Structure-based drug design and potent anti-cancer activity of tricyclic 5:7:5-fused diimidazo[4,5-d:4′,5′-f][1,3]diazepines

Article abstract of DOI:10.1016/j.bmc.2012.11.050

Judicial structural modifications of 5:7-fused ring-expanded nucleosides (RENs), based on molecular modeling studies with one of its known targets, human RNA helicase (hDDX3), led to the lead, novel, 5:7-5-fused tricyclic heterocycle (1). The latter exhibited promising broad-spectrum in vitro anti-cancer activity against a number of cancer cell lines screened. This paper describes our systematic, albeit limited, structure-activity relationship (SAR) studies on this lead compound, which produced a number of analogs with broad-spectrum in vitro anti-cancer activities against lung, breast, prostate, and ovarian cancer cell lines, in particular compounds 15i, 15j, 15m and 15n which showed IC ₅₀ values in submicromolar to micromolar range, and are worthy of further explorations. The SAR data also enabled us to propose a tentative SAR model for future SAR efforts for ultimate realization of optimally active and minimally toxic anti-cancer compounds based on the diimidazo[4,5-d:4′, 5′-f][1,3]diazepine structural skeleton of the lead compound 1.

Full text of DOI:10.1016/j.bmc.2012.11.050

Accepted Manuscript
Structure-based drug design and potent anti-cancer activity of tricyclic 5:7:5-
fused diimidazo[4,5-d:4’,5’-f][1,3]diazepines
Atul Kondaskar, Shilpi Kondaskar, James C. Fishbein, Brandon A. Carter-
Cooper, Rena G. Lapidus, Mariola Sadowska, Martin J. Edelman, Ramachandra
S. Hosmane
PII:
S0968-0896(12)00943-1
DOI:
http://dx.doi.org/10.1016/j.bmc.2012.11.050
BMC 10457
Reference:
To appear in:
Bioorganic & Medicinal Chemistry
Received Date:
Revised Date:
Accepted Date:
13 October 2012
26 November 2012
30 November 2012
Please cite this article as: Kondaskar, A., Kondaskar, S., Fishbein, J.C., Carter-Cooper, B.A., Lapidus, R.G.,
Sadowska, M., Edelman, M.J., Hosmane, R.S., Structure-based drug design and potent anti-cancer activity of
tricyclic 5:7:5-fused diimidazo[4,5-d:4’,5’-f][1,3]diazepines, Bioorganic & Medicinal Chemistry (2012), doi: http://
dx.doi.org/10.1016/j.bmc.2012.11.050
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Bioorganic & Medicinal Chemistry
journal homepage: www.elsevier.com
Structure-based drug design and potent anti-cancer activity of tricyclic 5:7:5-fused
diimidazo[4,5-d:4’,5’-f][1,3]diazepines
Atul Kondaskar a , Shilpi Kondaskar a , James C. Fishbein a , Brandon A. Carter-Cooper b , Rena G.
Lapidus b , Mariola Sadowska b , Martin J. Edelman b , and Ramachandra S. Hosmane a, c,
*
a
Laboratory for Drug Design & Synthesis, Department of Chemistry & Biochemistry, University of Maryland,
Baltimore County, 1000 Hilltop Circle, Baltimore, Maryland, 21250, USA.
Translational Core Laboratory, University of Maryland Marlene & Stewart Greenbaum Cancer Center, 22 South
Greene Street, Baltimore, Maryland 21201, USA
b
c
Retired
ARTICLE INFO
ABSTRACT
Article history:
Received
Received in revised form
Accepted
Judicial structural modifications of 5:7-fused ring-expanded nucleosides (RENs), based on
molecular modeling studies with one of its known targets, human RNA helicase (hDDX3), led
to the lead, novel, 5:7-5-fused tricyclic heterocycle (1). The latter exhibited promising broad-
spectrum in vitro anticancer activity against a number of cancer cell lines screened. This paper
describes our systematic, albeit limited, structure-activity relationship (SAR) studies on this lead
compound, which produced a number of analogs with broad-spectrum in vitro anticancer
activities against lung, breast, prostate, and ovarian cancer cell lines, in particular compounds
15i, 15j, 15m and 15n which showed IC50 values in submicromolar to micromolar range, and are
worthy of further explorations. The SAR data also enabled us to propose a tentative SAR model
for future SAR efforts for ultimate realization of optimally active and minimally toxic anticancer
compounds based on the diimidazo[4,5-d:4’,5’-f][1,3]diazepine structural skeleton of the lead
compound 1.
Available online
Keywords:
Organic synthesis and medicinal chemistry
Diimidazo[4,5-d:4’,5’-f][1,3]diazepines
Anti-cancer activity
Lung, breast, prostate and ovarian cancers
In vitro screening
Structure-activity relationship (SAR) studies
DDX3 as potential target
2009 Elsevier Ltd. All rights reserved.
1. Introduction
Our laboratory has been engaged in the design and synthesis
of ring expanded nucleosides (RENs) possessing broad spectrum
The conserved RNA helicase ‘human DDX3’ (hDDX3) is a
ubiquitously expressed 73 kD protein belonging to DEAD box
family of ATP-dependent RNA helicases. The ‘DEAD box’
name comes from conserved amino acid sequence D-E-A-D
(Asp-Glu-Ala-Asp) found in all members of the family. Different
stages of RNA life cycle from their transcription, splicing,
quality control, and transport to decay, are influenced by DDX3
in all species.1-3 hDDX3 has important roles in tumor
proliferation and viral infections in human.4, 5 hDDX3 is of major
medical importance due to its involvement in numerous cancers
as well as viral infections, including but not limited to hepatitis C
virus (HCV) and human immunodeficiency virus (HIV)
infections.6, 7 DDX3 has been validated as a target in anticancer
and antiviral therapy.8 hDDX3 is aggressively expressed in
certain forms of cancer. Benzopyran and benzopyran diepoxide
(BPDE), constituents of cigarette smoke, are two among the
many activators of DDX3. This activation in turn promotes
growth, proliferation and neoplastic transformation of breast
epithelial cells.9
antiviral/anticancer activities, which were confirmed to be
O
N
N
N
N
O
O
H
OH
HO
OH
A Ring-Expanded Nucleoside (REN)
inhibitors of viral NTPases/helicases.10-12 Recently, two leading
RENs were also experimentally demonstrated to be potent
inhibitors of hDDX3 in vitro.13 RENs possess the characteristic
5:7-fused imidazodiazepine heterocyclic ring system, and mimic
natural 5:6-fused purine nucleosides.
Inspired by positive biological results of many compounds
bearing the 5:7-fused REN moiety,14 we proceeded to make
further structural modifications of RENs through extensive
molecular modeling studies, employing the coordinates from the

reported crystal structure of hDDX3.15 These efforts ultimately
led to the design and synthesis of a 5:7:5-fused diimidazo[4,5-
d:4’,5’-f][1,3]diazepine-2-one, a novel tricyclic compound (1).16
The latter was indeed found to be a potent inhibitor of hDDX3
both in vitro and in vivo with an impressive selective
We used the visualization software Pymol® to analyze
interactions within 5Å. Purine nucleobase stacks over Tyr200
and mainly interacts with Q motif and the phosphate group
interacts mainly with P-loop. Gln207 of Q-motif interacts with
N6 and N-7 of purine. Arg202 interacts with N-1 of purine
through a molecule of water.
MeO
O
A few important protein-ligand (AMP) interactions are shown
in a cartoon representation in Figure 2A. It is known that the
presence of a water molecule makes a large volume available
around the purine binding region of active site, and results in
relaxed substrate specificity.20 Favorable binding is achieved on
displacement of water molecule from the active site as a result of
favorable entropy. Introduction of structural features that mimic
active site water molecule, such as urea, has been successfully
used to design an anti-HIV protease inhibitor.21, 22
N
N
N
N
N
N
OMe
1
cytotoxicity against cancer versus host.17,
Our preliminary
18
biological studies with a limited number of compounds bearing
the general structure 1 showed highly promising anticancer
activity against a number of cancer cell lines.18,
Good anti-
19
Taking into consideration these features as well as the
molecular structure of 1, along with visualization of DDX3-AMP
crystal structure through Pymol®, we constructed a working
model for SAR studies. The cartoon representation of the
proposed protein-ligand (1) interactions in this model is shown in
Figure 2B. The central diazepine ring of 1 is expected to interact
through π-π stacking interactions with Q motif residue Tyr200.
The benzyl group attached to the ureidate portion of 1 is likely to
embed in the hydrophobic region formed by backbone of
residues 203-205 and Phe182, and is suitably placed to form π-π
cancer activity coupled with an acceptable toxicity profile both in
vitro and in vivo encouraged us to launch systematic structure-
activity relationship studies (SARs) in order to improve upon
efficacy and toxicity profiles of this series of compounds. To that
end, we present here our SAR results that lead us to propose a
tentative SAR model which we believe would assist in future
SAR efforts for ultimate realization of one or more optimally
potent and minimally toxic anti-cancer compounds based on the
skeletal structure of 1.
stacking interaction with Phe182.
Likewise, the p-
2. Chemistry
methoxybenzyl group present on the imidazole ring is expected
to interact with the P loop. This is supported by our earlier
observation that the p-methoxybenzyl group can replace ribose
sugar on a nucleobase without significant loss of activity of the
2.1. DDX3 Crystal structure and Proposed SAR Model
The reported crystal structure of a complex of hDDX3 with
adenosine monophosphate [Protein Data Bank (PDB) code:
2I4I)] shows that it has two domains, N-terminal domain and C-
terminal domain, which form a cleft where ATP binds (Figure
1).15 The nucleobase stays toward the surface of protein whereas
the phosphate group buries deep inside the binding pocket.
O
2
1
3
N
9b
R3
N
9
7
9a
6a
N
8
4N
N
N
R15
R2
6
1G
parent compound.23, 24 Three positions, N-3, N-5, and N-7, were
selected for variations as shown in the general structure 1G based
on the proposed interactions described above.
Figure 1. Visualization (Pymol®) of interactions between DDX3 and
AMP from reported crystal structure in PDB.
A
B
O
N
H
O
Mg ion
N
H
MeO
O
O
H
2
NH2
P loop
Mg ion
P loop
1
7
N
3
H
6
5
N
N
9
N
1
N
Phe182
Phe182
8
2
8
4
N 9
4
N
5
N
O
P
O-
N 7
3
O
O-
Tyr200
N
O
6
Tyr200
OMe
OH
Charged
region
Charged
region
Q motif
Q motif
Figure 2. (A) Model for interactions between AMP and DDX3 (B) Proposed model for interactions between 1 and DDX3.

2.2. Organic Synthesis of Analogues of 1
12a-c. The latter, upon treatment with ethyl orthoformate,
furnished the target tricyclic compounds 13a-c.
5-Substituted analogues of 1 were synthesized as outlined in
Scheme 1. Diaminomalenonitrile (2) was converted into
Compounds with substitution at 3-position were synthesized
as shown in Scheme 3. Imidazole 5 was treated with appropriate
25
formimidate 3 by reaction with ethyl orthoformate.16,
The
reaction of 3 with p-methoxybenzylamine produced formamidine
4, which upon base catalyzed cyclization, furnished imidazole
5.16, 26 Treatment of 5 with 4-methoxybenzyl isocyanate produced
the intermediate ureidate (not shown) that underwent base-
O
O
NH
N
N
N
N
R
N
R
N
N
NC
H2N
a. R-NCO, MeCN, RT, 2-12 h
N
N
HC(OEt)3
N
N
NH
N
H2SO4 (cat.), MeCN,
Reflux, 2 h
b. DBU (cat.), MeCN, RT, 6-24 h
NH2
catalyzed ring closure to furnish the important precursor
26
diimidazole compound 6.16,
Ring-closure of the latter with
MeO
appropriate reagents produced the desired tricyclic 5:7:5-fused
MeO
MeO
14a-x
OMe
5
15a-x
NH
NH2
H
OC2H5
MeO
PhNH2.HCl (cat.),
N
N
N
NC
H2N
NC
NC
NH2
NH2
DBU (cat.)
CH(OEt)3 NC
Dioxane,
N
NC
NC
N
Scheme 3. Synthesis of 3-substituted analogues of 1.
EtOH, rt, 3 h
NC
NH2
EtOH, rt, 3 h, 65%
Reflux, 65%
NH2
2
4
3
O
MeO
O
N
5
isocyanates to give the respective ureidate intermediates (not
shown). The latter were treated with DBU to obtain imidazolones
14a-x, followed by reaction with ethyl orthoformate to obtain the
target 15a-x. It is to be noted that some necessary isocyanates
were synthesized in the laboratory from the corresponding acid or
amine. The preferred method for synthesis was from the
corresponding acid by reaction with diphenylphosphoryl azide.
For others, corresponding amine was treated with triphosgene in
the presence of a base to produce isocyanate.
N
N
N
N
N
a. 4-Methoxybenzyl
N
N
isocyanate, MeCN, rt, 6h
R
C(OEt)3
HN
H2N
N
N
H2SO4 (cat.),
MeCN, Reflux,
2 h
b. DBU (cat.), MeCN, rt, 3 h
MeO
MeO
R
MeO
6
7a: CH3
7b: C2H5
MeO
O
O
Ar-COCl,
Pyridine, rt, 2h
MeCN, cat. H2SO4
O
m
O
O
m = 1,2
N
N
N
N
N
N
N
N
N
N
N
MeO
N
Ar
MeO
HOOC
3. Biological Activity
MeO
MeO
8a: Ph
8b: p-CH3Ph
9a: m = 1
9b: m = 2
The above compounds were tested against the cancer cell lines
of lungs, prostate, breast and ovary. Activity against various
cancer cell lines is collected in Tables 1 and 2.
Scheme 1. Synthesis of 5-substituted analogues of 1.
As revealed by the collected data, even the small alkyl groups,
such as methyl (7a) and ethyl (7b) at 5-position, are detrimental
to activity. Similarly, phenyl (8a), p-toluyl (8b) and carboxylic
acid groups (9a and 9b) at 5-position lead to inactive compounds.
Our proposed model shows this part of scaffold (5-position) in
the vicinity of the backbone of Q motif. Hydrogen atom seems to
be the right size to occupy the available volume. Substitution
larger than hydrogen disrupts the binding of molecule. These
observations suggest that the volume in active site is completely
filled with the bulky 5:7:5-fused ring. It is possible that the water
molecule of the active site, through which ATP interacts with
backbone, is displaced. Such displacement of water molecule
from active site is reported to provide favorable entropy.27
heterocycles (7-9). For example, the reaction of 6 with triethyl
orthoacetate and triethyl orthopropionate produced compounds
with methyl (7a) and ethyl (7b) substitution at 5-position,
respectively. Likewise, precursor 6 was treated with appropriate
benzoyl chloride in the presence of a base to provide phenyl (8a)
and toluyl (8b) analogues. Reactions with succinic and glutaric
anhydrides gave compounds with alkyl chains bearing water-
solublizing carboxylic acid group, 9a and 9b, respectively.
Compounds with substitution at 7-position were synthesized
as shown in Scheme 2. Formimidate 3 was treated with
appropriate amine to produce formamidines (10a-10c) which,
NH
H
p-Methoxybenzyl group at 7-position was found to be
optimum for activity. Fluoro in place of methoxy (13c) is
tolerated, whereas, hydrogen (13a) is not. Changing this benzyl
group with ethyl group (13b) led to loss of activity. The
phosphate group of ATP interacts with P loop, which is highly
charged, with hydrogen bond donating residues. Hydrogen bond
acceptor such as methoxy or fluoro at this position is necessary
for molecule to interact successfully with this region. The benzyl
group is the right scaffold to orient and hold the hydrogen bond
acceptor in place for successful interaction.
NC
NC
N
OEt
NC
NC
N
N
DBU (cat.)
R-NH2
N
R
NC
H2N
EtOH, rt, 2-6 h
MeCN, RT, 6-24 h
N
NH2
NH2
R
3
10a: R = CH2Ph
10b: R = C2H5
10c: R = 4-F-C6H4CH2
11a-c
MeO
O
NCO
N
O
N
DBU (cat.)
MeO
MeCN,
N
N
HC(OEt)3
N
N
N
HN
H2SO4 (cat.),
MeCN,
Reflux, 2 h
MeCN,
RT, 6-24 h
N
N
H2N
RT, 2-12 h
N
R
MeO
R
12a-c
13a-c
As evident from results in Table 1, H at 5-position and p-
methoxy group at 7-position were optimum for activity. Keeping
these groups, we planned further changes at the 3-position.
Greater degree of change was tolerated at the 3-position and
significant modulation of activity was observed.
Scheme 2: Synthesis of 7-substituted analogues of 1
under base catalyzed conditions, provided imidazole compounds
11a-11c. Treatment with p-methoxybenzylisocyanate provided
the corresponding ureidate intermediates (not shown), which
underwent DBU catalyzed cyclization to provide imidazolones
Phenyl ring at 3-position is proposed to be involved in π-π
stacking interactions with Phe182. One carbon linker connects
this phenyl ring with the rest of molecule. Increasing (15c) or

