Synthesis and positive inotropic evaluation of 2-(4-(4-substituted benzyloxy)-3-methoxybenzyl)-1,4-diazepan-1-yl-n-(4,5-dihydro-1-methyl[1,2,4] triazolo[4,3-a]quinolin-7-yl)-acetamides

Article abstract of DOI:10.1002/ardp.200800132

In an attempt to search for more potent positive inotropic agents, a series of 2-(4-(4-substituted benzyloxy)-3-methoxybenzyl)-1,4-diazepan-1-yl)-N-(4,5- dihydro-1-methyl[1,2,4]triazolo[4,3-a]quinolin-7-yl)acetamides was synthesized and their positive inotropic activities were evaluated by measuring left atrium stroke volume on isolated rabbit-heart preparations. Several compounds showed favorable activity compared with the standard drug Milrinone among which 2-(4-(4-(2-chlorobenzyloxy)-3-methoxybenzyl)-1,4-diazepan-1-yl)-N-(4, 5-dihydro-1-methyl-[1,2,4]triazolo[4,3-a]quinolin-7-yl)acetamide 6e was found to have the most desirable potency with the 6.79 ± 0.18% increased stroke volume (Milrinone: 1.67 ± 0.64%) at a concentration of 1 × 10 ^-5 M in our in-vitro study. The chronotropic effects of those compounds having inotropic effects were also evaluated in this work.

Full text of DOI:10.1002/ardp.200800132

794
Arch. Pharm. Chem. Life Sci. 2008, 341, 794–799
Full Paper
Synthesis and Positive Inotropic Evaluation of 2-(4-(4-
Substituted benzyloxy)-3-methoxybenzyl)-1,4-diazepan-1-yl)-
N-(4,5-dihydro-1-methyl[1,2,4]triazolo[4,3-a]quinolin-7-yl)-
acetamides
Jing-Yuan Li1, Xun Cui2, Xue-Kun Liu1, Lan Hong2, Zhe-Shan Quan1, and Hu-Ri Piao1
1 Key Laboratory of Natural Resources and Functional Molecules of the Changbai Mountain, Affiliated Ministry
of Education, Yanbian University College of Pharmacy, Yanji, Jilin, PR China
2 Yanbian University College of Medicine, Yanji, Jilin, PR China
In an attempt to search for more potent positive inotropic agents, a series of 2-(4-(4-substituted
benzyloxy)-3-methoxybenzyl)-1,4-diazepan-1-yl)-N-(4,5-dihydro-1-methyl[1,2,4]triazolo[4,3-a]quino-
lin-7-yl)acetamides was synthesized and their positive inotropic activities were evaluated by
measuring left atrium stroke volume on isolated rabbit-heart preparations. Several compounds
showed favorable activity compared with the standard drug Milrinone among which 2-(4-(4-(2-
chlorobenzyloxy)-3-methoxybenzyl)-1,4-diazepan-1-yl)-N-(4,5-dihydro-1-methyl-[1,2,4]triazolo[4,3-
a]quinolin-7-yl)acetamide 6e was found to have the most desirable potency with the 6.79 l 0.18%
increased stroke volume (Milrinone: 1.67 l 0.64%) at a concentration of 1610– 5 M in our in-vitro
study. The chronotropic effects of those compounds having inotropic effects were also evaluated
in this work.
Keywords: 1,4-Diazepane / Positive inotropic activity / Stroke volume / [1,2,4]Triazolo[4,3-a]quinolines /
Received: July 7, 20087; accepted: September 8, 2008
DOI 10.1002/ardp.200800132
was approved for the treatment of CHF more than one
Introduction
decade ago. This agent, as an alternative synthetic
replacement, has been proven quite useful for seriously
ill patients with decompensated CHF. Nonetheless, the
significant ventricular arrhythmias and tachycardia asso-
ciated with the elevated cAMP level also limit the clinical
use of milrinone [2]. Similar cases were found in the
recently developed vesnarinone [3, 4] and toborinone [5].
These cardiotonic agents ultimately exert their inotropic
effects via an increase in intracellular calcium and conse-
quently possess strong arrhythmogenic effects that
caused increased mortality when used in CHF patients.
