Synthesis and bio-evaluation of novel salicylic acid-oriented thiourea derivatives with potential applications in agriculture

Article abstract of DOI:10.2174/15701808113109990045

A series of salicylic acid-oriented thiourea derivatives was conveniently synthesized via multi-steps mainly including alkylation, chlorination, nucleophilic substitution and addition reaction. The structure of all these newly synthesized derivatives was confirmed and characterized by IR, ¹H NMR and MS. The preliminary bioassay indicated that these new compounds have some herbicidal activity or plant growth regulating activity against tested plants.

Full text of DOI:10.2174/15701808113109990045

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98
Letters in Drug Design & Discovery, 2014, 11, 98-103
Synthesis and Bio-Evaluation of Novel Salicylic Acid-Oriented Thiourea
Derivatives with Potential Applications in Agriculture
Shaowei Li#, Huangyong Li#, Xiufang Cao* and Changshui Chen*
College of Science, Huazhong Agricultural University, Wuhan, 430070, China
Abstract: A series of salicylic acid-oriented thiourea derivatives was conveniently synthesized via multi-steps mainly in-
cluding alkylation, chlorination, nucleophilic substitution and addition reaction. The structure of all these newly synthe-
sized derivatives was confirmed and characterized by IR, 1H NMR and MS. The preliminary bioassay indicated that these
new compounds have some herbicidal activity or plant growth regulating activity against tested plants.
Keywords: Thiourea, Salicylic acid, Synthesis, Herbicidal activity, Plant growth regulating activity.
INTRODUCTION
330 instrument in KBr. 1H NMR spectra were measured on a
Brucker spectrometer in DMSO-d6 and the internal standard
was TMS. MicroMass Quattro micro™ API instrument was
used to get the mass spectra. Combustion analyses for ele-
mental composition were made with a Perkin-Elmer 2400
instrument. TLC was used to monitor the progress of reac-
tion and the spots were visualized by UV light. All the ana-
lytical reagents and analytical solvents were commercially
obtained, and dried before using.
Nowadays, urea or thiourea derivatives are not only a re-
search focus on anion sensing [1, 2], but also have occupied
a great concentration in agriculture and medicine because of
their significant biological activities [3-10], such as antimi-
crobial [11-17], antiviral [18-20], antifungal [21-23], antitu-
mor [24-28], anti-virus [29, 30], anti-nociceptive [31], insec-
ticidal activities [32] and so on. Many studies have indicated
that higher activities of these compounds can be obtained by
means of modifying amines of both sides of carbamide
bridge. On the other hand, salicylic acid is one of a wide
variety of natural phenolic compounds isolated from many
organisms [33], and which always plays an important role in
many biochemical processes including signal transduction
and pathogens defense.
Herbicidal Activity Testing
This test was carried out in the greenhouse with Amaran-
thus albus L. at the dosages of 50 mg/L of 5a-m, which were
dissolved in distilled water with a small amount of DMSO
and 0.1% Tween 80. The distilled water was made as CK,
the temperature was constant at 25 1 °C, and the relative
humidity (RH) was 80%, photoperiod for 8 h per day. Ten
seeds chosen for testing were put in the plate, whose diame-
ter was 9 cm. In each plate, there were ten seeds with 5 mL
solution of 5a-m (50 mg/L) separately, each experiment was
repeated twice. Finally, the hypocotyls and root of Amaran-
thus albus L were measured, and the inhibition efficiency
was indicated as percentage inhibition. The specific herbi-
cidal data is showen in Table 1.
In view of these considerations, this work focused on the
convenient synthesis, and bio-evaluation of novel series of
salicylic acid-oriented N-substituted acylthiourea derivatives.
We utilized thiourea scaffold as key prototype unit and
planed for the integration of salicylic acid group to the core
structure as shown in Fig. (1). The designed salicylic acid-
oriented thiourea derivatives can be conveniently prepared
via multistep mainly including alkylation, chlorination, nu-
cleophilic substitution and addition reactions. All the synthe-
sized compounds 5a-m gave satisfactory chemical analyses.
