Synthesis and acrosin inhibitory activities of 5-phenyl-1H-pyrazole-3- carboxylic acid amide derivatives

Article abstract of DOI:10.1016/j.bmcl.2013.05.031

A series of novel 5-phenyl-1H-pyrazole-3-carboxylic acid amide derivatives were designed, synthesized, and their acrosin inhibitory activities in vitro were evaluated. The results of the acrosin inhibitory activity showed that all target compounds were mo

Full text of DOI:10.1016/j.bmcl.2013.05.031

Bioorganic & Medicinal Chemistry Letters 23 (2013) 4177–4184
Contents lists available at SciVerse ScienceDirect
Bioorganic & Medicinal Chemistry Letters
journal homepage: www.elsevier.com/locate/bmcl
Synthesis and acrosin inhibitory activities of 5-phenyl-1H-
pyrazole-3-carboxylic acid amide derivatives
Wei Tian a, , Guangqian Han b, , Ju Zhu a, Jingjing Qi a, Qianqian Chen a, Juntao Zhao a, Canhui Zheng a,
Ling Zhang a, Youjun Zhou a, , Jiaguo Lv a,
⇑
⇑
a Department of Medicinal Chemistry, School of Pharmacy, Second Military Medical University, Shanghai 200433, PR China
b Department of Pharmacognosy, School of Food Science, Fujian Agriculture and Forestry University, Fujian 350002, PR China
a r t i c l e i n f o
a b s t r a c t
Article history:
A series of novel 5-phenyl-1H-pyrazole-3-carboxylic acid amide derivatives were designed, synthesized,
and their acrosin inhibitory activities in vitro were evaluated. The results of the acrosin inhibitory activity
showed that all target compounds were more potent than control TLCK. Compounds AQ-A1, AQ-D3, AQ-D4,
AQ-E4 and AQ-E5 exhibited stronger acrosin inhibitory activities than control ISO-1. Especially, compound
Received 21 January 2013
Revised 27 April 2013
Accepted 9 May 2013
Available online 22 May 2013
AQ-E5 displayed the most potent acrosin inhibitory activity in all the compounds, with an IC50 of 0.01 lmol/
mL. This study provided a new structural class for the development of novel acrosin inhibitory agents.
Keywords:
Acrosin inhibitory activity
Synthesize
Crown Copyright Ó 2013 Published by Elsevier Ltd. All rights reserved.
5-Phenyl-1H-pyrazole-3-carboxylic acid
amide
The contraceptive was one of the most important modern con-
traceptive methods, which had protected millions of couple world
widely from unwanted pregnancy and allowed them to take con-
trol over their reproduction. However, oral contraceptive pill was
only available for women and could lead to serious side effects,
including breakthrough menstrual bleeding, nausea, mood swings,
headaches, and an increased risk of rectal cancer.1–4 Therefore, it
was necessary to search for novel contraceptives which were easier
to use with fewer side effects and available for both men and
women.
Sperm acrosin was the major trypsin-like protease present in
the acrosome of all mammalian spermatozoa and played a critical
role in fertilization.5 Acrosin could lead to the lysis of the zona pel-
lucida and facilitate the penetration of the sperm through the
innermost glycoprotein layers of the oocytes.6 The levels of acrosin
activity were closely related to human infertility and its insuffi-
ciency could result in the failure of fertilization.7 The inhibition
of acrosin activities should block the fertilization and reduce the
success of fertilization. Thus, acrosin could be considered as a po-
tential target for the design of novel contraceptive agents used in
men.
AGB (C16H16N4O3, CAS No. 79126-29-7), DV-1006 (C17H23NO4,
CAS No. 34675-84-8), guanidylbenzenesulfonamides (KF950,
C16H15N3 O4, CAS No. 99450-778) and substituted isoxazolecarbal-
dehydes (Fig. 1) had been reported.8–10 However, there were some
problems with existing acrosin inhibitors: weak acrosin inhibitory
activities such as TLCK, AGB, and instable molecules such as KF950
etc. Thus, the search for new acrosin inhibitors was meaningful.
In recent years, our group had focused on the research of novel
acrosin inhibitors. Since no crystal structures of human acrosin had
been reported, in a previous study, we constructed a homologous
three dimensional model of human acrosin, which showed that
the active site of human acrosin could be divided into three parts:
P1 pocket, P2 pocket and G pocket.11,12 On the bases of the
constructed three dimensional model of human acrosin, several
classes of novel small acrosin inhibitors were designed and
synthesized, such as KF-950, 1H-benzoimidazole derivatives,13
and N-diaminomethylene-benzenesulfonamide derivatives.14
ISO-1 discovered by Gupta et al. was a lead compound of isox-
azoles with high acrosin inhibitory activity (0.39 lmol/mL). Analy-
sis of the binding mode (Fig. 2) found that ISO-1 molecule was only
located in P1 pocket without interactions with the P2 or G pocket.
While, ISO-1 molecular mainly interacted with acrosin through
hydrophobic interaction and formed only one H-bond with acrosin.
Since enhancing binding forces of inhibitors with acrosin, such as
H-bond and other binding forces, was beneficial to improving the
acrosin inhibitory activity, the isoxazole ring of ISO-1 molecule
was replaced by pyrazole ring which could form two H-bonds with
acrosin (Fig. 3) and a series of novel pyrazole compounds were
With the report of the acrosin functions, several classes of acro-
sin inhibitors, such as TLCK (C14H21ClN2O3S, CAS No. 2104-86-1),
⇑
Corresponding authors. Tel.: +86 021 81871234 (J.L.).
E-mail addresses: zhouyoujun2006@yahoo.com.cn (Y. Zhou), ljg20060508@
yahoo.com.cn (J. Lv).
Co-authors.
