Design, synthesis, and antihyperlipidemic evaluation of novel 2-[1-(Substitutedphenyl)-4-oxo-azetidin-2-yl]-5,6-disubstitutedthieno[2,3-d] pyrimidin-4(3H)-ones

Article abstract of DOI:10.1002/ardp.201300001

Novel thienopyrimidine derivatives of azetidinone possessing the combined features of the cholesterol absorption inhibitor drug ezetimibe and potential antihyperlipidemic 2-substitutedthienopyrimidin-4-ones were synthesized and characterized by spectrosco

Full text of DOI:10.1002/ardp.201300001

588
Arch. Pharm. Chem. Life Sci. 2013, 346, 588–595
Full Paper
Design, Synthesis, and Antihyperlipidemic Evaluation of Novel
2-[1-(Substitutedphenyl)-4-oxo-azetidin-2-yl]-5,6-disubstituted-
thieno[2,3-d]pyrimidin-4(3H)-ones
Nikhilesh Arya1,2, Manoj K. Munde3, Jaya Dwivedi2, Archana Y. Jagdale1, and Kishor S. Jain1
1
Department of Pharmaceutical Chemistry, Sinhgad Institute of Pharmaceutical Sciences, Lonavala, Pune,
India
2
Department of Chemistry, Banasthali University, Tonk, Rajasthan, India
Department of Pharmaceutical Chemistry, Modern College of Pharmacy, Pune, India
3
Novel thienopyrimidine derivatives of azetidinone possessing the combined features of the cholesterol
absorption inhibitor drug ezetimibe and potential antihyperlipidemic 2-substitutedthienopyrimidin-4-
ones were synthesized and characterized by spectroscopic data and elemental analysis. These
compounds were evaluated for their lipid-lowering activity in Wistar albino rats. Some of them showed
significant lipid-lowering effects comparable to those of the standard drug, gemfibrozil, at the same
dose levels.
Keywords: Antihyperlipidemic / Azetidinone / Gewald / Thienopyrimidines
Received: January 3, 2013; Revised: May 7, 2013; Accepted: June 12, 2013
DOI 10.1002/ardp.201300001
Introduction
drugs needed to be developed, to bring about regression of the
already existing atherosclerotic lesions and the most widely
used “statins” also suffer from limitations like cost, intoler-
ance, and adverse effects, ineffective, or only partially effective
in lowering of cholesterol levels and thus capable of reducing
only up to 40% risk of CHD.
Development of newer LLA with mechanism of action
distinct from statins are now required to achieve target
cholesterol and Tg levels in many individuals [2]. Antihyper-
lipidemic activity has been reported in some thieno[2,3-d]-
pyrimidine derivatives, 1–4 [3–6]. The detail pharmacokinetics
and pharmacodynamics studies on compound 4 suggested
the gastrointestinal tract to be the primary site of action for its
antihyperlipidemic activity [7].
Congestive heart disease (CHD) and stroke remain the leading
causes of death and disability across the world. In both cases,
the risk factor is directly related to atherosclerosis [1], which
in turn is linked to increased levels of lipids, mainly the
cholesterol and triglycerides (Tg) in the blood.
Though many drug therapies are available in the form of
the fibrates, lipid-lowering agents (LLA), including the statins
(HMG CoA reductase inhibitors), as well as the recently
introduced cholesterol absorption inhibitors drugs like
ezetimibe, a few limitations and drawbacks with these drugs
still continue to plague the current therapy for hyperlipid-
emia, with one or more of the problems; presently, no good
drugs are available for covering the hitherto untreatable cases
of type II hyperlipidemia, wherein drugs like clofibrate,
nicotinic acid, D-thyroxin, etc. are used without much success.
Also no drugs capable of blocking the stimuli that lead to the
formation of an atherosclerotic lesion are available. New
O
O
R1
R2
R1
R2
R
NH
N
S
S
N
COOH
S
S
N
O
SH
1
2
O
R1
R2
Correspondence: Dr. Kishor S. Jain, Department of Pharmaceutical
Chemistry, Sinhgad Institute of Pharmaceutical Sciences, S. No. 309/310,
Kusgaon (Bk.), Off. Mumbai-Pune Expressway, Lonavala, Pune 410 401,
Maharashtra, India.
E-mail: drkishorsjain@gmail.com
Fax: þ91-2114-270258
NH
NH
Cl
X
N
N
3
4
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Arch. Pharm. Chem. Life Sci. 2013, 346, 588–595
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589
Further, a detailed QSAR study, of isomeric 2-substituted-
thieno[3,2-d]pyrimidin-4(3H)-ones 5 and 6, indicated the
direct positive influence of the electronic nature of the 2-
substituents of these compounds on their antihyperlipidemic
activity [8]. Thus, the mechanism of action of these
compounds appears to be through the inhibition of
cholesterol absorption through the gastrointestinal tract.
have produced ligands that act on a variety of targets [13]. The
so called dual acting drugs can be designed by overlapping the
pharmacophores of two drugs into a single chemical entity by
taking advantage of common structural features of two or
more classes of drugs. There are numerous examples of hybrid
molecules wherein dual bioactivities have been packed into
a single chemical entity [13]. So it was thought to logically
hybridize these two potential pharmacophores, i.e., 2-substi-
tuted methylthienopyrimidin-4(3H)-one (A) and ezetimibe (B),
and evaluate the new hybrid structures in the series for their
lipid-lowering activities. Further, a systematic probe into the
synthesis and evaluation in the series I–III for their lipid-
lowering properties and detailed QSAR studies was planned.