Because of overall deleterious effects on long-term sur-
vival in CHF, this class of drugs should now be considered
most suitable for short-term use in acute episodes of
decompensated heart failure [6]. Levosimendan, which
exerts its positive inotropic effect by both increasing the
sensitivity of the myofilament to intracellular calcium
and inhibiting phosphodiesterase, could reduce mortal-
For many years, cardiac glycosides like digoxin have con-
sistently been among of the most frequently prescribed
medications used for the treatment of congestive heart
failure (CHF). Although they are the only medications
used without increasing the CHF patient's mortality
among those approved positive inotropic agents up to
now, the high toxicity and narrow therapeutic window
still limit their clinical application as positive inotropic
agents [1]. The phosphodiesterase-inhibiting agent milri-
none, having both vasodilator and inotropic properties,
Correspondence: Hu-Ri Piao, Yanbian University College of Pharmacy,
Yanji City, Jilin Province 133000, P.R. China.
E-mail: piaohuri@yahoo.com.cn
Fax: + 86-433-2659795
Abbreviations: congestive heart failure (CHF)
i 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Arch. Pharm. Chem. Life Sci. 2008, 341, 794–799
Synthesis, Inotropic Evaluation of Substituted Acetamids
795
in order to preliminarily investigate the contribution of
such a structural change to the biological activity. The
compounds synthesized were characterized by IR, NMR,
MS, and elemental analysis, and the positive inotropic
activities were evaluated by measuring their effect on left
atrium stroke volume in isolated rabbit-heart prepara-
tions.
Results and discussion
Figure 1. Cardiotonic agents used for the treatment of conges-
tive heart failure (CHF).
Synthesis
The synthesis of the compound 6a–m is presented in
Scheme 1. Compound 4 was synthesized through nitra-
tion, catalytic hydrogenation, sulfurization, and acyla-
tion reactions according to the previously described
methods by using commercially available 3,4-dihydro-
2(1H)-quinolinone as a starting material [11]. The amino
group at the 7-position of 4 was acylated with 2-chloroa-
cetyl chloride in dichloromethane at room temperature
to provide corresponding amide 5 in excellent yield.
Nucleophilic-substitution reaction of 5 with various
monosubstituted 1,4-diazepanes in refluxing methanol
in the presence of sodium carbonate afforded corre-
sponding compounds 6a–m in high yield.
ity in the short-term treatment of CHF, but it is uncertain
whether levosimendan will reduce the mortality in the
long-term treatment [7, 8]. Therefore, due to the lack of a
desirable inotropic agent for the treatment of cardiac
failure so far, the development of novel positive inotropic
agents with approved therapeutic properties in the treat-
ment of CHF, which not only improve the quality of life
but also reduce the mortality of CHF patients, is still an
important challenge for medicinal chemists [9]. Figure 1
shows cardiotonic agents used for the treatment of con-
gestive heart failure (CHF).
In our previous work to search for more potent positive
inotropic agents having fewer side effects, a series of 2-(4-
substitutedpiperazin-1-yl)-N-(3,4-dihydro-2(1H)-quinoli-
non-6-yl)acetamides was synthesized and tested for their
biological activity, among which the compound 2-(4-ben-
zylpiperazin-1-yl)-N-(3,4-dihydro-2(1H)-quinolinon-6-yl)a-
cetamide (PHR9612) showed moderate positive inotropic
activity [10]. In our present study to further optimize the
compound PHR9612, we incorporated a triazole ring to
the 1,2-position of 3,4-dihydro-2(1H)-quinolinone,
replaced the piperazine ring with a 1,4-diazepane ring
that was substituted by the 4-benzyloxy-3-methoxybenzyl
group at the 4-position, and changed the substituents on
the benzene ring of the benzyloxy group simultaneously
Biological evaluation
The method of measuring left atrium stroke volume was
adopted for the biological evaluation of the compounds
6a–m in the present work. The features of congestive
heart failure are cardiac dilatation, poor contractility of
cardiac muscle, decreased ejection fraction, and depres-
sion of left ventricular maximum pressure. Therefore,
the macroscopic measurement of the variance of left
atrium stroke volume can be used to estimate the posi-
tive inotropic effects of the compounds synthesized.
