Synthesis and antitumor activity of ureas containing pyrimidinyl group

Article abstract of DOI:10.1016/j.ejmech.2010.11.026

A novel series of ureas containing pyrimidinyl group were designed and synthesized. Some of the prepared compounds showed potential cytotoxicity against several human cancer cell lines. From the structure-activity relationships we may conclude that introd

Full text of DOI:10.1016/j.ejmech.2010.11.026

European Journal of Medicinal Chemistry 46 (2011) 429e432
Contents lists available at ScienceDirect
European Journal of Medicinal Chemistry
journal homepage: http://www.elsevier.com/locate/ejmech
Short communication
Synthesis and antitumor activity of ureas containing pyrimidinyl group
,
b,
Chuanfei Jin a, Yong-Ju Liang b, Hongwu He a , Liwu Fu
*
**
a Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, 152 Luoyu Road, Wuhan 430079, PR China
b State Key Laboratory of Oncology in South China, Cancer Center, Sun Yat-sen University, Guangzhou 510060, PR China
a r t i c l e i n f o
a b s t r a c t
Article history:
A novel series of ureas containing pyrimidinyl group were designed and synthesized. Some of the
prepared compounds showed potential cytotoxicity against several human cancer cell lines. From the
structure-activity relationships we may conclude that introduction of a sulfide bridge between phenyl
and pyrimidinyl rings would be critical for their biological activities.
Received 9 August 2010
Received in revised form
15 November 2010
Accepted 17 November 2010
Available online 24 November 2010
Ó 2010 Elsevier Masson SAS. All rights reserved.
Keywords:
Urea
4,6-Dimethy-2-(methylsulfonyl)pyrimidine
Cytotoxicity
1. Introduction
designed and synthesized novel ureas containing the pyrimidinyl
group. The bioactivities of the new compounds were evaluated.
Cancer is a major worldwide health problem. Although there
has been progress in the development of treatment and prevention
for cancer, this disease remains the second major cause of death
in the world. Still, the successful treatment of cancer remains
a challenge in the 21st century, and there is a need to search for
newer and safer anticancer agents that have a broader spectrum of
cytotoxicity to tumor cells.
Urea derivatives have been used for the treatment of a wide
range of solid tumors [1e6]. Urea-based prodrugs have been
reported as candidates for melanocyte-directed enzyme prodrug
therapy (MDEPT), in which they release the drug upon exposure to
tyrosinase [7]. Some related urea derivatives also have been
reported as protein tyrosine kinases (PTKs) inhibitors, and have
become an important class of potential anticancer drugs [8]. For
these reasons, the synthesis of urea and their functionalized
derivatives is of high interest.
2. Chemistry
Synthesis of these novel compounds was carried out in a
straightforward manner.
Compound 3 could be synthesized starting from 4-aminophenol
or 4-aminobenzenethiol 1 and 4,6-dimethy-2-(methylsulfonyl)
pyrimidine 2 in presence of K2CO3 in DMF [13]. Treatment of
equimolar amounts of substituted isocyanates with compound 3 in
dry CH2Cl2 afforded the corresponding urea derivatives (4ae4l)
(Scheme 1). The preparations are summarized in Table 1. The
chemical structures of the compounds were confirmed by 1H NMR,
13C NMR and elementary analysis and the results are presented
in Section 6.
3. Pharmacology
Bioisosterism is an effective way to design bioactive compounds
[9]. The pyrimidinyl group is a highly efficient pharmacophore and
is widely used in pesticide and drug molecular design [10e12].
We wanted to investigate whether there would be some new be-
neficial properties if pyrimidinyl group was combined in the urea
derivatives. In order to find more potent urea antitumor agents, we
The in vitro antitumor activity of the synthesized compounds
against four cancer cell lines, including KB (oral carcinoma cell),
CNE2 (nasopharyngeal carcinoma cell), MGC-803 (gastric carci-
noma cell), and MCF-7 (breast adenocarcinoma cell), were assayed
by MTT method. 5-FU was used as the reference drug. Table 2
reported the IC50 (mM) values (concentration required to achieve
50% inhibition of the tumor growth) of the tested compounds and
the standards. With respect to the in vitro cytotoxic activity
expressed in Table 2, most of the prepared compounds showed
potential cytotoxicity against several human cancer cell lines.
