Design, synthesis, antiproliferative and antibacterial evaluation of quinazolinone derivatives

Article abstract of DOI:10.1007/s00044-018-2276-8

A series of novel quinazolinone derivatives bearing a disulfide bond were designed and synthesized. Their in vitro antiproliferative activities were evaluated using CCK-8 assay against SMMC-7721, Hela, A549 and MCF-7 human cancer cell lines and normal cell lines L929. The preliminary bioassay results demonstrated that all compounds 7a–7h, 8a–8h and 9a–9h exhibited antiproliferation with various degrees, and some compounds showed better effects than positive control 5-fluorouracil against different cancer cell lines. Among these compounds, 8c and 9f showed significant antiproliferative activity against SMMC-7721 cells with IC₅₀ values of 2.88 and 2.56 μM, respectively. In Hela cells, compounds 9c and 9d showed highly effective biological activity with IC₅₀ values of 3.16 and 2.68 μM, respectively. Compounds 7a and 9a exhibited good inhibitory effect against A549 cells with IC₅₀ values of 3.53 and 3.54 μM, respectively. In MCF-7 cells, compounds 7e, 8e and 9e displayed excellent activity with IC₅₀ values of 1.26, 1.12 and 1.85 μM, respectively. Besides, most of the tested compounds showed low cytotoxic effect against the normal cell lines L929. Biological evaluation indicated that all the tested compounds possessed antibacterial activity with certain degrees.

Full text of DOI:10.1007/s00044-018-2276-8

MEDICINAL
CHEMISTRY
RESEARCH
Medicinal Chemistry Research
https://doi.org/10.1007/s00044-018-2276-8
ORIGINAL RESEARCH
Design, synthesis, antiproliferative and antibacterial evaluation of
quinazolinone derivatives
Hai-Xin Wang1 Hai-Ying Liu Wei Li Shuai Zhang Zheng Wu Xin Li Cai-Wen Li Yu-Ming Liu
1 ●
1 ●
1 ●
1 ●
1 ●
1 ●
1 ●
●
1
Bao-Quan Chen
Received: 20 September 2018 / Accepted: 8 December 2018
©
Springer Science+Business Media, LLC, part of Springer Nature 2019
Abstract
A series of novel quinazolinone derivatives bearing a disulfide bond were designed and synthesized. Their in vitro
antiproliferative activities were evaluated using CCK-8 assay against SMMC-7721, Hela, A549 and MCF-7 human cancer
cell lines and normal cell lines L929. The preliminary bioassay results demonstrated that all compounds 7a–7h, 8a–8h and
9
a–9h exhibited antiproliferation with various degrees, and some compounds showed better effects than positive control 5-
fluorouracil against different cancer cell lines. Among these compounds, 8c and 9f showed significant antiproliferative
activity against SMMC-7721 cells with IC50 values of 2.88 and 2.56 μM, respectively. In Hela cells, compounds 9c and 9d
showed highly effective biological activity with IC50 values of 3.16 and 2.68 μM, respectively. Compounds 7a and 9a
exhibited good inhibitory effect against A549 cells with IC50 values of 3.53 and 3.54 μM, respectively. In MCF-7 cells,
compounds 7e, 8e and 9e displayed excellent activity with IC50 values of 1.26, 1.12 and 1.85 μM, respectively. Besides,
most of the tested compounds showed low cytotoxic effect against the normal cell lines L929. Biological evaluation
indicated that all the tested compounds possessed antibacterial activity with certain degrees.
●
●
Keywords Quinazolinone Disulfides Antiproliferative and antibacterial activities
Introduction
et al. 2017). Quinazolinone derivatives constitute an
important class of biologically active compounds (Pouda-
pally et al. 2017). The quinazolinone core is found in both
natural products and in pharmaceuticals, representing a
privileged scaffold given the range of activities such as
antidiabetic (Wei et al. 2017), antibacterial (Pandey et al.
2009; Wang et al. 2014), antiinflammatory (Abdel-Aziz
et al. 2016; Nanthakumar et al. 2014), anticoagulant (Xing
et al. 2017), antioxidant (Mohamed and Rao 2017;
Haghighijoo et al. 2017), antiproliferative (Xuan et al. 2015;
Venkatesh et al. 2016), anticonvulsant (Amir et al. 2014;
Al-Salem et al. 2015), antifibrotic (Marzaro et al. 2016) and
antituberculosis (Lu et al. 2015). The potent anticancer
activities of luotonin and camptothecin family natural
alkaloids have drawn extreme interest worldwide (Fig. 1).
Their parent representative 2-substituted-quinazolin-4(3H)-
one analog acts as an excellent lead drug in anticancer
research.
Cancer is one of the major causes of death, and one of the
main reasons to which high mortality can be attributed is the
failure of the current treatment options (Vale et al. 2017).
Despite significant progress has been achieved in anticancer
therapy, the management of malignancies in humans still
constitutes one of the most intractable worldwide health
problems. Therefore, it is important to identify effective
drugs and new targets for the treatment of cancer (Alegaon
Supplementary information The online version of this article (https://
doi.org/10.1007/s00044-018-2276-8) contains supplementary
material, which is available to authorized users.
*
*
Cai-Wen Li
lcwlcw66@sina.com
Bao-Quan Chen
Meanwhile, disulfide derivatives are also known to dis-
play a wide spectrum of biological activities because the
disulfide group makes up the core structure of numerous
biologically active compounds with many types of biolo-
gical activities including antibacterial (Turos et al. 2008),
chenbaoquan66@126.com
1
Tianjin Key Laboratory of Organic Solar Cells and Photochemical
Conversion, School of Chemistry and Chemical Engineering,
Tianjin University of Technology, 300384 Tianjin, China

Medicinal Chemistry Research
active compounds at various concentrations was measured,
and their IC50 (the concentration that causes a 50% cell
proliferation inhibition) values were calculated and are
summarized in Table 1. Moreover, antimicrobial activities
of all compounds were evaluated against Escherichia coli
and Staphylococcus aureus strains. The results are pre-
sented in Table 2.
Fig. 1 Chemical structures of luotonin A and camptothecin
Antiproliferative activity
antitumor (Yi and Su 2013; Gaowa et al. 2015), antioxidant
As shown in Table 1, the tested compounds 7a–7h, 8a–8h
and 9a–9h exhibited antiproliferation with different
degrees, and some compounds showed better effects than
positive control 5-fluorouracil against various cancer cell
lines. This class of the compounds exhibited antiprolifera-
tion against SMMC-7721 cells with IC50 values range from
2.56 to 33.72 μM. As compared with compound 7a, which
(
Lakes et al. 2013), and anti-SARS (Wang et al. 2017).
Consequently, the importance of disulfide derivatives in the
field of medicinal chemistry has received much attention in
the past few decades (Fig. 2).
These mentioned facts encouraged us to carry on our
investigation on quinazolinone derivatives bearing a dis-
ulfide bond, in the pursuit of novel compounds with anti-
proliferative activity having the potential of becoming new
drugs. On the other hand, treatment of bacterial infections
still remains an important and challenging therapeutic pro-
blem, due to the emergence of bacterial resistance to current
therapeutic agents. We are also interested in exploring if
these new compounds have antibacterial activity.
has no substituent at the phenyl ring while R is 2-butyl
1
group, except compound 7f, the other compounds showed
reduced antiproliferative activities. Compound 7f electron-
donating group substituted showed high activity with an
IC50 value of 3.04 μM. As compared with compound 8a,
which has no substituent at the phenyl ring while R is n-
1
butyl group, compound 8c electron-donating group sub-
stituted displayed better activity with an IC50 value of 2.88
μM. As compared with compound 9a, which has no sub-
Results and discussion
stituent at the phenyl ring while R is i-butyl group, except
1
compound 9f, the other compounds showed reduced anti-
proliferative activities. Compound 9f electron-donating
group substituted showed significant activity with an IC50
Chemistry
As depicted in Scheme 1, the preparation method of S-alkyl-
thioisothiourea hydrochloride 3 was obtained from a
reported method (Sirakawa et al. 1970). Compound 5 was
prepared from compound 4 using a reported synthetic route
value of 2.56 μM. Especially, while R is the same sub-
1
stituent, electron-donating group substituted derivatives,
including 7f, 8c and 9f, displayed better activities than other
compounds. In Hela cells, compounds 9c and 9d carrying 4-
(
6
Hroch et al. 2017; Mandapati et al. 2017). Intermediates
a–6h were obtained by a reported literature method.