The preliminary bioactivity as herbicidal activity and plant
growth regulating activity was all tested, and the bioassay
results indicated that target molecute 5m has some herbicidal
activity, while 5c, 5g and 5l displayed some plant growth
regulating activity.
The Plant Growth Regulating Activity
Compounds 5a-m were dissolved in distilled water that
contains a small amount of DMSO and 0.1% Tween 80 to 50
mg/L. In each 9-cm-diameter plate with 5 mL solution of 5a-
m (50 mg/L), 10 seeds of Brassica campestris L and
Oryza.sativa L were chosen for testing. Then all of these
plates were put in greenhouse to germinate for 120 h, with a
constant humidity of 80% and temperature of 25 1°C. Each
experiment was repeated twice, the mixture solution of same
amount of distilled water, DMSO and Tween 80 was made
as CK. The hypocotyls and root of Brassica campestris L
and Oryza.sativa L were measured finally, and the specific
data is showen in Table 2.
EXPERIMENTAL
Material and Methods
All the melting points of these target molecules were ob-
tained by a digital melting point apparatus without corrected.
IR spectra were recorded on a Thermo-Nicolet FT-IT Avatar
RESULTS AND DISCUSSION
*Address correspondence to these authors at the College of Science, Huaz-
hong Agricultural University, Wuhan 430070, China;
Tel: +86-27-87288247; Fax: +86-27-87288247;
Synthesis of Target Molecules 5a-m
In the present study, thirteen novel salicylic acid-oriented
thiourea derivatives 5a-m were synthesized as potential agri-
E-mails: caoxiufang@mail.hzau.edu.cn, chenchang@mail.hzau.edu.cn
#These authors contributed equally to this work
1875-628X/14 $58.00+.00
©2014 Bentham Science Publishers

Synthesis and Bio-Evaluation of Novel Salicylic Acid-Oriented
Letters in Drug Design & Discovery, 2014, Vol. 11, No. 1 99
S
R1
R1
N
R2
O
O
S
N
H
R2
COOH
OH
H
N
H
N
H
Pharmacophores
Hybridization
Salicyl-Thiourea Derivatives
Salicylic acid
Fig. (1). Design strategy of salicylic acid-oriented thioureas derivatives.
Table 1. Specific Herbicidal Activity of 5a-m Against Amaranthus albus L.
Inhibition Rate (%) Against Amaranthus albus L.
Concentration
Entry
Compd. No.
(mg/L)
Root
Hypocotyls
1
2
5a
5b
5c
5d
5e
5f
50
50
50
50
50
50
50
50
50
50
50
50
50
49.71 1.8
42.39 2.1
63.57 3.1
62.50 2.6
49.66 1.4
50.89 1.8
46.17 2.2
32.97 1.9
26.99 1.7
58.07 2.7
50.99 2.8
38.67 1.4
89.16 2.6
40.18 2.7
17.51 1.2
5.34 1.3
13.24 1.5
8.67 1.6
14.81 1.3
9.34 1.5
24.42 2.1
4.57 1.3
10.76 2.1
15.97 1.2
5.66 1.1
55.34 2.3
3
4
5
6
7
5g
5h
5i
8
9
10
11
12
13
5j
5k
5l
5m
cultural agents. The general methods for the preparation of
target molecules are outlined in (Scheme 1).