As shown in Table 1, ten compounds out of the 13 test
compounds showed inotropic effects on isolated rabbit-
Scheme 1. Synthesis of compounds 6a–m.
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J.-Y. Li et al.
Arch. Pharm. Chem. Life Sci. 2008, 341, 794–799
Table 1. Positive inotropic activity of the test compounds.
Compd
R
Increased stroke volume (%)a)
6a
6b
6c
6d
6e
6f
6g
6h
6i
6j
6k
6l
H
2-F
3-F
4-F
2-Cl
4-Cl
2-OCH3
4-OCH3
4-CH3
3,4-(OCH3)2
3,4-(Cl)2
2,6-(Cl)2
2-Br
1.68 l 0.26
6.05 l 0.65*
15.55 l 1.54*
6.05 l 0.64*
6.79 l 0.18*
2.56 l 0.00*
b)
–
–
b)
6.95 l 0.75*
1.10 l 0.22
5.77 l 1.04*
4.43 l 0.32*
b)
6m
–
Milrinone
1.67 l 0.64
a)
The concentration for the test sample is 1610– 5 M.
None or negative stroke volume increase.
b)
* P a 0.05 vs. milrinone.
heart preparations. Compounds 6b, 6c, 6d, 6e, 6f, 6i, 6k,
and 6l exhibited more potent effects, while 6a showed
the same potency, compared with milrinone
(1.67 l 0.64%, 1610– 5 M). Compound 6c showed the
highest potency with 15.55 l 1.54% increased stroke vol-
ume. In contrast to the previously evaluated PHR9612
with a potency which was weaker compared with milri-
none (no data), several compounds showed significantly
increased inotropic activities through the structure mod-
ification of introducing a triazole ring to the 1,2-position
of 3,4-dihydro-2(1H)-quinolinone and replacing the piper-
azine moiety with 1,4-diazepan. As for the relationship
between inotropic activity and different substituents on
the benzene ring of the benzyloxy group (R), most com-
pounds having electron-withdrawing groups on the phe-
nyl ring displayed enhanced effects except compound
6m, while compounds 6g and 6h, having electron-donat-
ing substituents on the phenyl ring showed no or nega-
tive effects. However, reverse was found for compounds
6i and 6j, although both compounds possesed electron-
donating groups. Interestingly, for the halogen-substi-
tuted derivatives, those chloro- and fluoro-substituted
compounds showed good activity, but bromo-substituted
6m showed no potency. These results seem to indicate
that the contribution of the substituents at R to the bio-
logical effect might be different, and no clear regularity
was found for the stucture-activity relationship (SAR).
On the other hand, we investigated the dynamics of
the test compounds in perfused beating rabbit atria and
found that compound 6c did not show a desirable biolog-
ical dynamic profile, in which the stroke volume of 6c
was markedly decreased as the time progressed, in spite
of its significantly increased stroke volume, for which we
Figure 2. Effects of milrinone and compounds 6a, 6b, 6e, 6f, 6j,
and 6l on stroke volume in beating rabbit atria (1.5 Hz).
The atrium stroke volume was recorded at 2-min intervals. Val-
ues are means l SE. P a 0.001 vs. control.
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Arch. Pharm. Chem. Life Sci. 2008, 341, 794–799
Synthesis, Inotropic Evaluation of Substituted Acetamids
797
Table 2. Changes of heart rate caused by compounds in isolated
rabbit heart preparations.
uation, coronary vasodilating tests, and possible mecha-
nism-of-action studies in order to be selected as candi-
dates for further clinical trials.
Compound
mean l SEa)
mean l SEb)
6a
6e
6f
6l
104.50 l 0.58
128.90 l 0.07
68.30 l 0.13
137.60 l 0.21
81.70 l 0.58c
129.10 l 0.33
66.86 l 0.15
This work was supported by the National Natural Science Foun-
dation of China (No. 30560177).
123.50 l 0.51c)
The authors have declared no conflict of interest.
a)
Control.
b)
Data after using the test samples.
P a 0.01 vs. control.
c)
Experimental
still could not afford a reasonable explanation (Fig. 2D).
