, J =
7.27 Hz). MS (ESI): 488 [M + H] .
phenyl)-1,2,4-thiadiazol-3-yl]phenyl}prop-2-en-1-
one (7). 4-[(E)-3-(3,4,5-Trimethoxyphenyl)-3-oxoprop-
+
1
-enyl]benzonitrile (5) (20 g, 0.0617 mmol) and AlCl3
General method of synthesis of amide derivatives
1a–11j. The compound 9 (500 mg, 0.0010 mmol)
was dissolved in 10 mL of dry THF, and 0.0010 mmol
of one of benzoyl chlorides 10a–10j and 0.002 mmol
(
(
8.2 g, 0.0617 mmol) were mixed in n-butyl acetate
50 mL), and then, upon stirring at 70°C, 4-nitro-
1
benzothioamide 6 (3.9 mL, 0.030 mmol) was added
dropwise. The mixture was stirred at 70°C for 5 h.
After cooled down to room temperature and addition
of 0.3 mL of water the reaction mixture was stirred at
room temperature for 24 h. The organic and aqueous
layers were separated, and the aqueous layer was
extracted with ethyl acetate (3×20 mL). The combined
organic layers were dried over anhydrous Na SO ,
concentrated and purified by column chromatography
on silica gel, using ethyl acetate–petroleum ether (1 : 1)
as an eluent to afford pure compound 7. Yield 70%. H
NMR spectrum, δ, ppm: 3.93 s (3H), 3.96 s (6H), 7.28
s (2H), 7.57 d (1H, J = 15.6 Hz), 7.70 d (2H, J =
7
1
7
of Et N were added. The reaction mixture was stirred
3
at room temperature for 6 h, till completion of the
process (TLC), then it was washed with water and
extracted with CH Cl , dried over anhydrous Na SO .
2
2
2
4
The crude product was purified by column chromato-
graphy using ethyl acetate–hexane (1 : 1) as an eluent
to obtain the corresponding pure compound 11a–11j.
2
4
N-(4-{3-(4-[5-(3,4,5-Trimethoxyphenyl)isoxazol-
1
3
(
-yl]phenyl)-1,2,4-thiadiazol-5-yl}phenyl)benzamide
1
11a). Yield 51%, mp 300–302°C. H NMR spectrum,
δ, ppm: 3.93 s (3H), 3.96 s (6H), 6.66 s (1H), 7.28 s
2H), 7.52 t (1H), 7.56–7.66 m (2H), 7.70 d (2H, J =
.25 Hz), 7.75 d (2H, J = 7.25 Hz), 7.78 d (1H, J =
5.6 Hz), 7.83 d (2H, J = 7.27 Hz), 8.10 d (2H, J =
(
7
8
.24 Hz), 7.75 d (2H, J = 7.24 Hz), 7.78–7.88 m (4H),
+
.27 Hz). MS (ESI): 505 [M + H] .
13
.07 d (2H, J = 7.26 Hz), 8.57 s (1H). C NMR spec-
trum, δ, ppm: 57.4, 61.8, 96.4, 106.3, 123.8, 126.5,
3
-{4-[5-(3,4,5-Trimethoxyphenyl)isoxazol-3-yl]-
1
1
28.3, 129.4, 129.7, 130.4, 131.2, 132.7, 133.4, 134.7,
phenyl}-5-(4-nitrophenyl)-1,2,4-thiadia zole (8). A
mixture of compound 7 (20 g, 0.039 mmol) with
hydroxylamine hydrochloride (8.2 g, 0.117 mmol) was
dissolved in 50 mL of 2-propanol, then 3 mL of
pyridine were added and the reaction mixture was
stirred upon refluxing for 6 h. After completion of
reaction, according to TLC, the solvent was evaporated
under reduced pressure. The precipitated product was
washed with water (3×20 mL) and purified by column
chromatography using ethyl acetate–hexane (7 : 3) as
40.5, 145.3, 156.7, 158.6, 159.5, 160.7, 168.4, 170.4.
+
MS (ESI): 592 [M + H] .
3,4,5-Trimethoxy-N-(4-{3-(4-[5-(3,4,5-trimethoxy-
phenyl)isoxazol-3-yl]phenyl)-1,2,4-thiadiazol-5-yl}-
phenyl)benzamide (11b). Yield 47%, mp 317–319°C.