N
O
N
R
R
NH
NH
N
S
S
O
6
5
HO
F
R = H, Cl, OCH3, OC2H5, OH
O
N
F
NH
N
R
O
The condensed 2-substituted alkylpyrimidine nucleus, 7,
appears to be a potential pharmacophore for antihyperlipi-
demic activity.
OH
B
A
O
NH
O
R
R3
R1
R2
N
NH
S
N
N
7
O
_
Target compounds (5a l)
Recently, more potent analogs of 4 have been prepared
through subtle manipulation of the substituent at the 2-
and 4-positions of the condensed 2-substituted pyrimidine
pharmacophore, 7, and evaluated in hyperlipidemic rats to
give results comparable to gemfibrozil and ezetimibe [9, 10].
R2
N
X
N
R4
R3
R4
R4
R1
X
R1
R2
N
O
N
N
N
N
X
N
O
O
N
R1
R3
R3
R2
Ezetimibe, chemically an azetidinone, is
a selective
III
II
I
cholesterol absorption inhibitor, blocking Niemann-Pick C1-
Like1 (NPC1L1) protein involved in cholesterol absorption in
the proximal part of small intestine [11, 12]. It reduces LDL-C
between 10–19% in monotherapy. Interestingly, the reduction
Thus, with this broad goal in mind initially, we have
completed the work on series of 2-[1-(substitutedphenyl)-4-
azetidin-2-yl]-5,6-disubstitutedthieno[2,3-d]pyrimidin-4-ones
(5a–l), which were synthesized and their ability to inhibit
cholesterol absorption was evaluated.
of LDL-C in combination of ezetimibe with
a statin
(simvastatin or atorvastatin) is additive. It has opened the
doors for the design and synthesis of new potential cholesterol
absorption inhibiting drugs, in this class of compounds.
HO
F
O
R3
R1
R2
NH
F
N
S
N
N
O
O
_
5a l
OH
Ezetimibe
Rational designing approaches in which structural features
from selected ligands are combined into one single entity
where R1, R2 ¼ aryl, cycloalkyl, H, etc.; R3 ¼ H, alkyl, halo,
etc.
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N. Arya et al.
Arch. Pharm. Chem. Life Sci. 2013, 346, 588–595
O
O
N
R1
R2
R1
R2
OC2H5
NH2
NH
N
(a)
Cl
S
S
Cl
1
2
(b)
O
N
O
N
R1
R2
R1
R2
NH
Cl
NH
(c)
R3
R3
H
N
S
N
S
3
O
4
(d)
O
N
R1
R2
NH
R3
S
N
O
5
Where, R1, R2 = -(CH2)4-, -(CH2)5-, 4-ClC6H5 ;
Scheme 1. Reagents and conditions: (a) conc.
HCl/MWI; (b) Ar–NH2, DMF/reflux; (c) ClCH2COCl,
K2CO3, CH2Cl2/RT; (d) NaH/DMSO 60–65°C,
CH2Cl2/RT.
R3 = H, 2-CH3, 3-CH3, 4-CH3, 4-OCH3, 4-F, 4-Br.
Results and discussion
et al. [14]. The first step involved the cyclocondensation of 1,
with chloroacetonitrile under acidic conditions and MWI, to
yield the corresponding condensed 2-chloromethylpyrimidin-
4-ones (2a, 2b, and 2c, Table 2) in good yields by a procedure
reported by us [15]. The second step involved the nucleophilic
displacement of the chlorine of the 2-chloromethyl group
with various substituted anilines in refluxing DMF in
presence of three to four drops of conc. HCl as a catalyst,
Chemistry
The title compounds, 5a–l, were prepared through a 4-step
synthetic protocol as depicted in Scheme 1. The starting
materials, thiophene-o-aminoesters (1a, 1b, and 1c, Scheme 1,
Table 1) were chosen as the substrates and are often referred to
as “Gewalds” after the reported method given by Gewald
Table 1. Physical data of synthesized compounds 1a–c.
Compound
R1
R2
Molecular formula
Molecular weight
Melting point (°C)
1a
1b
1c
–(CH2)4–
4-ClC6H4
–(CH2)5–
C11H15NO2S
C13H12ClNO2S
C12H17NO2S
225.31
281.76
239.33
110–112
102–104
115–118
–H
Table 2. Physical data of synthesized compounds 2a–c.
Compound
R1
R2
Molecular formula
Molecular weight
Melting point (°C)
2a
2b
2c
–(CH2)4–
4-ClC6H4
–(CH2)5–
C11H11ClN2OS
C13H8Cl2N2OS
C12H13ClN2OS
254.74
311.19
268.76
275–277
233–234
261–265
–H
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Arch. Pharm. Chem. Life Sci. 2013, 346, 588–595
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Table 3. Physical data of synthesized compounds 3a–l.