various substituted anilines for 3 h at 60-70 °C, TLC was
used to detected the progress of the reaction, the final solution
was filtered and the precipitate was dried and recrystallized in
alcohol to afford the target molecules 5a-m. Their physico-
chemical properties and the spectra data are as follows:
As the synthetic route described in (Scheme 1), the sali-
cylic acid was selected as starting material, was were rou-
tinely transferred to the corresponding intermediates by clas-
sic reactions, and the yields were above 80%. The target
compounds can be easily obtained via nucleophilic addition
reaction of intermediate 4a-c with various substituted ani-
line. All the synthesized compounds 5a-m gave satisfactory
Compd. 5a 1-[2-(6-Chloropyridin-3-ylmethoxy)-benz-
oyl]-3-(4-nitrophenyl)thiourea
Light yellow powder, yield 95%, m.p. 229-230 °C, IR
(ꢀmax, KBr, cm-1): 3303.80 (NH), 1673.44 (NHC=O),
1291.31 (C=S); H NMR (400 MHz, DMSO-d6): ꢁH = 8.64
1
chemical analyses. The IR, H NMR, MS spectra and ele-
mental analyses were consistent with the assigned structures.
1
(s, 1H), 8.26 (d, J = 8.0 Hz, 2H), 8.16 (d, J = 8.0 Hz, 1H),
8.03 (d, J = 8.0 Hz, 2H), 7.86 (d, J = 8.0 Hz, 1H), 7.68 (t, J =
8.0 Hz, 1H), 7.56 (d, J = 8.0 Hz, 3H), 7.39 (d, J = 8.0 Hz,
1H), 7.19 (t, J = 8.0 Hz, 1H), 5.35 (s, 2H); 13C NMR (100
MHz, DMSO-d6): ꢁ = 168.34, 162.18, 155.57, 150.18,
147.61, 141.75, 139.25, 133.84, 131.35, 130.86, 127.98,
126.17, 124.65, 123.78, 122.21, 120.43, 116.27, 68.86; MS
(ESI) m/z 443.8 (M+H)+, calcd. for C20H15ClN4O4S m/z =
442.1; Anal. Calcd for C20H15ClN4O4S: C, 54.24; H, 3.41; N,
12.65. Found: C, 54.47; H, 3.53; N, 12.49.
General Methods for the Preparation of the Important
Intermediates 4a-c
The intermediates 4a-c can be obtained by four steps in-
cluding esterification, alkylation, saponification reactions
and nucleophilic addition reaction according to former re-
ported method.34
General Procedure for Synthesis of Target Molecules 5a-m
Target molecules 5a-m were prepared by means of clas-
sic methods via nucleophilic addition reaction as shown in
(Scheme 1), the intermediate 4 was directly reacted with
Compd. 5b 1-(2-(4-Fluorobenzyloxy)benzoyl)-3-(4-nitr-
ophenyl)thiourea

100 Letters in Drug Design & Discovery, 2014, Vol. 11, No. 1
Li et al.
R1
R1
R1
R1
O
O
O
S
O
O
O
NaOH
1) MeOH, H2SO4
1) SOCl2
Aniline
MeCN
R2
OH
O
O
O
O
N
H
N
H
2) Halides, K2CO3, MeCN
MeOH/H2O
2) KSCN, MeCN
OH
OH
NCS
5a-m
3a-c
4a-c
1
2a-c
NO2
NO2
NO2
CF3
O
O
S
O
O
S
O
O
S
O
O
S
Cl
N
N
H
N
H
F
N
H
N
H
N
H
N
H
N
H
N
H
5a
5c
5b
5d
F
F
O
O
S
O
O
S
O
O
S
O
O
S
O
O
S
Cl
N
N
H
N
H
F
N
H
N
H
NO2
N
H
N
H
CF3
N
H
N
H
N
H
N
H
NO2
F
F
5e
5g
5f
5h
5i
Cl
Cl
N
N
F
O
O
S
O
O
S
S
S
O
O
S
O
NH HN
O
N
H
N
H
NO2
N
H
N
H
N
H
N
H
O
NH
HN
O
NO2
5m
5j
5k
5l
Scheme (1). Synthetic route and structures for newly synthesized compounds 5a-m.