1
H NMR spectrum, δ, ppm: 3.87 s (6H), 3.90 s (3H),
3.93 s (3H), 3.96 s (6H), 6.65 s (1H), 7.27 s (2H), 7.32
s (2H), 7.69 d (2H, J = 7.23 Hz), 7.76 d (2H, J =
7.23 Hz), 7.80 d (2H, J = 7.25 Hz), 8.08 d (2H, J =
1
13
an eluent to afford pure compound 8. Yield 70%. H
7.25 Hz), 8.56 s (1H). C NMR spectrum, δ, ppm:
NMR spectrum, δ, ppm: 3.93 s (3H), 3.96 s (6H), 6.66
s (1H), 7.27 s (2H), 7.71 d (2H, J = 7.26 Hz), 7.77 d
56.5, 57.8, 61.2, 62.5, 96.3, 106.4, 107.8, 123.4, 126.5,
127.6, 129.8, 130.4, 130.8, 131.5, 133.6, 134.6, 139.6,
143.2, 145.6, 156.3, 157.8, 158.2, 160.5, 163.2, 169.3,
(
(
2H, J = 7.26 Hz), 7.82 d (2H, J = 7.28 Hz), 8.11 d
2H, J = 7.28 Hz). MS (ESI): 518 [M + H] .
+
+
170.6. MS (ESI): 682 [M + H] .
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 89 No. 2 2019

3
28
SHAHINSHAVALI et al.
3
,5-Dimethoxy-N-(4-{3-(4-[5-(3,4,5-trimethoxy-
NMR spectrum, δ, ppm: 3.93 s (3H), 3.96 s (6H), 6.67
s (1H), 7.27 s (2H), 7.69 d (2H, J = 7.28 Hz), 7.73 d
(2H, J = 7.28 Hz), 7.84–7.95 m (4H), 8.11 d (2H, J =
phenyl)isoxazol-3-yl]phenyl)-1,2,4-thiadiazol-5-yl}-
phenyl)benzamide (11c). Yield 62%, mp 312–314°C.
H NMR spectrum, δ, ppm: 3.77 s (6H), 3.92 s (3H),
1
13
7.30 Hz), 8.20 d (2H, J = 7.32 Hz), 8.59 s (1H). C
3
.95 s (6H), 6.66 s (1H), 7.27 s (2H), 7.30 s (2H), 7.68
NMR spectrum, δ, ppm: 57.4, 61.8, 96.7, 106.4, 123.4,
125.7, 126.5, 127.5, 129.7, 130.3, 130.8, 131.4, 133.6,
134.6, 136.5, 140.4, 145.6, 151.3, 156.7, 158.4, 160.5,
d (2H, J = 7.24 Hz), 7.77 d (2H, J = 7.24 Hz), 7.81 d
(
(
2H, J = 7.26 Hz), 8.09 d (2H, J = 7.26 Hz), 8.57 s
1H). C NMR spectrum, δ, ppm: 56.4, 57.3, 61.9,
1
3
+
161.7, 169.5, 170.7. MS (ESI): 637 [M + H] .
9
1
1
6
6.4, 106.3, 107.4, 118.4, 123.4, 126.7, 127.4, 129.6,
30.4, 130.8, 133.5, 134.5, 135.2, 139.6, 145.6, 156.4,
58.6, 160.4, 161.5, 164.7, 169.5, 170.7. MS (ESI):
N-(4-{3-(4-[5-(3,4,5-Trimethoxyphenyl)isoxazol-3-
yl)phenyl)-1,2,4-thiadiazol-5-yl)phenyl)-3,5-dinitro-
1
benzamide (11h). Yield 71%, mp 309–311°C. H
+
52 [M + H] .
NMR spectrum, δ, ppm: 3.93 s (3H), 3.96 s (6H), 6.68
s (1H), 7.27 s (2H), 7.70 d (2H, J = 7.28 Hz), 7.74 d
(2H, J = 7.28 Hz), 7.83 d (2H, J = 7.31 Hz), 8.12 d
(2H, J = 7.31 Hz), 8.30 s (1H), 8.36 s (2H), 8.59 s
4-Methoxy-N-(4-{3-(4-[5-(3,4,5-trimethoxyphenyl)-
isoxazol-3-yl]phenyl)-1,2,4-thiadiazol-5-yl}phenyl)-
benzamide (11d). Yield 59%, mp 307–309°C. H
NMR spectrum, δ, ppm: 3.79 s (3H), 3.93 s (3H), 3.95
s (6H), 6.65 s (1H), 7.27 s (2H), 7.55 d (2H, J =
1
13
(1H). C NMR spectrum, δ, ppm: 57.4, 61.9, 96.7, 106.8,
123.5, 124.7, 126.7, 128.4, 129.6, 130.7, 131.3, 131.7,
133.4, 134.5, 135.2, 136.5, 145.6, 148.3, 156.5, 158.6,
7
7
8
6
1
.20 Hz), 7.69 d (2H, J = 7.25 Hz), 7.73–7.80 m (4H),
.84 d (2H, J = 7.27 Hz), 8.09 d (2H, J = 7.27 Hz),
+
159.3, 160.4, 169.8, 171.8. MS (ESI): 682 [M + H] .