0960-894X/$ - see front matter Crown Copyright Ó 2013 Published by Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.bmcl.2013.05.031

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W. Tian et al. / Bioorg. Med. Chem. Lett. 23 (2013) 4177–4184
O
O
NH
O
O
O
S
O
O
O
O
NH CH
CH2
CH2Cl
O
NH
NH
NH
4
NH2
NH2
NH2
NH
AGB
KF950
TLCK
O
O
H
N
Cl
OH
N
O
H
O
N
NH2
O
O
H
O
Cl
S
N
NH2
O
O
NH2
R
(4b)
N-Diaminomethylene-benzenesulfonamide
isoxazolecarbaldehydes
ISO-1
DV-1006
Figure 1. TLCK, AGB, DV-1006, KF950, ISO-1, substituted isoxazolecarbaldehyde, N-diaminomethylene-benzenesulfonamide (4b).
(1H NMR, 13C NMR, IR, MS and HRMS).15 Besides, the title com-
pound AQ-A1 with high acrosin inhibition activity was character-
ized by X-ray diffraction in addition. The crystal structure,
packing diagram in a unit cell and specific related statistics of
AQ-A1 were shown in Figures 4 and 5 and Table 2, respectively.
The acrosin inhibitory activities of the title compounds were
evaluated according to the method of Kennedy et al.16 The acrosin
inhibitory activities of all compounds were listed in Table 1, in
which TLCK and ISO-1 were treated as the controls. The results
indicated that all title compounds had better inhibitory activities
than TLCK. Compounds AQ-A1, AQ-D3, AQ-D4, AQ-E4 and AQ-E5
(Fig. 6) exhibited better acrosin inhibitory activities than ISO-1.
Especially the acrosin inhibitory activity of AQ-E5 was 39 times
higher than that of ISO-1.
In general, compound (AQ-A1) bearing an electron donating
substituted phenyl ring (–OCH3) was more potent inhibitory activ-
ities than compounds (AQ-B1, AQ-C1, AQ-D1, AQ-E1) bearing an
electron withdrawing substituted phenyl ring (–NO2, –Br); com-
pounds bearing bromo (AQ-D1 to AQ-D8) analogs displayed better
inhibitory activity than compounds with nitro groups (AQ-B1 to
AQ-C9). Interestingly, compounds without substitutions (AQ-E1
to AQ-E9) had stronger inhibitory activity than those with an elec-
tron withdrawing substitution (AQ-B1 to AQ-D8). Two aliphatic
side chains with five-atom length (AQ-B5, AQ-E5) were appropri-
ate for acrosin inhibitory activity. Of all the compounds, AQ-E5
exhibited much better inhibitory activity than other compounds,
Figure 2. The docking mode of ISO-1 in the active site of acrosin.
with an IC50 of 0.01 lmol/mL.
The molecule docking study was carried out by DISCOVERY STUDIO
2.5 software package (AI, San Diego, CA, USA).17 The binding model
of compounds ISO-1, AQ-E4, AQ-E5 and KF950 with human acrosin
were presented in Figures 2, 7 and 8, respectively.
designed on the basis of the constructed three-dimensional model
of acrosin.
Here, we reported the synthesis and their acrosin inhibitory
activities in vitro of novel pyrazole compounds.
The chemical synthesis of 5-phenyl-1H-pyrazole-3-carboxylic
acid amide derivatives is outlined in Scheme 1. The 1-phenyl-eth-
anone compounds (compounds 1) were oxalated by diethyl oxalate
in the existence of sodium ethanol, affording b-diketoester (com-
pounds 2). The b-diketoester and hydrazine in refluxing ethanol
yielded ethyl 2,4-dioxo-4-phenyl-butyrate (compounds 3). Finally,
the target compounds (compounds 4) were prepared by the reac-
tion of compounds 3 with hydramine in pyridine. The structures
of the synthesized compounds were characterized by spectral data
Analysis of the binding mode found that compounds AQ-E4 and
AQ-E5 were all located in both P1 and P2 pockets, and ISO-1 was
only located in P1 pocket. Both AQ-E4 and AQ-E5 could form three
and four H-bond interactions with the key residues Gln218, Ser221
and Gly244 within P1 pocket, respectively. Moreover, AQ-E5 had
two aliphatic side chains, while AQ-E4 only had one aliphatic side
chain. The added H-bond and hydrophobic interaction in P1 pocket
could explain why compound AQ-E5 had better acrosin inhibitory
activity than AQ-E4. Moreover, KF950 formed four H-bond interac-
tions with the key residues, Thr216, Cys217, Asp220, Trp243 in p1

W. Tian et al. / Bioorg. Med. Chem. Lett. 23 (2013) 4177–4184
4179
Figure 3. Identification of regions where acrosin protein interacted with various pharmacophores in 5-phenyl-1H-pyrazole scaffold and 5-phenyl-1H-pyrazole scaffold in the
active site of acrosin.
O
O
N
O
HN
R3
R1
O
O
R3
R1
R3
R1
a
b
O
O
2
3
1
N
O
HN
C
c
R4
N
R2
R1
R3
4
Scheme 1. Synthesis of the target compounds. Reagents and conditions: (a) diethyl oxalate, C2H5ONa, C2H5OH, rt; (b) NH2NH2ÁH2O, ACOH, rf, 80 °C, 6 h; (c) pyridine,
hydramine, rf, 80 °C.
N
O
HN
C
NH
H3CO
HO
(1)
(2)
Figure 4. Chemical (1) and crystal (2) structure of AQ-A1.
pocket and van der Waals interactions with the key residues
Glu120, Thr241, Gly246, Cys247 and Gly254. Compared with KF-
950, compound AQ-E5 could also form four H-bond interactions
in p1 pocket and have van der Waals interactions with more key
residues, which could rationally explain why AQ-E5 have better
acrosin inhibitory activity than KF-950.
ADMET properties of compounds AQ-A1, AQ-D3, AQ-D4, AQ-E4,
AQ-E5 and 4b were analyzed by DISCOVERY STUDIO 2.5 software pack-
age (AI, San Diego, CA, USA) (Table 3). The results showed that AQ-
A1 and AQ-E5 had better ADMET properties than compound 4b
which is the compound with the most potent acrosin inhibitory
activity synthesized in previous study.