* Corresponding author. Tel./fax: þ86 (0)27 67867960.
** Corresponding author.
E-mail addresses: he1208@yahoo.com.cn (H. He), fulw@mail.sysu.edu.cn (L. Fu).
0223-5234/$ e see front matter Ó 2010 Elsevier Masson SAS. All rights reserved.
doi:10.1016/j.ejmech.2010.11.026

430
C. Jin et al. / European Journal of Medicinal Chemistry 46 (2011) 429e432
Table 2
ArNCO, CH2Cl2
5-7h, rt.
N
N
N
N
K2CO3, DMF
3-5h, 80oC
H2N
XH
MeO2S
H2N
X
Cytotoxic activity of urea compounds against human tumor cells.
Compound
In vitro cytotoxicity IC50
(
m
M)
MGC-803a
1
2
3
R1
KBa
CNE2a
MCF-7a
eb
e
e
O
4a
4b
4c
4d
4e
4f
4g
4h
4i
>50
>50
HN
N
X
HN
e
e
e
N
28.9 ꢁ 0.6
48.4 ꢁ 1.4
25.4 ꢁ 2.1
31.8 ꢁ 2.1
25.7 ꢁ 1.1
47.8 ꢁ 1.2
20.0 ꢁ 1.4
32.1 ꢁ 2.7
10.2 ꢁ 0.6
15.5 ꢁ 0.3
30.8 ꢁ 2.3
46.9 ꢁ 1.4
20.4 ꢁ 1.6
38.9 ꢁ 1.3
22.0 ꢁ 1.1
>50
22.8 ꢁ 1.6
34.1 ꢁ 1.3
13.5 ꢁ 1.1
23.2 ꢁ 1.7
>50
>50
>50
35.4 ꢁ 1.6
40.1 ꢁ 2.2
25.3 ꢁ 1.5
13.8 ꢁ 0.9
>50
>50
>50
>50
4
47.8 ꢁ 1.1
Scheme 1. General synthetic route for compounds 4a-l
>50
37.0 ꢁ 2.3
41.7 ꢁ 1.4
>50
4. Results and discussion
4j
4k
4l
4.1. Nuclear magnetic resonance spectral studies
26.1 ꢁ 1.6
35.3 ꢁ 2.5
>50
>50
The evidence for the formation of the compounds was obtained
from 1H NMR and 13C NMR spectra, which provide diagnostic tools
for the positional elucidation of the protons. Assignments of the
signals are based on the chemical shifts and intensity patterns.
The 1H NMR spectrum of all the compounds showed singlet for two
Cl
O
HN
>50
>50
e
>50
HN
OMe
OMe
(2 NH) protons at
dine-H) proton at
at (2.25e2.32). Thus on the basis of the above data the products
d
(8.20e9.48), another singlet for one (pyrimi-
Cl
d
(6.70e7.00) and a singlet for two (2 CH3) proton
Cl
O
d
>50
>50
>50
>50
HN
have been characterized as urea derivatives.
HN
13C NMR spectra of all the compounds were taken in DMSO-d6
and the signal obtained further confirmed the proposed structures.
All the compounds showed a signal at (151.9e152.6) ppm due to
(C]O) of urea derivatives. Urea derivative showed a signal at
(169.4e170.6) ppm due to (NeC¼N). Methyl carbon displayed
a signal at (23.3e23.4) ppm of urea derivatives. The characteristic
peaks observed within the 13C NMR spectra of urea derivatives
are given in Section 6.