decreasing (15a, 15b) the length of linker between phenyl and
imidazolone ring resulted in inactive compounds. π-π Stacking
between phenyl ring of molecule and Phe182 appeared to be
critical for activity and one methylene spacer puts phenyl ring of
the molecule at the right distance for this interaction. Compounds
(15e, 15f) bearing other polar groups in place of phenyl on
methylene linker showed weak activity.
methoxy)ethoxy analogue (15s) showed activity comparable to
the parent compound. p-(2-Hydroxy)ethoxy analogue (15t) was
2-3 fold less active than p-(2-methoxy)ethoxy analogue (15s).
Replacing phenyl ring with pyridine (15u) led to 2-3-fold loss of
activity. Similar activity was seen for p-dimethylamino analogue
(15v).
Piperidinylethyl (15w) and morpholinylethyl (15x)
analogues were completely inactive.
At this 3-benzyl group, unlike one at 7-position, hydrogen in
place of methoxy group (15g) showed higher potency.
Replacement of the methoxy group by halogens also improved
potency (15h-j). The anti-cancer activity is likely related to size
and/or polarizability of halogens. p-Bromo analogue is the most
active compound of this series with activity in the range of 0.5 to
1 μM against all cell lines. Changing the position of methoxy
group from p-position to m-position (15k) conferred higher
potency whereas taking it to o-position (15l) led to loss of
4. Conclusions
Structural scrutiny of the lead compound 1, in conjunction
with the reported crystal structure of DDX3-AMP complex,
guided the initial, albeit limited, SAR studies and led way to
develop a tentative model for better understanding of the activity
of the lead compound as well as for future undertaking of
extensive SAR studies. The azepine ring was not amenable for
changes. Limited changes were carried out on the imidazole and
the imidazolone rings of 1. In particular, the imidazolone ring
provided a useful handle for improvement of activity. In
summary, our initial structure activity relationship studies on the
title diimidazo[4,5-d:4’,5’-f][1,3]diazepine series of compounds
based on the hypothesized model led to potent anticancer
compounds worthy of further explorations. Compounds 15i, 15j,
15m and 15n showed excellent broad-spectrum anti-cancer
activity in the submicromolar to micromolar range.
activity.
An ortho substitution might interfere with the
orientation of the benzyl group. Similar gain in activity was seen
when fluoro group was shifted from p-position to m-position
(15h vs 15m). 3,4-Difluoro compound (15n) was more potent
than both monosubstituted analogues. Moving bulkier halogens
to m-position (15i vs 15o and 15j vs 15p) did not offer any
advantage over corresponding p-analogue.
We also incorporated groups that increase water solubility in
the core.
Phenolic analogue (15r) as well as p-(2-
Table 1. Effect of substituent at R1 and R2 having 4-Methoxybenzyl at R3
MeO
O
2
1
3
N
9b
N
9
7
9a
6a
N
8
4N
R25
N
N
R1
6
Entry R1
R2
IC50 (µM)a
A549 Lung H460 Lung MCF-7 MDA-MB-231 OVCAR-3 Ovarian PC-3 Prostate
Breast
7.59
Breast
4.05
1
4-MeO-C6H4CH2
H
2.56
2.87
14.50
4.90
7a
4-MeO- C6H4CH2 CH3
NE
NE
NE
NE
NE
NE
NE
NE
4.40
NE
NE
NE
NE
NE
NE
NE
NE
5.06
NE
NE
NE
NE
NE
NE
NE
NE
5.87
NE
NE
NE
NE
NE
NE
NE
NE
5.33
NE
NE
NE
NE
NE
NE
NE
NE
NE
NE
NE
NE
NE
NE
NE
NE
NE
7.67
7b
8a
4-MeO- C6H4CH2 CH2CH3
4-MeO- C6H4CH2 Ph
8b
9a
4-MeO- C6H4CH2 4-CH3Ph
4-MeO- C6H4CH2 (CH2)2COOH
4-MeO- C6H4CH2 (CH2)3COOH
9b
13a
13b
13c
PhCH2
H
H
H
CH2CH3
4-F- C6H4CH2
aNE - Not effective. Maximum dose did not inhibit the growth/proliferation by ≤ 75%
Table 2. Effect of substituent at R3
O
2
1
3
N
9b
R3
N
9
7
9a
6a
N
4N
8
N
N
5
6
MeO

Entry R3
IC50 (µM)a
A549 Lung H460 Lung MCF-7 MDA-MB-231 OVCAR-3 Ovarian PC-3 Prostate
Breast
Breast
15a
15b
15c
15d
15e
15f
15g
15h
15i
Ph
NE
NE
NE
NE
NE
NE
NE
NE
NE
NE
NE
4-MeO-Ph
NE
NE
4-MeO- C6H4CH2CH2
CH2CH3
NE
NE
NE
NE
NE
NE
NE
NE
NE
NE
NE
CH2COOEt
33.50
8.63
1.7
34.50
7.90
1.8
NE
37.00
NE
NE
NE
CH2CH2Cl
NE
NE
9.33
4.05
2.1
PhCH2
7.0
2.3
5.0
4-F- C6H4CH2
1.65
0.78
0.63
1.50
NE
1.5
4.05
2.38
1.02
6.00
NE
2.5
9.0
4-Cl- C6H4CH2
4-Br- C6H4CH2
3-MeO- C6H4CH2
2-MeO- C6H4CH2
3-F- C6H4CH2
0.85
0.57
1.55
NE
0.97
1.16
2.60
NE
0.88
1.62
2.50
NE
0.92
0.98
5.15
NE
15j
15k
15l
15m
15n
15o
15p
15q
15r
15s
15t
1.20
0.99
0.89
1.37
3.19
4.21
4.89
12.34
8.05
8.81
1.24
0.74
1.00
1.17
3.10
4.68
5.14
10.94
8.30
8.44
1.64
1.75
2.49
1.85
4.31
6.58
14.77
27.16
19.83
15.10
2.70
1.70
1.15
1.53
4.61
3.15
5.61
10.58
8.68
8.82
3.18
2.27
1.07
1.54
3.68
4.36
5.45
13.15
9.89
9.43
1.83
1.59
0.97
2.57
8.30
5.12
6.70
19.69
26.87
202.18
3,4-Di-F- C6H3CH2
3-Cl- C6H4CH2
3-Br- C6H4CH2
3-F3C- C6H4CH2
4-OH- C6H4CH2
4-(CH3OCH2CH2)O- C6H4CH2
4-(HOCH2CH2)O- C6H4CH2
3-Pyridylmethyl
4-(CH3)2N- C6H4CH2
CH2CH2Piperidinyl
CH2CH2Morpholinyl
15u
15v
15w
15x
NE
NE
NE
NE
NE
NE
NE
NE
NE
NE
NE
NE
aNE - Not effective. Maximum dose did not inhibit the growth/proliferation by ≤ 75%
followed by heating to 80°C for 1 h during which evolution of
nitrogen was observed. Solvent was removed at reduced pressure.
Unless otherwise mentioned, isocyanate was extracted by the
following method. Residue was stirred in hexane (10 mL/mmol)
and supernatant was collected. Hexane extraction was repeated
twice. Combined hexane layer was evaporated to get crude
isocyanate, which was used for next step without further
purification.
5. Experimental
5.1 General
The 1H and 13C NMR spectra were recorded on a JEOL-400
NMR spectrometer, operating at 400MHz for 1H and 100 MHz
for 13C NMR, respectively. Thin layer chromatography was
performed on Merck Kieselgel 60 F254 (0.2 mm thickness). Flash
chromatography was performed using 32-63 mesh silica gel.
Mass spectra were recorded on a Brucker Daltonics Esquire-3000
LC-Quadrupole ion trap spectrometer. High resolution mass
spectra were recorded a Bruker Daltonics (Billerica, MA) Apex
IV FTICR. Melting points were recorded on Hoover capillary
melting point apparatus and are uncorrected. Anhydrous solvents
were purchased and used without further drying.
5.2.2. 3,7-Bis(4-methoxybenzyl)-5-methyl-3,7-dihydro-2H-
diimidazo[4,5-d:4’,5’-f][1,3]diazepin-2-one (7a)
To a solution of 6 (0.1 g, 0.239 mmol, 1.0 equi.) in
acetonitrile (3 mL) was added triethyl orthoacetate (0.31 g, 1.90
mmol, 8.0 equi.) and a drop of H2SO4 and heated under reflux for
6 h under inert atmosphere. Solution was cooled to room
temperature. The precipitate was washed with acetonitrile and
dried under vacuum to get product (Yield = 0.08 g, 75%); m.p.:
228-229°C; 1H-NMR (DMSO-d6): δ = 2.81 (s, 3H, -CH3), 3.7 (s,
6H, -OCH3), 5.02 (s, 2H, -CH2), 5.45 (s, 2H, -CH2), 6.85-6.91
(m, 4H, Ar-H), 7.31 (d, J= 8.7 Hz, 2H, Ar-H), 7.38 (d, J= 8.7 Hz,
2H, Ar-H), 8.83 (s, 1H, Imid-H); 13C-NMR (DMSO-d6): δ =
30.35, 42.71, 46.33, 55.04, 55.09, 113.87, 114.06, 127.84,
128.09, 128.31, 129.43, 129.54, 147.76, 149.39, 155.22, 158.30,
158.69, 158.99, 160.42, 165.81; MS (m/z): 443.2 (M+1); Anal.
Calcd for C24H22N6O3. 0.25 H2O: C, 64.49; H, 5.07; N, 18.80;
found C, 64.58; H, 4.89; N, 18.81.
5.2. Synthetic Organic Chemistry
5.2.1. General procedure for synthesis of isocyanates from
acid
To a suspension of acid (1.5 g, 6.25 mmol, 1.0 equi) in
toluene, under inert atmosphere, was added triethylamine (0.76 g,
7.5 mmol, 1.2 equi) followed by slow addition of
diphenylphsophoryl azide (1.90 g, 6.87 mmol, 1.1 equi ).
Reaction mixture was stirred at room temperature for 15 min.,