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W. Tian et al. / Bioorg. Med. Chem. Lett. 23 (2013) 4177–4184
Table 2
Specific crystal structure statistics of AQ-A1
Empirical formula
C13H15N3O3
Temperature
293(2) K
Wavelength
0.71073 A
Crystal system, space group
Unit cell dimensions
Monoclinic, C2/c
a = 21.82(5) A alpha = 90° b = 10.08(2) A
beta = 110.53(3)° c = 12.28(3) A
gamma = 90°
Volume
2531(11) A3
Z, calculated density
Absorption coefficient
F(000)
8, 1.372 mg/m3
0.100 mmÀ1
1104
Crystal size
Theta range for data collection
Limiting indices
0.20 Â 0.15 Â 0.06 mm
1.99–25.50°
À26 6 h 6 10, À12 6 k 6 12, À13 6 l 6 14
5292/2366 [R (int) = 0.0736]
100.0%
Semi-empirical from equivalents
0.9940 and 0.9803
Full-matrix least-squares on F2
2366/0/175
Reflections collected/unique
Completeness to theta = 25.50
Absorption correction
Max. and min. transmission
Refinement method
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices [I > 2sigma(I)]
R indices (all data)
1.053
R1 = 0.0540, wR2 = 0.1462
R1 = 0.0664, wR2 = 0.1563
0.0026(8)
Extinction coefficient
Largest diff. peak and hole
0.263 and À0.303 e AÀ3
Figure 5. Packing diagram of the title compound in a unit cell.
trol TLCK. Compounds AQ-A1, AQ-D3, AQ-D4, AQ-E4 and AQ-E5
exhibited better acrosin inhibitory activities than the control ISO-
1. Especially, AQ-E5 had the most potent acrosin inhibitory activity
among all target compounds, with an IC50 of 0.01 lmol/mL and had
perfect ADMET properties and were worthy of further
In summary, a series of novel 5-phenyl-1H-pyrazole-3-carbox-
ylic acid amide derivatives compounds were designed and synthe-
sized. The acrosin inhibitory activities of all title compounds were
evaluated in vitro, and the results exhibited that all target com-
pounds had more potent acrosin inhibitory activities than the con-
investigation.
Table 1
Acrosin inhibitory activities of compounds AQ-A1 to AQ-E9
Compound
R
(IC50
)
lmol/mL
Formula
AQ-A1
AQ-A6
AQ-A8
AQ-B1
AQ-B2
AQ-B3
AQ-B4
AQ-B5
AQ-B6
AQ-B7
AQ-B8
AQ-B9
AQ-C1
AQ-C2
AQ-C3
AQ-C4
AQ-C6
AQ-C8
AQ-C9
AQ-D1
AQ-D2
AQ-D3
AQ-D4
AQ-D6
AQ-D8
AQ-E1
AQ-E2
AQ-E3
AQ-E4
AQ-E5
AQ-E6
AQ-E9
ISO-1
R1 = –OCH3, R2 = –CH2CH2OH R3 = H, R4 = H
R1 = –OCH3, R2 = –CH2CH2OH R3 = H, R4 = CH3
R1 = –OCH3, R2 = –CH2CH2OCH2CH2OH R3 = H, R4 = H
R1 = –NO2, R2 = –CH2CH2OH R3 = H, R4 = H
0.09
0.41
6.02
2.7
C13H15N3O3
C14H17N3O3
C15H19N3O4
C12H12N4O4
C14H16N4O5
C13H14N4O4
C13H14N4O4
C16H20N4O5
C13H14N4O4
C14H16N4O4
C14H16N4O5
C14H16N4O6
C12H12N4O4
C14H16N4O5
C13H14N4O4
C13H14N4O4
C13H14N4O4
C14H17N3O5
C14H16N4O6
C12H12BrN3O2
C14H16BrN3O3
C13H14BrN3O2
C13H14BrN3O2
C13H14BrN3O2
C14H16BrN3O3
C12H13N3O2
C14H17N3O3
C13H15N3O2
C13H15N3O2
C16H21N3O3
C13H15N3O2
C14H17N3O4
R1 = –NO2, R2 = –CH2CH2OH R3 = H, R4 = –CH2CH2OH
R1 = –NO2, R2 = –CH2CH2CH2OH R3 = H, R4 = H
R1 = –NO2, R2 = –CH2CH(OH)CH3 R3 = H, R4 = H
R1 = –NO2, R2 = –CH2CH(OH)CH3 R3 = H, R4 = –CH2CH(OH)CH3
R1 = –NO2, R2 = –CH2CH2OH R3 = H, R4 = –CH3
R1 = –NO2, R2 = –C(CH3)2CH2OH R3 = H, R4 = H
R1 = –NO2, R2 = –CH2CH2OCH2CH2OH R3 = H, R4 = H
R1 = –NO2, R2 = –C(CH2OH)3 R3 = H, R4 = H
5.6
3.07
2.95
1.21
2.0
1.875
2.07
5.22
0.76
2.4
0.78
1.83
0.79
9.1
0.76
0.53
1.52
0.38
0.33
0.88
10
2.8
1.7
0.54
0.06
0.01
3
0.94
0.39
R1 = H, R2 = –CH2CH2OH R3 = –NO2, R4 = H
R1 = H, R2 = –CH2CH2OH R3 = –NO2, R4 = –CH2CH2OH
R1 = H, R2 = –CH2CH2CH2OH R3 = –NO2, R4 = H
R1 = H, R2 = –CH2CH(OH)CH3 R3 = –NO2, R4 = H
R1 = H, R2 = –CH2CH2OH R3 = –NO2, R4 = –CH3
R1 = H, R2 = –CH2CH2OCH2CH2OH R3 = –NO2, R4 = H
R1 = H, R2 = –C(CH2OH)3 R3 = –NO2, R4 = H
R1 = –Br, R2 = –CH2CH2OH R3 = H, R4 = H
R1 = –Br, R2 = –CH2CH2OH R3 = H, R4 = –CH2CH2OH
R1 = –Br, R2 = –CH2CH2CH2OH R3 = H, R4 = H
R1 = –Br, R2 = –CH2CH(OH)CH3 R3 = H, R4 = H
R1 = –Br, R2 = –(CH3)CH2CH2OH R3 = H, R4 = H
R1 = –Br, R2 = –CH2CH2OCH2CH2OH R3 = H, R4 = H
R1 = H, R2 = –CH2CH2OH R3 = H,R4 = H
R1 = H,R2 = –CH2CH2OH R3 = H, R4 = –CH2CH2OH
R1 = H, R2 = –CH2CH2CH2OH R3 = H, R4 = H
R1 = H, R2 = –CH2CH(OH)CH3 R3 = H, R4 = H
R1 = H, R2 = –CH2CH(OH)CH3 R3 = H, R4 = –CH2CH(OH)CH3
R1 = H, R2 = –(CH3)CH2CH2OH R3 = H, R4 = H
R1 = H, R2 = –C(CH2OH)3 R3 = H, R4 = H
TLCK
142.6

W. Tian et al. / Bioorg. Med. Chem. Lett. 23 (2013) 4177–4184
4181
O
HN
O
HN
N
N
O
HN
N
HN
HN
NH
OH
H3CO
OH
OH
Br
O
Br
O
AQ-D4
AQ-D3
AQ-A1
N
HN
N
HN
OH
N
NH
OH
OH
AQ-E4
AQ-E5
Figure 6. Novel substituted 5-phenyl-1H-pyrazole-3-carboxylic acid amide derivatives.