methyl and 4-trifluoromethyl substituents, while R is i-
1
butyl group, displayed highly effective biological activities
with IC50 values of 3.16 and 2.68 μM, respectively. With
the exception of compounds 9c and 9d, the other com-
pounds exhibited better-to-moderate antiproliferative activ-
ities with IC50 values ranging from 4.06 to 29.32 μM. As
compared with compound 7a, which has no substituent at
Finally, the target compounds 7a–7h, 8a–8h and 9a–9h
were obtained by the reaction of compound 3 and inter-
mediates 6a–6h in the presence of NaHCO in methanol and
water at room temperature. All new synthesized compounds
7
3
a–7h, 8a–8h and 9a–9h were purified by silica gel column
chromatography and their structures were characterized by
IR, H NMR, C NMR and high resolution-electrospray
ionization mass spectrometer (HR-ESI-MS).
the phenyl ring while R is 2-butyl group, the other com-
pounds showed enhanced antiproliferative activities. As
compared with compound 8a, which has no substituent at
1
1
13
the phenyl ring while R is n-butyl group, except compound
1
Pharmacology and discussion
8e, the other compounds showed enhanced antiproliferative
activities. As compared with compound 9a, which has no
The synthesized compounds were evaluated for their
in vitro antiproliferative activity against SMMC-7721, Hela,
A549 and MCF-7 human cancer cell lines and L929 normal
cell lines by CCK-8[2-(2-methoxy-4-nitrophenyl)-3-(4-
nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium mono-
sodium salt] assay. Inhibition of cell proliferation by these
substituent at the phenyl ring while R is i-butyl group,
1
except compounds 9e, 9g and 9h, the other compounds
showed enhanced antiproliferative activities. The electronic
effects of substituents at the phenyl ring on antiproliferative
activity against Hela cells did not show apparent regularity.
Especially, while R is the same substituent, 2-butyl group
2

Medicinal Chemistry Research
Fig. 2 IC50 of compounds 7a–7h, 8a–8h and 9a–9h against SMMC-7721, Hela, A549, MCF-7 and L929 cells
derivatives displayed higher activities than n-butyl group
derivatives. In A549 cells, the majority of compounds
exhibited moderate antiproliferative activity. Among them,
compounds 7a and 9a, which have no substituent at the
revealed high antitumor activities with IC50 values of 3.53
and 3.54 μM, respectively. Especially, while compounds
has no substituent at the phenyl ring displayed higher
activities than other compounds. In MCF-7 cells,
most compounds showed better effects than positive control
phenyl ring while R are 2-butyl groups and i-butyl groups,
1

Medicinal Chemistry Research
Scheme 1 Synthesis of target
compounds 7a–7h, 8a–8h and
9
a–9h
5
-fluorouracil. While compounds with no substituent at the
degrees, but none of them showed better effects than the
positive control gentamicin against Gram-negative bacteria
E. coli and Gram-positive bacteria S. aureus. The results
obtained on Gram-negative bacteria E. coli showed that
compounds 7d, 7f–7h, 8e, 8h, 9b–9d and 9g exhibited
same activities with a minimum inhibitory concentration
(MIC) value of 64 µg/mL. The results obtained on Gram-
positive bacteria S. aureus showed that compounds 7a–7b,
7d, 7f, 7h, 8d, 8f–8h and 9e–9h displayed same activities
against S. aureus with an MIC value of 64 µg/mL. Espe-
cially noteworthy is that the compounds 7e and 8a showed a
promising antibacterial activity against E. coli and S. aureus
with an MIC value of 32 µg/mL. Other compounds showed
moderate activities with a same MIC value of 128 µg/mL.
phenyl ring displayed lower activities than other com-
pounds. Among these compounds, all carrying an electron-
drawing group substituted derivatives revealed higher
activities than the electron-donating group substituted
derivatives. Especially, while R is the same substituent, 4-
2
nitro substituted derivatives 7e, 8e and 9e displayed higher
activities with IC50 values of 1.12, 1.12 and 1.85 μM,
respectively, than other compounds. Furthermore, most of
the compounds 7a–7h, 8a–8h and 9a–9h exhibited a weak
cytotoxic activity against L929 cells, and all compounds
showed highly lower cytotoxic effect than 5-fluorouracil.
These results indicated that no matter R is a 2-butyl, n-
1
butyl or i-butyl group, the electronic effects of the sub-
stituents at the phenyl ring on the antiproliferative activity
against SMMC-7721, Hela, A549 and MCF-7 cells did not
show apparent regularity. Therefore, it is necessary that the
further investigation is carried out through structural trans-
formation for improving the potency and selectivity of this
class of compounds.
Conclusion
In summary, 24 novel quinazolinone derivatives bearing a
disulfide bond were designed and synthesized and gave
satisfactory analytical and spectroscopic data, which were in
full accordance with their depicted structures. All of the
synthetic compounds were evaluated for their in vitro
antiproliferative activities against SMMC-7721, Hela, A549
and MCF-7 human cancer cell lines by CCK-8 assay. In
Antibacterial activity
As shown in Table 2, all the tested compounds 7a–7h, 8a–
8
h and 9a–9h exhibited antibacterial activity with different

Medicinal Chemistry Research
Table 1 In vitro antiproliferative
activities of target compounds
against various cell lines
a
Compound
IC50 (μM)
SMMC-7721
Hela
A549
MCF-7
L929
7
7
7
7
7
7
7
7
8
8
8
8
8
8
8
8
9
9
9
9
9
9
9
9
5
a
b
c
3.18 ± 0.12
17.20 ± 0.74
17.20 ± 0.48
15.44 ± 0.67
30.52 ± 1.72
3.04 ± 0.15
20.72 ± 1.12
17.60 ± 1.18
15.60 ± 0.66
26.48 ± 0.97
2.88 ± 0.09
13.68 ± 0.45
20.84 ± 0.89
20.44 ± 1.21
15.84 ± 0.78
33.72 ± 2.15
6.32 ± 0.28
20.08 ± 0.59
13.20 ± 0.57
11.84 ± 0.33
9.20 ± 0.32
2.56 ± 0.17
8.56 ± 0.34
13.20 ± 0.40
5.62 ± 0.28
29.32 ± 3.11
5.80 ± 0.27
4.67 ± 0.22
4.06 ± 0.16
8.92 ± 0.43
4.92 ± 0.21
24.20 ± 0.99
22.84 ± 0.86
26.84 ± 1.67
11.80 ± 0.33
22.44 ± 0.85
6.68 ± 0.35
32.20 ± 1.58
23.32 ± 0.86
26.60 ± 2.12
25.48 ± 1.01
25.24 ± 1.22
6.20 ± 0.31
3.16 ± 0.12
2.68 ± 0.08
27.21 ± 1.43
23.72 ± 0.97
26.84 ± 1.03
26.44 ± 1.25
17.21 ± 0.27
3.53 ± 0.38
24.72 ± 0.91
28.72 ± 1.37
20.72 ± 0.98
41.32 ± 2.32
20.72 ± 0.77
31.53 ± 1.66
24.72 ± 1.36
5.12 ± 0.66
23.92 ± 0.87
32.72 ± 1.63
41.71 ± 2.78
5.53 ± 0.43
25.72 ± 1.41
34.33 ± 1.87
28.92 ± 1.55
3.54 ± 0.17
25.53 ± 1.09
6.54 ± 0.39
39.71 ± 2.06
13.12 ± 0.41
31.91 ± 1.69
36.33 ± 2.31
37.13 ± 2.11
8.13 ± 0.37
25.66 ± 0.96
4.60 ± 0.38
20.59 ± 0.87
3.30 ± 0.56
1.26 ± 0.08
12.16 ± 0.58
3.18 ± 0.36
6.16 ± 0.56
14.53 ± 0.78
2.96 ± 0.47
8.65 ± 0.87
3.37 ± 0.39
1.12 ± 0.10
5.26 ± 0.71
3.48 ± 0.32
6.42 ± 0.62
28.84 ± 1.68
8.35 ± 0.61
9.85 ± 1.02
5.33 ± 0.72
1.85 ± 0.33
10.45 ± 0.85
3.35 ± 0.68
12.43 ± 0.32
14.26 ± 0.66
>50
29.60 ± 1.68
28.76 ± 2.17
18.23 ± 1.13
>50
d
e
f
22.17 ± 1.24
30.48 ± 1.76
24.22 ± 1.66
18.58 ± 0.96
23.44 ± 0.95
29.69 ± 1.37
>50
g
h
a
b
c
d
e
28.33 ± 2.32
26.89 ± 1.77
22.08 ± 0.69
35.88 ± 2.37
27.84 ± 1.55
20.36 ± 1.22
16.43 ± 0.56
>50
f
g
h
a
b
c
d
e
15.69 ± 0.68
22.96 ± 0.92
38.11 ± 2.08
26.40 ± 1.59
2.98 ± 0.15
f
g
h
-FUb
aThe concentration that causes a 50% cell proliferation inhibition
bUsed as a positive control
particularly, compounds 8c and 9f showed significant
antiproliferative activity against SMMC-7721 cells with
IC50 values of 2.88 and 2.56 μM, respectively. In Hela cells,
compounds 9c and 9d showed highly effective biological
activity against with IC50 values of 3.16 and 2.68 μM,
respectively. In A549 cells, compounds 7a and 9a exhibited
good inhibitory effect with IC50 values of 3.53 and 3.54 μM,
respectively. In MCF-7 cells, compounds 7e, 8e and 9e
displayed excellent activity with IC50 values of 1.26, 1.12
and 1.85 μM, respectively. In addition, many of the tested
compounds showed low cytotoxic effect against the normal
cell lines L929. Therefore, the results will be significant in
the development of potent antitumor agents. Otherwise,
biological evaluation indicated that all the tested com-
pounds possessed antibacterial activity with certain degrees.