1
3
.57 s (1H). C NMR spectrum, δ, ppm: 57.4, 58.3,
1.8, 96.4, 106.3, 115.7, 123.4, 126.5, 128.6, 129.5, 130.4,
30.7, 131.6, 132.4, 133.6, 134.2, 140.7, 145.6, 156.3,
58.7, 160.3, 161.5, 164.6, 169.6, 170.8. MS (ESI): 622
4
-Cyano-N-(4-{3-(4-[5-(3,4,5-trimethoxyphenyl)-
isoxazol-3-yl]phenyl)-1,2,4-thiadiazol-5-yl}phenyl)-
1
benzamide (11i). Yield 82%, mp 269–271°C. H
1
NMR spectrum, δ, ppm: 3.93 s (3H), 3.96 s (6H), 6.68
s (1H), 7.27 s (2H), 7.68 d (2H, J = 7.26 Hz), 7.72 d
(2H, J = 7.26 Hz), 7.81–7.94 m (4H), 8.10 d (2H, J =
+
[M + H] .
4
-Chloro-N-(4-{3-(4-[5-(3,4,5-trimethoxyphenyl)-
13
isoxazol-3-yl]phenyl)-1,2,4-thiadiazol-5-yl}phenyl)-
benzamide (11e). Yield 70%, mp 288–290°C. H
NMR spectrum, δ, ppm: 3.93 s (3H), 3.95 s (6H), 6.66
s (1H), 7.27 s (2H), 7.63 d (2H, J = 7.30 Hz), 7.68 d
7.28 Hz), 8.18 d (2H, J = 7.27 Hz), 8.57 s (1H). C
NMR spectrum, δ, ppm: 57.6, 61.8, 96.5, 106.8, 114.5,
119.6, 123.5, 126.8, 129.7, 130.3, 130.7, 131.4, 131.9,
133.5, 134.5, 135.7, 139.4, 140.3, 145.5, 156.4, 158.6,
1
+
(
2H, J = 7.26 Hz), 7.70–7.81 m (4H), 7.86 d (2H, J =
160.7, 163.4, 169.8, 170.8. MS (ESI): 617 [M + H] .
13
7
.28 Hz), 8.10 d (2H, J = 7.28 Hz), 8.58 s (1H). C
N-(4-{3-(4-[5-(3,4,5-Trimethoxyphenyl)isoxazol-
NMR spectrum, δ, ppm: 57.6, 61.8, 96.4, 106.4, 123.7,
3
-yl]phenyl)-1,2,4-thiadiazol-5-yl}phenyl)-4-methyl-
1
1
1
26.4, 127.6, 129.7, 130.6, 131.3, 132.7, 133.4, 134.2,
34.7, 135.2, 140.3, 140.7, 145.4, 156.4, 158.3, 160.5,
1
benzamide (11j). Yield 54%, mp 265–267°C. H
NMR spectrum, δ, ppm: 2.43 s (3H), 3.93 s (3H), 3.96
s (6H), 6.66 s (1H), 7.24 s (2H), 7.46 d (2H, J =
7.19 Hz), 7.55 d (2H, J = 7.19 Hz), 7.68 d (2H, J =
7.23 Hz), 7.72 d (2H, J = 7.23 Hz), 7.80 d (2H, J =
+
61.6, 169.6, 170.7. MS (ESI): 626 [M + H] .
4
-Bromo-N-(4-{3-(4-[5-(3,4,5-trimethoxyphenyl)-
isoxazol-3-yl]phenyl)-1,2,4-thiadiazol-5-yl}phenyl)-
benzamide (11f). Yield 66%, mp 276–278°C. H
1
13
7.26 Hz), 8.09 d (2H, J = 7.26 Hz), 8.56 s (1H). C
NMR spectrum, δ, ppm: 3.92 s (3H), 3.96 s (6H), 6.67
s (1H), 7.26 s (2H), 7.65 d (2H, J = 7.31 Hz), 7.69 d
NMR spectrum, δ, ppm: 24.8, 57.6, 61.8, 96.4, 106.8,
123.4, 126.5, 128.5, 129.6, 130.4, 131.3, 131.7, 132.4,
133.5, 134.2, 135.4, 140.6, 143.5, 145.6, 156.7, 158.6,
(
2H, J = 7.27 Hz), 7.72–7.83 m (4H), 7.87 d (2H, J =
13
+
7
.29 Hz), 8.10 d (2H, J = 7.29 Hz), 8.58 s (1H). C
160.4, 163.6, 169.7, 170.9. MS (ESI): 606 [M + H] .