Figure 7. KF-950 interaction diagram and the mode of action of KF-950 on the active site of the homologous 3D model of human

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W. Tian et al. / Bioorg. Med. Chem. Lett. 23 (2013) 4177–4184
AQ- E5 interaction diagram
1
2
Superimposed AQ-E4 (1) and AQ- E5 (2)
Figure 8. AQ-E5 interaction diagram, the mode of action of compounds AQ-E4 (1) and AQ-E5 (2), superimposed on the active site of the homologous 3D model of human
acrosin.

W. Tian et al. / Bioorg. Med. Chem. Lett. 23 (2013) 4177–4184
4183
Table 3
ADMET analysis of AQ-A1, AQ-D3, AQ-D4, AQ-E4, AQ-E5 and 4b rather than ADMET analysis of AQ-D6, AQ-D8, AQ-E4, AQ-E5 and AQ-B9 and 4b
Name
ADMET-BBB-level
ADMET-absorption-level
ADMET-solubility-level
ADMET-hepatotoxicity-level
ADMET-PPB-level
AQ-A1
AQ-D3
AQ-D4
AQ-E4
AQ-E5
4b
Low
Low
Low
Low
Low
Undefined
Good absorption
Good absorption
Good absorption
Good absorption
Good absorption
Good absorption
Yes, optimal
Yes, good
Yes, good
Yes, good
Yes, optimal
Yes, good
Nontoxic
Nontoxic
Toxic
Nontoxic
Nontoxic
Toxic
Binding is > 90%
Binding is > 95%
Binding is > 95%
Binding is > 95%
Binding is > 90%
Binding is > 95%
ADMET-BBB-level: ADMET-blood–brain barrier-level.
ADMET-absorption-level: ADMET-human intestinal absorption (HIA)-level.
ADMET-solubility-level: ADMET-aqueous solubility-level.
ADMET-hepatotoxicity-level: ADMET-liver toxicity-level.
ADMET-PPB-level: ADMET-plasma–protein-level.
3374.04 (VO–H), 2980.27 (VCH3), 2872.27 (VCH2), 1626.46 (VC@O), 1586.46
(VC@C), 1407.21 (VC–N). HRMS: m/z (%): 289.0955 [MÀH]À. MS (ESI) m/z:
289.17 [MÀH]À, 291.17 [M+H]+. AQ-B7: white solid; yield: 80.3%; mp: 194–
195 °C; 1H NMR (600 MHz, DMSO) d 13.85 (s, 1H), 8.32 (d, J = 8.1 Hz, 2H), 8.06
(d, J = 8.1 Hz, 2H), 7.31 (s, 1H), 4.89 (s, 1H), 3.49 (d, J = 9.1 Hz, 2H), 1.33 (s, 6H);
13C NMR (300 MHz, DMSO) d 167.37, 149.80, 148.13, 142.43, 134.56, 127.69
(2C), 124.81 (2C), 104.35, 77.95, 45.07, 24.12 (2C); IR (cmÀ1): 3384.17 (VO–H),
2979.22 (VCH3), 2874.12 (VCH2), 1635.93 (VC@O), 1578.83 (VC@C), 1402.33
(VC–N); HRMS: m/z (%): 303.1108 [MÀH]À. MS (ESI) m/z: 303.22 [MÀH]À,
305.05 [M+H]+. AQ-B8: white solid; yield: 82.1%; mp: 188–189 °C; 1H NMR
(600 MHz, DMSO) d 13.48 (s, 1H), 8.32 (d, J = 8.2 Hz, 2H), 8.06 (d, J = 8.2 Hz,
2H), 7.39 (s, 1H), 4.71 (s, 1H), 3.56–3.30 (m, 8H); 13C NMR (300 MHz, DMSO) d
164.03, 149.89, 148.21, 142.67, 134.56, 127.29 (2C), 124.24 (2C), 104.56, 72.62,
71.08, 63.39, 43.25; IR (cmÀ1): 3369.00 (VO–H), 2897.03 (VCH2), 1631.66
(VC@O), 1581.31 (VC@C), 1427.90 (VC–N), 1111.27 (VC–O–C); HRMS: m/z (%):
319.1051 [MÀH]À. MS (ESI) m/z: 319.15 [MÀH]À, 321.04 [M+H]+. AQ-B9: white
solid; yield: 79%; mp: 194–196 °C; 1H NMR (600 MHz, DMSO) d 13.99 (s, 1H),
8.32 (d, J = 8.2 Hz, 2H), 8.09 (d, J = 8.2 Hz, 2H), 7.31 (s, 1H), 4.91 (s, 3H), 3.67 (s,
6H); 13C NMR (300 MHz, DMSO) d 167.73, 148.85, 147.16, 142.09, 135.54,
126.29(2C), 124.44(2C), 104.96, 65.29 (3C), 53.01; IR (cmÀ1): 3391.86 (VO–H),
2885.12 (VCH2), 1646.28 (VC@O), 1580.81 (VC@C), 1404.21 (VC–N); HRMS: m/