5-FU
11.9 ꢁ 1.1
13.1 ꢁ 1.5
12.6 ꢁ 1.6
15.2 ꢁ 2.6
a
KB cells were the drug sensitive human oral carcinoma cells, CNE2 cells were the
drug sensitive human nasopharyngeal carcinoma cells, MGC-803 cells were the drug
sensitive human gastric carcinoma cells and MCF-7 cells were the drug sensitive
human breast adenocarcinoma cells.
b
not tested.
displayed more or similar potent cytotoxic activities against certain
cancer cell lines in comparison with 5-FU. For KB cell line, the
compound 4k showed the best inhibitory activity with IC50
10.2 mM. Introduction of a sulfide bridge between phenyl and pyr-
imidinyl rings resulted in higher activity than did an ether link. For
4.2. In vitro cytotoxicity
The results indicated that the pyrimidinyl group introduced to
urea’s structure was useful for the improvement of antitumor
activity. For the compounds without pyrimidinyl group displayed
very weak antitumor activity against the tumor cells. As seen from
Table 2, most of prepared compounds showed potential cytotox-
icity against KB and CNE2 cancer cell lines, and some compounds
showed moderate cytotoxicity against MGC-803 cancer cell line.
However, most of the compounds showed weak cytotoxicity
against MCF-7 cancer cell line. In conclusion, the cytotoxicities
of the tested compounds against KB and CNE2 were higher than
MCF-7 cell line, reflecting the selectivity for a particular human
oral carcinoma and human nasopharyngeal carcinoma cancer cell
types.
example, among 4ie4l bearing a sulfide bridge moieties, the IC50
values of them are 20.0
respectively, which were superior to 4ce4f bearing an ether link
moieties with the IC50 values of 28.9 M, 48.4 M, 25.4 M and
31.8 M respectively. For CNE2 cell line, introduction of a sulfide
mM, 32.1 mM, 10.2 mM and 15.5 mM
m
m
m
m
bridge between phenyl and pyrimidinyl rings also resulted in
higher activity than did an ether link. The compound 4k showed
the best inhibitory activity with IC50 13.5 mM.
For MGC-803 cell line, most of compounds with an ether link
displayed very weak antitumor activity against the tumor cells.
However, the compound 4i showed the best inhibitory activity with
The cytotoxicities of the resulting urea derivatives appeared to
be related to the nature of the substituent group. Some compounds
IC50 13.8
low activity.
Still, the change of R1, also had a little influence on their activity.
mM. For MCF-7 cell lines, most of the compounds showed
Table 1
For example, 4-Cl substituted compounds (4e and 4k) demon-
The preparation of ureas 4a-l
strated the most strong cytotoxic activities against KB with IC50
Compound
X
R1
Yield(%)a
Mp (ꢀC)
25.4 and 10.2
mM respectively.
4a
4b
4c
4d
4e
4f
4g
4h
4i
O
O
O
O
O
O
S
S
S
S
S
H
86
86
76
85
83
83
86
80
82
84
81
86
187.3e190.0
213.3e214.8
208.8e210.5
219.6e220.4
225.8e226.7
220.3e222.1
211.4e213.2
196.1e197.8
218.8e219.5
207.9e210.0
228.3e229.4
246.8e248.5
3-Me
4-OCF3
4-F
4-Cl
2,4-diCl
H
3-Me
4-OCF3
4-F
4-Cl
2,4-diCl
5. Conclusion
In summary, we have designed and synthesized a novel series
of ureas derivatives. Some of the prepared compounds showed
potential cytotoxicity against several human cancer cell lines. Some
compounds displayed more or similar potent cytotoxic activities
against cancer cell lines in comparison with 5-FU. These findings
have encouraged us to continue the development and testing of
novel ureas and to conduct further studies to investigate SAR
and their mechanisms of action.
4j
4k
4l
S
a
Isolated yields.