Therefore, the results will be significant in the development
of potent antitumor agents. Meanwhile, all the compounds
effects on the growth of the bacterial E. coli strains and S.
aureus strains.
Experimental
Chemistry
Reactions were monitored by TLC performed on glass
packed silica gel GF254 plates. Melting points were deter-
mined by an X-6 microscope melting point apparatus and
are uncorrected. Infrared spectra were recorded in KBr
1
pellets on a Nicolet Avatar 370 spectrometer. H NMR and
1
3
C NMR spectra were collected at resonance frequencies of
400 MHz and 100 MHz, respectively. NMR spectra were
performed on a Bruker Avance III 400 MHz spectrometer
using DMSO-d as a solvent and tetramethylsilane as an
6
1
7
a–7h, 8a–8h and 9a–9h exhibited variable inhibitory
internal standard. The chemical shifts for H NMR are

Medicinal Chemistry Research
Table 2 In vitro antibacterial activities of compounds 6a–6h, 7a–7h
and 8a–8h against two bacterial strains
ml of absolute ethanol containing triethylamine (11 mmol)
was heated under reflux for 6 h. The reaction mixture was
filtered while hot, the solvent was removed under reduced
pressure and the solid obtained was dried and recrystallized
from ethanol.
Compound
Gram-negative bacteria
Gram-positive bacteria
Staphylococcus aureus
MIC (µg/mL)
Escherichia coli
a
MIC (µg/mL)
7
7
7
7
7
7
7
7
8
8
8
8
8
8
8
8
9
9
9
9
9
9
9
9
a
b
c
128
128
128
64
64
2
-Sulfhydryl-3-phenyl-quinazolin-4(3H)-one (6a)
64
128
64
White solid; yield 48.6%; m.p.: 296.5–298.7 °C; IR (KBr)
cm : 2516, 1662, 1531, 1453, 988; H NMR (400 MHz,
DMSO-d ) δ (ppm): 7.28 (d, J = 8.0 Hz, 2H, Ar–H), 7.34–
7
d
e
–1
1
32
32
6
f
64
64
.50 (m, 6H, Ar–H), 7.80 (t, J = 8.0 Hz, 1H, Ar–H), 7.96
g
h
a
b
c
64
128
64
(d, J = 8.0 Hz, 1H, Ar–H), 13.07 (s, 1H, SH); MS-ESI (m/
64
+
z): C H N OS [M+H] 255.1.
1
4
10
2
32
32
128
128
128
64
128
128
64
2
-Sulfhydryl-3-(4-chlorophenyl)-quinazolin-4(3H)-one (6b)
d
e
White solid; Yield 55.4%; m.p.: 286.5–288.3 °C; IR (KBr)
cm : 2516, 1662, 1531, 1453, 988; H NMR (400 MHz,
DMSO-d ) δ (ppm): 7.36 (t, J = 8.0 Hz, 3H, Ar–H), 7.45 (d,
J = 8.0 Hz, 1H, Ar–H), 7.55 (d, J = 8.0 Hz, 2H, Ar–H),
7.80 (t, J = 8.0 Hz, 1H, Ar–H), 7.96 (d, J = 8.0 Hz, 1H, Ar–
H), 13.10 (s, 1H, SH); MS-ESI (m/z): C H ClN OS [M
–1
1
128
64
f
128
128
64
6
g
h
a
b
c
64
64
128
64
128
128
128
128
64
1
4
9
2
+
+H] 289.0.
-Sulfhydryl-3-(4-methylphenyl)-quinazolin-4(3H)-one (6c)
White solid; yield 62.1%; m.p.: 306.5–307.1 °C; IR (KBr)
64
2
d
e
64
128
128
64
f
64
–1
1
cm : 2966, 2516, 1662, 1531, 1453, 988; H NMR (400
MHz, DMSO-d ) δ (ppm): 2.38 (s, 3H, CH ), 7.14 (d, J =
8.0 Hz, 2H, Ar–H), 7.28 (d, J = 12.0 Hz, H, Ar–H), 7.35 (t,
J = 8.0 Hz, 1H, Ar–H), 7.45 (d, J = 8.0 Hz, 1H, Ar–H),
7
g
h
64
6
3
128
2
64
Gentamicinb
2
aMinimum inhibitory concentration
bUsed as a positive control
.79 (t, J = 8.0 Hz, 1H,Ar–H), 7.95 (d, J = 8.0 Hz, 1H, Ar–
H), 13.04 (s, 1H, SH); MS-ESI (m/z): C H N OS [M+H]
1
5
12
2
+
270.1.
reported in ppm from tetramethylsilane (0 ppm) or refer-
2-Sulfhydryl-3-(4-trifluoromethylphenyl)-quinazolin-4(3H)-
enced to the solvent (DMSO-d 2.50) on the δ scale. Che-
one (6d)
6
mical shifts (δ) for 13C NMR spectra are referenced to the
signals for residual deuterated solvents (DMSO-d 39.5).
Multiplicities are reported by the following abbreviations: s
White solid; yield 56.3%; m.p.: 276.5–277.7 °C; IR (KBr)
cm : 2966, 2516, 1662, 1531, 1453, 988; H NMR (400
6
–1
1
(
singlet), d (doublet), t (triplet), m (multiplet), J (coupling
MHz, DMSO-d ) δ (ppm): 7.37 (t, J = 8.0 Hz, 1H, Ar–H),
6
constants in hertz). High-resolution mass data were taken
with a Waters Xevo G2 QT of mass spectrometer. The
products were purified by flash column chromatography
using silica gel (200–300 mesh) with indicated solvents.
7.47 (d, J = 8.0 Hz, 1H, Ar–H), 7.59 (d, J = 8.0 Hz, 2H,
Ar–H), 7.81 (t, J = 8.0 Hz, 1H, Ar–H), 7.88 (d, J = 8.0 Hz,
2H, Ar–H), 7.97 (d, J = 8.0 Hz, 1H, Ar–H), 13.15 (s, 1H,
+
SH); MS-ESI (m/z): C H F N O S [M+H] 323.0.
1
5
9
3
2
3
General procedure for the synthesis of
2-Sulfhydryl-3-(4-nitrophenyl)-quinazolin-4(3H)-one (6e)
intermediates 6a–6h
White solid; yield 45.8%; m.p.: 316.5–317.5 °C; IR (KBr)
cm : 2516, 1662, 1531, 1453, 988; H NMR (400 MHz,
–1
1
A mixture of substituted anthranilic acid (10 mmol) and
(
substituted-phenyl)-phenylisothiocyanate (10 mmol) in 30
DMSO-d ) δ (ppm): 7.38 (t, J = 8.0 Hz, 1H, Ar–H), 7.47 (d,
6

Medicinal Chemistry Research
J = 8.0 Hz, 1H, Ar–H), 7.67 (d, J = 8.0 Hz, 2H, Ar–H),
2-(2-Butyldisulfanyl)-3-phenyl-quinazolin-4(3H)-one (7a)
7
.82 (t, J = 8.0 Hz, 1H, Ar–H), 7.98 (d, J = 8.0 Hz, 1H, Ar–
1
H), 8.36 (d, J = 8.0 Hz, 2H, Ar–H), 13.19 (s, 1H, SH); MS-
ESI (m/z): C H N OS [M+H] 300.0.