The same cases were also observed for compounds 6b, 6c,
6d, 6i, and 6k (no figure afforded). Compounds 6e and 6l
exhibited similar atrial dynamic profiles to milrinone
with excellent increased stroke volume of 6.79 l 0.18%
and 4.43 l 0.32%, respectively (Fig. 2A and C). Much more
desirable atrial dynamic profiles were measured for the
compounds 6a, 6f, and 6j (Fig. 2B), although the lower
potency was observed for 6j (1.10 l 0.22%). As shown in
Table 2, compounds 6a, 6e, 6f, and 6l were also investi-
gated for their chronotropic effects in a beating atria and
no significantly increased heart rates (P A 0.05) were
observed for compounds 6e and 6f at the same concentra-
tion. Compounds 6a and 6l, however, showed the
changed heart rates unfortunately, for which an in-vivo
study was required in order to further investigate their
chronotropic effects.
Furthermore, based on our recent study of mechanism
of action for similar compounds bearing a piperazine
moiety instead of a 1,4-diazepan moiety, which has been
revealed that they exert the inotropic effect through
phosphodiesterase inhibition (unpublished), we pre-
sumed that the mechanism of the inotopic action for
these compounds synthesized might involve PDE inhibi-
tion.
Chemistry
Melting points were determined in open capillary tubes and are
uncorrected. Reaction courses were monitored by TLC on silica
gel precoated F254 Merck plates (Merck, Germany) and devel-
oped plates were examined with UV lamps (254 nm). Column
chromatographies were performed with Merck 200 mesh silica
1
gel. IR spectra were recorded (in KBr) on a FT-IR1730. H-NMR
spectra were measured on Bruker AV-300 spectrometer (Bruker
Bioscience, Billerica, MA, USA) using TMS as internal standard.
Mass spectra were measured on an HP1100LC (Agilent Technolo-
gies, USA). Elemental analyses for C, H, and N were within l 0.4%
of the theoretical values and were performed on a 204Q CHN
Rapid Analyzer (Perkin-Elmer, USA). The major chemicals were
purchased from Aldrich (Sigma-Aldrich Chemical Co., St. Louis,
MO, USA) and Fluka (Buchs, Switzerland) Companies. Monosub-
stituted 1,4-diazepanes were synthesized by the method similar
to prepare the monosubstituted piperazines [12].
2-Chloro-N-(4,5-dihydro-1-methyl-[1,2,4]triazolo[4,3-
a]quinolin-7-yl)acet-amide 5
To a stirred solution of 4 in dichloromethane was added drop-
wise a solution of 2-chloroacetyl chloride (0.40 g, 0.002 mol) in
20 mL of dichloromethane (2 h). The resulting yellow solid was
collected by filtration at the pump to afford 5 in 99% yield; m.p.:
306–3088C; 1H-NMR (CDCl3) d: 2.67 (s, 3H, CH3), 2.97 (m, 4H,
CH2CH2), 4.10 (s, 2H, CH2), 7.56–7.63 (m, 3H, Ar-H); IR (KBr) cm– 1
:
3350 (NH), 1707 (C=O); ESI-MS m/z: 277 [M + 1]; Anal. Calcd. for
C13H13ClN4O: C, 56.42; H, 4.74; N, 20.25. Found: C, 56.32; H, 4.71;
N, 20.45.
General procedure for compounds 6a–m
A mixture of 5 (0.28 g, 1.011 mmol), monosubstituted 1,4-diaze-
panes (2.022 mmol), and sodium carbonate anhydrous in reflux-
ing methanol was stirred for 10 h. The solvent was evaporated
under reduced pressure and the residue was dissolved in
dichloromethane and washed with water and brine, dried over
MgSO4, and the solvent was removed under reduced pressure.
The resulting residue was purified by silica gel column chroma-
tography (dichloromethane / methanol 10 : 1). The Yield melting
point, and spectra data of each compound are given below.