Compound
R1
R2
R3
Molecular formula
Molecular weight
Melting point (°C)
3a
3b
3c
3d
3e
3f
3g
3h
3i
–(CH2)4–
–(CH2)4–
–(CH2)4–
–(CH2)4–
4-ClC6H4
4-ClC6H4
4-ClC6H4
4-ClC6H4
–(CH2)4–
–(CH2)4–
–(CH2)4–
–(CH2)5–
–H
2-CH3
4-CH3
4-F
C17H17N3OS
C18H19N3OS
C18H19N3OS
311.4
186–190
220–223
160–162
150–152
75–77
111–115
170–172
85–88
152–155
171–175
140–143
180–183
325.43
325.43
329.39
367.85
381.88
381.88
385.84
325.43
341.43
390.3
C17H16FN3OS
C19H14ClN3OS
C20H16ClN3OS
C20H16ClN3OS
C19H13ClFN3OS
C18H19N3OS
C18H19N3O2S
C17H16BrN3OS
C18H18FN3OS
–H
–H
–H
–H
–H
2-CH3
4-CH3
4-F
3-CH3
4-OCH3
4-Br
3j
3k
3l
4-F
343.42
Table 4. Physical data of synthesized compounds 4a–l.
Compound
R1
R2
R3
Molecular formula
Molecular weight
Melting point (°C)
4a
4b
4c
4d
4e
4f
4g
4h
4i
–(CH2)4–
–(CH2)4–
–(CH2)4–
–(CH2)4–
4-ClC6H4
4-ClC6H4
4-ClC6H4
4-ClC6H4
–(CH2)4–
–(CH2)4–
–(CH2)4–
–(CH2)5–
–H
2-CH3
4-CH3
4-F
C19H18ClN3O2S
C20H20ClN3O2S
C20H20ClN3O2S
C19H17ClFN3O2S
C21H15Cl2N3O2S
C22H17Cl2N3O2S
C22H17Cl2N3O2S
C21H14Cl2FN3O2S
C20H20ClN3O2S
C20H20ClN3O3S
C19H17BrClN3O2S
C20H19ClFN3O2S
387.88
401.91
401.91
405.87
444.33
458.36
458.36
462.32
401.91
417.91
466.78
419.9
96–100
203–205
170–172
125–127
125–130
80–82
85–87
92–94
150–154
110–113
132–135
108–111
–H
–H
–H
–H
–H
2-CH3
4-CH3
4-F
3-CH3
4-OCH3
4-Br
4j
4k
4l
4-F
to afford the requisite 2-substitutedphenylaminomethyl-5,6-
disubstitutedthieno[2,3-d]pyrimidin-4-ones (3a–l, Table 3) in
good yields. These intermediates were further N-acylated
using chloroacetyl chloride under anhydrous conditions to
yield 4a–l (Scheme 1, Table 4), which on further cyclization
under basic conditions afforded the target molecules (5a–l,
Scheme 1, Table 5). The structural assignments of the
intermediates 2–4 and target compounds 5a–l are based on
the correct spectral data and elemental analysis of these
compounds.
Pharmacological activity
Hyperlipidemia is a condition characterized by increased
concentration of lipids (triglyceride, cholesterol) and
Table 5. Physical data of synthesized compounds 5a–l.
Compound
R1
R2
R3
Molecular formulaa)
Molecular weight
Melting point (°C)
5a
5b
5c
5d
5e
5f
5g
5h
5i
–(CH2)4–
–(CH2)4–
–(CH2)4–
–(CH2)4–
4-ClC6H4
4-ClC6H4
4-ClC6H4
4-ClC6H4
–(CH2)4–
–(CH2)4–
–(CH2)4–
–(CH2)5–
–H
2-CH3
4-CH3
4-F
C19H17N3O2S
C20H19N3O2S
C20H19N3O2S
C19H16FN3O2S
C21H14ClN3O2S
C22H16ClN3O2S
C22H16ClN3O2S
C21H13ClFN3O2S
C20H19N3O2S
351.42
365.45
365.45
369.41
407.87
421.9
70–72
210–212
182–185
206–208
190–192
180–182
186–188
179–182
140–143
135–138
126–130
130–133
–H
–H
–H
–H
–H
2-CH3
4-CH3
4-F
3-CH3
4-OCH3
4-Br
421.9
425.86
365.45
381.45
430.32
383.44
5j
5k
5l
C20H19N3O3S
C19H16BrN3O2S
C20H18FN3O2S
4-F
a)
Satisfactory elemental analysis (ꢀ0.4 of the calculated values of % C, % H, and % N obtained).
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Table 6. Biological data profile of synthesized compounds (5a–h).