White solid; yield 53.6%; m.p.: 124.3–125.6 °C; H NMR
+
(400 MHz, DMSO-d ) δ (ppm): 1.01 (t, J = 8.0 Hz, 3H,
1
4
9
3
6
CH ), 1.27 (d, J = 8.0 Hz, 3H, CH ), 1.49–1.68 (m, 2H,
3
3
2
-Sulfhydryl-3-(4-methoxyphenyl)-quinazolin-4(3H)-one (6f)
CH ), 3.08–3.16 (m, 1H, CH), 7.52–7.55 (m, 3H, Ar–H),
2
7.58–7.61 (m, 3H, Ar–H), 7.68 (d, J = 8.0 Hz, 1H, Ar–H),
White solid; yield 65.9%; m.p.: 301.8–302.9 °C; IR (KBr)
cm : 2966, 2516, 1662, 1531, 1453, 988; H NMR (400
7.88 (t, J = 8.0 Hz, 1H, Ar–H), 8.11 (d, J = 8.0 Hz, 1H, Ar–
–1
1
13
H); C NMR (100 MHz, DMSO-d ) δ (ppm): 11.72, 20.36,
6
MHz, DMSO-d ) δ (ppm): 3.36 (s, 3H, CH ), 7.01 (d, J =
28.84, 48.25, 120.38, 126.84, 126.98, 127.14, 130.01 (2C),
130.05 (2C), 130.61, 135.47, 136.10, 147.61, 156.22,
6
3
8
.0 Hz, 2H, Ar–H), 7.18 (d, J = 8.0 Hz, 2H, Ar–H), 7.35 (t,
J = 8.0 Hz, 1H, Ar–H), 7.45 (d, J = 8.0 Hz, 1H, Ar–H),
.78 (t, J = 4.0 Hz, 1H, Ar–H), 7.95 (d, J = 8.0 Hz, 1H, Ar–
H), 13.02 (s, 1H, SH); MS-ESI (m/z): C H N O S
–1
–1
161.27; IR (KBr, cm ): 1687, 1576, 1552, 769, 500 cm ;
HR-MS (ESI): m/z 343.0957 [M+H]+ (calcd. for
C H N OS : 343.0939).
7
15
12
2
2
18 19
2
2
+
[
M+H] 285.1
2-(2-Butyldisulfanyl)-3-(4-chlorophenyl)-quinazolin-4(3H)-
2
-Sulfhydryl-3-(3-chlorophenyl)-quinazolin-4(3H)-one (6g)
one (7b)
1
White solid; yield 63.7%; m.p.: 289.3–290.6 °C; IR (KBr)
cm : 2516, 1662, 1531, 1453, 988; H NMR (400 MHz,
White solid; yield 47.3%; m.p.: 142.2–143.6 °C; H NMR
–1
1
(400 MHz, DMSO-d ) δ (ppm): 1.01 (t, J = 8.0 Hz, 3H,
6
DMSO-d ) δ (ppm): 7.31 (d, J = 8.0 Hz, 1H, Ar–H), 7.36
CH ), 1.27 (d, J = 8.0 Hz, 3H, CH ), 1.49–1.68 (m, 2H,
6
3
3
(
(
t, J = 8.0 Hz, 1H, Ar–H), 7.45–7.50 (m, 4H, Ar–H), 7.80
t, J = 8.0 Hz, 1H, Ar–H), 7.96 (d, J = 4.0 Hz, 1H, Ar–H),
CH ), 3.08–3.17 (m, 1H, CH), 7.53 (t, J = 8.0 Hz, 1H, Ar–
H), 7.61 (d, J = 8.0 Hz, 2H, Ar–H), 7.68 (d, J = 8.0 Hz, 3H,
2
1
3.11 (s, 1H, SH); MS-ESI (m/z): C H ClN OS [M+H]
2
Ar–H), 7.88 (t, J = 8.0 Hz, 1H, Ar–H) 8.10 (d, J = 8.0 Hz,
14
9
2
+
13
89.0.
-Sulfhydryl-3-(3-methylphenyl)-quinazolin-4(3H)-one (6h)
White solid; yield 57.1%; m.p.: 275.6–277.4 °C; IR (KBr)
1H, Ar–H); C NMR (100 MHz, DMSO-d ) δ (ppm):
6
11.73, 20.36, 28.83, 48.31, 120.32, 126.86, 127.06, 127.15,
2
130.18 (2C), 132.03 (2C), 135.01, 135.40, 135.57, 147.57,
–
1
1
55.84, 161.29; IR (KBr, cm ): 1694, 1577, 1556, 771,
–1
+
509 cm ; HR-MS (ESI): m/z 377.0563 [M+H] (calcd. for
–1
1
cm : 2966, 2516, 1662, 1531, 1453, 988; H NMR (400
C H N OS Cl: 377.0549).
1
8
18
2
2
MHz, DMSO-d ) δ (ppm): 2.35 (s, 3H, CH ), 7.09 (s, 2H,
6
3
Ar–H), 7.22 (d, J = 4.0 Hz, H, Ar–H), 7.36 (s, 2H, Ar–H),
.45(d, J = 8.0 Hz, 1H, Ar–H), 7.79 (t, J = 8.0 Hz, 1H, Ar–
2-(2-Butyldisulfanyl)-3-(4-methylphenyl)-quinazolin-4(3H)-
one (7c)
7
H), 7.95 (d, J = 8.0 Hz, 1H, Ar–H), 13.04 (s, 1H, SH); MS-
+
1
ESI (m/z): C H N OS [M+H] 270.0.
White solid; yield 63.9%; m.p.: 123.3–124.8 °C; H NMR
1
5
12
2
(
400 MHz, DMSO-d ) δ (ppm): 1.01 (t, J = 8.0 Hz, 3H,
6
General procedure for the synthesis of compounds
a–7h, 8a–8h and 9a–9h
CH ), 1.26 (d, J = 8.0 Hz, 3H, CH ), 1.49–1.65 (m, 2H,
CH ), 2.42 (s, 3H, CH ), 3.07–3.15 (m, 1H, CH), 7.39 (s,
2 3
3
3
7
4H, Ar–H), 7.53 (t, J = 8.0 Hz, 1H, Ar–H), 7.67 (d, J = 8.0
S-Alkyl-thioisothiourea hydrochloride 2 (2.2 mmol) and 2-
sulfhydryl-3-(4-substituted-phenyl)-quinazolin-4(3H)-one
Hz, 1H, Ar–H), 7.87 (t, J = 8.0 Hz, 1H, Ar–H), 8.10 (d, J =
1
3
8.0 Hz, 1H, Ar–H); C NMR (100 MHz, DMSO-d ) δ
6
6
a–6h (2.0 mmol) were dissolved in 5 mL of water and 15
(ppm): 11.73, 20.37, 28.84, 48.17, 55.96, 115.19, 120.34,
126.82, 126.92, 127.15, 128.41 (2C), 131.25 (2C), 135.43,
mL of ethanol. A solution of NaHCO (3.0 mmol) in 4 mL
3
–
1
of water was added dropwise with vigorous stirring at room
temperature. The mixture was stirred for additional 6 h. The
insoluble solid was collected and purified by silica gel
column chromatography with petroleum ether/ethyl acetate
147.63, 156.87, 160.74, 161.50; IR (KBr, cm ): 1688,
–
1
1576, 1553, 769, 516 cm ; HR-MS (ESI): m/z 357.1113
+
[M+H] (calcd. for C H N OS : 357.1095).
1
9
21
2
2
(
10: 1, volume ratio) as an eluent to afford the desired
2-(2-Butyldisulfanyl)-3-(4-trifluoromethylphenyl)-
quinazolin-4(3H)-one (7d)
products. The newly synthesized compounds 7a–7h, 8a–8h
and 9a–9h were purified by silica gel column chromato-
graphy and their structures were characterized by IR, H
1
1
White solid; yield 43.9%; m.p.: 133.2–135.1 °C; H NMR
1
3
NMR, C NMR and HR-ESI-MS.