Light yellow powder, yield 84%, m.p. 201-203 °C, IR
(ꢀmax, KBr, cm-1): 3285.05 (NH), 1660.48 (NHC=O),
1223.69 (C=S); H NMR (400 MHz, DMSO-d6): ꢁH = 12.85
(s, 1H), 11.42 (s, 1H), 8.28 (d, J = 9.2 Hz, 2H), 8.08 (d, J =
8.8 Hz, 2H), 7.89 (d, J = 7.6 Hz, 1H), 7.67 (t, J = 8 Hz, 3H),
7.40 (d, J = 8.4 Hz, 1H), 7.25-7.17 (m, 3H), 5.32 (s, 2H); MS
(ESI) m/z 426.7 (M+H)+, calcd. for C21H16FN3O4S m/z =
425.1.
Compd. 5e 1-(2,6-Difluorophenyl)-3-(2-methoxybenz-
oyl)thiourea
1
Light yellow needle crystal, yeild 89%, m.p. 149-150 °C,
IR (ꢀmax, KBr, cm-1): 3314.15 (NH), 1651.02 (NHC=O),
1241.86 (C=S); H NMR (400 MHz, DMSO-d6): ꢁH = 11.68
1
(s, 1H), 11.46(s, 1H), 7.90(d, J = 8.0 Hz, 1H), 7.67 (t, J = 8.0
Hz, 1H), 7.46 (t, J = 6.0 Hz, 1H), 7.20 (m, J = 8.0 Hz, 4H),
4.00 (s, 3H); 13C NMR (100 MHz, DMSO-d6): ꢁ = 169.07,
162.23, 160.85, 148.54, 138.52, 132.76, 129.28, 126.78,
124.63, 122.08, 119.84, 114.52, 53.18; MS (ESI) m/z 323.1
(M+H)+, calcd. for C16H13F3N2O2S m/z = 322.1; Anal. Calcd
for C15H12F2N2O2S: C, 55.89; H, 3.75; N, 8.69. Found: C,
55.67; H, 3.84; N, 8.85.
Compd. 5c 1-(2-Methoxybenzoyl)-3-(4-nitrophenyl)th-
iourea
Yellow powder, yeild 88%, m.p. 219-221 °C, IR (ꢀmax
,
KBr, cm-1): 3290.60(NH), 1665.74 (NHC=O), 1235.98
(C=S); 1H NMR (400 MHz, DMSO-d6): ꢁH = 8.28 (d, J = 12
Hz, 2H), 8.03 (d, J = 8.0 Hz, 2H), 7.89 (t, J = 4.0 Hz, 1H),
7.66 (t, J = 8.0 Hz, 1H), 7.28 (d, J = 8.0 Hz, 1H), 7.16 (t, J =
8.0 Hz, 1H), 4.00 (s, 3H); 13C NMR (100 MHz, DMSO-d6):
ꢁ = 168.33, 161.58, 152.57, 144.72, 140.68, 131.45, 128.51,
127.62, 123.44, 121.12, 118.55, 113.41, 52.32; MS (ESI) m/z
352.5 (M+Na)-, calcd. for C15H13N3O4S m/z = 331.1; Anal.
Calcd for C15H13N3O4S: C, 54.37; H, 3.95; N, 12.68. Found:
C, 54.55; H, 3.81; N, 12.44.
Compd. 5f 1-(2,4-Difluorophenyl)-3-(2-methoxyben-
zoyl)thiourea
White needle crystal, yield 82%, m.p. 126-127 °C, IR
(ꢀmax, KBr, cm-1): 3322.22 (NH), 1670.38 (NHC=O),
1250.80 (C=S); H NMR (400 MHz, DMSO-d6): ꢁH = 12.21
1
(s, 1H), 11.39(s, 1H), 7.90(t, J = 6.8 Hz, 2H), 7.66 (d, J = 5.2
Hz, 1H), 7.43 (t, J = 10.0 Hz, 1H), 7.30 (d, J = 8.4 Hz, 1H),
7.16 (t, J = 7.6 Hz, 2H), 3.99 (s, 3H); MS (ESI) m/z 322.8
(M+H)+, calcd. for C16H13F3N2O2S m/z = 322.1.