= 8.7 Hz, 2H, Ar-H), 6.86 (d, J = 8.7 Hz, 2H, Ar-H), 7.29 (d, J =
8.7 Hz, 2H, Ar-H), 7.36 (d, J = 8.7 Hz, 2H, Ar-H), 8.81 (s, 1H,
Imid-H), 12.23 (s, 1H, -COOH); 13C-NMR (DMSO-d6): δ =
31.40, 37.04, 42.76, 46.23, 55.05, 55.09, 113.88, 114.10, 127.67,
128.14, 128.36, 129.51, 129.56, 147.83, 149.14, 155.27, 158.33,
158.71, 159.02, 161.80, 165.84, 174.08; MS (m/z) 501.4 (M+1);
Anal. Calcd. for C26H24N6O5.0.5H2O:C, 61.29; H, 4.95; N, 16.49;
found C, 61.65; H, 4.69; N, 16.53.
5.2.3. 3,7-Bis(4-methoxybenzyl)-5-ethyl-3,7-dihydro-2H-
diimidazo[4,5-d:4’,5’-f][1,3]diazepin-2-one (7b)
The procedure is similar to that of 7a above, but using triethyl
orthopropionate (16 equi.), Yield = 0.12 g, 55%; m.p.: 208-
210°C; 1H-NMR (DMSO-d6): δ = 1.35 (t, J = 7.32 Hz, 3H, -
CH3), 3.08 (q, J = 7.32 Hz, 2H, -CH2), 3.70 (s, 3H, -OCH3), 3.73
(s, 3H, -OCH3), 5.03 (s, 2H, -CH2), 5.47 (s, 2H, -CH2), 6.85-6.91
(m, 4H, Ar-H), 7.31 (d, J = 8.7 Hz, 2H, Ar-H), 7.38 (d, J = 8.7
Hz, 2H, Ar-H), 8.86 (s, 1H, Imid-H); 13C-NMR (DMSO-d6): δ =
12.57, 35.89, 42.8, 46.47, 55.11, 55.15, 113.93, 114.12, 127.79,
128.23, 128.42, 129.49, 129.54, 147.89, 149.5, 155.24, 158.46,
158.75, 159.05, 164.11, 165.95; MS (m/z): 457.2 (M+1); Anal.
Calcd for C25H24N6O3: C; 65.78; H; 5.30; N; 18.41; found: C;
65.75; H; 5.33; N; 18.38.
5.2.7. 3,7-Bis(4-methoxybenzyl)-5-(2-carboxypropyl)-3,7-
dihydro-2H-diimidazo[4,5-d:4’,5’- f][1,3]diazepin-2-one (9b)
Procedure similar to that of 9a (Yield = 30 mg, 25%); m.p.:
148-150°C; 1H-NMR (DMSO-d6): δ = 2.09 (m, 2H, CH2), 2.33 (t,
2H, CH2), 3.07 (t, 2H, CH2), 3.70 (s, 6H), 5.02 (s, 2H, CH2), 5.45
(s, 2H, CH2), 6.85 (d, J = 8.7 Hz, 2 H, Ar-H), 6.88 (d, J = 8.7 Hz,
2 H, Ar-H), 7.32 (d, J = 8.7 Hz, 2 H, Ar-H), 7.38 (d, J = 8.7 Hz, 2
H, Ar-H), 8.86 (s, 1H, Imid-H), 12.08 (s, 1H, -COOH); 13C-NMR
(DMSO-d6): δ = 23.72, 33.33, 42.15, 43.31, 46.98, 55.58, 55.63,
114.40, 114.59, 128.38, 128.68, 128.85, 130.06, 130.13, 148.34,
149.91, 155.90, 159.02, 159.24, 159.54, 163.17, 166.41, 174.91;
MS (ESI) (m/z) 515.3 (M+1); Anal. Calcd. for C27H26N6O5: C,
63.03; H, 5.09; N, 16.33; found C, 62.66; H, 5.13; N, 16.05.
5.2.4. 3,7-Bis(4-methoxybenzyl)-5-phenyl-3,7-dihydro-2H-
diimidazo[4,5-d:4’,5’-f][1,3]diazepin-2-one (8a)
To a solution of 6 (50 mg, 0.12 mmol, 1.0 equi.) in pyridine (5
mL) was added benzoyl chloride (0.020 mg, 0.144 mmol, 1.2
equi.) and stirred at room temperature for 6 h under inert
atmosphere. The reaction mixture was poured on crushed ice and
the precipitate formed was filtered. The residue was washed with
water and dried to get crude product which as purified by
5.2.8. 2-(5-Amino-1-benzyl-1H-imidazol-4-yl)-2-iminoaceto-
nitrile (11a)
recrystallization from acetone (Yield = 52 mg, 87.6%); m.p.:
>260°C. 1H-NMR (DMSO-d6): δ = 3.68 (s, 6 H, 2 X OCH3), 5.19
(s, 2 H, CH2), 5.62 (s, 2 H, CH2), 6.86 (d, J = 8.7 Hz, 2 H, Ar-H),
6.89 (d, J = 8.7 Hz, 2 H, Ar-H), 7.36 (d, J = 8.7 Hz, 2 H, Ar-H),
7.40 (d, J = 8.7 Hz, 2 H, Ar-H), 7.58 (m, 3H), 8.58 (m, 2H), 8.93
(s, 1 H, Imid-H). 13C-NMR (DMSO-d6): δ = 42.89, 46.51, 54.95,
54.99, 113.84, 114.02, 128.23, 128.43, 128.77, 129.05, 129.12,
129.47, 131.62, 138.64, 148.56, 149.44, 154.36, 155.43, 158.59,
158.70, 158.88, 165.90. HRMS (m/z): Calcd for C29H25N6O3
(MH+) 505.1943; found, 505.1982; Anal. Calcd for C29H24N6O3:
C, 69.04; H, 4.79; N, 16.66; found: C, 68.77; H, 4.90; N, 16.65.
To a solution of formimidate 3 (1.0 g., 6.1 mmol) in ethanol
(5 mL) was added benzylamine (0.65 g., 6.1 mmol) and aniline
hydrochloride (5 mg), under inert atmosphere, at room
temperature and stirred for 4 h (starting material completely
consumed on TLC). The solvent was evaporated under reduced
pressure. Resulting residue was suspended in ethanol (5 mL)
under inert atmosphere and 2 drops DBU was added at room
temperature followed by stirring for 5 h (starting material
completely consumed on TLC). Reaction mixture was diluted
with diethyl ether (20 mL). Precipitate formed was filtered,
washed with diethyl ether (2 X 10 mL) and dried to obtain the
product (Yield = 0.67 g, 50.0%); 1H-NMR (DMSO-d6): δ = 5.12
(s, 2H, -CH2), 6.78 (brs, 2H, -NH2), 7.22-7.36 (m, 6H, Ar-H),
10.90 (s, 1H, -NH); HRMS (m/z): Calcd.for C12 H12N5 (MH+):
226.1087; found, 226.1087.
5.2.5. 3,7-Bis(4-methoxybenzyl)-5-(4-methylphenyl)-3,7-
dihydro-2H-diimidazo[4,5-d:4’,5’- f][1,3]diazepin-2-one (8b)
Procedure analogous to that of 8a above; m.p.: >260°C. 1H-
NMR (DMSO-d6): δ = 2.40 (s, 3 H, CH3), 3.68 (s, 6 H, 2 X
OCH3), 5.17 (s, 2 H, CH2), 5.60 (s, 2 H, CH2), 6.87 (d, J = 8.7
Hz, 2 H, Ar-H), 6.89 (d, J = 8.7 Hz, 2 H, Ar-H), 7.37 (m, 6 H,
Ar-H), 8.47 (d, J = 8.24 Hz, 2 H, Ar-H), 8.91 (s, 1 H, Imid-H).
13C-NMR (DMSO-d6): δ = 21.07, 42.96, 46.57, 55.04, 55.07,
113.93, 114.10, 128.37, 128.54, 129.15, 129.22, 129.51, 129.61,
136.07, 141.94, 146.62, 148.55, 149.64, 154.62, 155.43, 158.68,
158.88, 158.96, 166.00; MS (ESI, m/z) 519.4 (M +1). Anal.
Calcd. for C30H26N6O3. 0.5H2O: C, 68.30; H, 5.16; N, 15.93;
found: C, 68.19; H, 5.56; N, 14.26.
5.2.9. 2-(5-Amino-1-ethyl-1H-imidazol-4-yl)-2-iminoaceto-
nitrile (11b)
To a acetonitrile (7 mL) solution of 3 (2.2 g, 13.41 mmol, 1
equi.) was added ethylamine hydrochloride (1.20 g, 14.75 mmol,
1.1 equi.) and triethylamine (1.63 g, 16.09, 1.2 equi.), at room
temperature under inert atmosphere, and stirred for 12 h.
Reaction mixture was filtered and washed with diethyl ether. The
filtrate was concentrated and purified by column chromatography
(gradient elution using ethyl acetate in hexane) (Yield = 1.0 g,
45.6%); 1H-NMR (DMSO-d6): δ = 1.27 (t, J = 7.3 Hz, 3H, -CH3),
3.86 (q, J = 7.3 Hz, 2H, -CH2), 6.70 (brs, 2H, -NH2), 7.25 (s, 1H,
Imid-H), 10.83 (s, 1H, -NH).
5.2.6. 3,7-Bis(4-methoxybenzyl)-5-(2-carboxyethyl)-3,7-
dihydro-2H-diimidazo[4,5-d:4’,5’- f][1,3]diazepin-2-one (9a)
To a solution of 6 (0.1 g, 0.24 mmol, 1.0 equi.) in DMF (2
mL) was added succinic anhydride (0.12 g, 1.2 mmol, 5 equi.)
and a drop of H2SO4 and heated at 60°C for 12 h under inert
atmosphere. Reaction mixture was cooled and poured over
crushed ice. The precipitate was filtered and washed with water
and dried under vacuum to get crude product (0.12 g). The
compound was purified by recrystallization in acetone (Yield =
20 mg, 16.7%); m.p.: 229-231°C; 1H-NMR (DMSO-d6): δ =
2.78 (t , J = 6.6 Hz, 2H), 3.30 (m, 2H), 3.66 (s, 3 H, OCH3), 3.68
(s, 3 H, OCH3), 5.00 (s, 2 H, CH2), 5.43 (s, 2 H, CH2), 6.82 (d, J
5.2.10. 2-(1-(4-Fluorobenzyl)-5-amino-1H-imidazol-4-yl)-2-
iminoacetonitrile (11c)
To a solution of formimidate 3 (0.5 g., 3.05 mmol) in
acetonitrile (5 mL) was added 4-fluorobenzylamine (0.38 g., 3.05
mmol) and aniline hydrochloride (2 mg), under inert atmosphere,
at 0°C. The reaction mixture was allowed to come to room
temperature followed by stirring at for 12 h. The solvent was
evaporated under reduced pressure. Resulting residue was

suspended in ethyl acetate (5 mL) under inert atmosphere and 3
drops DBU was added at room temperature followed by stirring
for 24 h (starting material completely consumed on TLC).
Reaction mixture was diluted with diethyl ether (20 mL).
Supernatant was decanted, and residue was washed with diethyl
ether (2 X 10 mL). The combined organic layer was evaporated
to dryness. Residue was triturated with diethyl ether (2X 10 mL)
and dried to get product (Yield = 0.540 g., 73%); 1H-NMR
(DMSO-d6): δ = 5.12 (s, 2H, -CH2), 6.78 (brs, 2H, -NH2), 7.17-
7.23 (m, 2H, Ar-H), 7.28-7.32 (m, 2H, Ar-H), 7.35 (s, 1H, Imid-
H), 10.91 (brs, 1H, -NH).
To a solution of 12a (0.2 g, 0.51 mmol, 1.0 equi.) in
acetonitrile (5 mL) was added triethyl orthoformate (0.42 g, 4.12
mmol, 8.0 equi.) and a drop of H2SO4 and heated under reflux for
2 h under inert atmosphere. The reaction mixture was cooled to
room temperature. Precipitate formed was filtered, washed with
diethyl ether (2X10 mL), and dried to get product (Yield = 0.16
g, 79%); m.p.: 168-170°C; 1H-NMR (DMSO-d6): δ = 3.70 (s, 3H,
-OCH3), 5.08 (s, 2H, -CH2), 5.61 (s, 2H, -CH2), 6.86 (d, J = 8.7
Hz , 2H, Ar-H), 7.28-7.35 (m, 7H, Ar-H), 8.73 (s, 1H, azepine
H), 8.95 (s, 1H, Imid-H); 13C-NMR (DMSO-d6): δ = 42.86,
46.90, 55.07, 113.89, 127.48, 127.95, 128.75, 129.12, 136.32,
148.53, 149.88, 149.93, 155.88, 158.69, 159.77, 165.79; HRMS
(m/z): Calcd. for C22H19N6O2: 399.1564; found 399.1564; Anal.
Calcd for C22H18N6O2.0.5H2O: C, 64.85; H, 4.70; N, 20.63; found
C, 64.65; H, 4.50; N, 20.44.
5.2.11. 1-(4-Methoxybenzyl)-4-(5-amino-1-benzyl-1H-
imidazol-4-yl)-5-imino-1H-imidazol-2(5H)-one (12a)
To a suspension of 11a (0.6 g., 2.67 mmol, 1.0 equi.) in 5 mL
acetonitrile was added 4-methoxybenzyl isocyanate (1.30 g., 8.0
mmol, 3.0 equi.) and stirred at room temperature for 12 h. The
precipitate formed was filtered, washed with diethyl ether (2X10
mL) and dried. This precipitate was suspended in 5 mL
acetonitrile. DBU (2 drops) was added to it and stirred for 3 h.
The resulting precipitate was filtered, washed with diethyl ether
and dried to give 12a (Yield = 0.45 g., 43.5%); m.p.: 214-216°C;
1H-NMR (DMSO-d6): δ = 3.70 (s, 3H, -OCH3), 4.62 (s, 2H, -
CH2), 5.20 (s, 2H, -CH2), 6.85 (d, J=8.7 Hz, 2H, Ar-H), 7.20-
7.26 (m, 4H, Ar-H), 7.30-7.33 (m, 1H, Ar-H), 7.37-7.40 (m, 2H,
Ar-H), 7.75 (s, 1H, Imid-H), 7.92 (brs, 2H, -NH2), 9.78 (s, 1H, -
NH); 13C-NMR (DMSO-d6): δ = 41.12, 45.83, 55.03, 113.73,
127.15, 127.85, 128.79, 128.83, 129.64, 135.83, 139.07, 151.89,
156.99, 158.37, 159.57, 166.74; HRMS (m/z): Calcd. For
C21H21N6O2 (MH+): 389.1720; found 389.1720; Anal. Calcd. for
C21H20N6O2.0.2H2O: C, 64.34; H, 5.25; N, 21.44; found: C,
64.41; H, 5.22; N, 21.22.
5.2.15. 7-Ethyl-3-(4-methoxybenzyl)-3,7-dihydro-2H-
diimidazo[4,5-d:4’,5’-f][1,3]diazepin-2-one (13b)
Procedure similar to that of 13a except for washing of the
precipitate with ethyl acetate (2X5 mL), instead of diethyl ether
(Yield = 0.13 g, 63%); m.p.:176-179°C; 1H-NMR (DMSO-d6): δ
= 1.44 (t, J = 7.1 Hz, 3H, -CH3), 3.7 (s, 3H, -OCH3), 4.37 (q, J =
7.1 Hz, 2H, -CH2), 5.09 (s, 2H, -CH2), 6.86 (d, J = 8.7 Hz, 2H,
Ar-H), 7.31 (d, J = 8.7 Hz, 2H, Ar-H), 8.75 (s, 1H, diazepine-H),
8.87 (s, 1H, Imid-H); 13 C-NMR (DMSO-d6): δ = 15.26, 42.91,
55.12, 113.95, 128.03, 128.91, 129.17, 148.44, 149.62, 149.95,
155.66, 158.74, 159.61, 165.85; MS (m/z): 337.1 (M+1); Anal.
Calcd for C17H16N6O2: C, 60.71; H, 4.79; N, 24.99; found C,
60.57; H, 4.75; N, 24.88.
5.2.16. 7-(4-Fluorobenzyl)-3-(4-methoxybenzyl)-3,7-dihydro-
2H-diimidazo[4,5-d:4’,5’-f][1,3]diazepin-2-one (13c)
5.2.12. 1-(4-Methoxybenzyl)-4-(5-amino-1-ethyl-1H-
imidazol-4-yl)-5-imino-1H-imidazol-2(5H)-one (12b)
Procedure similar to that of 13a (Yield = 0.12 g, 43.4 %);
m.p.: 196-198°C. 1H-NMR (DMSO-d6): δ = 3.70 (s, 3H, -OCH3),
5.08 (s, 2H, -CH2), 5.58 (s, 2H, -CH2), 6.86 (d, J = 8.7 Hz, 2H,
Ar-H), 7.18 (m, 2H, Ar-H), 7.29 (d, J = 8.7 Hz, 2H, Ar-H), 7.42
(dd, J = 5.5 Hz, 8.7 Hz, 2H, Ar-H), 8.73 (s, 1H, diazepine- H),
8.94 (s, 1H, Imid-H); 13C-NMR (DMSO-d6): δ = 42.87, 46.23,
55.07, 113.88, 115.45, 115.67, 127.93, 128.70, 129.12, 129.85,
129.92, 132.52, 132.55, 148.42, 149.89, 155.88, 158.70, 159.77,
160.55, 162.97, 165.78; Anal. Calcd for C22H17FN6O2: C, 63.46;
H,4.11; N,20.18; found C,63.19; H,4.08; N,20.12; HRMS (m/z):
Calcd. For C23H18FN6O2 (MH+) 417.1469; found 417.1469.
Procedure analogous to that of 12a (Yield = 0.24 g., 30.4 %);
m.p.:200-202°C; 1H-NMR (DMSO-d6): δ = 1.27 (t, J = 7.1 Hz,
3H, -CH3), 3.71 (s, 3H, -OCH3), 3.90 (q, J = 7.1 Hz, 2H, -CH2),
4.66 (s, 2H, -CH2), 6.86 (d, J = 8.7 Hz, 2H, -CH2), 7.21 (d, J =
8.7 Hz, 2H, -CH2), 7.68 (s, 1H, Imid-H), 7.81 (brs, 2H, -NH2),
9.78 (s, 1H, -NH); 13C-NMR (DMSO-d6): δ = 14.33, 39.29,
39.92, 55.04, 113.74, 113.87, 128.84, 129.64, 138.61, 151.66,
157.01, 158.37, 159.59, 166.79; MS (m/z): 327.1 (M+1); Anal.
Calcd. for C16H18N6O2: C, 58.88; H, 5.56; N, 25.75; found: C,
58.58; H, 5.60, N, 25.64.
5.2.17. 4-(1-(4-Methoxybenzyl)-5-amino-1H-imidazol-4-yl)-5-
imino-1-phenyl-1H-imidazol-2(5H)-one (14a)
5.2.13. 4-(1-(4-Fluorobenzyl)-5-amino-1H-imidazol-4-yl)-1-
(4-methoxybenzyl)-5-imino-1H-imidazol-2(5H)-one (12c)
To a suspension of 5 (0.25 g., 0.98 mmol) in 5 mL acetonitrile
was added phenyl isocyanate (0.35 g, 2.94 mmol, 3 equi.) and
stirred at room temperature, under inert atmosphere, till TLC
showed complete consumption of starting material (3 h). The
precipitate formed was filtered, washed with diethyl ether (3 X
10 mL) and dried. This precipitate was suspended in 4 mL
acetonitrile under inert atmosphere. DBU (2 drops) was added to
it and stirred for 2 h. The resulting precipitate was filtered,
washed with diethyl ether and dried to give 14a (Yield = 0.17 g.
46.4 %); m.p.: 192-193°C; 1H-NMR (DMSO-d6): δ = 3.73 (s, 3H,
-OCH3), 5.14 (s, 2H, -CH2), 6.94 (d, J = 8.7 Hz, 2H, Ar-H), 7.27
(d, J = 8.7 Hz, 2H, Ar-H), 7.32 (m, 1H), 7.45 (d, J = 4.1 Hz, 4H,
Ar-H), 7.78 (s, 1H, Imid-H), 8.00 (brs, 2H, -NH2), 10.06 (s, 1H, -
NH); 13C-NMR (DMSO-d6): δ = 41.47, 55.14, 113.83, 114.20,
126.61, 127.59, 128.49, 128.93, 133.92, 139.17, 151.92, 156.76,
159.00, 159.60, 165.49; Anal. Calcd for C20H18N6O2: C,64.16;
Procedure similar to that of 12a (Yield = 0.30 g., 40.8 %);
m.p.: 222-224°C; 1H-NMR (DMSO-d6): δ = 3.72 (s, 3H, -OCH3),
4.62 (s, 2H, -CH2), 5.19 (s, 2H, -CH2), 6.85 (d, J = 8.7 Hz, 2H,
Ar-H), 7.20-7.24 (m, 4H, Ar-H), 7.33 (dd, J = 5.5 Hz, 8.7 Hz,
2H, Ar-H), 7.76 (s, 1H, Imid-H), 7.90 (brs, 2H, -NH2), 9.79 (s,
1H, -NH); 13C-NMR (DMSO-d6): δ = 41.65, 45.71, 55.55,
114.20, 116.04, 116.26, 129.36, 130.01, 130.09, 130.12, 132.49,
139.33, 152.13, 157.74, 158.90, 160.03, 161.04, 163.48, 167.25;
Anal. Calcd. for C21H19FN6O2 .0.2H2O: C,61.52; H,4.77;
N,20.50; found: C,61.62; H,4.65; N,20.41. HRMS (m/z): Calcd.
for C21H20FN6O2(MH+): 407.1626; found 407.1626.
5.2.14. 7-Benzyl-3-(4-methoxybenzyl)-3,7-dihydro-2H-
diimidazo[4,5-d:4’,5’-f][1,3]diazepin-2-one (13a)