% Reduction in total
cholesterol (mg/dL)
% Reduction in total
triglyceride (mg/dL)
% Change in total
HDL (mg/dL)
Compound
R1
R2
R3
5a
5b
5c
5d
5e
5f
5g
5h
Std
–(CH2)4–
–(CH2)4–
–(CH2)4–
–(CH2)4–
4-ClC6H4
4-ClC6H4
4-ClC6H4
4-ClC6H4
Gemfibrozil
–H
2-CH3
4-CH3
4-F
33.50 ꢀ 3.35
46.83 ꢀ 3.01
7.15 ꢀ 1.84
24.83 ꢀ 2.21
38.16 ꢀ 2.13
19.77 ꢀ 3.01
26.37 ꢀ 1.99
22.74 ꢀ 1.63
42.42 ꢀ 1.2
22.97 ꢀ 3.09
67.42 ꢀ 2.70
54.77 ꢀ 3.25
41.47 ꢀ 2.55
48.22 ꢀ 2.82
72.62 ꢀ 2.84
44.81 ꢀ 2.66
23.30 ꢀ 2.55
37.57 ꢀ 1.68
31.87 ꢀ 2.36
27.49 ꢀ 2.40
33.17 ꢀ 2.98
19.14 ꢀ 2.24
19.90 ꢀ 3.12
28.87 ꢀ 1.86
27.62 ꢀ 2.72
24.21 ꢀ 2.73
35.1 ꢀ 1.3
–H
–H
–H
–H
–H
2-CH3
4-CH3
4-F
Results are expressed as mean ꢀ standard error, statistically significant (p < 0.05, t-test, n ¼ 6). The results of the eight compounds
selected for screening were correlated statistically. Triton WR 1339 model with regression r ¼ 0.9, i.e., showed good correlation.
lipoprotein (LDL and VLDL) in the blood. Triton WR 1339
induced hyperlipidemia in Wistar albino rat [16] was the
model used for the biological evaluation of title compounds.
This model is less time consuming, rapid, robust, and requires
smaller quantity of test compounds for evaluation. The lipid
profile (cholesterol, triglycerides, and HDL) for the hyper-
lipidemic and control Wistar albino rats were studied
with oral administration of selected test compounds (5a–h,
serum triglyceride levels in the test animals; i.e., % reduction
72.62 ꢀ 2.84, 67.42 ꢀ 2.70, 54.77 ꢀ 3.25, 48.22 ꢀ 2.82,
44.81 ꢀ 2.66, 41.47 ꢀ 2.55, respectively, as compared to
standard 37.57 ꢀ 1.68% (Fig. 2).
The test compounds 5c and 5a have elevated the serum
HDL levels (31.87 ꢀ 2.36% and 33.17 ꢀ 2.98%, respectively)
though slightly less than the standard (35.1 ꢀ 1.3%) (Fig. 3).
Table 6). Total eight test compounds were evaluated and, thus, Conclusion
eight test groups were involved in the study. Besides this,
gemfibrozil was administered to the standard group. Further,
two more animal groups were taken, the control group and
the cholesterol control group, to assess and compare the
effects of cholesterol and the test compounds as well as
standard drug, on the lipid levels of test animals in the study.
It was found from the results that the test compounds
showed significant changes in lipid profile, i.e., decrease in
total cholesterol, triglycerides and increase in HDL at dose of
400 mg/kg body weight p.o. as compared to the hyper-
lipidemic group (Figs. 1–3).
The compounds 5b, 5e, and 5a have shown good reduction
in % cholesterol level showing 46.83 ꢀ 3.01%, 38.16 ꢀ 2.13%,
and 33.50 ꢀ 3.35%, respectively, which is comparable to the
standard 42.42 ꢀ 1.2% (Fig. 1). The test compounds 5f, 5b,
5c, 5e, 5g, and 5d have shown good ability in reducing the
Some novel 2-(N-aryl-4-oxo)azetidinyl-5,6-disubstitutedthieno-
[2,3-d]pyrimidin-4(3H)-one derivatives (5a–l) were synthesized
and were screened in Triton WR 1339-induced hyperlipidemic
rats, for antihyperlipidemic activity. The present investigation
showed significant antihyperlipidemic activity to some of
these compounds, comparable to the standard drug, gemfi-
brozil. Compound 5b was found to be the most active of all
the compounds, exhibiting significant lipid-lowering effects
like reducing serum levels of cholesterol and triglycerides in
test animals. Another derivative, compound 5c significantly
elevated the serum HDL levels in test animals.
Hence the present series could be developed and evaluated
to obtain potential antihyperlipidemic agents. However,
further structural modifications are planned towards lead
optimization.
Figure 1. % Reduction in total serum choles-
terol levels.
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Arch. Pharm. Chem. Life Sci. 2013, 346, 588–595
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Figure 2. % Reduction in serum triglyceride
levels.
Figure 3. % Change in serum HDL level.
Experimental
General procedure for the preparation of compounds 3a–l
The reaction mixture of the condensed 2-chloromethylpyrimidin-
4-one (2) (0.01 mol), aryl amine (0.015 mol), and three to four
drops of conc. HCl in DMF (20 mL) was refluxed for 8–10 h. On
completion of reaction (TLC), the reaction mixture was cooled and
poured onto ice-water mixture (50 mL). The solid separated was
washed with dilute HCl followed by water and filtered under
vacuum, dried, and recrystallized to give the desired compound 3.