C. Jin et al. / European Journal of Medicinal Chemistry 46 (2011) 429e432
431
6. Experimental protocols
(s, 1H, NH), 8.67 (s, 1H, NH); 13C NMR (DMSO-d6, 125 MHz): 21.3,
23.3, 115.2, 115.3, 118.7, 119.2, 121.8, 122.5, 128.7, 136.5, 138.0, 139.7,
147.5, 152.6, 164.7, 169.4; Anal. Calcd. for C20H20N4O2 (%): C 68.95,
H 5.79, N 16.08; Found: C 69.03, H 5.53, N 16.16.
6.1. General procedures
1H NMR spectra were recorded at 600 MHz, in CDCl3 or DMSO-
d6 solution on a Varian Mercury-Plus 600 spectrometer and
chemical shifts were recorded in parts per million (ppm) with TMS
as the internal reference. MS spectra were determined using
a TraceMS 2000 organic mass spectrometry, and signals were given
in m/z. Melting points were taken on a Buchi B-545 melting point
apparatus. Elemental analysis (EA) was measured on a Vario ELIII
CHNSO elemental analyzer. All commercially available solvents and
reagents were used as supplied by Acros Organics unless otherwise
stated. The silica gel (200e300 meshes) for flash column chroma-
tography was from Qingdao Marine Chemical Factory in China.
6.4.5. 1-(4-(4,6-Dimethylpyrimidin-2-yloxy)phenyl)-3-(4-
(trifluoromethoxy)phenyl)urea (4c)
White solid, yield: 76%, mp 208.8e210.5 ꢀC; 1H NMR (DMSO-d6,
600 MHz): 2.32 (s, 6H, CH3), 7.00 (s, 1H, CH), 7.08 (d, 2H, J ¼ 9.0 Hz,
ArH), 7.29 (d, 2H, J ¼ 9.0 Hz, ArH), 7.47 (d, 2H, J ¼ 9.0 Hz, ArH), 7.57
(d, 2H, J ¼ 9.6 Hz, ArH), 8.76 (s, 1H, NH), 8.90 (s, 1H, NH); 13C NMR
(DMSO-d6, 125 MHz): 23.3, 115.2, 119.4, 119.6, 121.1, 121.8, 122.0,
136.3, 139.0, 142.6, 147.7, 152.6, 164.7, 169.4; Anal. Calcd. for
C20H17F3N4O3 (%): C 57.42, H 4.10, N 13.39; Found: C 57.33, H 3.98,
N 13.01.
6.2. Procedure for preparation of compound 3a,3b
6.4.6. 1-(4-(4,6-Dimethylpyrimidin-2-yloxy)phenyl)-3-(4-
fluorophenyl)urea (4d)
A
solution of 4,6-dimethyl-2-(methylsulfonyl)pyrimidine
White solid, yield: 85%, mp 219.6e220.4 ꢀC; 1H NMR (DMSO-d6,
600 MHz): 2.32 (s, 6H, CH3), 6.99(s, 1H, CH), 7.07 (d, 2H, J ¼ 9.0 Hz,
ArH), 7.12 (d, 2H, J ¼ 9.0 Hz, ArH), 7.45e7.50 (m, 4H, ArH), 8.69
(s, 1H, NH), 8.72 (s, 1H, NH); 13C NMR (DMSO-d6, 125 MHz): 23.3,
115.3, 119.4, 120.0, 121.8, 136.1, 136.5, 147.5, 152.7, 156.6, 158.1, 164.7,
169.4; Anal. Calcd. for C19H17FN4O2 (%): C 64.76, H 4.86, N 15.90;
Found: C 64.38, H 4.60, N 15.60.
(18 mmol), 4-aminophenol or 4-aminobenzenethiol (18 mmol) and
K2CO3 (36 mmol) in DMF (50 mL) was stirred at 100 ꢀC for 2 h. The
reaction mixture was poured into water and extracted with EtOAc.
The organic layer was washed with water and saturated brine,
dried over Na2SO4 and evaporated. The residue was purified by
column chromatography on silica gel (PE:EA ¼ 2:1) to give the
compound 3a,3b.