H,4.85; N,22.45; found C,64.17; H,4.79; N,22.32. HRMS (m/z)
Calcd for C18H20N6O4: C, 56.24; H, 5.24; N, 21.86; found C,
56.02; H, 5.14; N, 21.77.
Calcd for C20H19N6O2 (MH+) 375.1564; found 375.1564.
5.2.18. 4-(1-(4-Methoxybenzyl)-5-amino-1H-imidazol-4-yl)-5-
imino-1-(4-methoxyphenyl)-1H-imidazol-2(5H)-one (14b)
5.2.22. 4-(1-(4-Methoxybenzyl)-5-amino-1H-imidazol-4-yl)-1-
(2-chloroethyl)-5-imino-1H-imidazol-2(5H)-one (14f)
The necessary isocyanate was synthesised by the general
procedure described above. The procedure for 14 b is similar to
that of 14a. (Yield = 0.2 g., 42%). The initial reaction of
isocyanate was carried out for 24 h; m.p.: 176-178°C. 1H-NMR
(DMSO-d6): δ = 3.73 (s, 6H, -OCH3), 5.11 (s, 2H, -CH2), 6.94 (d,
J = 8.7 Hz, 2H, Ar-H), 7.00 (d, J = 8.7 Hz, 2H, Ar-H), 7.27 (d, J
= 8.7 Hz, 2H, Ar-H), 7.31 (d, J = 8.7 Hz, 2H, Ar-H), 7.75 (s,
1H, Imid-H), 8.1 (brs, 2H, -NH2), 9.90 (s, 1H, -NH); 13C-NMR
(DMSO-d6): δ = 45.35, 55.13, 55.31, 113.77, 113.96, 114.17,
126.63, 127.73, 128.03, 128.92, 139.28, 152.18, 156.35, 157.76,
158.97, 159.98, 165.77. MS (m/z): 405.2 (M+1); Anal. Calcd for
C21H20N6O3: C, 62.37; H, 4.98; N, 20.58; found C, 62.65; H,
5.00; N, 20.98.
Procedure similar to that of 14a. (Yield = 0.1 g., 68%). Initial
reaction of isocyanate was carried out for 3 h; m.p.:174-175°C;
1H-NMR (DMSO-d6): δ = 3.73 (s, 3H, -OCH3), 3.85 (s, 4H, -
CH2), 5.12 (s, 2H, -CH2), 6.93 (d, J = 8.7 Hz, 2H, Ar-H), 7.23-
7.27 (m, 2H, Ar-H), 7.75 (s, 1H, Imid-H), 7.91 (brs, 2H, -NH2),
9.78 (s, 1H, -NH); 13C-NMR (DMSO-d6): δ = 40.96, 42.08,
43.39, 45.35, 45.43, 55.12, 55.17, 113.77, 114.19, 127.60,
128.93, 139.02, 151.68, 156.90, 158.99, 159.41, 166.47; MS
(m/z): 361.1 (M+1); Anal. Calcd for C16H17ClN6O2 .0.5 H2O: C,
51.97; H, 4.91; N, 22.73; found C, 51.62; H, 4.68; N, 22.38.
5.2.23. 4-(1-(4-Methoxybenzyl)-5-amino-1H-imidazol-4-yl)-1-
benzyl-5-imino-1H-imidazol-2(5H)-one (14g)
5.2.19. 4-(1-(4-Methoxybenzyl)-5-amino-1H-imidazol-4-yl)-1-
(4-methoxyphenethyl)-5-imino-1H-imidazol-2(5H)-one (14c)
Procedure similar to that of 14a. (Yield = 0.2 g, 63%). Initial
reaction of isocyanate was carried out for 12 h; m.p.: 230-231°C;
1H-NMR (DMSO-d6): δ = 3.73 (s, 3H, OCH3), 4.71 (s, 2H, CH2),
5.13 (s, 2H, CH2), 6.94 (d, J = 8.7 Hz, 2H, Ar-H), 7.28 (m, 7 H,
Ar-H), 7.74 (s, 1H, Imid-H), 7.92 (brs, 2H, -NH2), 9.80 (s, 1H, -
NH); 13C-NMR (DMSO-d6): δ = 41.53, 45.33, 55.03, 113.69,
114.07, 126.95, 127.14, 127.51, 128.27, 128.84, 137.48, 138.83,
151.54, 157.04, 158.88, 159.44, 166.66; MS (ESI) m/z = 389.3
(M+1); Anal. Calcd for C21H20N6O2: C, 64.94; H, 5.19; N, 21.64;
found C, 64.76; H, 5.12; N, 21.61.
The necessary isocyanate was synthesised by the general
procedure. The procedure for 14c is similar to that of 14a. (Yield
= 0.14 g., 55%). The initial reaction of isocyanate was carried out
for 24 h; m.p.: 232-233°C; 1H-NMR (DMSO-d6): δ = 2.83 (t, J =
7.3 Hz, 2H, -CH2), 3.68-3.73 (m, 8H, -OCH3, -CH2), 5.10 (s, 2H,
-CH2), 6.82 (d, J = 8.7 Hz, 2H, Ar-H), 6.95 (d, J=8.7 Hz, 2H, Ar-
H), 7.1 (d, J=8.7 Hz, 2H, Ar-H), 7.27 (d, J = 8.7 Hz, 2H, Ar-H),
7.72 (s, 1H, Imid-H), 7.86 (brs, 2H, -NH2), 9.74 (s, 1H, -NH);
13C-NMR (DMSO-d6): δ = 32.24, 45.40, 54.92, 55.14, 113.61,
113.76, 114.18, 127.66, 129.00, 129.60, 130.44, 138.72, 151.49,
156.99, 157.71, 158.99, 159.59, 166.64. MS (m/z): 433.2 (M+1);
Anal. Calcd for C23H24N6O3: C, 63.88; H, 5.59; N, 19.43; found
C, 63.62; H, 5.54; N, 19.31.
5.2.24. 1-(4-Fluorobenzyl)-4-(1-(4-methoxybenzyl)-5-amino-
1H-imidazol-4-yl)-5-imino-1H-imidazol-2(5H)-one (14h)
Procedure similar to that of 14a. (Yield = 0.32 g, 40.2%).
Initial reaction of isocyanate was carried out for 12 h; m.p.: 233-
235°C; 1H-NMR (DMSO-d6): δ = 3.69 (s, 3H, OCH3), 4.68 (s,
2H, CH2), 5.11 (s, 2H, CH2), 6.93 (d, J = 8.7 Hz, 2H, Ar-H), 7.12
(m, 2 H, Ar-H), 7.25 (d, J = 8.7 Hz, 2H, Ar-H), 7.28 (m, 2H, Ar-
H), 7.73 (s, 1H, Imid-H), 7.89 (brs, 2H, NH2), 9.78 (s, 1H, -NH);
13C-NMR (DMSO-d6): δ = 40.95, 45.41, 55.12, 113.86, 114.16,
115.02, 115.23, 127.62, 128.93, 129.38, 129.45, 133.78, 139.02,
151.74, 157.02, 158.98, 159.48, 166.67; MS (m/z): 407.3 (M+1);
Anal. Calcd for C21H19FN6O2: C, 62.06; H, 4.71; N, 20.68; found
C, 61.92; H, 4.76; N, 20.62.
5.2.20. 4-(1-(4-Methoxybenzyl)-5-amino-1H-imidazol-4-yl)-1-
ethyl-5-imino-1H-imidazol-2(5H)-one (14d)
Procedure similar to that of 14a. (Yield = 0.25 g., 40%).
Reaction of isocyanate was carried out for 12 h; m.p.: 193-
195°C; 1H-NMR (DMSO-d6): δ = 1.1 (t, J = 7.3 Hz, 3H, -CH3),
3.54 (q, J = 7.3 Hz, 2H, -CH2), 3.73 (s, 3H, -OCH3), 5.11 (s, 2H,
-CH2), 6.94 (d, J = 8.7 Hz, 2H, Ar-H), 7.25 (d, J = 8.7 Hz, 2H,
Ar-H), 7.71 (s, 1H, Imid-H), 7.83 (brs, 2H, -NH2), 9.73 (s, 1H, -
NH); 13C-NMR (DMSO-d6): δ = 13.15, 33.18, 45.41, 55.13,
113.56, 114.17, 127.63, 128.93, 138.59, 151.37, 157.31, 158.98,
159.44, 166.64. MS (m/z): 327.1 (M+1); Anal. Calcd for
C16H18N6O2 0.25 H2O: C, 58.08; H, 5.64; N, 25.40; found C,
58.33; H, 5.51; N, 25.44.
5.2.25. 1-(4-Chlorobenzyl)-4-(1-(4-methoxybenzyl)-5-amino-
1H-imidazol-4-yl)-5-imino-1H-imidazol-2(5H)-one (14i)
The necessary isocyanate was synthesised by the general
procedure described above. The procedure for 14i is similar to
that of 14a. (Yield = 0.45 g., 56.6 %). Initial reaction of
isocyanate was carried out for 12 h; m.p.: 248-249°C; 1H-NMR
(DMSO-d6): δ = 3.72 (s, 3H, OCH3), 4.68 (s, 2H, -CH2), 5.11 (s,
2H, -CH2), 6.93 (d, J = 8.7 Hz, 2H, -CH2), 7.25 (d, J = 8.7 Hz,
2H, -CH2), 7.28 (d, J = 8.7 Hz, 2H, -CH2), 7.36 (d, J = 8.7 Hz,
2H, -CH2), 7.73 (s, 1H, Imid-H), 7.92 (br s, 2H, -NH2), 9.77 (s,
1H, NH); 13C-NMR (DMSO-d6): δ = 40.13, 45.43, 55.14, 113.85,
114.19, 127.58, 128.35, 128.94, 129.19, 131.67, 136.57, 139.03,
151.72, 157.07, 158.99, 159.44, 166.64; HRMS (m/z): Calcd. for
C21H20ClN6O2 (MH+) 423.1330; found: 423.1333; Anal. Calcd
for C21H19ClN6O2: C, 59.65; H, 4.53; N, 19.87; found C, 59.87;
H, 4.46; N, 19.82.
5.2.21. Ethyl 2-(4-(1-(4-methoxybenzyl)-5-amino-1H-
imidazol-4-yl)-5-imino-2-oxo-2H-imidazol-1(5H)-yl)acetate
(14e)
Procedure similar to that of 14a. (Yield = 0.1 g, 33.3%).
Reaction of isocyanate was carried out for 12 h; m.p.: 200-
202°C; 1H-NMR (DMSO-d6): δ = 1.19 (t, J = 7.1 Hz, 3H, CH3),
3.73 (s, 3H, OCH3), 4.12 (q, J = 7.1 Hz, 2H, CH2), 4.28 (s, 2H,
CH2), 5.12 (s, 2H, CH2), 6.94 (d, J = 8.7 Hz, 2H, Ar-H), 7.26 (d,
J = 8.7 Hz, 2H, Ar-H), 7.75 (s, 1H, Imid-H), 7.96 (brs, 2H, -
NH2), 9.72 (s, 1H, -NH); 13C-NMR (DMSO-d6): δ =14.56, 45.98,
55.68, 61.53, 114.43, 114.73, 128.11, 129.49, 139.77, 152.40,
157.5, 159.59, 166.82, 168.52; MS (m/z): 385.2 (M+1); Anal.
5.2.26. 1-(4-Bromobenzyl)-4-(1-(4-methoxybenzyl)-5-amino-
1H-imidazol-4-yl)-5-imino-1H-imidazol-2(5H)-one (14j)