NMR spectrum, δ, ppm: 57.3, 61.8, 96.5, 106.4, 123.4,
MTT assay. Individual wells of a 96-well tissue
1
1
1
24.6, 126.5, 129.5, 130.3, 130.8, 131.4, 131.7, 133.4,
34.7, 135.4, 135.8, 140.4, 145.6, 156.3, 158.3, 160.4,
62.8, 168.9, 170.7. MS (ESI): 671 [M + H] .
culture microtiter plate were inoculated with 100 µL of
4
complete medium containing 1×10 cells. The plates
+
were incubated at 37°C in a humidified 5% CO2
incubator for 18 h prior to the experiment. After
medium removal, 100 µL of fresh medium containing
the test compounds and etoposide at different
N-(4-{3-(4-[5-(3,4,5-Trimethoxyphenyl)isoxazol-
3
-yl]phenyl)-1,2,4-thiadiazol-5-yl]phenyl)-4-nitro-
1
benzamide (11g). Yield 73%, mp 283–285°C. H
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 89 No. 2 2019

SYNTHESIS AND ANTICANCER ACTIVITY OF AMIDE DERIVATIVES
329
concentrations (0.5, 1, 2 µM) were added to each well
and incubated at 37°C for 24 h. The medium was
discarded and replaced with 10 µL MTT dye. Plates
were incubated at 37°C for 2 h. The resulting formazan
crystals were solubilized in 100 µL extraction buffer.
Optical density (O.D.) was measured at 570 nm with a
micro plate reader (Multi-mode Varioskan Instrument-
Themo Scientific). The percentage of DMSO in the
medium never exceeded 0.25%.
doi 10.2174/1570180816666181031125946
10. Mohamed, S.F., Abdel-Hafez, N.A., Amr, A.E., and
Awad, H.M., Russ. J. Gen. Chem., 2017, vol. 87,
p. 1264. doi 10.1134/S1070363217060226
1. Chakrapani, B., Ramesh, V., Rao, G.P.C.,
Ramachandran, D., Reddy, T.M., and Chakravarthy, A.K.,
Russ. J. Gen. Chem., vol. 88, p. 1020. doi 10.1134/
S1070363218050304
2. Reddy, G.S., Mohanty, S., Kumar J., and Rao, B.V.,
Russ. J. Gen. Chem., 2018, vol. 88, p. 2394. doi
10.1134/S1070363218110233
3. Ravikumar, P., Raolji, G.S.B., Sastry, K.V., Kalidasu, S.,
and Balaraju, T., Russ. J. Gen. Chem., 2018, vol. 88,
p. 2183. doi 10.1134/S1070363218100250
1
1
1
CONCLUSIONS
A number of amide derivatives of 1,2-isoxazole com-
bined with 1,2,4-thiadiazole 11a–11j is synthesized.
All the compounds are tested for their anticancer
activity against four types of human cancer cell lines
including MCF-7 (breast), A549 (lung), Colo-205
1
1
1
4. Rathod, A.S. and Biradar, J.S., Russ. J. Gen. Chem.,
2018, vol. 88, p. 2190. doi 10.1134/S1070363218100262
5. Dang, T.T., Dang, T.T., and Langer, P., Synlett, 2011,
p. 2633. doi 10.1055/s-0031-1289550
6. Kumar, V., Aggarwal, R., and Singh, S.P.,
(
colon) and A2780 (ovarian). Most of the compounds
demonstrate significant anticancer activity, and 11b,
1c, 11d, 11e, 11g, and 11j exhibit more potent activity
1
Heterocycles, 2008, vol. 75, p. 2893. doi 10.3987/REV-
than etoposide. The compound 11g demonstrates the
superior activity.
0
8-634
1
7. Giomi, D., Cordero, F., and Machetti, F., Com-
prehensive Heterocyclic Chemistry III; Katrizky, A.R.,
Ramsden, C.A., Scriven, E.F.V., Taylor, R.J.K., and
Joule, J., Eds., Oxford: Elsevier, 2008, vol. 4.
CONFLICT OF INTEREST
No conflict of interest was declared by the authors.
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