z (%): 335.1003 [MÀH]À. MS (ESI) m/z: 335.19 [MÀH]À, 337.07 [M+H]+. AQ-C1:
white solid; yield: 90%; mp: 197–198 °C; 1H NMR (600 MHz, DMSO) d 13.93 (s,
1H), 8.69 (s, 1H), 8.24 (d, J = 7.4 Hz, 1H), 8.23 (d, J = 7.7 Hz, 1H), 7.76 (t,
J = 8.0 Hz, 1H), 7.30 (s, 1H), 4.77 (s, 1H), 3.36–3.33 (m, 4H); MS (ESI) m/z:
311.63 [M+Cl]À. AQ-C2: white solid; yield: 86%; mp: 198–199 °C; 1H NMR
(600 MHz, DMSO) d 13.79 (s, 1H), 8.65 (s, 1H), 8.28 (d, J = 7.4 Hz, 1H), 8.27 (d,
J = 7.7 Hz, 1H), 7.75 (t, J = 8.0 Hz, 1H), 7.25 (s, 1H), 4.80 (s, 2H), 3.76 (t,
J = 12.1 Hz, 4H), 3.61(t, J = 12.1 Hz, 4H); MS (ESI) m/z: 319.21 [MÀH]À, 663.01
[2M+Na]+. AQ-C3: white solid; yield: 87%; mp: 186–187 °C; 1H NMR (600 MHz,
DMSO) d 13.86 (s, 1H), 8.60 (s, 1H), 8.24 (d, J = 7.4 Hz, 1H), 8.23 (d, J = 7.7 Hz,
1H), 7.76 (t, J = 8.0 Hz, 1H), 7.27 (s, 1H), 4.50 (s, 1H), 3.48 (t, J = 6.1 Hz, 2H), 3.33
(t, J = 6.7 Hz, 2H), 1.69–1.65 (m, 2H); MS (ESI) m/z: 325.55 [M+Cl]À, 604.21
[2M+Na]+. AQ-C4: white solid; yield: 83.3%; mp: 193–195 °C; 1H NMR
(600 MHz, DMSO) d 13.86 (s, 1H), 8.55 (s, 1H), 8.22 (d, J = 7.4 Hz, 1H), 8.18
(d, J = 7.7 Hz, 1H), 7.78 (t, J = 8.0 Hz, 1H), 7.49 (s, 1H), 4.79 (s, 1H), 3.79–3.77 (m,
1H), 3.30–3.11 (m, 2H), 1.07 (d, J = 6.1 Hz, 3H); 13C NMR (300 MHz, DMSO) d
166.78, 149.88, 148.92, 137.79, 134.62, 133.45, 129.98, 123.67, 122.22, 103.99,
69.70, 55.56, 20.02; IR (cmÀ1): 3396.65 (VO–H), 2935.09 (VCH3), 2870.09
(VCH2), 1633.53 (VC@O), 1586.02 (VC@C), 1425.12 (VC–N); HRMS: m/z (%):
289.0956 [MÀH]À. MS (ESI) m/z: 289.26 [MÀH]À. AQ-C6: white solid; yield:
87.3%; mp: 197–198 °C; 1H NMR (600 MHz, DMSO) d 13.79 (s, 1H), 8.67 (s, 1H),
8.18 (d, J = 7.4 Hz, 1H), 8.17 (d, J = 7.7 Hz, 1H), 7.74 (t, J = 8.0 Hz, 1H), 7.25 (s,
1H), 4.78 (s, 1H), 3.66 (s, 3H), 3.39–3.34 (m, 4H); 13C NMR (300 MHz, DMSO) d
165.60, 149.77, 148.74, 137.77, 134.82, 133.35, 129.02, 123.67, 122.98, 104.36,
71.70, 47.42, 17.14; IR (cmÀ1): 3414.59 (VO–H), 2981.07 (VCH3), 2871.93
(VCH2), 1631.04 (VC@O), 1581.31 (VC@C), 1415.94 (VC–N); HRMS: m/z (%):
289.0948 [MÀH]À. MS (ESI) m/z: 289.92 [MÀH]À, 603.42 [2M+Na]+. AQ-C8:
white solid; yield: 83.5%; mp: 194–195 °C; 1H NMR (600 MHz, DMSO), d 13.88
(s, 1H), 8.61 (s, 1H), 8.19 (d, J = 7.4 Hz, 1H), 8.17 (d, J = 7.7 Hz, 1H), 7.77 (t,
J = 8.0 Hz, 1H), 7.39 (s, 1H), 4.60 (s, 1H), 3.59–3.31 (m, 8H); 13C NMR (300 MHz,
Acknowledgment
Financial support was provided from the Science and Technol-
ogy, Support Program, Jiang Su 2010, BE2010682.
References and notes
1. Winner, B.; Peipert, J. F.; Zhao, Q.; Buckel, C. N. Engl. J. Med. 2012, 366, 1998.
2. Peipert, J. F.; Madden, T.; Allsworth, J. E.; Secura, G. M. Obstet. Gynecol. 2012,
120, 1291.
3. Finer, L. B.; Kost, K. Perspect. Sex. Reprod. Health 2011, 43, 78.
4. Trussell, J. Contraception 2007, 75, 168.
5. Rosatti, M. I.; Beconi, M. T.; Cordoba, M. Biocell 2004, 28, 311.
6. Cui, Y. H.; Zhao, R. L.; Wang, Q.; Zhang, Z. Y. J. Asian Androl. 2000, 2, 229.
7. Dejonge, C. J.; Tarchala, S. M.; Rawlins, R. J.; Radwanska, E. Hum. Reprod. 1993,
8, 253.