General
All the synthesized compounds were characterized by spectral
data (UV, IR, mass, and 1H NMR). The ultraviolet (UV) absorption
spectra were determined in methanol on JASCO V-530, UV–Visible
double beam spectrophotometer (Easton, USA). The IR spectra of
the synthesized compounds were recorded on Perkin Elmer
BX-FTIR spectrophotometer (Massachusetts, USA) in potassium
bromide discs. The 1H NMR were taken on a NMR Varian Mercury
YH-300 MHz spectrometer (California, USA) using CDCl3 as
solvent and TMS as an internal standard (chemical shift in d
ppm). Mass spectra were obtained on a Shimadzu GCMS-QP2010
spectrometer (Kyoto, Japan). The purity of the compounds was
monitored by elemental analysis and thin-layer chromatography.
Elemental analyses for compounds were obtained using a Flash
EA 1112 Thermofinnigan instrument (San Diego, USA). TLC silica
gel 60 F254 plates (200 mm; Merck, Darmstadt, Germany) were
used to assess preliminary purity of compounds. All melting
points were taken in open capillaries using a Veego electronic
melting point apparatus model MP-D (Mumbai, India) containing
silicon oil bath with stirrer and are uncorrected.
General procedure for the preparation of compounds 4a–l
To a vigorously stirred mixture of 3 (0.01 mol) and activated
potassium carbonate (0.01 mol) in anhydrous DCM (50 mL) at RT
was added chloroacetyl chloride (0.015 mol) dropwise over
30 min. On completion of the reaction (TLC), the reaction
mixture was poured onto ice-water (100 mL), the organic layer
separated and was washed successively with aqueous sodium
bicarbonate solution (10% w/v), brine solution, and water. The
dried organic layer (Na2SO4) was distilled (vacuum) and the
product was recrystallized to give the desired compound 4.
General procedure for the preparation of compounds 5a–l
Sodium hydride (50% w/w, 0.6 g, 0.02 mol) in DMSO (10 mL) was
warmed on oil bath at 60–65°C under vigorous stirring until the
color of the solution turned light brown and then cooled to RT. To
the above suspension, the solution of 4 (0.01 mol) in DCM (30 mL)
was added dropwise with stirring. The reaction mixture was
further stirred till the completion of reaction (TLC) and thereafter
quenched with water. The organic layer was washed with dilute
HCl. The dried organic layer (Na2SO4) was distilled (vacuum) and
the product was recrystallized to give the desired compound 5.
Triton WR 1339 (Sigma, Bangalore, India) were procured
commercially. The total lipid profile was determined by using
infinite liquid cholesterol solution ready to use diagnostic kits
(Accurex India Biomedicals, Mumbai, India). All the biological
activity carried out in this study was approved by the Institutional
Animal Ethics Committee (SCOP/IAEC/Approval/2008-09/24).
Chemistry
The starting materials, thiophene-o-aminoesters (1a, 1b, and 1c)
and the condensed 2-chloro-methylpyrimidin-4-ones (2a, 2b,
and 2c) were prepared as per reported methods [14, 15]. The
synthetic steps a, b, and c are based on literature reported
procedures [5, 17, 18].
2-[1-Phenyl-4-oxo-azetidin-2-yl]-5,6,7,8-tetrahydrobenzo-
(b)thieno[2,3-d]pyrimidin-4(3H)-one (5a)
IR (KBr): 3310, 2926, 2854, 1754, 1682, 1450, 1240, 1034 cmꢁ1
;
1H NMR (300 MHz, CDCl3): d ¼ 8.04 (s, 1H, NH), 7.11–7.62 (m, 5H,
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ArH), 4.24 (m, 1H, CH at azetidinyl-2), 3.65 (d, 2H, CH2 at
azetinidinyl-3), 2.66–2.75 (t, 4H, CH2 at 5 and 8), 2.34–2.41 (m, 4H,
CH2 at 6 and 7); MS (TOF): m/z ¼ 352 (Mþ1); C19H17N3O2S (351.42);
requires (Found): C, 64.94 (64.57); H, 4.88 (4.66); N, 11.96 (11.68).
5-(4-Chlorophenyl)-2-[1-(4-fluorophenyl)-4-oxo-azetidin-2-
yl]thieno[2,3-d]pyrimidin-4(3H)-one (5h)
IR (KBr): 3270, 2937, 1689, 1536, 1278, 814 cmꢁ1 1H NMR
;
(300 MHz, CDCl3): d ¼ 8.0 (s, 1H, NH), 7.1–7.73 (m, 9H, ArH and H
at 6), 4.15 (m, 1H, CH at azetidinyl-2), 3.45 (m, 2H, CH2 at
azetidinyl-3); C21H13ClFN3O2S (425.86); requires (Found): C, 59.23
(59.61); H, 3.08 (2.97); N, 9.87 (9.82).