(400 MHz, DMSO-d ) δ (ppm): 1.01 (t, J = 8.0 Hz, 3H,
6

Medicinal Chemistry Research
CH ), 1.27 (d, J = 8.0 Hz, 3H, CH ), 1.49–1.68 (m, 2H,
7.61–7.69 (m, 3H, Ar–H), 7.79 (s, 1H, Ar–H), 7.88 (t, J =
3
3
13
CH ), 3.09–3.18 (m, 1H, CH), 7.54 (t, J = 8.0 Hz, 1H, Ar–
8.0 Hz, 1H, Ar–H) 8.10 (d, J = 8.0 Hz, 1H, Ar–H);
C
2
H), 7.69 (d, J = 8.0 Hz, 1H, Ar–H), 7.85 (d, J = 8.0 Hz, 2H,
Ar–H), 7.89 (t, J = 8.0 Hz, 1H, Ar–H), 8.00 (d, J = 8.0 Hz,
NMR (100 MHz, DMSO-d ) δ (ppm): 11.73, 20.36, 28.85,
6
48.34, 120.38, 126.87, 127.06, 127.15, 129.06, 130.17,
130.76, 131.61, 134.07, 135.57, 137.48, 147.56, 155.69,
13
1
H, Ar–H), 8.11 (d, J = 8.0 Hz, 1H, Ar–H); C NMR (100
–
1
–1
MHz, DMSO-d ) δ (ppm):11.71, 20.33, 28.83, 48.37,
161.22; IR (KBr, cm ): 1692, 1577, 1556, 768, 529 cm ;
HR-MS (ESI): m/z 377.0558 [M+H]+ (calcd. for
C H N OS Cl: 377.0549).
6
1
20.37, 124.31(J = 271.0 Hz), 126.90, 127.10, 127.17 (2C,
J = 5.0 Hz), 127.15, 130.91 (2C, J = 32.0 Hz), 131.35,
1
8
18
2
2
–
1
1
1
4
35.61, 139.90, 147.57, 155.34, 161.25; IR (KBr, cm ):
–
1
688, 1578, 1556, 770, 509 cm ; HR-MS (ESI): m/z
11.0835 [M+H] (calcd. for C H N OS F : 411.0813).
2-(2-Butyldisulfanyl)-3-(3-methylphenyl)-quinazolin-4(3H)-
one (7h)
+
19
18
2
2 3
1
2
-(2-Butyldisulfanyl)-3-(4-nitrophenyl)-quinazolin-4(3H)-
White solid; yield 49.1%; m.p.: 121–122.6 °C; H NMR
one (7e)
(400 MHz, DMSO-d ) δ (ppm): 1.00 (t, J = 4.0 Hz, 3H,
6
CH ), 1.25 (d, J = 8.0 Hz, 3H, CH ), 1.45–1.66 (m, 2H,
3
3
1
White solid; yield 65.2%; m.p.: 193.3–194.5 °C; H NMR
400 MHz, DMSO-d ) δ (ppm): 1.01 (t, J = 8.0 Hz, 3H,
CH ), 2.38 (s, 3H, CH ), 3.06–3.14 (m, 1H, CH), 7.31 (d,
2 3
(
J = 8.0 Hz, 2H, Ar–H), 7.39 (d, J = 8.0 Hz, 1H, Ar–H),
7.45–7.53 (m, 2H, Ar–H), 7.67 (d, J = 8.0 Hz, 1H, Ar–H),
7.86 (t, J = 8.0 Hz, 1H, Ar–H), 8.09 (d, J = 8.0 Hz, 1H, Ar–
6
CH ), 1.27 (d, J = 4.0 Hz, 3H, CH ), 1.50–1.68 (m, 2H,
CH ), 3.10–3.18 (m, 1H, CH), 7.55 (t, J = 8.0 Hz, 1H, Ar–
H), 7.70 (d, J = 8.0 Hz, 1H, Ar–H), 7.88–7.94 (m, 3H, Ar–
H), 8.12 (d, J = 8.0 Hz, 1H, Ar–H), 8.45 (d, J = 8.0 Hz, 2H,
Ar–H); C NMR (100 MHz, DMSO-d ) δ (ppm): 11.74,
0.38, 28.83, 48.43, 120.36, 125.28 (2C), 126.92, 127.16,
27.19, 131.92 (2C), 135.71, 141.91, 147.53, 148.83,
54.98, 161.19; IR (KBr, cm ): 1690, 1578, 1558, 778,
25 cm ; HR-MS (ESI): m/z 388.0806 [M+H] (calcd. for
3
3
2
1
3
H); C NMR (100 MHz, DMSO-d ) δ (ppm): 11.65, 20.28,
6
21.20, 28.82, 48.25, 120.20, 126.80, 126.85, 126.97,
127.08, 129.86, 130.10, 131.28, 135.44, 135.86, 139.76,
1
3
6
–
1
2
1
1
5
147.54, 156.24, 161.27; IR (KBr, cm ): 1695, 1577, 1556,
–
1
+
770, 536 cm ; HR-MS (ESI): m/z 357.1109 [M+H]
–
1
(calcd. for C H N OS : 357.1095).
1
9
21
2
2
–1
+
C H N O S : 388.0789).
2-(n-Butyldisulfanyl)-3-phenyl-quinazolin-4(3H)-one (8a)
1
8
18
3
3 2
1
2
-(2-Butyldisulfanyl)-3-(4-methoxyphenyl)-quinazolin-4
White solid; yield 50.4%; m.p.: 92.9–93.5 °C; H NMR
(
3H)-one (7f)
(400 MHz, DMSO-d ) δ (ppm): 0.87 (t, J = 8.0 Hz, 3H,
6
CH ), 1.38–1.47 (m, 2H, CH ), 1.57–1.64 (m, 2H, CH ),
3
2
2
1
White solid; yield 56.3%; m.p.: 130.2–131.6 °C; H NMR
400 MHz, DMSO-d ) δ (ppm): 1.01 (t, J = 4.0 Hz, 3H,
2.94 (t, J = 8.0 Hz, 2H, CH ), 7.51–7.60 (m, 6H, Ar–H),
2
(
7.70 (d, J = 8.0 Hz, 1H, Ar–H), 7.89 (t, J = 8.0 Hz, 1H, Ar–
6
1
3
CH ), 1.26 (d, J = 8.0 Hz, 3H, CH ), 1.48–1.67 (m, 2H,
H), 8.11 (d, J = 8.0 Hz, 1H, Ar–H); C NMR (100 MHz,
3
3
CH ), 3.06–3.15 (m, 1H, CH), 3.85 (s, 3H, CH ), 7.12 (d,
DMSO-d ) δ (ppm):13.92, 21.30, 30.56, 37.80, 120.38,
2
3
6
J = 12.0 Hz, 2H, Ar–H), 7.43 (d, J = 8.0 Hz, 2H, Ar–H),
.51 (t, J = 8.0 Hz, 1H, Ar–H), 7.66 (d, J = 8.0 Hz, 1H, Ar–
H), 7.86 (t, J = 8.0 Hz, 1H, Ar–H), 8.10 (d, J = 4.0 Hz, 1H,
126.89, 126.98, 127.13, 130.01 (2C), 130.04 (2C), 130.62,
–
1
7
135.45, 136.01, 147.68, 156.11, 161.25; IR (KBr, cm ):
–
1
1685, 1578, 1556, 768, 498 cm ; HR-MS (ESI): m/z
1
3
+
Ar–H); C NMR (100 MHz, DMSO-d ) δ (ppm): 11.74,
343.0955 [M+H] (calcd. for C H N OS : 343.0939).
6
18 19
2
2
2
1
1
7
0.38, 28.86, 48.16, 55.95, 115.18 (2C), 120.37, 126.81,
26.87, 127.15, 128.42, 131.25 (2C), 135.38, 147.64,
2-(n-Butyldisulfanyl)-3-(4-chlorophenyl)-quinazolin-4(3H)-
one (8b)
–
1
56.88, 160.74, 161.48; IR (KBr, cm ): 1686, 1578, 1558,
–
1
+
73, 528 cm ; HR-MS (ESI): m/z 373.1061 [M+H]
1
(
calcd. for C H N O S : 373.1044).