8. Bourinbaiar, A. S.; Lee-Huang, S. Contraception 1995, 51, 319.
9. Gupta, G.; Jain, R. K.; Maikhuri, J. P.; Shukla, P. K.; Kumar, M.; Roy, A. K.; Patra,
A.; Singh, V.; Batra, S. Hum. Reprod. 2005, 20, 2301.
10. Sumi, H. T. Experientia 1980, 36, 1103.
11. Zhang, J.; Zheng, C. H.; Sheng, C. Q.; Zhou, Y. J.; Zhu, J.; Lv, J. G. Chem. J Chin.
Univ. 2009, 30, 2409.
12. Jiang, J. H.; Liu, X. F.; Zheng, C. H.; Zhou, Y. J.; Zhu, J.; Lv, J. G.; Sheng, C. Q. Chin.
Chem. Lett. 2011, 22, 272–275.
13. Ding, L. L.; Zhu, J.; Zheng, C. H. Bioorg. Med. Chem. Lett. 2011, 21, 6674.
14. Liu, X. F.; Zhu, J.; Chen, Q. Q.; Zhu, J. Bioorg. Med. Chem. Lett. 2012, 22, 3554.
15. Structural data for compounds AQ-A1 to AQ-E9: AQ-A1: white solid; yield:
80.5%; mp: 202–204 °C; 1H NMR (300 MHz, DMSO) d 13.47 (s, 1H), 7.73 (d,
J = 8.5 Hz, 2H), 7.21 (s, 1H), 6.97 (d, J = 8.5 Hz, 2H), 4.80 (s, 1H), 3.79 (s, 3H),
3.35–3.34 (m, 4H); 13C NMR (300 MHz, DMSO) d 167.25, 162.72, 148.08,
134.00, 128.24, 127.88 (2C), 114.73(2C), 104.51, 64.45, 56.01, 46.12; IR (cmÀ1):
3367.14 (VO–H), 2896.84 (VCH2), 1636.81 (VC@O), 1580.01 (VC@C), 1402.12
(VC–N); HRMS: m/z (%): 260.1042 [MÀH]À. MS (ESI) m/z: 260.67 [MÀH]À,
262.66 [M+H]+. AQ-A6: white solid; yield: 86.5%; mp: 192–196 °C; 1H NMR
(600 MHz, DMSO) d 13.43 (s, 1H), 7.71 (d, J = 8.7 Hz, 2H), 7.23 (s, 1H), 7.03 (d,
J = 8.7 Hz, 2H), 4.76 (s, 1H), 3.78 (s, 3H), 3.62 (s, 3H), 3.39–3.34 (m, 4H); MS
(ESI) m/z: 274.90 [MÀH]À, 573.85 [2M+Na]+. AQ-A8: white solid; yield: 85%;
mp: 194–195 °C; 1H NMR (600 MHz, DMSO) d 13.44 (s, 1H), 7.73 (d, J = 8.7 Hz,
2H), 7.13 (s, 1H), 7.03 (d, J = 8.7 Hz, 2H), 4.60 (s, 1H), 3.79 (s, 3H), 3.54–3.33 (m,
8H); MS (ESI) m/z: 304.13 [MÀH]À, 306.17 [M+H]+. AQ-B1: White solid; yield:
81.3%; mp: 210–212 °C; 1H NMR (300 MHz, DMSO) d 13.97 (s, 1H), 8.29 (d,
J = 8.1 Hz, 2H), 8.05 (d, J = 8.1 Hz, 2H), 7.39 (s, 1H), 4.80 (s, 1H), 3.37–3.34 (m,
4H); 13C NMR (300 MHz, DMSO) d 165.88, 149.21, 147.54, 142.63, 135.62,
126.31 (2C), 124.64 (2C), 105.62, 64.93, 47.93; IR (cmÀ1): 3389.31 (VO–H),
2873.21 (VCH2), 1636.49 (VC@O), 1584.24 (VC@C), 1429.29 (VC–N); HRMS: m/
z (%): 275.0789 [MÀH]À. MS (ESI) m/z: 275.65 [MÀH]À, 277.70 [M+H]+. AQ-B2:
white solid; yield: 78.3%; mp: 182–184 °C; 1H NMR (300 MHz, DMSO) d 14.02
(s, 1H), 8.30 (d, J = 8.1 Hz, 2H), 8.10 (d, J = 8.1 Hz, 2H), 7.26 (s, 1H), 4.80 (s, 2H),
3.73 (t, J = 12.1 Hz, 4H), 3.60 (t, J = 12.1 Hz, 4H); MS (ESI) m/z: 319.68 [MÀH]À,
322.33 [M+H]+. AQ-B3: white solid; yield: 72.2%; mp: 203–204 °C; 1H NMR
(600 MHz, DMSO) d 13.94 (s, 1H), 8.31 (d, J = 8.1 Hz, 2H), 8.04 (d, J = 8.1 Hz,
2H), 7.36 (s, 1H), 4.49 (s, 1H), 3.48–3.43 (m, 2H), 3.37–3.27 (m, 2H), 1.69–1.67
(m, 2H); MS (ESI) m/z: 289.19 [MÀH]À, 291.12 [M+H]+. AQ-B4: white solid;
yield: 89%; mp: 215–217 °C; 1H NMR (300 MHz, DMSO) d 13.96 (s, 1H), 8.31 (d,
J = 8.2 Hz, 2H), 8.05 (d, J = 8.2 Hz, 2H), 7.42 (s, 1H), 4.80 (s, 1H), 3.79–3.77 (m,
1H), 3.30–3.11 (m, 2H), 1.07 (d, J = 6.1 Hz, 3H); MS (ESI) m/z: 289.15 [MÀH]À,
291.20 [M+H]+. AQ-B5: white solid; yield: 84.2%; mp: 180–181 °C; 1H NMR
(600 MHz, DMSO) d 13.98 (s, 1H), 8.30 (d, J = 8.1 Hz, 2H), 8.13 (d, J = 8.1 Hz,
2H), 7.25 (s, 1H), 4.34 (s, 2H), 3.62–3.59 (m, 2H), 1.34 (d, J = 7.1 Hz, 4H), 1.06 (d,
J = 12.8 Hz, 6H); MS (ESI) m/z: 347.73 [MÀH]À, 735.08 [2M+Na]+. AQ-B6: white
solid; yield: 83.1%; mp: 209–210 °C; 1H NMR (300 MHz, DMSO) d 14.01 (s, 1H),
8.29 (d, J = 8.1 Hz, 2H), 8.10 (d, J = 8.1 Hz, 2H), 7.29 (s, 1H), 4.79 (s, 1H), 3.63 (s,