6.4.7. 1-(4-chlorophenyl)-3-(4-(4,6-dimethylpyrimidin-2-yloxy)
phenyl)urea (4e)
6.3. General procedure for preparation of compounds 4ae4l
White solid, yield: 83%, mp 225.8e226.7 ꢀC; 1H NMR (DMSO-d6,
600 MHz): 2.32 (s, 6H, CH3), 6.99 (s, 1H, CH), 7.07 (d, 2H, J ¼ 8.4 Hz,
ArH), 7.33 (d, 2H, J ¼ 9.0 Hz, ArH), 7.45e7.50 (m, 4H, ArH), 8.73
(s, 1H, NH), 8.83 (s, 1H, NH); 13C NMR (DMSO-d6, 125 MHz): 23.3,
115.3, 119.4, 119.6, 122.0, 125.3, 128.6, 136.3, 138.8, 147.6, 152.5,
164.6, 169.4; Anal. Calcd. for C19H17ClN4O2 (%): C 61.87, H 4.65, N
15.19; Found: C 62.08, H 4.37, N 15.06.
Compound 3 (1 mmol) was dissolved in 15 mL dichloromethane.
Temperature was maintained at 0 ꢀC, then substituted phenyl
isocyanate (1 mmol) was added drop wise with constant stirring.
After 1 h, formation of white solid and the resultant solid product
was filtered, washed with little ethanol and dried under vacuum.
Recrystallization with ethanol afforded the desired solid urea.
6.4. Structural data
6.4.8. 1-(2,4-dichlorophenyl)-3-(4-(4,6-dimethylpyrimidin-2-
yloxy)phenyl)urea (4f)
6.4.1. 4-(4,6-Dimethylpyrimidin-2-yloxy)benzenamine (3a) [14]
Yellow solid, yield: 95%, mp 139.1e140.3 ꢀC; 1H NMR (CDCl3,
600 MHz): 1H NMR (CDCl3, 600 MHz): 2.38 (s, 6H, CH3), 6.68 (s, 1H,
CH), 6.70 (d, 2H, J ¼ 8.4 Hz, ArH), 6.99 (d, 2H, J ¼ 8.4 Hz, ArH). MS
(EI, 70 eV): m/z 215 (Mþ, 63), 200 (40), 119 (100), 91 (40), 69 (41).
White solid, yield: 83%, mp 220.3e222.1 ꢀC; 1H NMR (DMSO-d6,
600 MHz): 2.32 (s, 6H, CH3), 6.70 (s, 1H, CH), 7.09 (d, 2H, J ¼ 9.0 Hz,
ArH), 7.40e7.48 (m, 3H, ArH), 7.63 (s,1H, ArH), 8.21 (d, 2H,
J ¼ 9.0 Hz, ArH), 8.40 (s, 1H, NH), 9.48 (s, 1H, NH); 13C NMR (DMSO-
d6, 125 MHz): 23.3, 115.3, 119.4, 122.0, 122.5, 126.0, 127.6, 127.7,
128.5, 135.3, 136.1, 147.8, 152.0, 164.6, 169.4; Anal. Calcd. for
C19H16Cl2N4O2 (%): C 56.59, H 4.00, N 13.89; Found: C 56.77, H 3.84,
N 14.28.
6.4.2. 4-(4,6-Dimethylpyrimidin-2-ylthio)benzenamine (3b) [14]
Yellow solid, yield: 75%, mp 162.2e164.3 ꢀC; 1H NMR (CDCl3,
600 MHz): 2.33 (s, 6H, CH3), 6.66 (s, 1H, CH), 6.70 (d, 2H, J ¼ 8.4 Hz,
ArH), 7.38 (d, 2H, J ¼ 8.4 Hz, ArH). MS (EI, 70 eV): m/z 231 (Mþ, 100),
216 (27), 124 (29), 80 (27), 67 (28).