166.68; MS (m/z): 407.2 (M+1); HRMS (m/z) Calcd for
The necessary isocyanate was synthesised by the general
procedure. Procedure for 14j is similar to that of 14a. (Yield =
0.21 g., 77.7%). Initial reaction of isocyanate was carried out for
3 h; m.p.: 236-238°C; 1H-NMR (DMSO-d6): δ = 3.73 (s, 3H, -
OCH3), 4.67 (s, 2H, -CH2), 5.12 (s, 2H, -CH2), 6.94 (d, J = 8.7
Hz, 2H, Ar-H), 7.22 (d, J = 8.7 Hz, 2H, Ar-H), 7.25 (d, J = 8.7
Hz, 2H, Ar-H), 7.48 (d, J = 8.7 Hz, 2H, Ar-H), 7.74 (s, 1H, Imid-
H), 7.95 (brs, 2H, -NH2), 9.77 (s, 1H, -NH); 13C-NMR (DMSO-
d6): δ = 41.06, 45.41, 55.12, 55.15, 113.86, 114.17, 120.15,
127.59, 128.93, 129.53, 131.27, 137.00, 139.04, 151.73, 157.03,
158.98, 159.43, 166.62; MS (m/z): 467.2, 469.2 (M, M+2); Anal.
Calcd for C21H19BrN6O2: C, 53.97; H, 4.10; N, 17.98; found C,
53.83; H, 4.00; N, 17.74.
C21H20FN6O2 (MH+) 407.1626 ; found 407.1609
5.2.30. 1-(3,4-Difluorobenzyl)-4-(1-(4-methoxybenzyl)-5-
amino-1H-imidazol-4-yl)-5-imino-1H-imidazol-2(5H)-one
(14n)
The necessary isocyanate was synthesised by the general
procedure described above. Procedure for 14n is similar to that of
14a. (Yield = 0.27 g., 65%). Initial reaction of isocyanate was
carried out for 12 h; m.p.:253-256°C; 1H-NMR (DMSO-d6): δ =
3.73 (s, 3H, -OCH3), 4.69 (s, 2H, -CH2), 5.12 (s, 2H, -CH2), 6.93
(d, J = 8.7 Hz, 2H, Ar-H), 7.10-7.12 (m, 1H, Ar-H), 7.25-7.37
(m, 4H, Ar-H), 7.75 (s, 1H, Imid-H), 7.93 (brs, 2H, -NH2), 9.78
(s, 1H, -NH); 13C-NMR (DMSO-d6): δ = 40.72, 45.42, 55.11,
55.16, 113.90, 114.17, 116.34, 116.48, 117.35, 117.52, 124.05,
127.59, 128.93, 135.32, 139.05, 147.27, 147.39, 147.90, 148.02,
149.70, 149.83, 150.34, 150.47, 151.74, 157.07, 158.98, 159.42,
166.58; MS (m/z): 425.2 (M+1); Anal. Calcd for C21H18F2N6O2:
C, 59.43; H, 4.27; N, 19.80; found C, 59.20; H, 4.25; N, 19.70.
5.2.27. 1-(3-Methoxybenzyl)-4-(1-(4-methoxybenzyl)-5-
amino-1H-imidazol-4-yl)-5-imino-1H-imidazol-2(5H)-one
(14k)
The necessary isocyanate was synthesised by the general
procedure. Procedure for 14k is similar to that of 14a. (Yield =
0.56 g, 68%). Initial reaction of isocyanate was carried out for 12
h; m.p.: 213-215°C; 1H-NMR (DMSO-d6): δ = 3.73 (s, 3H,
OCH3), 3.76 (s, 3H, OCH3), 4.68 (s, 2H, CH2), 5.08 (s, 2H, CH2),
6.81-6.82 (m, 3H, Ar-H), 6.94 (d, J = 8.7 Hz, 2H, Ar-H), 7.21 (t,
J = 7.8 Hz, 1 H, Ar-H), 7.27 (d, J = 8.7 Hz, 2H, Ar-H), 7.74 (s,
1H, Imid-H), 7.91 (s, 2H, -NH2), 9.80 (s, 1H, Ar-H); 13C-NMR
(DMSO-d6): δ = 41.59, 45.43, 54.96, 55.14, 112.31, 113.06,
113.80, 114.18, 119.29, 127.61, 128.95, 129.49, 138.95, 139.16,
151.66, 157.13, 158.99, 159.26, 159.55, 166.75; MS (ESI) m/z =
419.3 (M+1); Anal. Calcd for C22H22N6O3.0.4H2O: C, 62.08; H,
5.40; N, 19.74; found C, 62.22; H, 5.11; N, 19.41.
5.2.31. 1-(3-Chlorobenzyl)-4-(1-(4-methoxybenzyl)-5-amino-
1H-imidazol-4-yl)-5-imino-1H-imidazol-2(5H)-one (14o)
The necessary isocyanate was synthesised by the general
procedure described above. Procedure for 14o is similar to that of
14a. (Yield = 0.12 g, 50.8%). Initial reaction of isocyanate was
carried out for 12 h; m.p.: 185-186°C; 1H-NMR (DMSO-d6): δ =
3.73 (s, 3H, -OCH3), 4.71 (s, 2H, -CH2), 5.12 (s, 2H, -CH2), 6.94
(d, J= 8.2 Hz, 2H, Ar-H), 7.12-7.36 (m, 6H, Ar-H), 7.75 (s, 1H,
Imid-H), 7.95 (brs, 2H, -NH2), 9.79 (s, 1H, -NH); 13C-NMR
(DMSO-d6): δ = 41.12, 45.43, 55.15, 113.91, 114.18, 125.93,
127.08, 127.40, 127.59, 128.93, 130.36, 132.99, 139.08, 140.10,
151.77, 158.99, 159.45, 166.64; MS (ESI) (m/z) 423.1 (M+1);
HRMS (m/z) Calcd for C21H20ClN6O2 (MH+): 423.1330; found :
423.1314.
5.2.28. 1-(2-Methoxybenzyl)-4-(1-(4-methoxybenzyl)-5-
amino-1H-imidazol-4-yl)-5-imino-1H-imidazol-2(5H)-one
(14l)
The necessary isocyanate was synthesised by the general
procedure described above. Procedure for 14l is similar to that of
14a. (Yield = 0.43 g, 52%). Initial reaction of isocyanate was
carried out for 12 h; m.p.: 198-199°C; 1H-NMR (DMSO-d6): δ =
3.73 (s, 3H, OCH3), 3.83 (s, 3H, OCH3), 4.67 (s, 2H, CH2), 5.13
(s, 2H, CH2), 6.81-6.84 (m, 2H, Ar-H), 6.83 (d, J = 8.2 Hz, 2H,
Ar-H), 6.99 (d, J = 8.2 Hz, 1H, Ar-H), 7.22 (m, 1H), 7.28 (d, J =
8.2 Hz, 2H, Ar-H), 7.75 (s, 1H, Imid-H), 7.93 (brs, 2H, -NH2),
9.76 (s, 1H, -NH); 13C-NMR (DMSO-d6): δ = 36.87, 45.45,
55.15, 55.38, 110.49, 113.80, 114.18, 120.15, 124.77, 125.88,
127.64, 127.95, 128.98, 138.88, 151.63, 156.28, 157.26, 159.00,
159.67, 166.83; MS (ESI) (m/z) 419.3 (M+1). Anal. Calcd for
C22H22N6O3: C, 63.15; H, 5.30; N, 20.08; found C, 62.89; H,
5.30; N, 19.87.
5.2.32. 1-(3-Bromobenzyl)-4-(1-(4-methoxybenzyl)-5-amino-
1H-imidazol-4-yl)-5-imino-1H-imidazol-2(5H)-one (14p)
The necessary isocyanate was synthesised by general
procedure. To a suspension of 2 (0.15 g, 0.580 mmol, 1.0 equi.)
in 5 mL acetonitrile was added isocyanate (3 equi.) and stirred at
room temperature for 12 h. Precipitate formed was filtered off.
The solution was purified by column chromatography (gradient
elution using methanol in dichloromethane) to obtain the solid.
The solid obtained was suspended in 5 mL acetonitrile. 2 drops
DBU was added to it and stirred for 1 h. The resulting precipitate
was filtered, washed with diethyl ether and dried to give 14p
(Yield = 0.13 g, 47.4%); m.p.: 224-225°C; 1H NMR (DMSO-d6):
δ = 3.73 (s, 3H, -OCH3), 4.68 (s, 2H, -CH2), 5.07 (s, 2H, -CH2),
6.92 (d, J = 8.7 Hz, 2H, Ar-H), 7.23-7.27 (m, 4H, Ar-H), 7.44-
7.45 (m, 2H, Ar-H), 7.71 (s, 1H, Imid-H), 7.98 (br s, 2H, -NH2),
9.66 (s, 1H, -NH); 13C-NMR (DMSO-d6): δ = 41.01, 45.17,
55.13, 113.97, 114.16, 121.58, 126.32, 127.62, 128.92, 129.95,
130.64, 139.16, 140.37, 151.90, 158.97, 159.46, 166.62; MS
(ESI) (m/z) 467.1 (M+1); Anal. Calcd for C21H19BrN6O2: C,
53.97; H, 4.10; N, 17.98; found C, 53.98; H, 4.06; N, 17.69.
5.2.29. 1-(3-Fluorobenzyl)-4-(1-(4-methoxybenzyl)-5-amino-
1H-imidazol-4-yl)-5-imino-1H-imidazol-2(5H)-one (14m)
The necessary isocyanate was synthesised by the general
procedure. Procedure for 14m is similar to that of 14a. (Yield =
0.45 g., 56.5%). Initial reaction of isocyanate was carried out for
12 h; m.p.:208-211°C; 1H-NMR (DMSO-d6): δ = 3.71 (s, 3H, -
OCH3), 4.71 (s, 2H, -CH2), 5.1 (s, 2H, -CH2), 6.94 (d, J = 8.7 Hz,
2H, Ar-H), 7.05-7.1(m, 3H, Ar-H), 7.2 (d, J = 8.7 Hz, 2H, Ar-H),
7.32-7.36 (m, 1H, Ar-H), 7.74 (s, 1H, Imid-H), 8.01 (brs, 2H, -
NH2), 9.77 (s, 1H, -NH); 13C-NMR (DMSO-d6): δ = 41.17,
45.39, 55.14, 114.03, 114.09, 114.17, 123.17, 127.67, 128.94,
130.37, 130.46, 139.20, 140.55, 151.99, 156.78, 158.98, 159.54,
5.2.33. 1-(3-(Trifluoromethyl)benzyl)-4-(1-(4-methoxybenzyl)
-5-amino-1H-imidazol-4-yl)-5-imino-1H-imidazol-2(5H)-one
(14q)
The necessary isocyanate was synthesised by the general
procedure described above. Procedure is similar to that of 14p
(Yield = 0.16 g, 45.7%); The product from isocyanate reaction

was purified by column chromatography (gradient elution using
methanol in dichloromethane); m.p.: 218-220°C. 1H-NMR
(DMSO-d6): δ = 3.73 (s, 3H, -OCH3), 4.8 (s, 2H, -CH2), 5.08 (s,
2H, -CH2), 6.93 (d, J = 8.7 Hz, 2H, Ar-H), 7.26 (d, J = 8.7 Hz,
2H, Ar-H), 7.53-7.56 (m, 2H, Ar-H), 7.59-7.63 (m, 2H, Ar-H),
7.75 (s, 1H, Imid-H), 7.94 (brs, 2H, -NH2), 9.78 (s, 1H, -NH);
13C-NMR (DMSO-d6): δ = 41.24, 45.41, 55.13, 108.28, 113.95,
114.17, 122.78, 123.80, 123.84, 125.49, 127.59, 128.93, 129.23,
129.58, 131.38, 139.04, 139.15, 151.86, 156.93, 158.97, 159.48,
166.64; MS (ESI): 457.2 (M+1); Anal. Calcd for C22H19F3N6O2:
C, 57.89; H, 4.20; N, 18.41; found C, 58.18; H, 4.14; N, 18.34.
5.2.35. 1-(4-(2-Methoxyethoxy)benzyl)-4-(1-(4-
methoxybenzyl)-5-amino-1H-imidazol-4-yl)-5-imino-1H-
imidazol-2(5H)-one (14s)
The synthesis of the title compound comprises the
following three steps:
(a) Ethyl 2-(4-(2-Methoxyethoxy)phenyl)acetate: To a
solution of Ethyl 4-hydroxyphenylacetate (1.0 g, 5.55 mmol) in
DMF under inert atmosphere was added potassium carbonate
(2.30g, 16.65 mmol) and 2-Methoxyethylbromide (0.92g, 6.66
mmol) and stirred overnight at 60°C. Reaction mixture was
diluted with ethyl acetate and washed with water, brine, dried
over MgSO4 and evaportated to get product (Yield = 1.2 g., 91.0
%), which was used for the next step without further purification.
(b) 2-(4-(2-Methoxyethoxy)phenyl)acetic Acid: To a
solution of ester (1.2g, 5.04 mmol) obtained in previous step, in
20 mL THF: water (1:1) was added LiOH.H2O (0.32g, 7.56
mmol) and stirred at room temperature for 4 h. Reaction mixture
was diluted with water and washed with ethyl acetate. The pH of
aqueous layer was adjusted to 4-5 by citric acid, and extracted
with ethyl acetate. The organic layer was washed wih water,
brine, dried over MgSO4 and evaportated to obtain the product
(Yield = 0.95 g., 90%); 1H-NMR (CDCl3,): δ = 3 43 (s, 3H), 3.55
(s, 2H), 3.72 (t, J = 4.8 Hz, 2H), 4.08 (t, J = 4.8 Hz, 2H), 6.86 (d,
J = 8.7 Hz, 2H), 7.16 (d, J=8.7 Hz, 2H).
5.2.34. 1-(4-((2-Methoxyethoxy)methoxy)benzyl)-4-(1-(4-
methoxybenzyl)-5-amino-1H-imidazol-4-yl)-5-imino-1H-
imidazol-2(5H)-one (14r)
The synthesis of the title compound comprises the following four
steps:
(a) Ethyl 4-Hydroxyphenylacetate: To ethanolic solution (50
mL) of 4-hydroxy-phenylacetic acid (10 g) was added a 0.2 mL
of conc. H2SO4 and refluxed for 12 h. Solvent was removed at
reduced pressure, residue was cooled and carefully neutralized
with saturated aquesous NaHCO3. Resulting solution was diluted
with ethyl acetate and washed with water, brine, dried over
MgSO4 and evaporated to dryness to get 11.2 g of the product,
which was directly used in the next step.
(c) 1-(4-(2-Methoxyethoxy)benzyl)-4-(1-(4-
(b) Ethyl 2-(4-((2-Methoxyethoxy)methoxy)phenyl) acetate:
To a solution of Ethyl 4-hydroxyphenylacetate (1.5 g, 8.33
mmol) and DIPEA (3.2 g, 25.0 mmol) in DCM was added
MEMCl (1.56 g, 12.50 mmol) under intert atmosphere at 0-5°C.
The reaction mixture was allowed to come to room temperature
and stirred overnight. Reaction mixture was diluted with ethyl
acetate and washed wih water, brine, dried over MgSO4 and
evaportated to get product. The crude was purified by column
chromatography (Yield = 2.0 g, 89.7 %), and directly employed
in the next step.
(c) 2-(4-((2-Methoxyethoxy)methoxy)phenyl)acetic acid: To a
solution of Ethyl 2-(4-((2-methoxyethoxy)methoxy)phenyl)
acetate (1.9g, 7.09 mmol) in 30 mL THF: water (1:1) was added
LiOH.H2O (2.38g, 56.71 mmol) and stirred at room temperature
for 4 h. Reaction mixture was diluted with water, pH adjusted to
4-5 by citric acid, and extracted with ethyl acetate. The organic
layer was washed wih water, brine, dried over MgSO4 and
evaportated to get product (Yield = 1.5g, 88.2%); 1H-NMR
(CDCl3): δ = 3.36 (s, 3H), 3.52-3.54 (m, 2H), 3.57 (s, 2H), 3.79-
3.81 (m, 2H), 5.24 (s, 2H), 7.00 (d, J = 8.7 Hz, 2H), 7.17 (d, J =
8.7 Hz, 2H).
methoxybenzyl)-5-amino-1H-imidazol-4-yl)-5-imino-1H-
imidazol-2(5H)-one (14s): The necessary isocyanate was
synthesised by the general procedure. Procedure for 14s is similar
to that of 14a. (Yield = 0.2 g., 44.0%); m.p.: 205-207°C. 1H-
NMR (DMSO-d6,): δ = 3.27 (s, 3H), 3.62 (t, J = 4.6Hz, 2H), 3.72
(s, 3H), 4.03 (t, J = 4.6 Hz, 2H), 4.62 (s, 2H), 5.11 (s, 2H), 6.86
(d, J = 8.7 Hz, 2H), 6.93 (d, J = 8.7 Hz, 2H), 7.19 (d, J = 8.7 Hz,
2H), 7.25 (d, J = 8.7 Hz, 2H), 7.73 (s, 1H), 7.90 (brs, 2H), 9.77
(s, 1H); 13C-NMR (DMSO-d6): δ = 41.09, 45.38, 55.14, 58.13,
66.82, 70.34, 113.80, 114.16, 114.26, 127.66, 128.81, 128.93,
129.71, 138.96, 151.71, 156.96, 157.57, 158.97, 159.56, 166.75;
Anal. Calcd for C24H26N6O4: C, 62.33; H, 5.67; N, 18.17; found
C, 61.97; H, 5.64; N, 18.01; HRMS (m/z) Calcd for C24H27N6O4
(MH+) 463.2088; found 463.2086.
5.2.36. 1-(4-(2-((2-Methoxyethoxy)methoxy)ethoxy)benzyl)-4-
(1-(4-methoxybenzyl)-5-amino-1H-imidazol-4-yl)-5-imino-
1H-imidazol-2(5H)-one (14t)
The synthesis of the title compound comprises the
following four steps:
(d) 1-(4-((2-Methoxyethoxy)methoxy) benzyl)-4-(1-(4-
methoxybenzyl)-5-amino-1H-imidazol-4-yl)-5-imino-1H-
imidazol-2(5H)-one (14r): The necessary isocyanate was
synthesised by the general procedure. Procedure for 14r is
similar to that of 14p (Yield = 0.45 g, 70.4%). Product from
isocyanate reaction was purified by column chromatography
(gradient elution using methanol in dichloromethane); m.p.: 200-
202°C; 1H-NMR (DMSO-d6): δ = 3.20 (s, 3H), 3.43 (t, J = 4.8
Hz, 2H), 3.68 (t, J = 4.8 Hz, 2H), 3.73 (s, 3H), 4.63 (s, 2H), 5.11
(s, 2H), 5.20 (s, 2H), 6.92- 6.95 (m, 4H), 7.20 (d, J = 8.7 Hz,
2H), 7.25 (d, J = 8.7 Hz, 2H), 7.73 (s, 1H), 7.89 (brs, 2H), 9.77
(s, 1H); 13C-NMR (DMSO-d6): δ = 41.10, 45.41, 55.14, 58.01,
67.27, 70.96, 92.88, 113.74, 114.18, 116.05, 127.61, 128.71,
128.93, 130.80, 138.89, 151.60, 155.95, 157.13, 158.98, 159.51,
166.72; Anal. Calcd for C25H28N6O5: C, 60.96; H, 5.73; N, 17.06;
found C, 60.76; H, 5.78; N, 17.01; HRMS (m/z) Calcd for
C25H29N6O5 (MH+) 493.2194; found 493.2194.
(a) 2-((2-Methoxyethoxy)methoxy)ethyl 4-
Methylbenzene Sulfonate: To a solution of tosylate (1.0 g., 4.63
mmol) in DCM, under inert atmosphere, at room temperature
was added diisopropyl ethylamine (1.49 g., 11.57 mmol)
followed by dropwise addition of MEM-Cl (0.69 g., 5.55 mmol)
and stirred for 2 h. Reaction mixture was diluted with DCM and
washed with water. The organic layer was washed with brine,
dried over MgSO4 and evaporated to get product. The product
was used for the next reaction without further purification.
(b) 2-(4-(2-((2-Methoxyethoxy)methoxy)ethoxy)phenyl)-
acetic Acid Ethyl ester: To a suspension of 4-hydroxyphenyl-
acetic acid (0.36 g, 2.0 mmol) in acetontirle (5 mL), under inert
atmosphere, was added potassium carbonate (0.83g, 6.0 mmol)
followed by tosylate (0.67g, 2.2 mmol), and refluxed for 6 h.
Reaction mixture was cooled and filtered. The filtrate was
washed with water, brine, dried over MgSO4, and evaporated to
give desired product. (Yield: 0.6 g, 96%); 1H-NMR (CDCl3): δ =
1.23 (t, 3H), 3.38 (s, 3H), 3.53-3.55 (m, 4H), 3.72 (t, J = 4.6Hz,