3H), 3.32–3.29 (m, 4H); 13C NMR (300 MHz, DMSO) d 166.04, 148.91, 148.01,
142.71, 135.92, 127.03 (2C), 124.91 (2C), 105.82, 61.54, 54.58, 34.02. IR (cmÀ1):
DMSO)
d 167.42, 149.42, 148.53, 137.61, 134.21, 133.21, 129.79, 123.51,
122.23, 104.23, 72.96, 71.68, 63.40, 43.12; IR (cmÀ1): 3379.78 (VO–H), 2870.34
(VCH2), 1633.96 (VC@O), 1580.28 (VC@C), 1427.84 (VC–N), 1111.62 (VC–O–C);
HRMS: m/z (%): 319.1052 [MÀH]À. MS (ESI) m/z: 319.82 [MÀH]À, 321.40
[M+H]+. AQ-C9: white solid; yield: 79.5%; mp: 218–219 °C; 1H NMR (600 MHz,
DMSO) d 13.86 (s, 1H), 8.66 (s, 1H), 8.29 (d, J = 7.4 Hz, 1H), 8.21 (d, J = 7.7 Hz,
1H), 7.77 (t, J = 8.0 Hz, 1H), 7.30 (s, 1H), 4.84 (s, 3H), 3.68 (s, 6H); MS (ESI) m/z:
335.19 [MÀH]À, 337.07 [M+H]+. AQ-D1: white solid; yield: 89.5%; mp: 204–
205 °C; 1H NMR (600 MHz, DMSO) d 13.68 (s, 1H), 7.80 (d, J = 8.4 Hz, 2H), 7.71
(d, J = 8.4 Hz, 2H), 7.09 (s, 1H), 4.76 (s, 1H), 3.35–3.33 (m, 4H); MS (ESI) m/z:
308.10 [MÀH]À, 310.02 [M+H]+. AQ-D2: white solid; yield: 90.5%; mp: 193–
194 °C; 1H NMR (600 MHz, DMSO) d 13.58 (s, 1H), 7.77 (d, J = 8.4 Hz, 2H), 7.65
(d, J = 8.4 Hz, 2H), 7.06 (s, 1H), 4.79 (s, 2H), 3.70 (t, J = 12.1 Hz, 4H), 3.65 (t,
J = 12.1 Hz, 4H); 13C NMR (300 MHz, DMSO) d 166.08, 149.49, 135.28, 134.32,
132.51 (2C), 129.87 (2C), 123.78, 104.55, 62.56 (2C), 50.43 (2C); IR (cmÀ1):

4184
W. Tian et al. / Bioorg. Med. Chem. Lett. 23 (2013) 4177–4184
3386.12 (VO–H), 2875.31 (VCH2), 1632.32 (VC@O), 1588.50 (VC@C), 1416.36
1583.27 (VC@C), 1405.43 (VC–N); HRMS: m/z (%): 274.1200 [MÀH]À. MS (ESI)
m/z: 274.83 [MÀH]À, 573.91 [2M+Na]+. AQ-E3: white solid; yield: 87.5%; mp:
182–184 °C; 1H NMR (600 MHz, DMSO) d 13.58 (s, 1H), 7.80 (d, J = 7.4 Hz, 2H),
7.31 (t, J = 7.5 Hz, 2H), 7.35–7.29 (m, 1H), 7.06 (s, 1H), 4.50 (s, 1H), 3.45 (t,
J = 6.1 Hz, 2H), 3.34 (t, J = 6.7 Hz, 2H), 1.68–1.63 (m, 2H); 13C NMR (300 MHz,
DMSO) d 164.44, 149.39, 136.70, 134.11,129.55 (2C), 128.80, 127.52 (2C),
104.12, 60.24, 39.96, 34.69; IR (cmÀ1): 3388.27 (VO–H), 2877.73 (VCH2),
1616.93 (VC@O), 1589.87 (VC@C), 1421.04 (VC–N); HRMS: m/z (%): 244.1094
[MÀH]À. MS (ESI) m/z: 244.24 [MÀH]À. AQ-E4: white solid; yield: 88.4%; mp:
191–194 °C; 1H NMR (300 MHz, DMSO) d 13.59 (s, 1H), 7.80 (d, J = 7.4 Hz, 2H),
7.31 (t, J = 7.5 Hz, 2H), 7.34–7.28 (m, 1H),7.13 (s, 1H), 4.73 (s, 1H), 3.81–3.76
(m, 1H), 3.30–3.11 (m, 2H), 1.17 (d, J = 6.1 Hz, 3H); 13C NMR (300 MHz, DMSO)
d 165.27, 149.33, 136.18, 134.31, 129.06 (2C), 128.07, 127.64 (2C), 103.98,
69.78, 53.03, 20.68; IR (cmÀ1): 3388.56 (VO–H), 2934.07 (VCH3), 2878.91
(VCH2), 1638.77 (VC@O), 1595.65 (VC@C), 1422.39 (VC–N); HRMS: m/z (%):
244.1092 [MÀH]À. MS (ESI) m/z: 244.17 [MÀH]À, 246.17 [M+H]+. AQ-E5: white
solid; yield: 89.1%; mp: 195–196 °C; 1H NMR (600 MHz, DMSO) d 13.95 (s, 1H),
7.79 (d, J = 7.4 Hz, 2H), 7.30 (t, J = 7.5 Hz, 2H), 7.32–7.27 (m, 1H), 7.24 (s, 1H),
4.32 (s, 2H), 3.62–3.59 (m, 2H), 1.35 (d, J = 7.1 Hz, 4H), 1.06 (d, J = 12.8 Hz, 6H);
MS (ESI) m/z: 302.24 [MÀH]À. AQ-E6: white solid; yield: 83.3%; mp: 176–
178 °C; 1H NMR (300 MHz, DMSO) d 13.60 (s, 1H), 7.82 (d, J = 7.4 Hz, 2H), 7.33
(t, J = 7.5 Hz, 2H), 7.30–7.26 (m, 1H), 6.98 (s, 1H), 4.76 (s, 1H), 3.62 (s, 3H),
3.37–3.33 (m, 4H); MS (ESI) m/z: 244.80 [MÀH]À, 513.72 [2M+Na]+. AQ-E9:
white solid; yield: 89.1%; mp: 179–181 °C; 1H NMR (600 MHz, DMSO) d 13.63
(s, 1H), 7.82 (d, J = 7.4 Hz, 2H), 7.40 (t, J = 7.5 Hz, 2H), 7.37–7.29 (m, 1H), 7.06 (s,
1H), 4.92 (s, 3H), 3.66 (s, 6H); MS (ESI) m/z: 325.97 [M+Cl]À.