6.4.9. 1-(4-(4,6-Dimethylpyrimidin-2-ylthio)phenyl)-
3-phenylurea (4g)
White solid, yield: 86%, mp 211.4e213.2 ꢀC; 1H NMR (DMSO-d6,
600 MHz): 2.26 (s, 6H, CH3), 6.94 (s, 1H, CH), 6.97e6.99 (m, 1H,
ArH), 7.26e7.29 (m, 2H, ArH), 7.44e7.52 (m,6H, ArH), 8.73 (s, 1H,
NH), 8.87 (s, 1H, NH); 13C NMR (DMSO-d6, 125 MHz): 23.3, 116.4,
118.2, 118.4, 121.0, 122.0, 128.8, 135.9, 139.4, 140.7, 152.3, 167.2,
170.5; Anal. Calcd. for C19H18N4OS (%): C 65.12, H 5.18, N 15.99;
Found: C 65.39, H 4.96, N 15.98.
6.4.3. 1-(4-(4,6-Dimethylpyrimidin-2-yloxy)phenyl)-
3-phenylurea (4a)
White solid, yield: 86%, mp 187.3e190.0 ꢀC; 1H NMR (DMSO-d6,
600 MHz): 2.32 (s, 6H, CH3), 6.94e6.98 (m, 1H, ArH), 6.99 (s, 1H,
CH), 7.07 (d, 2H, J ¼ 9.0 Hz, ArH), 7.27e7.29 (m, 2H, ArH), 7.46e7.47
(m, 4H, ArH), 8.68 (s, 1H, NH), 8.70 (s, 1H, NH); 13C NMR (DMSO-d6,
125 MHz): 23.3, 115.2, 118.1, 119.3, 121.8, 122.0, 128.7, 136.5, 139.8,
147.5, 152.6, 164.6, 169.4; Anal. Calcd. for C19H18N4O2 (%): C 68.25, H
5.43, N 16.76; Found: C 68.47, H 5.07, N 16.61.
6.4.10. 1-(4-(4,6-Dimethylpyrimidin-2-ylthio)phenyl)-3-m-
tolylurea (4h)
White solid, yield: 80%, mp 196.1e197.8 ꢀC; 1H NMR (DMSO-d6,
600 MHz): 2.25 (s, 9H, CH3), 6.78 (s, 1H, ArH), 6.93 (s, 1H, CH),
7.12e7.28 (m, 3H, ArH), 7.43 (d, 2H, J ¼ 7.8 Hz, ArH), 7.50 (d, 2H,
J ¼ 8.4 Hz, ArH), 8.63 (s, 1H, NH), 8.83 (s, 1H, NH); 13C NMR (DMSO-
d6, 125 MHz): 21.2, 23.4, 115.6, 116.4, 118.4, 118.8, 121.0, 122.7, 128.7,
135.9, 138.0, 139.3, 140.7, 152.3, 167.2, 170.5; Anal. Calcd. for
6.4.4. 1-(4-(4,6-Dimethylpyrimidin-2-yloxy)phenyl)-3-m-tolylurea
(4b)
White solid, yield: 86%, mp 213.3e214.8 ꢀC; 1H NMR (DMSO-d6,
600 MHz): 2.28 (s, 3H, CH3), 2.32 (s, 6H, CH3), 6.79 (s, 1H, ArH), 6.99
(s, H, CH), 7.06e7.30 (m, 5H, ArH), 7.46 (d, 2H, J ¼ 7.8 Hz, ArH), 8.59

432
C. Jin et al. / European Journal of Medicinal Chemistry 46 (2011) 429e432
C20H20N4OS (%): C 65.91, H 5.53, N 15.37; Found: C 65.64, H 5.15,
N 15.59.
formazan product, mainly by mitochondrial reductase activity
inside living cells. The cells used in cytotoxicity assay were cultured
in RPMI 1640 medium supplemented with 10% fetal calf serum.
Cells suspended in the medium (2Y0 104/mL) were plated in
96-well culture plates and incubated at 37 ꢀC in a 5% CO2 incubator.