White solid; yield 57.8%; m.p.: 104.9–106.5 °C; H NMR
1
9
21
2
2 2
(
400 MHz, DMSO-d ) δ (ppm): 0.87 (t, J = 8.0 Hz, 3H,
6
2
-(2-Butyldisulfanyl)-3-(3-chlorophenyl)-quinazolin-4(3H)-
CH ), 1.35–1.47 (m, 2H, CH ), 1.57–1.64 (m, 2H, CH ),
3 2 2
one (7g)
2.94 (t, J = 8.0 Hz, 2H, CH ), 7.54 (t, J = 8.0 Hz, 1H, Ar–
2
H), 7.60 (d, J = 8.0 Hz, 2H, Ar–H), 7.68 (t, J = 8.0 Hz, 3H,
Ar–H), 7.89 (t, J = 8.0 Hz, 1H, Ar–H), 8.11 (d, J = 8.0 Hz,
1
White solid; yield 42.6%; m.p.: 133.3–135.6 °C; H NMR
400 MHz, DMSO-d ) δ (ppm): 1.01 (t, J = 8.0 Hz, 3H,
1
3
(
1H, Ar–H); C NMR(100 MHz, DMSO-d ) δ (ppm):
6
6
CH ), 1.27 (d, J = 8.0 Hz, 3H, CH ), 1.49–1.68 (m, 2H,
13.92, 21.31, 30.57, 37.83, 120.35, 126.90, 127.01, 127.13,
130.14 (2C), 132.02 (2C), 134.94, 135.40, 135.50, 147.65,
3
3
CH ), 3.09–3.17 (m, 1H, CH), 7.51–7.58 (m, 2H, Ar–H),
2

Medicinal Chemistry Research
–
1
1
5
55.76, 161.24; IR (KBr, cm ): 1682, 1578, 1556, 770,
2-(n-Butyldisulfanyl)-3-(4-methoxyphenyl)-quinazolin-4
(3H)-one (8f)
–1
+
10 cm ; HR-MS (ESI): m/z 377.0566 [M+H] (calcd. for
C H N OS Cl: 377.0549).
1
8
18
2
2
1
White solid; yield 66.5%; m.p.: 140.8–141.9 °C; H NMR
2
-(n-Butyldisulfanyl)-3-(4-methylphenyl)-quinazolin-4(3H)-
(400 MHz, DMSO-d ) δ (ppm): 0.87 (t, J = 8.0 Hz, 3H,
6
one (8c)
CH ), 1.37–1.47 (m, 2H, CH ), 1.57–1.64 (m, 2H, CH ),
3
2
2
2
.93 (t, J = 4.0 Hz, 2H, CH ), 3.85 (s, 3H, CH ), 7.11 (d,
2 3
1
White solid; yield 64.8%; m.p.: 81.7–83.4 °C; 1H NMR
400 MHz, DMSO-d ) δ (ppm): 0.86 (t, J = 4.0 Hz, 3H,
J = 8.0 Hz, 2H, Ar–H), 7.42 (d, J = 8.0 Hz, 2H, Ar–H),
7.53 (t, J = 8.0 Hz, 1H, Ar–H), 7.68 (d, J = 8.0 Hz, 1H, Ar–
H), 7.87 (t, J = 8.0 Hz, 1H, Ar–H), 8.10 (d, J = 8.0 Hz, 1H,
(
6
CH ), 1.36–1.45 (m, 2H, CH ), 1.55–1.63 (m, 2H, CH ),
3
2
2
1
3
2
.42 (s, 3H, CH ), 2.92 (t, J = 4.0 Hz, 2H, CH ), 7.37 (s,
Ar–H); C NMR (100 MHz, DMSO-d ) δ (ppm): 13.94,
3
2
6
4
H, Ar–H), 7.52 (t, J = 8.0 Hz, 1H, Ar–H), 7.68 (d, J = 8.0
21.30, 30.56, 37.70, 55.96, 115.18 (2C), 120.37, 126.87,
126.90, 127.15, 128.33, 131.26 (2C), 135.39, 147.71,
Hz, 1H, Ar–H), 7.87 (t, J = 8.0 Hz, 1H, Ar–H), 8.10 (d, J =
8
.0 Hz, 1H, Ar–H); 13C NMR (100 MHz, DMSO-d ) δ
156.78, 160.75, 161.47; IR (KBr, cm ): 1685, 1575, 1553,
–1
6
–
1
+
(
ppm): 13.92, 21.28, 21.34, 30.54, 37.73, 120.33, 126.89,
775, 528 cm ; HR-MS (ESI): m/z 373.1060 [M+H]
1
1
1
26.97, 127.14, 129.71 (2C), 130.56 (2C), 133.33, 135.45,
(calcd. for C H N O S : 373.1044).
1
9
21
2
2 2
–
1
40.41, 147.68, 156.36, 161.33; IR (KBr, cm ): 1687,
–
1
578, 1556, 764, 514 cm ; HR-MS (ESI): m/z 357.1112
2-(n-Butyldisulfanyl)-3-(3-chlorophenyl)-quinazolin-4(3H)-
one (8g)
+
[
M+H] (calcd. for C H N OS : 357.1095).
19
21
2
2
1
2
-(n-Butyldisulfanyl)-3-(4-trifluoromethylphenyl)-
White solid; yield 53.7%; m.p.: 94.7–95.8 °C; H NMR
quinazolin-4(3H)-one (8d)
(400 MHz, DMSO-d ) δ (ppm): 0.87 (t, J = 4.0 Hz, 3H,
6
CH ), 1.38–1.46 (m, 2H, CH ), 1.57–1.64 (m, 2H, CH ),
3
2
2
1
White solid; yield 57.6%; m.p.: 122.3–124.6 °C; H NMR
400 MHz, DMSO-d ) δ (ppm): 0.87 (t, J = 8.0 Hz, 3H,
2.94 (t, J = 8.0 Hz, 2H, CH ), 7.51–7.56 (m, 2H, Ar–H),
2
(
7.60–7.70 (m, 3H, Ar–H), 7.77 (s, 1H, Ar–H), 7.88 (t, J =
6
13
CH ), 1.38–1.47 (m, 2H, CH ), 1.58–1.65 (m, 2H, CH ),
8.0 Hz, 1H, Ar–H), 8.10 (d, J = 8.0 Hz, 1H, Ar–H);
C
3
2
2
2
.95 (t, J = 8.0 Hz, 2H, CH ), 7.55 (t, J = 8.0 Hz, 1H, Ar–
NMR (100 MHz, DMSO-d ) δ (ppm): 13.94, 21.32, 30.59,
2
6
H), 7.71 (d, J = 8.0 Hz, 1H, Ar–H), 7.83 (d, J = 8.0 Hz, 2H,
Ar–H), 7.90 (t, J = 8.0 Hz, 1H, Ar–H), 8.00 (d, J = 8.0 Hz,
37.87, 120.39, 126.93, 127.07, 127.14, 129.06, 130.17,
130.77, 131.60, 134.07, 135.56, 137.41, 147.63, 155.61,
13
–1
–1
1
H, Ar–H), 8.12 (d, J = 8.0 Hz, 1H, Ar–H); C NMR (100
161.21; IR (KBr, cm ): 1693, 1577, 1554, 771, 520 cm ;
HR-MS (ESI): m/z 377.0560 [M+H]+ (calcd. for
C H N OS Cl: 377.0549).
MHz, DMSO-d ) δ (ppm): 13.90, 21.30, 30.55, 37.85,
6
1
(
1
20.37, 126.29 (J = 271.0 Hz), 126.95, 127.11, 127.16
2C, J = 4.0 Hz), 127.15, 130.92 (2C, J = 32.0 Hz),
31.34, 135.60, 139.82, 147.64, 155.26, 161.24; IR (KBr,
1
8
18
2
2
2-(n-Butyldisulfanyl)-3-(3-methylphenyl)-quinazolin-4(3H)-
one (8h)
–1
–1
cm ): 1683, 1578, 1557, 770, 507 cm ; HR-MS (ESI):
m/z 411.0832 [M+H] (calcd. for C H N OS F :
+
19
18
2
2 3
1
4
11.0813).