2H), 3.90 (t, J = 4.6Hz, 2H), 4.10 (m, 4H), 4.80 (s, 2H), 6.86 (d,
J = 8.3 Hz, 2H), 7.18 (d, J = 8.3 Hz, 2H).
C23H25N7O2: C, 64.02; H, 5.84; N, 22.72; found C, 63.83; H,
5.82; N, 22.47.
(c) 2-(4-(2-((2-Methoxyethoxy)methoxy)ethoxy)phenyl)-
acetic Acid: To a solution of ester (0.6g, 1.92 mmol) obtained in
previous step, in 20 mL THF: water (1:1) was added LiOH.H2O
(0.64g, 15.38 mmol) and stirred at room temperature for 6 h.
Reaction mixture was diluted with water and washed with ethyl
acetate. The pH of aqueous layer was adjusted to 4-5 by citric
acid, and extracted with ethyl acetate. The organic layer was
washed wih water, brine, dried over MgSO4 and evaportated to
get product (Yield = 0.42 g., 78.0%); 1H-NMR (CDCl3): δ = 3.37
(s, 3H), 3.53-3.55 (m, 4H), 3.72 (m, 2H), 3.88 (m, 2H), 4.10 (m,
2H), 4.80 (s, 2H), 6.85 (d, J = 8.7 Hz, 2H), 7.17 (d, J = 8.7 Hz,
2H).
(d) 1-(4-(2-((2-Methoxyethoxy)methoxy)ethoxy)benzyl)-
4-(1-(4-methoxybenzyl)-5-amino-1H-imidazol-4-yl)-5-imino-
1H-imidazol-2(5H)-one (14t): The necessary isocyanate was
synthesised by the general procedure. Procedure for 14t is similar
to that of 14p (Yield = 0.225g, 59%). Product from isocyanate
reaction was purified by column chromatography (gradient
elution using methanol in dichloromethane). The final product
14t was also purified by column chromatography (gradient
elution using methanol in dichloromethane); m.p.: 181-183°C;
1H-NMR (DMSO-d6): δ = 3.00 (s, 3H), 3.43 (m, 2H), 3.57 (m,
2H), 3.72 (s, 3H), 3.76 ( m, 2H), 4.06 (m, 2H), 4.62 (s, 2H), 4.66
(s, 2H), 5.10 (s, 2H), 6.86 (d, J = 8.2 Hz, 2H), 6.93 (d, J = 8.2
Hz, 2H), 7.20 (d, J = 8.2 Hz, 2H), 7.25 (d, J = 8.2 Hz, 2H), 7.72
(s, 1H), 7.91 (brs, 2H), 9.76 (s, 1H); 13C-NMR (DMSO-d6): δ =
41.09, 45.39, 55.13, 57.98, 65.55, 66.23, 66.98, 71.13, 94.70,
113.77, 114.16, 114.29, 127.63, 128.81, 128.92, 129.73, 138.93,
151.68, 157.54, 158.97, 159.54, 166.73; Anal. Calcd for
C27H32N6O6: C, 60.44; H, 6.01; N, 15.66; found C, 60.27; H,
5.95; N, 15.54; HRMS (m/z) Calcd for C27H33N6O6 (MH+):
537.2456; found 537.2450.
5.2.39. 7-(4-Methoxybenzyl)-3-phenyl-3,7-dihydro-2H-
diimidazo[4,5-d:4’,5’-f][1,3]diazepin-2-one (15a)
To a suspension of 14a (0.12 g., 0.33 mmol) in 3 mL
acetonitrile was added triethyl orthoformate (0.39 g, 2.67 mmol,
8.0 equi.) and a drop of H2SO4 and heated under reflux for 1 h
under inert atmosphere. The reaction mixture was cooled to room
temperature. Precipitate formed was filtered, washed with diethyl
ether (2 X 10 mL), and dried to get the product (Yield = 0.65 g,
51.3 %); m.p.: 249-251°C; 1H-NMR (DMSO-d6): δ = 3.71 (s, 3H,
-OCH3), 5.53 (s, 2H, -CH2), 6.91 (d, J = 8.7 Hz, 2H, Ar-H), 7.34
(d, J = 8.7 Hz, 2H, Ar-H), 7.48-7.52 (m, 3H, Ar-H), 7.56-7.60
(m, 2H, Ar-H), 8.62 (s, 1H, diazepine- H), 8.97 (s, 1H, Imid-H);
13C-NMR (DMSO-d6): δ = 46.55, 55.12, 114.12, 127.67, 128.22,
128.61, 128.80, 128.93, 129.27, 132.87, 148.40, 149.70, 150.05,
156.08, 159.03, 160.17, 164.99; HRMS (m/z): Calcd for
C21H16N6O2 (MH+) 385.1407; found 385.1407; Anal. Calcd for
C21H16N6O2.0.5H2O: C, 64.11; H, 4.36; N, 21.36; found C, 63.84;
H, 4.04; N, 21.29.
5.2.40. 7-(4-Methoxybenzyl)-3-(4-methoxyphenyl)-3,7-
dihydro-2H-diimidazo[4,5-d:4’,5’-f][1,3]diazepin-2-one (15b)
Procedure similar to that of 15a (Yield = 0.1g, yield:
81.3%); m.p.: 255-257°C; 1H-NMR (DMSO-d6): δ = 3.73 (s, 3H,
-OCH3), 3.83 (s, 3H, -OCH3), 5.53 (s, 2H, -CH2), 6.91 (d, J = 6.8
Hz , 2H, Ar-H), 7.11 (d, J = 6.8 Hz, 2H, Ar-H), 7.34 (d, J = 8.7
Hz, 2H, Ar-H), 7.41 (d, J = 8.7 Hz, 2H, Ar-H), 8.61 (s, 1H,
diazepine- H), 8.95 (s, 1H, Imid-H); 13C-NMR (DMSO-d6): δ =
46.55, 55.13, 55.48, 114.13, 114.19, 125.39, 128.26, 128.71,
128.85, 129.27, 148.35, 149.71, 150.05, 156.03, 159.03, 159.23,
160.31, 165.25; MS (m/z) 415.2 (M+1); Anal. Calcd for
C22H18N6O3: C, 63.76; H, 4.38; N, 20.28; found C, 63.52; H,
4.31; N, 20.16.
5.2.37. 4-(1-(4-Methoxybenzyl)-5-amino-1H-imidazol-4-yl)-5-
imino-1-((pyridin-3-yl)methyl)-1H-imidazol-2(5H)-one (14u)
The necessary isocyanate was synthesised by the general
procedure described above. Procedure is similar to that of 14a.
(Yield = 0.1 g, 44.5%). Initial reaction of isocyanate was carried
out for 12 h; m.p.: 238-241°C; 1H-NMR (DMSO-d6): δ = 3.73 (s,
3H, -OCH3), 4.74 (s, 2H, -CH2), 5.08 (s, 2H, -CH2), 6.92-6.95
(m, 2H, Ar-H), 7.24-7.35 (m, 3H, Ar-H), 7.65-7.70 (m, 1H, Ar-
H), 7.74 (s, 1H, Imid-H), 7.93 (br s, 2H, -NH2), 8.45-8.52 (m,
2H, Ar-H), 9.78 (s, 1H, -NH); 13C-NMR (DMSO-d6): δ = 45.5,
55.13, 113.92, 114.17, 123.56, 127.59, 128.92, 133.11, 135.19,
139.10, 148.42, 148.82, 151.80, 158.97, 159.43, 166.59; MS
(ESI): 390.2 (M+1); Anal. Calcd for C20H19N7O2: C, 61.69; H,
4.92; N, 25.18; found C, 61.41; H, 4.89; N, 25.02.
5.2.41. 7-(4-Methoxybenzyl)-3-(4-methoxyphenethyl)-3,7-
dihydro-2H-diimidazo[4,5-d:4’,5’-f][1,3]diazepin-2-one (15c)
Procedure similar to that of 15a (Yield = 0.04g, yield:
32.7%).; m.p.: 156-157°C; 1H-NMR (DMSO-d6): δ = 2.9 (t, J =
7.32 Hz, 2H, -CH2), 3.62 (s, 3H, -OCH3), 3.66 (s, 3H, -OCH3),
4.07 (t, J = 7.32 Hz, 2H, -CH2), 5.46 (s, 2H, -CH2), 6.75 (d, J =
8.7 Hz, 2H, Ar-H), 6.87 (d, J = 8.7 Hz, 2H, Ar-H), 7.05 (d, J =
8.7 Hz, 2H, Ar-H), 7.30 (d, J = 8.7 Hz, 2H, Ar-H), 8.67 (s, 1H,
diazepine- H), 8.87 (s, 1H, Imid-H); 13C-NMR (DMSO-d6): δ =
32.38, 41.65, 46.48, 55.09, 113.80, 114.12, 129.29, 129.72,
129.78, 148.35, 149.70, 155.57, 157.88, 159.02, 159.72, 165.66;
MS (m/z) 443.2 (M+1); Anal. Calcd for C24H22N6O3: C, 65.15; H,
5.01; N, 18.99; found C, 64.88; H, 5.01; N, 18.70.
5.2.38. 1-(4-(Dimethylamino)benzyl)-4-(1-(4-methoxybenzyl)-
5-amino-1H-imidazol-4-yl)-5-imino-1H-imidazol-2(5H)-one
(14v)
5.2.42. 3-Ethyl-7-(4-methoxybenzyl)-3,7-dihydro-2H-
diimidazo[4,5-d:4’,5’-f][1,3]diazepin-2-one (15d)
The necessary isocyanate was synthesised by the general
procedure. Procedure is similar to that of 14a. (Yield = 0.11 g,
43.4%). Initial reaction of isocyanate was carried out for 12 h;
m.p.: 216-218°C; 1H-NMR (DMSO-d6): δ = 2.86 (s, 6H, -CH3),
3.72 (s, 3H, -OCH3), 4.56 (s, 2H, -CH2), 5.11 (s, 2H, -CH2), 6.64
(d, J = 8.7 Hz, 2H, Ar-H), 6.93 (d, J= 8.7 Hz, 2H, Ar-H), 7.12 (d,
J= 8.7 Hz, 2H, Ar-H), 7.25 (d, J = 8.7 Hz, 2H, Ar-H), 7.72 (s,
1H, Imid-H), 7.87 (brs, 2H, -NH2, 9.77 (s, 1H, -NH); 13C-NMR
(DMSO-d6): δ = 41.23, 45.38, 55.12, 112.24, 113.66, 114.16,
125.15, 127.62, 128.52, 128.91, 138.77, 149.67, 151.53, 158.96,
159.57, 166.77. MS (ESI) (m/z) 432.2 (M+1); Anal. Calcd for
Procedure similar to that of 15a; the precipitated product
was washed with ethyl acetate instead of diethyl ether (Yield =
0.13 g, 50%); m.p.: 186-188°C; 1H-NMR (DMSO-d6): δ = 1.24
(t, J = 7.1 Hz, 3H, -CH3), 3.71 (s, 3H, -OCH3), 3.98 (q, J = 7.1
Hz, 2H, -CH2), 5.52 (s, 2H, -CH2), 6.91 (d, J = 8.7 Hz, 2H, Ar-
H), 7.33 (d, J = 8.7 Hz, 2H, Ar-H), 8.74 (s, 1H, diazepine- H),
8.91 (s, 1H, Imid-H); 13C-NMR (DMSO-d6): δ = 13.11, 38.89,
46.46, 55.12, 114.10, 128.27, 128.43, 129.25, 148.25, 149.68,
149.74, 155.80, 159.01, 159.67, 165.74. MS (m/z) 337.2 (M+1);