2-[1-(2-Methylphenyl)-4-oxo-azetidin-2-yl]-5,6,7,8-
tetrahydrobenzo(b)thieno[2,3-d]pyrimidin-4(3H)-one (5b)
IR (KBr): 3248, 2932, 2856, 1748, 1686, 1532, 1492, 1237, 1194,
2-[1-(3-Methylphenyl)-4-oxo-azetidin-2-yl]-5,6,7,8-
1155, 1036, 966 cmꢁ1
;
1H NMR (300 MHz, CDCl3): d ¼ 7.2–7.8
tetrahydrobenzo(b)thieno[2,3-d]pyrimidin-4(3H)-one (5i)
(m, 5H, ArH and NH), 3.72–3.73 (m, 1H, CH at azetidinyl-2), 3.54–
3.59 (d, 2H, CH2 at azetinidinyl-3), 2.88–3.02 (m, 4H, CH2 at 5 and
8), 2.68–2.72 (s, 3H, CH3), 2.2–2.34 (m, 4H, CH2 at 6 and 7); MS (TOF):
m/z ¼ 366 (Mþ1); C20H19N3O2S (365.45); requires (Found): C, 65.73
(66.02); H, 5.24 (5.61); N, 11.50 (11.37).
IR (KBr): 3250, 2936, 2363, 1776, 1654, 1598, 1232, 1119,
965 cmꢁ1
;
1H NMR (300 MHz, CDCl3): d ¼ 7.2–7.9 (m, 5H, ArH
and NH), 3.46–3.53 (m, 1H, CH at azetidinyl-2), 2.90–3.04 (m, 2H,
CH2 at azetidinyl-3), 2.51–2.62 (m, 4H, CH2 at 5 and 8), 2.28 (s, 3H),
1.85–2.01 (m, 4H, CH2 at 6 & 7); MS (TOF): m/z ¼ 366 (Mþ1);
C20H19N3O2S (365.45); requires (Found): C, 65.73 (65.63); H, 5.24
(5.42); N, 11.50 (11.27).
2-[1-(4-Methylphenyl)-4-oxo-azetidin-2-yl]-5,6,7,8-
tetrahydrobenzo(b)thieno[2,3-d]pyrimidin-4(3H)-one (5c)
IR (KBr): 3275, 2929, 1676, 1608, 1452, 1210, 1035, 975 cmꢁ1
;
2-[1-(4-Methoxyphenyl)-4-oxo-azetidin-2-yl]-5,6,7,8-
1H NMR (300 MHz, CDCl3): d ¼ 6.93–7.67 (m, 5H, ArH and NH),
3.24–3.30 (m, 1H, CH at azetidinyl-2), 2.8–2.92 (d, 2H, CH2 at
azetinidinyl-3), 2.67–2.70 (s, 3H, CH3), 2.55–2.63 (m, 4H, CH2 at 5
and 8), 1.83–1.94 (m, 4H, CH2 at 6 and 7); C20H19N3O2S (365.45);
requires (Found): C, 65.73 (65.52); H, 5.24 (5.43); N, 11.50 (11.64).
tetrahydrobenzo(b)thieno[2,3-d]pyrimidin-4(3H)-one (5j)
IR (KBr): 3275, 2948, 2878, 2348, 1651, 1455, 1237, 1002 cmꢁ1; 1H
NMR (300 MHz, CDCl3): d ¼ 7.2–7.9 (m, 5H, ArH and NH), 3.30–3.38
(m, 1H, CH at azetidinyl-2), 3.19 (d, 2H, CH2 at azetidinyl-3), 2.88 (s,
3H, ArOCH3), 2.37–2.51 (m, 4H, CH2 at 5 and 8), 1.94–2.10 (m, 4H, CH2
at 6 and 7); MS (TOF): m/z ¼ 382 (Mþ1); C20H19N3O3S (381.45);
requires (Found): C, 62.98 (63.11); H, 5.02 (5.31); N, 11.02 (11.13).
2-[1-(4-Fluorophenyl)-4-oxo-azetidin-2-yl]-5,6,7,8-
tetrahydrobenzo(b)thieno[2,3-d]pyrimidin-4(3H)-one (5d)
IR (KBr): 2937, 2856, 1752, 1683, 1509, 1448, 1231, 1155, 1034,
966, 840 cmꢁ1; 1H NMR (300 MHz, CDCl3): d ¼ 7.14–7.77 (m, 5H,
ArH and NH), 3.19–3.33 (m, 1H, CH at azetidinyl-2), 2.73–2.77 (d,
2H, CH2 at azetinidinyl-3), 2.15–2.26 (m, 4H, CH2 at 5 and 8), 1.7–
2.0 (m, 4H, CH2 at 6 and 7); MS (TOF): m/z ¼ 370 (Mþ1);
C19H16FN3O2S (369.41); requires (Found): C, 61.78 (62.07); H, 4.37
(4.70); N, 11.37 (11.75).