White solid; yield 46.3%; m.p.: 119.9–121.7 °C; 1H NMR
(
400 MHz, DMSO-d ) δ (ppm): 0.83 (t, J = 4.0 Hz, 3H, CH ),
6
3
2
-(n-Butyldisulfanyl)-3-(4-nitrophenyl)-quinazolin-4(3H)-
1.34–1.43 (m, 2H, CH ), 1.53–1.61 (m, 2H, CH ), 2.36 (s, 3H,
2 2
one (8e)
CH ), 2.90 (t, J = 4.0 Hz, 2H, CH ), 7.29 (d, J = 8.0 Hz, 2H,
3
2
Ar–H), 7.37 (d, J = 8.0 Hz, 1H, Ar–H), 7.43–7.50 (m, 2H,
Ar–H), 7.68 (d, J = 8.0 Hz, 1H, Ar–H), 7.83 (t, J = 8.0 Hz,
1H, Ar–H), 8.09 (d, J = 8.0 Hz, 1H, Ar–H); C NMR (100
1
White solid; yield 42.7%; m.p.: 159–160.5 °C; H NMR
400 MHz, DMSO-d ) δ (ppm): 0.87 (t, J = 8.0 Hz, 3H,
13
(
6
CH ), 1.38–1.47 (m, 2H, CH ), 1.58–1.65 (m, 2H, CH ),
MHz, DMSO-d ) δ(ppm): 13.92, 21.25, 21.37, 30.63, 37.88,
3
2
2
6
2
.96 (t, J = 8.0 Hz, 2H, CH ), 7.56 (t, J = 8.0 Hz, 1H, Ar–
120.33, 126.88 (2C), 126.95, 127.11, 129.81, 130.20, 131.23,
2
–
H), 7.71 (d, J = 8.0 Hz, 1H, Ar–H), 7.91 (d, J = 8.0 Hz, 3H,
Ar–H), 8.12 (d, J = 8.0 Hz, 1H, Ar–H), 8.44 (d, J = 8.0 Hz,
135.32, 135.87, 139.69, 147.68, 156.20, 161.19; IR (KBr, cm
1
–1
): 1695, 1577, 1556, 768, 536 cm ; HR-MS (ESI): m/z
1
3
+
2
1
1
1
7
H, Ar–H); C NMR (100 MHz, DMSO-d ) δ (ppm):
357.1112 [M+H] (calcd. for C H N OS : 357.1095).
6
19 21
2
2
3.92, 21.29, 30.55, 37.88, 120.36, 125.27 (2C), 126.97,
27.16, 127.18, 131.92 (2C), 135.68, 141.83, 147.60,
2-(i-Butyldisulfanyl)-3-phenyl-quinazolin-4(3H)-one (9a)
–
1
48.81, 154.90, 161.17; IR (KBr, cm ): 1686, 1576, 1558,
–
1
+
1
67, 521 cm ; HR-MS (ESI): m/z 388.0808 [M+H]
White solid; yield 53.1%; m.p.: 90.5–91.6 °C; H NMR
(
calcd. for C H N O S : 388.0789).
(400 MHz, DMSO-d ) δ (ppm): 0.99 (d, J = 4.0 Hz, 6H,
1
8
18
3
3
2
6

Medicinal Chemistry Research
CH ), 1.83–1.93 (m, 1H, CH), 2.81 (d, J = 4.0 Hz, 2H,
Hz), 126.95, 127.10, 127.22 (2C, J = 6.0 Hz), 127.16,
130.93 (2C, J = 32.0 Hz), 131.36, 135.62, 139.83, 147.65,
3
CH ), 7.50–7.60 (m, 6H, Ar–H), 7.69 (d, J = 8.0 Hz, 1H,
2
–
1
Ar–H), 7.89 (t, J = 8.0 Hz, 1H, Ar–H), 8.11 (d, J = 8.0 Hz,
155.26, 161.25; IR (KBr, cm ): 1687, 1577, 1555, 774,
1
3
–1
+
1
2
1
1
4
H, Ar–H); C NMR (100 MHz, DMSO-d ) δ (ppm):
508 cm ; HR-MS (ESI): m/z 411.0832 [M+H] (calcd. for
6
1.95 (2C), 27.91, 47.34, 120.38, 126.88, 126.98, 127.14,
30.02 (2C), 130.03 (2C), 130.62, 135.47, 135.99, 147.68,
56.11, 161.26; IR (KBr, cm ): 1687, 1577, 1555, 770,
C H N OS F : 411.0813).
1
9
18
2
2 3
–
1
2-(i-Butyldisulfanyl)-3-(4-nitrophenyl)-quinazolin-4(3H)-one
(9e)
–1
+
96 cm ; HR-MS (ESI): m/z 343.0955 [M+H] (calcd. for
C H N OS : 343.0939).
1
8
19
2
2
1
White solid; yield 55.6%; m.p.: 143.3–144.6 °C; H NMR
2
-(i-Butyldisulfanyl)-3-(4-chlorophenyl)-quinazolin-4(3H)-
(400 MHz, DMSO-d ) δ (ppm): 1.00 (d, J = 8.0 Hz, 6H,
6
one (9b)
CH ), 1.87–1.95 (m, 1H, CH), 2.84 (d, J = 8.0 Hz, 2H,
3
CH ), 7.56 (t, J = 8.0 Hz, 1H, Ar–H), 7.71 (d, J = 8.0 Hz,
2
1
White solid; yield 50.3%; m.p.: 100.8–102.1 °C; H NMR
400 MHz, DMSO-d ) δ (ppm): 0.99 (d, J = 4.0 Hz, 6H,
1H, Ar–H), 7.90 (d, J = 8.0 Hz, 3H, Ar–H), 8.12 (d, J = 4.0
1
3
(
Hz, 1H, Ar–H), 8.44 (d, J = 8.0 Hz, 2H, Ar–H); C NMR
6
CH ), 1.84–1.94 (m, 1H, CH), 2.82 (d, J = 8.0 Hz, 2H,
(100 MHz, DMSO-d ) δ (ppm): 21.92(2C), 27.84, 47.29,
3
6
CH ), 7.54 (t, J = 8.0 Hz, 1H, Ar–H), 7.59 (d, J = 8.0Hz,
120.37, 125.29 (2C), 126.97, 127.17, 127.19, 131.93 (2C),
135.72, 141.83, 147.61, 148.83, 154.90, 161.19; IR
2
2
H, Ar–H), 7.68 (t, J = 8.0 Hz, 3H, Ar–H), 7.89 (t, J = 8.0
13
–1
–1
Hz, 1H, Ar–H), 8.11 (d, J = 8.0 Hz, 1H, Ar–H); C NMR
100 MHz, DMSO-d ) δ (ppm): 21.94 (2C), 27.89,
(KBr, cm ): 1688, 1577, 1557, 766, 524 cm ; HR-MS
(
(ESI): m/z 388.0807 [M+H]+ (calcd. for C H N O S :
6
18 18
3
3 2
4
7.33, 120.36, 126.90, 127.01, 127.14, 130.14 (2C), 132.04
388.0789).
(
(
(
2C), 134.94, 135.39, 135.52, 147.65, 155.75, 161.25; IR
–1
–1
KBr, cm ): 1696, 1579, 1555, 765, 508 cm ; HR-MS
2-(i-Butyldisulfanyl)-3-(4-methoxyphenyl)-quinazolin-4(3H)-
one (9f)
ESI): m/z 377.0566 [M+H]+ (calcd. for C H N OS Cl:
18
18
2
2
3
77.0549).