Conclusion
In conclusion, based on the structure of PHR9612, we syn-
thesized 2-(4-(4-substitutedbenzyloxy) -3-methoxybenzyl)-
1,4-diazepan-1-yl)-N-(4,5-dihydro-1-methyl[1,2,4]tria-
zolo[4,3-a]quinolin-7-yl)acetamides and tried to find
more potent compounds for cardiac contractility with-
out increasing the heart rate. As a result, we obtained sev-
eral compounds having enhanced inotropic effects and
desirable biological profiles in our present study, in
which compounds 6e and 6f exhibited more promising
cardiovascular profiles. These compounds are now
undergoing further biological tests including in-vivo eval-
2-(4-(4-Benzyloxy-3-methoxybenzyl)-1,4-diazepan-1-yl]-
N-(4,5-dihydro-1-methyl-[1,2,4]triazolo[4,3-a]quinolin-7-
yl)acetamide 6a
Yield 71%; m.p.: 72–748C; 1H-NMR (CDCl3) d: 1.26 (m, 2H, CH2),
2.74 (s, 3H, CH3), 2.86–2.90 (m, 8H, CH2), 3.02 (t, J = 7.4 Hz, 2H,
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Arch. Pharm. Chem. Life Sci. 2008, 341, 794–799
CH2), 3.12 (t, J = 7.4 Hz, 2H, CH2), 3.31 (s, 2H, CH2), 3.65 (s, 2H,
CH2), 3.89 (s, 3H, CH3), 5.14 (s, 2H, CH2), 6.77–7.72 (m, 11H, Ar-H),
9.49 (s, 1H, NH); IR (KBr) cm– 1: 3445 (NH), 1695 (C=O); ESI-MS m/z:
567 [M + 1]; Anal. Calcd. for C33H38N6O3: C, 69.94; H, 6.76; N,
14.83. Found: C, 70.12; H, 6.78; N, 14.75.
601 [M + 1]; Anal. Calcd. for C33H37ClN6O3: C, 65.93; H, 6.20; N,
13.98. Found: C, 66.05; H, 6.21; N, 13.87.
2-(4-(4-(2-Methoxybenzyloxy)-3-methoxybenzyl)-1,4-
diazepan-1-yl]-N-(4,5-dihydro-1-methyl-
[1,2,4]triazolo[4,3-a]quinolin-7-yl)acetamide 6g
2-(4-(4-(2-Fluorobenzyloxy)-3-methoxybenzyl)-1,4-
diazepan-1-yl]-N-(4,5-dihydro-1-methyl-
[1,2,4]triazolo[4,3-a]quinolin-7-yl)acetamide 6b
Yield 75%; m.p.: 53–558C; 1H-NMR (CDCl3) d: 1.25 (m, 2H, CH2),
2.73 (s, 3H, CH3), 2.83–2.90 (m, 8H, CH2), 2.98 (t, J = 7.3 Hz, 2H,
CH2), 3.10 (t, J = 7.3 Hz, 2H, CH2), 3.30 (s, 2H, CH2), 3.66 (s, 2H,
CH2), 3.72 (s, 3H, CH3), 3.73 (s, 3H, CH3), 5.11 (s, 2H, CH2), 6.66–
7.71 (m, 10H, Ar-H), 9.48 (s, 1H, NH); IR (KBr) cm– 1: 3452 (NH),
1685 (C=O); ESI-MS m/z: 597 [M + 1]; Anal. Calcd. for C34H40N6O4:
C, 68.43; H, 6.76; N, 14.08. Found: C, 68.45; H, 6.73; N, 14.26.
Yield 72%; m.p.: 56–588C; 1H-NMR (CDCl3) d: 1.26 (m, 2H, CH2),
2.73 (s, 3H, CH3), 2.85–2.90 (m, 8H, CH2), 2.99 (t, J = 6.6 Hz, 2H,
CH2), 3.11 (t, J = 6.6 Hz, 2H, CH2), 3.30 (s, 2H, CH2), 3.64 (s, 2H,
CH2), 3.88 (s, 3H, CH3), 5.19 (s, 2H, CH2), 6.80–7.72 (m, 10H, Ar-H),
9.48 (s, 1H, NH); IR (KBr) cm– 1: 3443 (NH), 1655 (C=O); ESI-MS m/z:
585 [M + 1]; Anal. Calcd. for C33H37FN6O3: C, 67.79; H, 6.38; N,
14.37. Found: C, 67.92; H, 6.35; N, 14.46.
2-(4-(4-(4-Methoxybenzyloxy)-3-methoxybenzyl)-1,4-
diazepan-1-yl]-N-(4,5-dihydro-1-methyl-
[1,2,4]triazolo[4,3-a]quinolin-7-yl)acetamide 6h
2-(4-(4-(3-Fluorobenzyloxy)-3-methoxybenzyl)-1,4-
diazepan-1-yl]-N-(4,5-dihydro-1-methyl-
[1,2,4]triazolo[4,3-a]quinolin-7-yl)acetamide 6c
Yield 72%; m.p.: 54–568C; 1H-NMR (CDCl3) d: 1.26 (m, 2H, CH2),
2.69 (s, 3H, CH3), 2.74–2.88 (m, 8H, CH2), 3.00 (t, J = 7.1 Hz, 2H,
CH2), 3.12 (t, J = 7.1 Hz, 2H, CH2), 3.30 (s, 2H, CH2), 3.65 (s, 2H,
CH2), 3.79 (s, 3H, CH3), 3.80 (s, 3H, CH3), 5.30 (s, 2H, CH2), 6.62–
7.69 (m, 10H, Ar-H), 9.54 (s, 1H, NH); IR (KBr) cm– 1: 3428 (NH),
1687 (C=O); ESI-MS m/z: 597 [M + 1]; Anal. Calcd. for C34H40N6O4:
C, 68.43; H, 6.76; N, 14.08. Found: C, 68.41; H, 6.78; N, 14.16.
Yield 75%; m.p.: 54–568C; 1H-NMR (CDCl3) d: 1.27 (m, 2H, CH2),
2.68 (s, 3H, CH3), 2.83–2.91 (m, 8H, CH2), 3.00 (t, J = 7.8 Hz, 2H,
CH2), 3.09 (t, J = 7.8 Hz, 2H, CH2), 3.30 (s, 2H, CH2), 3.61(s, 2H, CH2),
3.87 (s, 3H, CH3), 5.10 (s, 2H, CH2), 6.73–7.70 (m, 10H, Ar-H), 9.47
(s, 1H, NH); IR (KBr) cm– 1: 3350 (NH), 1697 (C=O); ESI-MS m/z: 585
[M + 1]; Anal. Calcd. for C33H37FN6O3: C, 67.79; H, 6.38; N, 14.37.
Found: C, 67.86; H, 6.37; N, 14.26.
2-(4-(4-(4-Methylbenzyloxy)-3-methoxybenzyl)-1,4-
diazepan-1-yl]-N-(4,5-dihydro-1-methyl-
[1,2,4]triazolo[4,3-a]quinolin-7-yl)acetamide 6i
2-(4-(4-(4-Fluorobenzyloxy)-3-methoxybenzyl)-1,4-
diazepan-1-yl]-N-(4,5-dihydro-1-methyl-
[1,2,4]triazolo[4,3-a]quinolin-7-yl)acetamide 6d
1
ield 75%; m.p.: 53–558C; H-NMR (CDCl3) d: 1.26 (m, 2H, CH2),
2.34 (s, 3H, CH3), 2.74 (s, 3H, CH3), 2.84–2.90 (m, 8H, CH2), 3.31 (t,
J = 7.2 Hz, 2H, CH2), 3.12(t, J = 7.2 Hz, 2H, CH2), 3.31 (s, 2H, CH2),
3.63 (s, 2H, CH2), 3.87 (s, 3H, CH3), 5.10 (s, 2H, CH2), 6.77–7.72 (m,
10H, Ar-H), 9.49 (s, 1H, NH); IR (KBr) cm– 1: 3462 (NH), 1680 (C=O);
ESI-MS m/z: 581 [M + 1]; Anal. Calcd. for C34H40N6O3: C, 70.32; H,
6.94; N, 14.47. Found: C, 70.36; H, 6.91; N, 14.28.