Compd. 5d 1-(2-Methoxybenzoyl)-3-(4-trifluoromethyl-
phenyl)thiourea
Compd. 5g 1-[2-(6-Chloropyridin-3-ylmethoxy)-benz-
oyl]-3-(2-nitrophenyl)thiourea
Yellow crystal, yield 90%, m.p. 127-129 °C, IR (ꢀmax
,
KBr, cm-1): 3287.11 (NH), 1662.74 (NHC=O), 1262.61
(C=S); H NMR (600 MHz, DMSO-d6): ꢁH = 12.71 (s, 1H),
Yellow crystal, yield 88%, m.p. 196-198 °C, IR (ꢀmax
,
1
KBr, cm-1): 3314.15 (NH), 1668.68 (NHC=O), 1247.75
(C=S); H NMR (400 MHz, DMSO-d6): ꢁH = 12.74 (s, 1H),
11.36(s, 1H), 7.99(d, J = 8.4Hz, 2H), 7.92 (d, J = 7.8 Hz,
1H), 7.81 (d, J = 7.8 Hz, 2H), 7.68 (t, J = 7.8 Hz, 1H), 7.30
(d, J = 8.4 Hz, 1H), 7.518 (t, J = 7.5 Hz, 1H), 4.01 (s, 3H);
MS (ESI) m/z 378.5 (M+Na)+, calcd. for C16H13F3N2O2S m/z
= 354.1; Anal. Calcd for C16H13F3N2O2S: C, 54.23; H, 3.70;
N, 7.91. Found: C, 54.38; H, 3.82; N, 7.75.
1
11.45(s, 1H), 8.63(d, J = 2.0 Hz, 1H), 8.14 (t, J = 7.6 Hz,
2H), 7.98 (d, J = 8.0 Hz, 1H), 7.88 (d, J = 6.0 Hz, 1H), 7.79
(t, J = 4.8 Hz, 1H), 7.71-7.53 (m, 3H), 7.40 (d, J = 8.4 Hz,
1H), 7.20 (t, J = 7.6 Hz, 1H), 5.35 (s, 2H); MS (ESI) m/z
443.8 (M+H)+, calcd. for C20H15ClN4O4S m/z = 442.1; Anal.

Synthesis and Bio-Evaluation of Novel Salicylic Acid-Oriented
Letters in Drug Design & Discovery, 2014, Vol. 11, No. 1 101
Table 2. The Plant Growth Regulating Activities of Target Compounds 5a-m.
Promotion Rate (%) Against Oryza. sativa L
Promotion Rate (%) Against Brassica campestris L.
Compd.
No.
Concentration
(mg/L)
Entry
Root
Hypocotyls
Root
Hypocotyls
1
2
5a
5b
5c
5d
5e
5f
50
50
50
50
50
50
50
50
50
50
50
50
50
-50.86 3.3
-61.43 2.4
-64.38 1.7
-44.79 1.5
-54.44 2.1
-39.86 1.9
-33.42 2.3
-55.37 1.9
-44.01 2.7
-29.96 1.7
-45.44 2.4
8.14 2.1
-1.14 0.3
-15.48 1.5
1.75 0.2
-50.17 2.4
-20.40 1.4
-51.09 3.4
-12.68 1.3
-17.84 2.2
-32.21 2.5
11.95 1.7
-25.50 2.3
-9.36 1.4
-14.45 2.1
-28.03 1.7
-42.33 2.8
-33.48 2.8
-34.71 2.3
-39.25 3.1
-22.28 1.9
-8.64 1.1
3
4
-9.27 1.2
-6.12 0.8
-2.93 0.7
-6.78 1.1
-3.34 0.4
-2.96 1.2
5.78 1.3
5
6
7
5g
5h
5i
8
9
-29.77 2.1
-38.20 2.5
-35.36 2.8
-24.70 1.6
-30.99 1.9
10
11
12
13
5j
-12.32 1.7
-25.40 1.7
12.05 1.2
-60.32 2.7
5k
5l
-10.73 1.6
4.88 0.3
5m
-77.91 2.9
-19.27 1.2
Calcd for C20H15ClN4O4S: C, 54.24; H, 3.41; N, 12.65.