1
White solid; yield 43.9%; m.p.: 143.9–145.1 °C; H NMR
2
-(i-Butyldisulfanyl)-3-(4-methylphenyl)-quinazolin-4(3H)-
(400 MHz, DMSO-d ) δ (ppm): 0.99 (d, J = 4.0 Hz, 6H,
6
one (9c)
CH ), 1.83–1.93 (m, 1H, CH), 2.81 (d, J = 8.0 Hz, 2H,
3
CH ), 3.85 (s, 3H, CH ), 7.11 (d, J = 8.0 Hz, 2H, Ar–H),
2
3
°
1
White solid; yield 54.1%; m.p.: 107.7–109.1 C; H NMR
400 MHz, DMSO-d ) δ (ppm): 0.98 (d, J = 8.0 Hz, 6H,
7.42 (d, J = 8.0 Hz, 2H, Ar–H), 7.53(t, J = 8.0 Hz, 1H, Ar–
H), 7.68 (d, J = 8.0 Hz, 1H, Ar–H), 7.88 (t, J = 8.0 Hz, 1H,
(
6
1
3
CH ), 1.82–1.90 (m, 1H, CH), 2.41 (s, 3H, CH ), 2.79 (d,
Ar–H), 8.10 (d, J = 8.0 Hz, 1H, Ar–H); C NMR (100
3
3
J = 8.0 Hz, 2H, CH ), 7.37 (s, 4H, Ar–H), 7.51 (t, J = 8.0
MHz, DMSO-d ) δ (ppm): 21.96 (2C), 27.89, 47.24, 55.96,
2
6
Hz, 1H, Ar–H), 7.68 (d, J = 8.0 Hz, 1H, Ar–H), 7.86 (t, J =
115.17 (2C), 120.37, 126.86, 126.89, 127.16, 128.32,
131.27 (2C), 135.40, 147.72, 156.78, 160.75, 161.48; IR
1
3
8
.0 Hz, 1H, Ar–H), 8.10 (d, J = 8.0 Hz, 1H, Ar–H);
C
–1
–1
NMR (100 MHz, DMSO-d ) δ (ppm): 21.35, 21.94 (2C),
(KBr, cm ): 1690, 1576, 1552, 779, 529 cm ; HR-MS
6
2
1
1
7.89, 47.29, 120.33, 126.87, 126.93, 127.15, 129.71 (2C),
30.56 (2C), 133.32, 135.42, 140.38, 147.69, 156.37,
(ESI): m/z 373.1057 [M+H]+ (calcd. for C H N O S :
1
9
21
2
2 2
373.1044).
–1
–1
61.32; IR (KBr, cm ): 1689, 1577, 1555, 770, 514 cm ;
+
HR-MS (ESI): m/z 357.1110 [M+H]
(calcd. for
2-(i-Butyldisulfanyl)-3-(3-chlorophenyl)-quinazolin-4(3H)-
C H N OS : 357.1095).
one (9g)
1
9
21
2
2
1
2
4
-(i-Butyldisulfanyl)-3-(4-trifluoromethylphenyl)-quinazolin-
(3H)-one (9d)
White solid; yield 57.6%; m.p.: 114.4–115.3 °C; H NMR
(400 MHz, DMSO-d ) δ (ppm): 1.00 (d, J = 8.0 Hz, 6H,
6
CH ), 1.83–1.94 (m, 1H, CH), 2.82 (d, J = 4.0 Hz, 2H,
3
1
White solid; yield 59.1%; m.p.: 126.8–127.9 °C; H NMR
CH ), 7.52–7.56 (m, 2H, Ar–H), 7.60–7.70 (m, 3H, Ar–H),
2
(
400 MHz, DMSO-d ) δ (ppm): 1.00 (d, J = 8.0 Hz, 6H,
7.77 (s, 1H, Ar–H), 7.89 (t, J = 8.0 Hz, 1H, Ar–H), 8.11 (d,
6
1
3
CH ), 1.85–1.95 (m, 1H, CH), 2.83 (d, J = 8.0 Hz, 2H,
J = 8.0 Hz, 1H, Ar–H); C NMR (100 MHz, DMSO-d ) δ
3
6
CH ), 7.55 (t, J = 8.0 Hz, 1H, Ar–H), 7.71 (d, J = 8.0 Hz,
(ppm):21.95, 21.98, 27.92, 47.37, 120.38, 126.92, 127.06,
2
1
H, Ar–H), 7.83 (d, J = 8.0 Hz, 2H, Ar–H), 7.90 (t, J = 8.0
127.15, 129.07, 130.17, 130.77, 131.60, 134.05, 135.58,
–
1
Hz, 1H, Ar–H), 7.99 (d, J = 8.0 Hz, 2H, Ar–H), 8.12 (d,
J = 8.0 Hz, 1H, Ar–H); C NMR (100 MHz, DMSO-d ) δ
137.39, 147.63, 155.61, 161.22; IR (KBr, cm ): 1694,
13
–1
1577, 1555, 769, 520 cm ; HR-MS (ESI): m/z 377.0560
6
+
(
ppm): 21.93 (2C), 27.86, 47.36, 120.39, 124.30(J = 271.0
[M+H] (calcd. for C H N OS Cl: 377.0549).
1
8
18
2
2

Medicinal Chemistry Research
2
-(i-Butyldisulfanyl)-3-(3-methylphenyl)-quinazolin-4(3H)-
Determination of MIC
one (9h)
Aiming to determine the MIC, a stock solution of Gram-
negative bacteria E. coli and Gram-positive bacteria S.
aureus was prepared. Briefly, Gram-negative bacteria E.
coli and Gram-positive bacteria S. aureus were cultured in
5 mL of liquid LB (supplemented with 50 μg/mL) broth at
37 °C on a constant temperature shaker at 170 rpm. After
incubation overnight, the concentration of the bacterial
suspension was diluted with pure nutrient broth to ~105
CFU/mL and measured with a UV-3900. A sample of
compounds 7a–7h, 8a–8h and 9a–9h was dissolved in
deionized water and diluted from 512 to 2 μg/mL by a series
of twofold dilutions using the nutrient broth. The diluted
bacterial solution (100 μL) and the samples (1 mL) with
varying concentration were incubated at 37 °C in glass
culture tubes, respectively. After incubation for 16 h, the
viability of bacteria was determined by measuring OD600
on a UV-3390 instrument. In comparison to a positive
control, the MIC was defined as the lowest polymer con-
centration that inhibited more than 90% of the germ growth.
1
White solid; yield 66.7%; m.p.: 120.3–121.3 °C; H NMR
400 MHz, DMSO-d ) δ (ppm): 0.99 (d, J = 4.0 Hz, 6H,
(
6
CH ), 1.83–1.93 (m, 1H, CH), 2.38 (s, 3H, CH ), 2.81 (d,
J = 8.0 Hz, 2H, CH ), 7.29 (d, J = 8.0 Hz, 2H, Ar–H), 7.39
d, J = 8.0 Hz, 1H, Ar–H), 7.44–7.55 (m, 2H, Ar–H), 7.68
d, J = 8.0 Hz, 1H, Ar–H), 7.88 (t, J = 8.0 Hz, 1H, Ar–H),
.10 (d, J = 8.0 Hz, 1H, Ar–H); C NMR (100 MHz,
DMSO-d ) δ (ppm): 21.24, 21.94, 21.98, 27.94, 47.35,
20.34, 126.89, 126.98 (2C), 127.13, 129.83, 130.20,
31.28, 135.45, 135.86, 139.69, 147.67, 156.19, 161.24; IR
3
3
2
(
(
8
13
6
1
1
(
–1
–1
KBr, cm ): 1698, 1577, 1558, 788, 545 cm ; HR-MS
(
ESI): m/z 357.1111 [M+H]+ (calcd. for C H N OS :
19
21
2
2
3
57.1095).
Cell culture
Compounds 7a–7h, 8a–8h and 9a–9h, 5-fluorouracil was
dissolved in DMSO to make stock solutions at a con-
centration of 1.0 × 10 mol/L. During the experiment, cell
culture medium RPMI-1640 was used to dilute the stock
solution to the desired concentration. Cells in the expo-
–2
Acknowledgements We are grateful to the National Natural Science
Foundation of China (20971097), the Tianjin Municipal Natural Sci-
ence Foundation (13JCYBJC24500) and the Training Project of
Innovation Team of Colleges and Universities in Tianjin (TD13-5020)
for financial support.
nential phase were seeded in 96-well culture plates at the
confluence of 1 × 10 cells/well, kept in a 37 °C, 5% CO
4
2
incubator for 24 h. The medium containing different con-
centrations of compounds was replaced with a fresh med-
Compliance with ethical standards
ium, and kept in a 37 °C, 5% CO incubator for 48 h. Then,
2
Conflict of interest The authors declare that they have no conflict of
interest.
9
0 μL of fresh medium and 10 μL of CCK-8 were added,
kept at 37 °C and 5% CO for 1 h. The sample cell was
2
added into 96-well microplate reader and read at 450 nm,
and the absorbance value (optical density (OD)) was
recorded. Cell viability was calculated from the mean values
for three wells using the following formula: Relative cell
viability = (OD value for the test group-blank OD) / (con-
trol OD value-blank OD value) × 100%.
Publisher’s note: Springer Nature remains neutral with regard to
jurisdictional claims in published maps and institutional affiliations.
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