After 12 h, the test sample (2 mL) was added to the cells (2Y0 104) in
96-well plates and cultured at 37 ꢀC for 3 days. The cultured cells
were mixed with 20 mL of MTT solution and incubated for 4 h at
37 ꢀC. The supernatant was carefully removed from each well and
100 mL of DMSO was added to each well to dissolve the formazan
crystals which were formed by the cellular reduction of MTT.
After mixing with a mechanical plate mixer, the absorbance of
each well was measured by a microplate reader using a test
6.4.11. 1-(4-(4,6-Dimethylpyrimidin-2-ylthio)phenyl)-3-(4-
(trifluoromethoxy)phenyl) urea (4i)
White solid, yield: 82%, mp 218.8e219.5 ꢀC; 1H NMR (DMSO-d6,
600 MHz): 2.25 (s, 6H, CH3), 6.93 (s, 1H, CH), 7.27 (d, 2H, J ¼ 9.0 Hz,
ArH), 7.44 (d, 2H, J ¼ 8.4 Hz, ArH), 7.50e7.55 (m, 4H, ArH), 8.91
(s, 1H, NH), 8.93 (s, 1H, NH); 13C NMR (DMSO-d6, 125 MHz): 23.3,
116.4, 118.7, 119.4, 119.5, 121.4, 121.8, 135.9, 138.9, 140.5, 142.8, 152.3,
167.1, 170.6; Anal. Calcd. for C20H17F3N4O2S (%): C 55.29, H 3.94,
N 12.90; Found: C 55.66, H 4.14, N 12.76.
6.4.12. 1-(4-(4,6-Dimethylpyrimidin-2-ylthio)phenyl)-3-(4-
fluorophenyl)urea (4j)
wavelength of 570 nm. The results were expressed as the IC50,
which is the concentration of the drugs inducing a 50% inhibition of
cell growth of treated cells when compared to the growth of control
cells. Each experiment was performed at least 3 times. There was
a good reproducibility between replicate wells with standard
errors below 10%.
White solid, yield: 84%, mp 207.9e210.0 ꢀC; 1H NMR (DMSO-d6,
600 MHz): 2.28 (s, 6H, CH3), 6.96 (s, 1H, CH), 7.13 (d, 2H, J ¼ 8.4 Hz,
ArH), 7.45e7.48 (m, 4H, ArH), 7.53 (d, 2H, J ¼ 8.4 Hz, ArH), 8.79
(s, 1H, NH), 8.89 (s, 1H, NH); 13C NMR (DMSO-d6, 125 MHz): 23.4,
115.3, 116.4, 118.5, 120.1, 121.1, 135.9, 140.7, 152.5, 156.7, 158.3, 167.1,
170.6; Anal. Calcd. for C19H17FN4OS (%): C 61.94, H 4.65, N 15.21;
Found: C 62.21, H 4.32, N 15.18.
Acknowledgement
This work was supported by the National Natural Science
Foundation of China (20772042).
6.4.13. 1-(4-chlorophenyl)-3-(4-(4,6-dimethylpyrimidin-2-ylthio)
phenyl)urea (4k)
White solid, yield: 81%, mp 228.3e229.4 ꢀC; 1H NMR (DMSO-d6,
600 MHz): 2.28 (s, 6H, CH3), 6.96 (s, 1H, CH), 7.33e7.54 (m, 8H,
ArH), 8.90 (s, 1H, NH), 8.93 (s, 1H, NH); 13C NMR (DMSO-d6,
125 MHz): 23.4, 116.4, 118.6, 119.7, 121.3, 125.6, 128.6, 135.9, 138.6,
140.5, 152.3, 167.1, 170.5; Anal. Calcd. for C19H17ClN4OS (%): C 59.29,
H 4.45, N 14.56; Found: C 59.60, H 4.46, N 14.34.
References
[1] C.T. Gnewuch, G. Sosnovsky, Chem. Rev. 97 (1997) 829e1013.
[2] S. Liu, A.M. Crider, C. Tang, B. Ho, M. Ankersen, C.E. Stidsen, J. Med. Chem.