Anal. Calcd for C17H16N6O2. 0.25 H2O: C, 59.90; H, 4.88; N,
24.66; found C, 60.17; H, 4.64; N, 24.27.
Ar-H), 8.71 (s, 1H, diazepine-H), 8.94 (s, 1H, Imid-H); 13C-NMR
(DMSO-d6): δ = 42.68, 46.50, 55.12, 114.66, 128.78, 129.01,
129.34, 129.83, 129.98, 132.70, 135.52, 148.98, 150.35, 156.56,
159.58, 160.41, 166.27; HRMS (m/z): calcd for C22H18ClN6O2
(MH+) 433.1174; found 433.1178; Anal. Calcd for
C22H17ClN6O2: C, 61.04; H, 3.96; N, 19.41; found C, 61.31; H,
3.85; N, 19.48.
5.2.43. 3-Ethoxycarbonylmethyl-7-(4-Methoxybenzyl)-3,7-
dihydro-2H-diimidazo[4,5-d:4’,5’-f][1,3]diazepin-2-one (15e)
Procedure similar to that of 15a; the precipitated product
was washed with ethyl acetate instead of diethyl ether (Yield =
0.04 g, 39.2%); m.p.: 179-180°C; 1H-NMR (DMSO-d6): δ = 1.20
(t, J = 7.1 Hz, 3H, CH3), 3.71 (s, 3H, OCH3), 4.16 (q, J= 7.1 Hz,
2H, CH2), 4.78 (s, 2H, CH2), 5.53 (s, 2H, CH2), 6.89 (d, J= 8.7
Hz, 2H, Ar-H), 7.34 (d, J = 8.7 Hz, 2H, Ar-H), 8.75 (s, 1H,
diazepine- H), 8.98 (s, 1H, Imid-H); 13C-NMR (DMSO-d6): δ =
13.97, 40.14, 46.59, 55.11, 61.57, 114.12, 128.11, 128.87,
129.27, 148.91, 149.72, 149.95, 155.69, 159.02, 159.41, 165.12,
166.97; MS (m/z) 395.3 (M+1); Anal. Calcd for C19H18N6O4 : C,
57.86; H, 4.60; N, 21.31; found C, 57.78; H, 4.58; N, 21.20.
5.2.48. 3-(4-Bromobenzyl)-7-(4-methoxybenzyl)-3,7-dihydro-
2H-diimidazo[4,5-d:4’,5’- f][1,3]diazepin-2-one (15j)
Procedure similar to that of 15a (Yield = 0.09g, yield:
49.2%); m.p.: 147-148°C; 1H-NMR (DMSO-d6): δ = 3.71 (s, 3H,
-OCH3), 5.12 (s, 2H, -CH2), 5.52 (s, 2H, -CH2), 6.89 (d, J = 8.7
Hz, 2H, Ar-H), 7.30 (d, J = 8.7 Hz, 2H, Ar-H), 7.32 (d, J = 8.7
Hz, 2H, Ar-H), 7.5 (d, J = 8.7 Hz, 2H, Ar-H), 8.73 (s, 1H,
diazepine- H), 8.94 (s, 1H, Imid-H); 13C-NMR (DMSO-d6): δ =
42.73, 46.49, 55.14, 114.10, 120.65, 128.23, 128.79, 129.27,
129.76, 131.38, 135.39, 148.43, 149.79, 156.02, 159.02, 159.87,
165.71; MS (m/z) 477.1 and 479.1 (M+, M+2). Anal.: Calcd for
C22H17BrN6O2: C, 55.36; H, 3.59; N, 17.61; found C, 55.04; H,
3.54; N, 17.29.
5.2.44. 3-(2-Chloroethyl)-7-(4-methoxybenzyl)-3,7-dihydro-
2H-diimidazo[4,5-d:4’,5’-f][1,3]diazepin-2-one (15f)
Procedure similar to that of 15a (Yield = 0.04g, yield:
39.2%); m.p.:183-184°C; 1H-NMR (DMSO-d6): δ = 3.71 (s, 3H,
-OCH3), 3.96 (t, J = 6.4 Hz, 2H, -CH2), 4.3 (t, J = 6.4 Hz, 2H, -
CH2), 5.52 (s, 2H, -CH2), 6.9 (d, J = 8.7 Hz, 2H, Ar-H), 7.34 (d,
J = 8.7 Hz, 2H, Ar-H), 8.76 (s, 1H, diazepine- H), 8.95 (s, 1H,
Imid-H); 13C-NMR (DMSO-d6): δ = 41.34, 42.25, 47.11, 55.67,
114.66, 128.73, 129.19, 129.82, 149.14, 150.27, 150.32, 156.22,
159.58, 160.41, 166.07; MS (m/z) 371.1 (M+1); Anal. Calcd for
C17H15ClN6O2: C, 55.07; H, 4.08; N, 22.66; found C, 54.86; H,
3.99; N, 22.43.
5.2.49. 3-(3-Methoxybenzyl)-7-(4-methoxybenzyl)-3,7-
dihydro-2H-diimidazo[4,5-d:4’,5’-f][1,3]diazepin-2-one (15k)
Procedure similar to that of 15a (Yield = 0.15 g, 71%);
m.p.: 202-203°C; 1H-NMR (DMSO-d6): δ = 3.70 (s, 6H,
2XOCH3), 5.12 (s, 2H, CH2), 5.51 (s, 2H, CH2), 6.81-6.90 (m,
5H, Ar-H), 7.20 (t, J = 7.8 Hz, 1 H, Ar-H), 7.34 (d, J = 8.72 Hz,
2H, Ar-H), 8.74 (s, 1H, diazepine-H), 8.94 (s, 1H, Imid-H); 13C-
NMR (DMSO-d6): δ = 43.27, 46.48, 55.02, 55.12, 112.74,
113.26, 114.10, 119.43, 128.24, 128.77, 129.28, 129.64, 137.49,
148.40, 149.81, 155.94, 159.00, 159.35, 159.87, 165.79. MS
(ESI): (m/z) 429.3 (M+1); Anal. Calcd for C23H20N6O3: C, 64.48;
H, 4.71; N, 19.62; found C, 64.73; H, 4.59; N, 19.75.
5.2.45. 3-Benzyl-7-(4-methoxybenzyl)-3,7-dihydro-2H-
diimidazo[4,5-d:4’,5’-f][1,3]diazepin-2-one (15g)
Procedure similar to that of 15a (Yield = 0.12 g, 67%);
m.p.: 181-183°C; 1H-NMR (DMSO-d6): δ = 3.70 (s, 3H, OCH3),
5.15 (s, 2H, CH2), 5.52 (s, 2H, CH2), 6.88 (d, J = 8.7 Hz, 2H, Ar-
H), 7.32 (m, 7 H, Ar-H), 8.90 (s, 1H, , diazepine-H), 8.94 (s, 1H,
Imid-H); 13C-NMR (DMSO-d6): δ = 43.32, 46.47, 55.11, 114.09,
127.43, 128.23, 128.51, 128.65, 129.26, 135.97, 148.41, 149.81,
155.91, 159.01, 159.87, 165.79; MS (ESI) (m/z) 399.3 (M+1);
Anal. Calcd. for C22H18N6O2: C, 66.32; H, 4.55; N, 21.09; found
C, 66.29; H, 4.45; N, 21.08.
5.2.50. 3-(2-Methoxybenzyl)-7-(4-methoxybenzyl)-3,7-
dihydro-2H-diimidazo[4,5-d:4’,5’- f][1,3]diazepin-2-one (15l)
Procedure similar to that of 15a (Yield = 0.08 g, 78%);
m.p.: 225-227°C; 1H-NMR (DMSO-d6): δ = 3.71 (s, 3H, OCH3),
3.85 (s, 3H, OCH3), 5.09 (s, 2H, CH2), 5.52 (s, 2H, CH2), 6.76-
6.84 (m, 2H, Ar-H), 6.90 (d, J = 8.72 Hz, 2H, Ar-H), 7.03 (d, J =
8.24 Hz, 1H, Ar-H), 7.24 (m, 1H), 7.35 (d, J = 8.72 Hz, 2H, Ar-
H), 8.67 (s, 1H, diazepine-H), 8.95 (s, 1H, Imid-H); 13C-NMR
(DMSO-d6): δ = 46.49, 55.11, 55.50, 110.61, 114.10, 120.21,
123.21, 126.48, 128.24, 128.45, 128.73, 129.30, 148.37, 149.77,
156.02, 156.29, 159.02, 160.12, 165.77; MS (ESI) (m/z) 429.3
(M+1); Anal. Calcd. for C23H20N6O3.H2O: C, 61.87; H, 4.97; N,
18.82; found C, 61.48; H, 4.54; N, 18.68.
5.2.46. 3-(4-Fluorobenzyl)-7-(4-methoxybenzyl)-3,7-dihydro-
2H-diimidazo[4,5-d:4’,5’-f][1,3]diazepin-2-one (15h)
Procedure similar to that of 15a (Yield = 0.15 g, 73.5%);
m.p.: 178-180°C; 1H-NMR (DMSO-d6): δ = 3.70 (s, 3H, OCH3),
5.13 (s, 2H, CH2), 5.52 (s, 2H, CH2), 6.89 (d, J = 8.24 Hz, 2H,
Ar-H), 7.12 (t, J = 8.9 Hz, 2 H, Ar-H), 7.32-7.41 (m, 4H, Ar-H),
8.73 (s, 1H, diazepine-H), 8.99 (s, 1H, Imiid-H); 13C-NMR
(DMSO-d6): δ = 42.64, 46.49, 55.12, 114.10, 115.18, 115.39,
128.24, 128.78, 129.27, 129.67, 129.75, 132.17, 148.41, 149.80,
156.0, 159.02, 159.84, 165.74; MS (m/z) 417.3 (M+1); Anal.
Calcd for C22H17FN6O2: C, 63.46; H, 4.11; N, 20.18; found C,
63.23; H, 3.90; N, 19.89.
5.2.51. 3-(3-Fluorobenzyl)-7-(4-methoxybenzyl)-3,7-dihydro-
2H-diimidazo[4,5-d:4’,5’-f][1,3]diazepin-2-one (15m)
Procedure similar to that of 15a; the residue was washed
with acetonitrile and diethyl ether followed by drying. (Yield =
0.15 g, 36.6%); m.p.: 187-188°C; 1H-NMR (DMSO-d6): δ = 3.71
(s, 3H, -OCH3), 5.17 (s, 2H, -CH2), 5.53 (s, 2H, -CH2), 6.88-6.92
(m, 2H, Ar-H), 7.06-7.12 (m, 1H, Ar-H), 7.16-7.18 (m, 2H, Ar-
H), 7.33-7.38 (m, 3H, Ar-H), 8.73 (s, 1H, diazepine-H), 8.99 (s,
1H, Imid-H); 13C-NMR (DMSO-d6): δ = 42.79, 46.50, 55.13,
114.11, 114.29, 114.39, 123.37, 128.25, 128.84, 129.29, 130.46,
130.55, 138.75, 138.83, 148.37, 149.82, 156.13, 159.04, 159.98,
165.74; MS (m/z): 417.1 (M+1); Anal. Calcd for C22H17FN6O2: C,
63.46; H, 4.11; N, 20.18; found C, 63.25; H, 4.03; N, 20.08.
5.2.47. 3-(4-Chlorobenzyl)-7-(4-methoxybenzyl)-3,7-dihydro-
2H-diimidazo[4,5-d:4’,5’-f][1,3]diazepin-2-one (15i)
Procedure similar to that of 15a (Yield = 150 mg, yield:
69.4%); m.p.: 188-189°C; 1H-NMR (DMSO-d6): δ = 3.71 (s, 3H,
OCH3), 5.14 (s, 2H, -CH2), 5.52 (s, 2H, -CH2), 6.89 (d, J = 8.7
Hz, 2H, -CH2), 7.25 (d, J = 8.7 Hz, 2H, -CH2), 7.33-7.36 (m, 6H,

The synthesis of the title compound involved the following
two steps:
5.2.52. 3-(3,4-DifluoroBenzyl)-7-(4-methoxybenzyl)-3,7-
dihydro-2H-diimidazo[4,5-d:4’,5’- f][1,3]diazepin-2-one (15n)
(a) 7-(4-Methoxybenzyl)-3-(4-((2-methoxyethoxy)
methoxy)benzyl)-3,7-dihydro-2H-diimidazo[4,5-d:4’,5’-
f][1,3]diazepin-2-one (14r-ii)
Procedure similar to that of 15a; the residue was washed
with acetonitrile and diethyl ether followed by drying. (Yield =
0.12 g, 48.9%); m.p.:188-189°C; 1H-NMR (DMSO-d6): δ = 3.71
(s, 3H, -OCH3), 5.14 (s, 2H, -CH2), 5.53 (s, 2H, -CH2), 6.9 (d,
J=8.7 Hz , 2H, Ar-H), 7.21 (m, 1H, Ar-H), 7.34 - 7.44 (m, 4H,
Ar-H), 8.73 (s, 1H, diazepine- H), 8.95 (s, 1H, Imid-H); 13C-
NMR (DMSO-d6): δ = 42.29, 46.49, 55.11, 114.09, 116.51,
116.69, 117.40, 117.57, 124.29, 128.23, 128.81, 129.28, 133.64,
148.33, 149.72, 149.78, 156.17, 159.03, 159.96, 165.66; MS
(m/z): 435.1 (M+1); Anal. Calcd for C22H16F2N6O2: C, 60.83; H,
3.71; N, 19.35; found C, 60.75; H, 3.63; N, 19.21.
To a suspension of 14r (0.425 g, 0.86 mmol) in acetonitrile
(5 mL) was added triethyl orthoformate (1.02 g, 6.91 mmol) and
a drop of conc. H2SO4 and refluxed for 1 h. Solvent was
evaporated and the residue was recrystalized from ethyl acetate
(Yield = 0.375 g, 87%); m.p.: 126-128°C; 1H-NMR (DMSO-d6):
δ = 3.19 (s, 3H), 3.42 (m, 2H), 3.66 (m, 2H), 3.71 (s, 3H), 5.09
(s, 2H), 5.20 (s, 2H), 5.52 (s, 2H), 6.90 (d, J=8.7 Hz, 2H), 6.95
(d, J=8.7 Hz, 2H), 7.28 (d, J=8.7 Hz, 2H), 7.33 (d, J=8.7 Hz,
2H), 8.75 (s, 1H), 8.93 (s, 1H); 13C-NMR (DMSO-d6): δ = 42.83,
46.46, 55.10, 57.99, 67.27, 70.93, 93.40, 114.64, 116.71, 128.77,
129.53, 129.68, 129.78, 148.93, 150.35, 156.39, 156.81, 159.55,
160.29, 166.32; HRMS (m/z) Calculated for C26H27N6O5 (MH+)
503.2037; found 503.2040; Anal. Calcd for C26H26N6O5: C,
62.14; H, 5.21; N, 16.72; found C, 61.84; H, 5.23; N, 16.69.
(b) 3-(4-Hydroxybenzyl)-7-(4-methoxybenzyl)-3,7-
dihydro-2H-diimidazo[4,5-d:4’,5’-f][1,3]diazepin-2-one (15r)
To a solution of 14r-ii (0.3g) in DCM (5 mL) was added TFA
(0.6 mL) and stirred for 4 h. The reaction mixture was diluted
with DCM, washed with water, brine and dried over MgSO4 and
evaporated to get product (Yield = 0.21g, 85%); m.p.: 216-
218°C; 1H-NMR (DMSO-d6): δ = 3.71 (s, 3H), 5.03 (s, 2H), 5.51
(s, 2H), 6.67 (d, J = 8.7 Hz, 2H), 6.89 (d, J = 8.7 Hz, 2H), 7.17
(d, J = 8.7 Hz, 2H), 7.33 (d, J = 8.7 Hz, 2H), 8.75 (s, 1H), 8.92
(s, 1H), 9.38 (s, 1H); 13C-NMR (DMSO-d6): δ = 42.98, 46.47,
55.12, 114.11, 115.19, 126.21, 128.25, 128.66, 129.16, 129.24,
148.39, 149.82, 155.77, 156.86, 159.00, 159.70, 165.80; HRMS
(m/z) Calculated for C22H19N6O3 (MH+) 415.1513; found
415.1517; Anal. Calcd for C22H18N6O3.H2O: C, 61.10; H, 4.66; N,
19.43; found C, 61.39; H, 4.33; N, 19.26;
5.2.53. 3-(3-Chlorobenzyl)-7-(4-methoxybenzyl)-3,7-dihydro-
2H-diimidazo[4,5-d:4’,5’-f][1,3]diazepin-2-one (15o)
Procedure similar to that of 15a; the residue was washed
with acetonitrile and diethyl ether followed by drying. (Yield =
0.039 g, 38.2%); m.p.: 183-185°C; 1H-NMR (DMSO-d6): δ =
3.71 (s, 3H, -OCH3), 5.16 (s, 2H, -CH2), 5.53 (s, 2H, -CH2), 6.9
(d, J= 8.7 Hz, 2H, Ar-H), 7.23-7.45 (m, 6H, Ar-H), 8.74 (s, 1H,
diazepine-H), 8.95 (s, 1H, Imid-H); 13C-NMR (DMSO-d6): δ =
42.73, 46.48, 55.12, 114.11, 126.09, 127.17, 127.48, 128.25,
128.83, 129.28, 130.38, 133.18, 138.45, 148.34, 149.81, 156.19,
159.03, 160.00, 165.76; MS (ESI): 433.1 (M+1); Anal. Calcd for
C22H17ClN6O2: C, 61.04; H, 3.96; N, 19.41; found C, 61.09; H,
3.93; N, 19.37.
5.2.54. 3-(3-Bromobenzyl)-7-(4-methoxybenzyl)-3,7-dihydro-
2H-diimidazo[4,5-d:4’,5’-f][1,3]diazepin-2-one (15p)
Procedure similar to that of 15a; the residue was washed
with acetonitrile and diethyl ether followed by drying. (Yield =
0.05 g, 49%); m.p.: 172-173°C; 1H-NMR (DMSO-d6): δ = 3.71
(s, 3H, -OCH3), 5.16 (s, 2H, -CH2), 5.53 (s, 2H, -CH2), 6.9 (d, J=
8.7 Hz, 2H, Ar-H), 7.25-7.36 (m, 4H, Ar-H), 7.46-7.48 (m, 1H,
Ar-H), 7.56 (s, 1H, Ar-H), 8.74 (s, 1H, diazepine-H), 8.94 (s, 1H,
Imid-H); 13C-NMR (DMSO-d6): δ = 42.68, 46.48, 55.12, 114.10,
121.78, 126.49, 128.23, 128.82, 129.28, 130.04, 130.39, 130.66,
138.68, 148.34, 149.79, 156.16, 159.02, 159.97, 165.75; MS
(ESI) (m/z) 477.1 (M+1); Anal. Calcd for C22H17BrN6O2: C,
55.36; H, 3.59; N, 17.61; found C, 55.39; H, 3.53; N, 17.50.
5.2.57. 3-(4-(2-Methoxyethoxy)benzyl)-7-(4-methoxybenzyl)-
3,7-dihydro-2H-diimidazo[4,5-d:4’,5’-f][1,3]diazepin-2-one
(15s)
Procedure similar to that of 15a; the residue was washed
with acetonitrile and diethyl ether followed by drying. (Yield =
0.090 g, 48.9%); m.p.:160-161°C. 1H-NMR (DMSO-d6): δ = 3.27
(s, 3H), 3.61 (t, J = 4.6 Hz, 2H), 3.71 (s, 3H), 4.03 (t, J = 4.6 Hz,
2H), 5.08 (s, 2H), 5.52 (s, 2H), 6.86 (d, J = 8.7 Hz, 2H), 6.89 (d,
J = 8.7 Hz, 2H), 7.27 (d, J = 8.7 Hz, 2H), 7.33 (d, J = 8.7 Hz,
2H), 8.75 (s, 1H), 8.93 (s, 1H); 13C-NMR (DMSO-d6): δ = 42.85,
46.47, 55.11, 58.12, 66.85, 70.32, 114.09, 114.39, 128.02,
128.22, 128.76, 129.11, 129.25, 148.39, 149.80, 155.79, 157.91,
158.99, 159.70, 165.77; HRMS (m/z) Calcd for C25H25N6O4
(MH+) 473.1931; found 473.1936; Anal. Calcd for C25H24N6O4:
C, 63.55; H, 5.12; N, 17.796; found C, 63.42; H, 5.01; N, 17.68.
5.2.55. 3-(3-(Trifluoromethyl)benzyl)-7-(4-methoxybenzyl)-
3,7-dihydro-2H-diimidazo[4,5-d:4’,5’-f][1,3]diazepin-2-one
(15q)
Procedure similar to that of 15a; the residue was washed
with acetonitrile and diethyl ether followed by drying. (Yield =
0.039 g, 19%); m.p.: 176-177°C; 1H-NMR (DMSO-d6): δ = 3.74
(s, 3H, -OCH3), 5.25 (s, 2H, -CH2), 5.53 (s, 2H, -CH2), 6.9 (d, J=
8.7 Hz, 2H, Ar-H), 7.35 (d, J= 8.7 Hz, 2H, Ar-H), 7.52-7.65 (m,
3H, Ar-H), 7.75 (s, 1H, Ar-H), 8.74 (s, 1H, diazepine-H), 8.95 (s,
1H, Imid-H); 13C-NMR (DMSO-d6): δ = 42.87, 46.49, 55.12,
114.11, 122.74, 124.25, 125.46, 128.23, 128.83, 129.04, 129.29,
129.61, 131.54, 137.42, 148.36, 149.79, 156.21, 159.03, 160.05,
165.79; MS (ESI) (m/z) 467.1 (M+1); Anal. Calcd for
C23H17F3N6O2: C, 59.23; H, 3.67; N, 18.02; found C, 59.17; H,
3.54; N, 17.78.
5.2.58. 3-(4-(2-Hydroxyethoxy)benzyl)-7-(4-methoxybenzyl)-
3,7-dihydro-2H-diimidazo[4,5-d:4’,5’-f][1,3]diazepin-2-one
(15t)
The synthesis of the title compound involved the following
two steps:
(a) 7-(4-Methoxybenzyl)-3-(4-(2-((2-Methoxyethoxy)
methoxy)ethoxy)benzyl)-3,7-dihydro-2H-diimidazo[4,5-
d:4’,5’-f][1,3]diazepin-2-one (14t-ii)To a solution of 14t (0.2g,
0.37 mmol) in acetonitrile (4 mL) was added triethyl
orthoformate (0.44g, 3.0 mmol) and a drop of conc. H2SO4 and
refluxed for 1 h. All volatiles were removed under reduced
pressure. Residue was recrystalised from ethyl acetate. (Yield =
0.18 g, 88.9%); m.p.: 121-123°C; 1H-NMR (DMSO-d6): δ = 3.21
5.2.56. 3-(4-Hydroxybenzyl)-7-(4-methoxybenzyl)-3,7-
dihydro-2H-diimidazo[4,5-d:4’,5’-f][1,3]diazepin-2-one (15r)