Found: C, 54.05; H, 3.53; N, 12.48.
11.38 (s, 1H), 8.79(d, J = 2.0 Hz, 1H), 8.14 (d, J = 6.0 Hz,
1H), 8.05 (d, J = 8.0 Hz, 1H), 7.90 (d, J = 6.0 Hz, 1H), 7.74-
7.64 (m, 2H), 7.29 (d, J = 8.4 Hz, 1H), 7.17 (d, J = 4.0 Hz,
1H), 4.00 (s, 3H); MS (ESI) m/z 352.8 (M+Na)+, calcd. for
C15H13N3O4S m/z = 331.1.
Compd. 5h 1-[2-(4-Fluorobenzyloxy)-benzoyl]-3-(3-
nitrophenyl)thiourea
White needle crystal, yield 97%, m.p. 206-207 °C, IR
(ꢀmax, KBr, cm-1): 3287.11 (NH), 1655.71 (NHC=O),
1227.32(C=S); H NMR (400 MHz, DMSO-d6): ꢁH = 12.67
Compd. 5k 1-(2-Methoxybenzoyl)-3-(2-nitrophenyl)thi-
ourea
1
(s, 1H), 11.40 (s, 1H), 8.78 (s, 1H), 8.12 (d, J = 7.2 Hz, 1H),
8.02 (d, J = 6.8 Hz, 1H), 7.89 (d, J = 6.4 Hz, 1H), 7.68 (d, J
= 6.4 Hz, 4H), 7.40 (d, J = 8.0 Hz, 1H), 7.20 (m, 3H), 5.31
(s, 2H); 13C NMR (100 MHz, DMSO-d6): ꢁ = 171.52,
163.42, 158.21, 151.74, 149.55, 142.71, 136.35, 135.12,
132.51, 131.92, 129.54, 127.18, 125.64, 124.07, 123.45,
121.86, 120.55, 118.87, 67.12; MS (ESI) m/z 426.2 (M+H)+,
calcd. for C21H16FN3O4S m/z = 425.1.
Light yellow needle crystal, yield 86%, m.p. 204-206 °C,
IR (ꢀmax, KBr, cm-1): 3307.65 (NH), 1661.58 (NHC=O),
1283.67 (C=S); H NMR (600 MHz, DMSO-d6): ꢁH = 12.77
(s, 1H), 11.44(s, 1H), 8.14(d, J = 9.0 Hz, 1H), 8.02 (d, J =
7.8 Hz, 1H), 7.94 (d, J = 7.8 Hz, 1H), 7.82 (t, J = 7.8 Hz,
1H), 7.69 (t, J = 7.8 Hz, 1H), 7.58 (t, J = 8.1 Hz, 1H),7.31 (d,
J = 8.4 Hz, 1H), 7.18 (t, J = 7.8 Hz, 1H), 4.01 (s, 3H); MS
(ESI) m/z 354.2 (M+Na)+, calcd. for C15H13N3O4S m/z =
331.1; Anal. Calcd for C15H13N3O4S: C, 54.37; H, 3.95; N,
12.68. Found: C, 54.21; H, 3.82; N, 12.84.
1
Compd. 5i 1-(2-Methoxybenzoyl)-3-(3-trifluoromethyl-
phenyl)thiourea
Compd. 5l 1-(4-Fluorophenyl)-3-(2-methoxybenzoyl)-
thiourea.