41 (1998) 4693e4705.
[3] J. Legault, J.F. Gaulin, E. Mounetou, N. Ritchot, J. Lacroix, P. Poyet, C.R. Gaudreault,
Cancer Res. 60 (2000) 985e992.
[4] J. Easmon, G. Purstinger, G. Heinisch, T. Roth, H.H. Fiebig, W. Holzer, W. Jager,
M. Jenny, J. Hofmann, J. Med. Chem. 44 (2001) 2164e2171.
[5] Y. Dai, K. Hartandi, Z. Ji, A.A. Ahmed, D.H. Albert, L. Arnold, S.S. Arries,
T. Barlozzari, J.L. Bauch, J.J. Bouska, P.F. Bousquet, G.A. Cunha, K.B. Glaser,
J. Guo, J. Li, P.A. Marcotte, K.C. Marsh, M.D. Moskey, L.J. Pease, K.D. Stewart,
V.S. Stoll, P. Tapang, N. Wishart, S.K. Davidsen, M.R. Michaelides, J. Med. Chem.
50 (2007) 1584e1597.
[6] R.A. Smith, V. Cokkinides, O.W. Brawley, CA Cancer J. Clin. 59 (2009) 27e41.
[7] A.M. Jordan, T.H. Khan, H. Malkin, H.M. Osborn, Bioorg. Med. Chem. 10 (2002)
2625e2633.
[8] S. Wilhelm, C. Carter, M. Lynch, T. Lowinger, J. Dumas, R.A. Smith, B. Schwartz,
R. Simantov, S. Kelley, Nat. Rev. Drug Discov. 5 (2006) 835e844.
[9] L.M. Lima, E.J. Barreiro, Curr. Med. Chem. 12 (2005) 23e49.
[10] S.J. Tangeda, A. Garlapati, Eur. J. Med. Chem. 45 (2010) 1453e1458.
[11] C. Mugnaini, E. Petricci, M. Botta, F. Corelli, P. Mastromarino, G. Giorgi,
Eur. J. Med. Chem. 42 (2007) 256e262.
6.4.14. 1-(2,4-dichlorophenyl)-3-(4-(4,6-dimethylpyrimidin-
2-ylthio)phenyl)urea (4l)
White solid, yield: 86%, mp 246.8e248.5 ꢀC; 1H NMR (DMSO-d6,
600 MHz): 2.28 (s, 6H, CH3), 6.97 (s, 1H, CH), 7.40e7.55 (m, 6H,
ArH), 7.65 (s, 1H, ArH), 8.20 (s, 1H, NH), 8.47 (s, 1H, NH); 13C NMR
(DMSO-d6, 125 MHz): 23.4, 116.4, 118.6, 121.6, 122.1, 122.7, 126.3,
127.6, 128.5, 135.1, 136.0, 140.2, 151.9, 167.1, 170.5; Anal. Calcd. for
C19H16Cl2N4OS (%): C 54.42, H 3.85, N 13.36; Found: C 54.52, H 3.58,
N 13.27.
6.5. Pharmacology
[12] D. Raffa, M.C. Edler, G. Daidone, B. Maggio, M. Merickech, S. Plescia,
D. Schillaci, R. Bai, E. Hamel, Eur. J. Med. Chem. 39 (2004) 299e304.
[13] H. Okada, T. Koyanagi, N. Yamada, T. Haga, Chem. Pharm. Bull. 39 (1991)
2308e2315.
[14] E. Sturm, J.J. Gallay, G. Pissiotas, The Barbituric-acid derivatives (1986)
191474.
The in vitro cytotoxicity of the synthesized compounds against
different cancer cell lines was performed with the MTT assay
according to the Mosmann’s method [15]. The MTT assay is
based on the reduction of the soluble 3-(4,5-dimethyl-2-thiazolyl)-
2,5-diphenyl-2H-tetrazolium bromide (MTT) into a blueepurple
[15] T. Mosmann, J. Immunol. Methods 65 (1983) 55e63.