(s, 3H), 3.42 (m, 2H), 3.56 (m, 2H), 3.71 (s, 3H), 3.76 (m, 2H),
4.06 (m, 2H), 4.65 (s, 2H), 5.08 (s, 2H), 5.52 (s, 2H), 6.86 (d, J =
8.2 Hz, 2H), 6.90 (d, J = 8.2 Hz, 2H), 7.28 (d, J = 8.2 Hz, 2H),
7.33 (d, J = 8.2 Hz, 2H), 8.75 (s, 1H), 8.92 (s, 1H); 13C-NMR
(DMSO-d6): δ = 42.83, 46.46, 55.10, 57.96, 65.51, 66.22, 66.99,
71.11, 94.68, 114.09, 114.42, 128.04, 128.22, 129.08, 129.24,
148.39, 149.80, 155.83, 157.87, 158.99, 159.73, 165.77; HRMS
(m/z) Calcd for C28H31N6O6 (MH+) 547.2299; found 547.2301;
Anal. Calcd for C28H30N6O6.0.25H2O: C, 61.03; H, 5.58; N,
15.25; found C, 60.97; H, 5.34; N, 15.11.
potassium iodide (0.004g, 0.027 mmol, 0.1 equi.), potassium
carbonate (0.055g, 0.40 mmol, 1.5 equi.). The mixture was
stirred for 18 h at 60°C. It was allowed to cool to room
temperature and water and ethyl acetate was added. The organic
layer was washed with water. After the solvent was concentrated
under reduced pressure, to the residue was added EtOAc/Et2O.
The resulting precipitate was filtered, washed with diethyl ether
and dried to give product (Yield = 0.03 g, 26.5%); m.p.: 221-
223°C; 1H-NMR (DMSO-d6): δ = 1.12-1.24 (m, 8H, CH2), 2.11-
2.16 (m, 2H, CH2), 3.53-3.58 (m, 1H, -CH2), 3.67 (s, 3H, -
OCH3), 3.81-3.84 (m, 2H, -CH2), 4.42 (t, J = 8.7 Hz, 1H, -CH2),
5.2 (q, J = 15.12 Hz, 2H, -CH2), 6.81 (d, J = 8.7 Hz, 2H, Ar-H),
7.12 (d, J = 8.7 Hz, 2H, Ar-H), 7.56 (s, 1H, diazepine- H), 7.99
(s, 1H, Imid-H); 13C-NMR (DMSO-d6): δ = 24.10, 25.15, 43.76,
44.33, 45.43, 52.29, 55.07, 97.07, 113.73, 121.65, 128.35,
129.54, 138.78, 141.10, 147.05, 158.62, 171.39, 172.58; MS
(m/z) 420.2 (M+1); Anal. Calcd for C22H25N7O2. 0.5 H2O: C,
61.67; H, 6.12; N, 22.88; found C, 61.69; H, 5.84; N, 22.75.
(b) 3-(4-(2-Hydroxyethoxy)benzyl)-7-(4-methoxybenzyl)
-3,7-dihydro-2H-diimidazo[4,5-d:4’,5’-f][1,3]diazepin-2-one
(15t)
To a solution of 14t-ii (0.15g, 0.27 mmol) in DCM (5 mL)
was added TFA (1.1 mL) and stirred for 8 h. The reaction
mixture was diluted with DCM, washed with water, brine and
dried over MgSO4 and evaporated to get product (Yield = 0.10 g,
79.5%); m.p.:213-215°C; 1H-NMR (DMSO-d6): δ = 3.66 (m,
2H), 3.71 (s, 3H), 3.92 (t, J = 5.0 Hz, 2H), 4.81 (t, J = 5.7 Hz,
1H), 5.08 (s, 2H), 5.52 (s, 2H), 6.86 (d, J = 8.7 Hz, 2H), 6.89 (d,
J = 8.7 Hz, 2H), 7.27 (d, J = 8.7 Hz, 2H), 7.33 (d, J = 8.7 Hz,
2H), 8.73 (s, 1H), 8.92 (s, 1H); 13C-NMR (DMSO-d6): δ = 42.86,
46.47, 55.11, 59.50, 69.47, 114.10, 114.43, 127.89, 128.24,
128.71, 129.08, 129.24, 148.40, 149.81, 155.83, 158.13, 159.00,
159.74, 165.79; HRMS (m/z) Calcd for C24H23N6O4 (MH+)
459.1775; found 459.1773; Anal. Calcd for C24H22N6O4: C,
62.87; H, 4.84; N, 18.33; found C, 62.59; H, 4.91; N, 18.25.
5.2.61. 3-((2-Morpholin-4-yl)ethyl)-7-(4-methoxybenzyl)-3,7-
dihydro-2H-diimidazo[4,5-d:4’,5’-f][1,3]diazepin-2-one (15x)
Procedure similar to that of 15w (Yield = 0.027 g. 23.8%);
m.p.: 214-216°C; 1H-NMR (DMSO-d6): δ = 2.17-2.19 (m, 2H,
CH2), 2.32-2.50 (m, 2H, CH2), 3.2-3.41 (m, 4H, CH2), 3.58-3.62
(m, 1H, -CH2), 3.71 (s, 3H, -OCH3), 3.84-3.89 (m, 2H, -CH2),
4.44 (t, J = 8.7 Hz, 1H, -CH2), 5.24 (q, J =15.12 Hz, 2H, -CH2),
6.86 (d, J = 8.7 Hz, 2H, Ar-H), 7.16 (d, J = 8.7 Hz, 2H, Ar-H),
7.60 (s, 1H, diazepine- H), 8.03 (s, 1H, Imid-H); 13C-NMR
(DMSO-d6): δ = 43.73, 43.98, 45.51, 52.39, 55.14, 65.75, 96.74,
113.86, 128.43, 129.52, 139.10, 141.31, 158.67, 172.44. MS
(m/z) 422.2 (M+1); Anal. Calcd for C21H23N7O3.0.25 H2O : C,
59.21; H, 5.56; N, 23.02; found C, 59.14; H, 5.35; N, 22.76.
5.2.58. 7-(4-Methoxybenzyl)-3-((pyridin-3-yl)methyl)-3,7-
dihydro-2H-diimidazo[4,5-d:4’,5’-f][1,3]diazepin-2-one (15u)
Procedure similar to that of 15a; the residue was washed
with acetonitrile and diethyl ether followed by drying. (Yield =
0.045 g, 54.8%); m.p.: 162-163°C; 1H-NMR (DMSO-d6): δ =
3.71 (s, 3H, -OCH3), 5.19 (s, 2H, -CH2), 5.53 (s, 2H, -CH2), 6.9
(d, J= 8.7 Hz, 2H, Ar-H), 7.31-7.35 (m, 3H, Ar-H), 7.73-7.75 (m,
1H, Ar-H), 8.48 (d, 1H, Ar-H), 8.62 (s, 1H, Ar-H), 8.74 (s, 1H,
diazepine-H), 8.94 (s, 1H, Imid-H); 13C-NMR (DMSO-d6): δ =
41.06, 46.48, 55.11, 114.09, 123.58, 128.23, 128.81, 129.24,
131.66, 135.41, 148.37, 148.74, 148.95, 149.77, 156.09, 159.01,
159.91, 165.68. MS (ESI) (m/z) 400.2 (M+1); Anal. Calcd for
C21H17N7O2: C, 63.15; H, 4.29; N, 24.55; found C, 62.86; H,
4.26; N, 24.53.
5.3. Biological Procedures
In Vitro Screening: New anticancer compounds were
screened using the following cell lines: lung cancer: A549 and
H460; breast cancer: MCF-7 and MDA-MB-231; ovarian cancer:
OVCAR-3 and prostate cancer: PC-3. Cells (0.5-1.7 x 103
cells/50 µL/well) were seeded in RPMI + 10% FBS in 96-well
plate the day before adding the drug dilutions. DMSO was used
to dissolve all compounds (stock concentrations ranged from 100
mM to 200 mM). Each compound was tested at nine different
concentrations ranging from 100 μM to 5 nM. Every drug
dilution for each drug was tested in 4-replicates within each
experiment, and each experiment was repeated 1x or 2x. Cells
treated with DMSO (equivalent volume) were used as a “vehicle
control”. After addition of the drug, cells were cultured for 72h
at 37°C, 5% CO2. The experiment was terminated by adding
WST-1 Cell Proliferation Reagent (Roche, Mannheim, Germany)
to each well and additional incubation for 4h at 37°C, 5% CO2.
The colorimetric readouts of cellular metabolic activity was
performed by measuring absorbance at 450-690 nm using a
Synergy HT Multi-Detection Microplate Reader and Gen5
software (Bio-Tek, Winoski, VT). Data analysis and IC50
calculation was done using GraphPad Prism software, v.5 (La
Jolla, CA).
5.2.59. 3-(4-(Dimethylamino)benzyl)-7-(4-methoxybenzyl)-
3,7-dihydro-2H-diimidazo[4,5-d:4’,5’-f][1,3]diazepin-2-one
(15v)
Procedure similar to that of15a; the residue was washed
with acetonitrile and diethyl ether followed by drying. (Yield =
0.065 g, 79.4%); m.p.: 150-152°C; 1H-NMR (DMSO-d6): δ =
2.86 (s, 6H, -CH3), 3.7 (s, 3H, -OCH3), 5.02 (s, 2H, -CH2), 5.51
(s, 2H, -CH2), 6.62 (d, J = 8.7 Hz, 2H, Ar-H), 6.89 (d, J= 8.7 Hz,
2H, Ar-H), 7.19 (d, J = 8.7 Hz, 2H, Ar-H), 7.32 (d, J = 8.7 Hz,
2H, Ar-H), 8.75 (s, 1H, diazepine-H), 8.91 (s, 1H, Imid-H); 13C-
NMR (DMSO-d6): δ = 43.05, 46.44, 55.09, 112.22, 114.08,
123.30, 128.22, 128.61, 128.82, 129.21, 148.38, 149.78, 149.91,
155.68, 158.99, 159.59, 165.82. MS (ESI) (m/z) 442.2 (M+1);
Anal. Calcd for C24H23N7O2: C, 65.29; H, 5.25; N, 22.21; found
C, 64.99; H, 5.22; N, 22.13.
Acknowledgments
5.2.60. 3-((2-Piperidin-1-yl)ethyl)-7-(4-methoxybenzyl)-3,7-
dihydro-2H-diimidazo[4,5-d:4’,5’-f][1,3]diazepin-2-one (15w)
This paper is dedicated to RSH’s doctoral mentor Professor
Dr. Stewart W. Schneller of Auburn University, Alabama on the
occasion of his 70th birthday. The research was supported by a
grant (#1R01 GM087738-01A1) from the National Institute of
General Medical Sciences of the National Institutes of Health.
To a suspension of 15f (0.1g, 0.27 mmol, 1.0 equi.) in 4 ml
DMF was added piperidine (0.034 g, 0.40 mmol, 1.5 equi.),

26. Kondaskar, A.; Kondaskar, S.; Kumar, R.; Fishbein, J. C.;
Muvarak, N.; Lapidus, R. G.; Sadowska, M.; Edelman, M. J.;
Bol, G. M.; Vesuna, F.; Raman, V.; Hosmane, R. S. ACS Med.
Chem. Lett. 2011, 2, 252.
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Graphical abstract
Strucutre-based drug design and anti-
cancer activity of 5:7:5-fused
diimidazo[4,5-d:4’,5’-f][1,3]diazepines
Atul Kondaskar, Shilpi Kondaskar, James C. Fishbein, , Brandon A. Carter-Cooper, Rena G.
Lapidus, Mariola Sadowska, Martin J. Edelman, and Ramachandra S. Hosmane
A
B
O
H
n
o
i
g
N
e
O
r
d
Mg ion
P loop
e
N
H
s
o
p
x
MeO
E
t
O
n
O
H
e
2
NH2
5
v
l
Mg ion
P loop
o
1
7
N
3
H
6
S
N
N
9
N
1
N
Phe182
Phe182
8
2
8
4
N 9
4
N
N
3
O
N
7
O-
Tyr200
5
O
P
O-
N
O
6
Tyr200
OMe
OH
Charged
region
Charged
region
Q motif
Q motif
Figure 2. (A) Model for interactions between AMP and DDX3 (B) Proposed model for interactions between 1 and DDX3.