(VC–N); HRMS: m/z (%): 354.0445 [M+H]+, 252.0302 [MÀH]À. MS (ESI) m/z:
352.17 [MÀH]À, 354.10 [M+H]+. AQ-D3: white solid; yield: 91.2%; mp: 199–
200 °C; 1H NMR (600 MHz, DMSO) d 13.65 (s, 1H), 7.74 (d, J = 8.4 Hz, 2H), 7.66
(d, J = 8.4 Hz, 2H), 7.16 (s, 1H), 4.50 (s, 1H), 3.48 (t, J = 6.1 Hz, 2H), 3.33 (t,
J = 6.7 Hz, 2H), 1.70–1.65 (m, 2H); 13C NMR (300 MHz, DMSO) d 165.35, 149.51,
135.49, 134.12, 133.16 (2C), 129.98 (2C), 123.80, 105.12, 60.52, 40.24, 34.97; IR
(cmÀ1): 3372.22 (VO–H), 2869.81 (VCH2), 1631.08 (VC@O), 1588.30 (VC@C),
1408.23 (VC–N); HRMS: m/z (%): 324.0199 [M+H]+. MS (ESI) m/z: 322.13
[MÀH]À, 324.06 [M+H]+. AQ-D4: white solid; yield: 88.3%; mp: 209–211 °C; 1
H
NMR (600 MHz, DMSO)
d 13.61 (s, 1H), 7.75 (d, J = 8.4 Hz, 2H), 7.66 (d,
J = 8.4 Hz, 2H), 7.20 (s, 1H), 4.78 (s, 1H), 3.79–3.75 (m, 1H), 3.30–3.10 (m, 2H),
1.17 (d, J = 6.1 Hz, 3H); MS (ESI) m/z: 322.14 [MÀH]À, 324.11 [M+H]+. AQ-D6:
white solid; yield: 86.5%; mp: 213–215 °C; 1H NMR (600 MHz, DMSO) d 13.62
(s, 1H), 7.82 (d, J = 8.4 Hz, 2H), 7.66 (d, J = 8.4 Hz, 2H), 7.03 (s, 1H), 4.76 (s, 1H),
3.62 (s, 3H), 3.38–3.34 (m, 4H); MS (ESI) m/z: 322.15 [MÀH]À, 324.10 [M+H]+.
AQ-D8: white solid; yield: 82.1%; mp: 192–193 °C; 1H NMR (600 MHz, DMSO)
d 13.47 (s, 1H), 7.75 (d, J = 8.4 Hz, 2H), 7.66 (d, J = 8.4 Hz, 2H), 7.17 (s, 1H), 4.59
(s, 1H), 3.51–3.30 (m, 8H); 13C NMR (75 MHz, DMSO) d 166.85, 149.00, 135.33,
134.23, 132.34 (2C), 129.22 (2C), 123.65, 104.68, 72.83, 71.38, 63.57, 43.48; IR
(cmÀ1): 3400.83 (VO–H), 2874.25 (VCH2), 1639.19 (VC@O), 1429.00 (VC–N),
1587.68 (VC@C), 1118.82 (VC–O–C); HRMS: m/z (%): 352.0302 [MÀH]À. MS
(ESI) m/z: 354.86 [M+H]+. AQ-E1: white solid; yield: 78.5%; mp: 191–194 °C;
1H NMR (300 MHz, DMSO) d 13.62 (s, 1H), 7.84 (d, J = 7.4 Hz, 2H), 7.44 (t,
J = 7.5 Hz, 2H), 7.39–7.30 (m, 1H),7.36 (s, 1H), 4.80 (s, 1H), 3.82–3.71 (m, 4H);
MS (ESI) m/z: 230.27 [MÀH]À, 232.14 [M+H]+. AQ-E2: white solid; yield: 77.5%;
mp: 190–192 °C; 1H NMR (300 MHz, DMSO) d 13.77 (s, 1H), 7.83 (d, J = 7.4 Hz,
2H), 7.41 (t, J = 7.5 Hz, 2H), 7.40–7.32 (m, 1H), 7.01 (s, 1H), 4.80 (s, 2H), 3.71 (t,
J = 12.1 Hz, 4H), 3.59(t, J = 12.1 Hz, 4H); 13C NMR (300 MHz, DMSO) d 162.20,
149.63, 136.55, 134.72, 129.93 (2C), 128.56, 127.32 (2C), 105.10, 62.77 (2C),
50.49 (2C); IR (cmÀ1): 3391.57 (VO–H), 2876.52 (VCH2), 1623.54 (VC@O),
16. Kennedy, W. P.; Kaminski, J. N.; Vanderven, H. H.; Jeyendran, R. S.; Reid, D. S.;
Blackwell, J.; Bielfeld, P.; Zaneveld, L. J. J. Androl. 1989, 10, 221.
17. DISCOVERY STUDIO 2.5 Software Package AI, San Diego, CA (USA): <http://
www.accelrys.com>.