Yield 78%; m.p.: 50–528C; 1H-NMR (CDCl3) d: 1.25 (m, 2H, CH2),
2.74 (s, 3H, CH3), 2.85–2.90 (m, 8H, CH2), 2.99 (t, J = 8.0 Hz, 2H,
CH2), 3.11 (t, J = 8.0 Hz, 2H, CH2), 3.31 (s, 2H, CH2), 3.63 (s, 2H,
CH2), 3.88 (s, 3H, CH3), 5.08 (s, 2H, CH2), 6.78–7.72 (m, 10H, Ar-H),
9.48 (s, 1H, NH); IR (KBr) cm– 1: 3431 (NH), 1685 (C=O); ESI-MS m/z:
585 [M + 1]; Anal. Calcd. for C33H37FN6O3: C, 67.79; H, 6.38; N,
14.37. Found: C, 67.84; H, 6.36; N, 14.51.
2-(4-(4-(3,4-Dimethoxybenzyloxy)-3-methoxybenzyl)-1,4-
diazepan-1-yl]-N-(4,5-dihydro-1-methyl-
[1,2,4]triazolo[4,3-a]quinolin-7-yl)acetamide 6j
2-(4-(4-(2-Chlorobenzyloxy)-3-methoxybenzyl)-1,4-
diazepan-1-yl]-N-(4,5-dihydro-1-methyl-
1
Yield 78%; m.p.: 68–708C; H-NMR (CDCl3) d: 1.35 (m, 2H, CH2),
2.84 (s, 3H, CH3), 2.95–3.07 (m, 8H, CH2), 3.07 (t, J = 7.8 Hz, 2H,
CH2), 3.23 (t, J = 7.8 Hz, 2H, CH2), 3.36 (s, 2H, CH2), 3.70 (s, 2H,
CH2), 3.78 (s, 3H, CH3), 3.83 (s, 3H, CH3), 4.00 (s, 3H, CH3), 5.26 (s,
[1,2,4]triazolo[4,3-a]quinolin-7-yl)acetamide 6e
1
Yield 70%; m.p.: 53–558C; H-NMR (CDCl3) d: 1.23 (s, 2H, CH2),
2.74 (s, 3H, CH3), 2.83–2.90 (m, 8H, CH2), 3.01 (t, J = 7.2 Hz, 2H,
CH2), 3.08 (t, J = 7.2 Hz, 2H, CH2), 3.30 (s, 2H, CH2), 3.65 (s, 2H,
CH2), 3.89 (s, 3H, CH3), 5.29 (s, 2H, CH2), 6.62–7.69 (m, 10H, Ar-H),
9.44 (s, 1H, NH); IR(KBr)cm– 1: 3451 (NH), 1695 (C=O); ESI-MS m/z:
601 [M + 1]; Anal. Calcd. for C33H37ClN6O3: C, 65.93; H, 6.20; N,
13.98. Found: C, 66.02; H, 6.23; N, 13.76.
2H, CH2), 6.75–7.71 (m, 9H, Ar-H), 9.54 (s, 1H, NH); IR (KBr) cm– 1
:
3458 (NH), 1687 (C=O); ESI-MS m/z: 627 [M + 1]; Anal. Calcd. for
C35H42N6O5: C, 67.07; H, 6.75; N, 13.41. Found: C, 67.12; H, 6.73;
N, 13.28.
2-(4-(4-(3,4-Dichlorobenzyloxy)-3-methoxybenzyl)-1,4-
diazepan-1-yl]-N-(4,5-dihydro-1-methyl-
[1,2,4]triazolo[4,3-a]quinolin-7-yl)acetamide 6k
2-(4-(4-(4-Chlorobenzyloxy)-3-methoxybenzyl)-1,4-
diazepan-1-yl]-N-(4,5-dihydro-1-methyl-
Yield 79%; m.p.: 63–648C; 1H-NMR (CDCl3) d: 1.26 (m, 2H, CH2),
2.75 (s, 3H, CH3), 2.84–2.92 (m, 8H, CH2), 3.09 (t, J = 7.2 Hz, 2H,
CH2), 3.20 (t, J = 7.2 Hz, 2H, CH2), 3.31 (s, 2H, CH2), 3.62 (s, 2H,
CH2), 3.89 (s, 3H, CH3), 5.07 (s, 2H, CH2), 6.76–7.71 (m, 9H, Ar-H),
9.46 (s, 1H, NH); IR (KBr) cm– 1: 3446 (NH), 1687 (C=O); ESI-MS m/z:
635 (M+1); Anal. Calcd. for C33H36Cl2N6O3: C, 62.36; H, 5.71; N,
13.22. Found: C, 62.37; H, 5.75; N, 13.32.
[1,2,4]triazolo[4,3-a]quinolin-7-yl)acetamide 6f
1
Yield 70%; m.p.: 51–538C; H-NMR (CDCl3) d: 1.26 (m, 2H, CH2),
2.75 (s, 3H, CH3), 2.89–2.90 (m, 8H, CH2), 2.98 (t, J = 7.5 Hz, 2H,
CH2), 3.09 (t, J = 7.5 Hz, 2H, CH2), 3.31 (s, 2H, CH2), 3.60 (s, 2H,
CH2), 3.85 (s, 3H, CH3), 5.08 (s, 2H, CH2), 6.65–7.70 (m, 10H, Ar-H),
9.50 (s, 1H, NH); IR (KBr) cm– 1: 3446 (NH), 1686 (C=O); ESI-MS m/z:
i 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.archpharm.com

Arch. Pharm. Chem. Life Sci. 2008, 341, 794–799
Synthesis, Inotropic Evaluation of Substituted Acetamids
799
The control period (12 min as an experimental cycle) was fol-
lowed by infusion of the test compounds or milrinone for
36 min.
2-(4-(4-(2,6-Dichlorobenzyloxy)-3-methoxybenzyl)-1,4-
diazepan-1-yl]-N-(4,5-dihydro-1-methyl-
[1,2,4]triazolo[4,3-a]quinolin-7-yl)acetamide 6l
The compounds were investigated using the single dose tech-
nique at a concentration of 1610– 5 M. Samples were dissolved
in DMSO and diluted with the HEPES buffer to a concentration
of 0.1% of DMSO. The biological evaluation data for these com-
pounds were expressed in means of increased stroke volume per-
centage as shown in Table 1. Heart-rate measurements for those
selected compounds were carried out in isolated rabbit hearts
by recording the electrocardiogram in the volume conduction
model. In order to assess differences, repeated measurements
were compared by means of an ANOVA test followed by the Bon-
ferroni's multiple-comparison test. Statistical significance was
defined as P a 0.05 and the data is presented as means l SE.
1
Yield 70%; m.p.: 60–628C; H-NMR (CDCl3) d: 1.26 (m, 2H, CH2),
2.73 (s, 3H, CH3), 2.85–3.00 (m, 8H, CH2), 3.00 (t, J = 7.6 Hz, 2H,
CH2), 3.12 (t, J = 7.6 Hz, 2H, CH2), 3.31 (s, 2H, CH2), 3.63 (s, 2H,
CH2), 3.85 (s, 3H, CH3), 5.30 (s, 2H, CH2), 6.86–7.74 (m, 9H, Ar-H),
9.49 (s, 1H, NH); IR (KBr) cm– 1: 3452 (NH), 1686 (C=O); ESI-MS m/z:
635 [M + 1]; Anal. Calcd. for C33H36Cl2N6O3: C, 62.36; H, 5.71; N,
13.22. Found: C, 62.34; H, 5.72; N, 13.12.
2-(4-(4-(2-Bromobenzyloxy)-3-methoxybenzyl)-1,4-
diazepan-1-yl]-N-(4,5-dihydro-1-methyl-
[1,2,4]triazolo[4,3-a]quinolin-7-yl)acetamide 6m
Yield 73%; m.p.: 65–678C; 1H-NMR (CDCl3) d: 1.26 (m, 2H, CH2),
2.75 (s, 3H, CH3), 2.86–2.91 (m, 8H, CH2), 3.00 (t, J = 7.1 Hz, 2H,
CH2), 3.12 (t, J = 7.1 Hz, 2H, CH2), 3.31 (s, 2H, CH2), 3.64 (s, 2H,
CH2), 3.88 (s, 3H, CH3), 5.20 (s, 2H, CH2), 6.78–7.86 (m, 10H, Ar-H),
9.48 (s, 1H, NH); IR (KBr) cm– 1: 3455 (NH), 1688 (C=O); ESI-MS m/z:
645 [M + 1]; Anal. Calcd. for C33H37BrN6O3: C, 61.39; H, 5.78; N,
13.02. Found: C, 61.42; H, 5.75; N, 13.11.
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i 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.archpharm.com