White needle crystal, yield 92%, m.p. 158-160 °C, IR
(ꢀmax, KBr, cm-1): 3292.98 (NH), 1661.58 (NHC=O),
1250.80 (C=S); H NMR (400 MHz, DMSO-d6): ꢁH = 12.60
(s, 1H), 11.33(s, 1H), 8.20(s, 1H), 7.89(t, J = 8.0Hz, 2H),
7.65 (t, J = 6.0 Hz, 3H), 7.28 (d, J = 8.4 Hz, 1H), 7.16 (s,
1H), 4.00 (s, 3H); 13C NMR (100 MHz, DMSO-d6): ꢁ =
168.37, 161.14, 150.46, 136.39, 134.82, 133.34, 130.54,
127.37, 126.52, 125.88, 124.24, 121.15, 117.67, 115.83,
51.76; MS (ESI) m/z 354.9 (M+H)+, calcd. for
C16H13F3N2O2S m/z = 354.1.
1
White crystal, yield 87%, m.p. 167-168 °C, IR (ꢀmax,
KBr, cm-1): 3325.25 (NH), 1658.65 (NHC=O), 1233.19
(C=S); H NMR (400 MHz, DMSO-d6): ꢁH = 12.42 (s, 1H),
1
11.25(s, 1H), 7.92(d, J = 8.0Hz, 1H), 7.68 (m, J = 4.0 Hz,
3H), 7.29 (t, J = 8.0 Hz, 3H), 7.17 (t, J = 8.0 Hz, 1H), 4.01
(s, 3H); MS (ESI) m/z 305.2 (M+H)+, calcd. for
C15H13FN2O2S m/z = 304.1.
Compd. 5m N,N'-(1,2-phenylenebis(azanediyl))bis(thio-
xomethylene)bis(2-((6-chloropyridin-3-yl)methoxy)benza-
mide).
Compd. 5j 1-(2-Methoxybenzoyl)-3-(3-nitrophenyl)thi-
ourea
White needle crystal, yield 85%, m.p. 216-218 °C, IR
(ꢀmax, KBr, cm-1): 3278.31(NH), 1661.58 (NHC=O), 1286.01
(C=S); H NMR (400 MHz, DMSO-d6): ꢁH = 12.67 (s, 1H),
Light yellow powder, yield 87%, m.p. 183.3-184.5 °C, IR
(ꢀmax, KBr, cm-1): 3318.69 (NH), 1670.09 (NHC=O),
1288.79 (C=S); H NMR (400 MHz, DMSO-d6): ꢁH = 12.36
1
1

102 Letters in Drug Design & Discovery, 2014, Vol. 11, No. 1
Li et al.
(s, 2H), 11.26 (s, 2H) , 8.54 (s, 2H), 8.11 (d, J = 8.4 Hz, 2H),
7.93 (d, J = 3.6 Hz, 2H), 7.65 (m, J = 7.6 Hz, 4H), 7.46 (d, J
= 8.4 Hz, 2H), 7.36 (t, J = 7.6 Hz, 4H), 7.07 (t, J = 7.6 Hz,
2H), 5.29 (s, 4H); 13C NMR (100 MHz, DMSO-d6): ꢁ =
169.84, 161.35, 157.67, 152.23, 145.47, 140.17, 139.78,
135.32, 130.44, 129.72, 125.65, 123.93, 123.14, 121.46,
115.48, 110.34, 69.72; MS (ESI) m/z 718.1 (M+H)+, calcd.
for C34H26Cl2N6O4S2 m/z = 717.6; Anal. Calcd for
C34H26Cl2N6O4S2: C, 56.90; H, 3.65; N, 11.71. Found: C,
56.73; H, 3.57; N, 11.83.
ACKNOWLEDGEMENTS
We gratefully acknowledge the support of this work by
the National Natural Science Foundation of China
(31101467) and the National Undergraduate Innovational
Experimentation Program (201210504018).
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CONFLICT OF INTEREST
The authors confirm that this article content has no con-
flict of interest.

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Received: April 25, 2013
Revised: July 02, 2013
Accepted: July 19, 2013