2-[1-(4-Bromophenyl)-4-oxo-azetidin-2-yl]-5,6,7,8-
tetrahydrobenzo(b)thieno[2,3-d]pyrimidin-4(3H)-one (5k)
IR (KBr): 3111, 2942, 2875, 1775, 1654, 1507, 1425, 1203, 1058,
1
963 cmꢁ1; H NMR (300 MHz, CDCl3): d ¼ 7.26–7.97 (m, 5H, ArH
and NH), 3.10–3.24 (m, 1H, CH at azetidinyl-2), 2.70–2.81 (m, 2H,
CH2 at azetidinyl-3), 2.25–2.44 (m, 4H, CH2 at 5 and 8), 1.9–2.12
(m, 4H, CH2 at 6 and 7); MS (TOF): m/z ¼ 430, 432 (Mþ2);
C19H16BrN3O2S (430.32); requires (Found): C, 53.03 (53.27); H, 3.75
(3.99); N, 9.76 (10.12).
5-(4-Chlorophenyl)-2-[1-phenyl-4-oxo-azetidin-2-yl]-
thieno[2,3-d]pyrimidin-4(3H)-one (5e)
2-[1-(4-Fluorophenyl)-4-oxo-azetidin-2-yl]-3,5,6,7,8,9-
IR (KBr): 3362, 2921, 1670, 1596, 1394, 958, 720 cmꢁ1 1H NMR
;
hexahydro-10-thia-1,3-diazabenzoazulen-4-one (5l)
(300 MHz, CDCl3): d ¼ 8.12 (s, 1H, NH), 6.9–7.83 (m, 10H, ArH and
H at 6), 4.02 (m, 1H, CH at azetidinyl-2), 3.25 (d, 2H, CH2 at
azetinidinyl-3); C21H14ClN3O2S (407.87); requires (Found): C, 61.84
(62.09); H, 3.46 (3.56); N, 10.30 (10.52).
IR (KBr): 3107, 2919, 1889, 1665, 1596, 1506, 1204, 1044,
922 cmꢁ1
;
1H NMR (300 MHz, CDCl3): d ¼ 7.92 (s, 1H, NH),
7.02–7.70 (m, 4H, ArH), 4.44 (m, 1H, CH at azetidinyl-2), 3.58
(m, 2H, CH2 at azetidinyl-3), 2.60–2.65 (m, 4H, CH2 at 5 and 9), 2.23–
2.30 (m, 4H, CH2 at 6 and 8), 1.92–2.0 (m, 2H, CH2 at 7); MS (TOF):
m/z ¼ 384 (Mþ1); C20H18FN3O2S (383.44); requires (Found): C, 62.65
(62.69); 4.73 (5.02); N, 10.96 (10.66).
5-(4-Chlorophenyl)-2-[1-(2-methylphenyl)-4-oxo-
azetidin-2-yl]-thieno[2,3-d]pyrimidin-4(3H)-one (5f)
IR (KBr): 3239, 2949, 1686, 1614, 1552, 1410, 1092, 979, 772 cmꢁ1
;
1H NMR (300 MHz, CDCl3): d ¼ 7.99 (s, 1H, NH), 6.84–7.65 (m, 9H,
ArH and H at 6), 3.94–4.11 (m, 1H, CH at azetidinyl-2), 3.34 (d, 2H,
CH2 at azetinidinyl-3), 2.51 (s. 3H, Ar–CH3); C22H16ClN3O2S (421.9);
requires (Found): C, 62.63 (62.25); 3.82 (3.93); N, 9.96 (10.11).
Pharmacological activity
The experiments were carried out with Wistar Albino rats (170–
200 g). The animals were housed at a temperature of 30 ꢀ 5°C and
humidity of 40–50 ꢀ 5% with 12 h light and 12 h dark cycles. The
animals were given food and water ad libitum, unless specified
otherwise. For all studies animals of either sex were selected at
random.
5-(4-Chlorophenyl)-2-[1-(4-methylphenyl)-4-oxo-
azetidin-2-yl]-thieno[2,3-d]pyrimidin-4(3H)-one (5g)
Triton WR 1339, a surfactant, chemically isooctyl-polyoxy-
ethylene phenol (tyloxapol) was used to induce hyperlipidemia.
The animals were divided into four groups of six animals each:
IR (KBr): 3340, 2937, 1689, 1555, 1446, 1120, 1035, 686 cmꢁ1; 1H
NMR (300 MHz, CDCl3): d ¼ 8.14 (s, 1H, NH), 6.80–7.71 (m, 9H, ArH
and H at 6), 3.48–3.69 (m, 1H, CH at azetidinyl-2), 3.34 (m, 2H, CH2
at azetidinyl-3), 2.51 (s. 3H, Ar–CH3); C22H16ClN3O2S (421.9);
requires (Found): C, 62.63 (62.41); 3.82 (3.68). N, 9.96 (10.09).
Group I – control group: the control group received only vehicle
(2% w/v acacia gum aqueous solution p.o.).
ß 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.archpharm.com

Arch. Pharm. Chem. Life Sci. 2013, 346, 588–595
Fused Pharmacophores
595
Group II – cholesterol-control group: the cholesterol-control
group received Triton WR 1339 in vehicle solution (200 mg/kg/
day i.p.).
Group III – test group: The test drug treated group received Triton
WR 1339 (200 mg/kg i.p.) as well as test drug suspension (5a–h;
400 mg/kg/day p.o.) in 2% acacia gum solution.
Group IV – the standard group received Triton WR 1339 (200 mg/
kg i.p.) as well as gemfibrozil as standard drug (400 mg/kg/day
p.o.) in 2% acacia gum solution.
[5] C. J. Shishoo, M. B. Devani, V. S. Bhadti, K. S. Jain, I. S. Rathod,
R. K. Goyal, T. P. Gandhi, R. B. Patel, S. R. Naik, Arzneimittel-
Forsch. 1990, 40, 567–572.
[6] a) C. J. Shishoo, M. B. Devani, V. S. Bhadti, Indian Pat. 1981,
151, 496; b) Chem. Abstr. 1984, 100, 209858.
[7] C. J. Shishoo, T. R. Gandhi, I. S. Rathod, K. S. Jain, R. K. Goyal,
Arzneimittel-Forsch. 1997, 47, 1125–1129.
[8] C. J. Shishoo, K. S. Jain, I. S. Rathod, B. J. Thakkar, S. B.
Brahmabhatt, T. P. Gandhi, R. Bangaru, R. K. Goyal, Arzneimittel-
Forsch. 1996, 46, 273–276.
As such eight test groups for eight test compounds were
formed of six animals of either sex per group. Blood samples were
collected from the retro-orbital plexus of the eyes of the animals,
initially and after 24 h. The samples were analyzed for serum
cholesterol (total) levels, serum triglyceride (total) levels, and
serum HDL (total) levels.
[9] M. K. Kathiravan, C. J. Shishoo, K. G. Kumar, S. K. Roy, K. R.
Mahadik, S. S. Kadam, K. S. Jain, Arzneimittel-Forsch. 2007, 57,
599–606.
[10] K. S. Jain, R. R. Kulkarni, D. P. Jain, M. A. Nagras, S. H. Misal,
Indian J. Pharm. Educ. Res. 2011, 45, 272–281.
[11] L. Kvaerno, M. Werder, H. Hauser, M. C. Erick, J. Med. Chem.
2005, 48, 6035–6053.
The authors acknowledge the contributions of Prof. M. N. Navale, President
and Dr. (Mrs.) S. M. Navale, Secretary, Sinhgad Technical Education Society,
Pune, India for providing encouragement, facilities to carry out the
synthetic work and basic spectroscopic analysis. The spectral and elemental
analyses were done at Department of Chemistry, Saurashtra University,
Rajkot, Gujarat, India and Department of Chemistry, University of Pune,
India, respectively.
[12] M. K. Kathiravan, M. K. Munde, D. P. Jain, K. S. Jain, Indian
Drugs 2009, 46, 91–103.
[13] a) P. Zhan, X. Liu, Curr. Pharm. Des. 2009, 15, 1893–1917; b) D.
A. Brooks, G. J. Etgen, C. J. Rito, A. J. Shuker, S. J. Dominianni,
A. M. Warshawsky, R. Ardecky, J. R. Paterniti, J. Tyhonas, D. S.
Karanewsky, R. F. Kauffman, C. L. Broderick, B. A. Oldham, C.
R. Montrose, L. L. Winneroski, M. M. Faul, J. R. McCarthy, J.
Med. Chem. 2001, 44, 2061–2064; c) V. Cecchetti, A. Fravolini,
F. Schiaffella, O. Tabarrini, G. Bruni, G. Segre, J. Med. Chem.
1993, 36, 157–161.
The authors have declared no conflict of interest.
[14] K. Gewald, E. Schinke, H. Böttcher, Chem. Ber. 1966, 99, 94–100.
References
[15] K. S. Jain, J. B. Bariwal, M. S. Phoujdar, M. A. Nagras, R. D.
Amrutkar, M. K. Munde, R. S. Tamboli, S. A. Khedkar, R. H.
Khiste, N. C. Vidyasagar, V. V. Dabholkar, M. K. Kathiravan, J.
Heterocycl. Chem. 2009, 46, 178–185.
[1] K. S. Jain, R. R. Kulkarni, D. P. Jain, Mini-Rev. Med. Chem. 2010,
10, 232–262.
[2] K. S. Jain, M. K. Kathiravan, R. S. Somani, C. J. Shishoo, Bioorg.
Med. Chem. 2007, 15, 4674–4699.
[16] M. C. Chrysselis, E. A. Rekka, P. N. Kourounakis, J. Med. Chem.
2000, 43, 609–612.
[3] a) M. Shiroki, Jpn. Kokai 1976, 43, 796; b) Chem. Abstr. 1976, 85,
[17] P. S. N. Reddy, T. Vasantha, C. A. Nagaraju, Indian J. Chem.
1999, 38B, 40–44.
94398.
[4] a) F. Sauter, Ger. Offen. 1972, 210, 503; b) Chem. Abstr. 1972, 77,
[18] S. Kanwar, S. D. Sharma, Indian J. Chem. 2005, 44B, 2637–2671.
164752.
ß 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.archpharm.com